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# 38 Overview of Infrastructure Utility Classes

The ESMF utilities are a set of tools for quickly assembling modeling applications.

The ESMF Attribute class enables models to be self-describing via metadata, which are instances of Attribute name-value pairs.

The Time Management Library provides utilities for time and time interval representation and calculation, and higher-level utilities that control model time stepping, via clocks, as well as alarming.

The ESMF Config class provides configuration management based on NASA DAO's Inpak package, a collection of methods for accessing files containing input parameters stored in an ASCII format.

The ESMF LogErr class consists of a variety of methods for writing error, warning, and informational messages to log files. A default Log is created during ESMF initialization. Other Logs can be created later in the code by the user.

The DELayout class provides a layer of abstraction on top of the Virtual Machine (VM) layer. DELayout does this by introducing DEs (Decomposition Elements) as logical resource units. The DELayout object keeps track of the relationship between its DEs and the resources of the associated VM object. A DELayout can be shaped by the user at creation time to best match the computational problem or other design criteria.

The ESMF VM (Virtual Machine) class is a generic representation of hardware and system software resources. There is exactly one VM object per ESMF Component, providing the execution environment for the Component code. The VM class handles all resource management tasks for the Component class and provides a description of the underlying configuration of the compute resources used by a Component. In addition to resource description and management, the VM class offers the lowest level of ESMF communication methods.

The ESMF Fortran I/O utilities provide portable methods to access capabilities which are often implemented in different ways amongst different environments. Currently, two utility methods are implemented: one to find an unopened unit number, and one to flush an I/O buffer.

# 39 Attribute Class

## 39.1 Description

The ESMF Attribute class is a metadata utility that supports emerging standards in a flexible way. The Attribute class is useful for documenting data provenance and encourages models to be more self describing. Attributes can also be used to automate some aspects of model execution and coupling.

Metadata, which is data about data, is broken down into name-value pairs by the Attribute class. Attributes can be attached at any level of the ESMF object hierarchy, and in some cases the Attributes of different ESMF objects can be linked together to form a corresponding Attribute hierarchy. Attribute hierarchies are linked up automatically for the most part, with the exception of links between Components and between a Component and a State. Attribute hierarchies can also be unlinked, copied, and moved around as needed.

ESMF Attribute packages are used to aggregate, store, and output model metadata. They can be nested inside each other to make larger organized packages, distributed across processors and updated at runtime, and expanded to suit specific needs. The ESMF-supplied Attribute packages are designed around accepted metadata conventions, such as: climate and forecast (CF) [11], ISO standards [2], and the METAFOR Common Information Model (CIM) [3] [8].

Most of the ESMF deep objects can host Attributes, and every object that can hold individual Attributes can also hold Attribute packages. Attribute hierarchies are supported for a majority of the Attribute bearing classes. More information on the various Attribute capabilities, and the classes for which they are supported appear in the following sections.

Reading Attribute XML files requires the Xerces C++ library, v3.1.0 or better. For more details, see the "ESMF Users Guide", "Building and Installing the ESMF, Third Party Libraries, Xerces". Writing Attribute XML files is performed with the standard C++ output file stream facility.

### 39.1.1 Schemas and Controlled Vocabularies

There are two pieces to the information stored in Attributes. One piece is the property name and type, and its relation to other properties; this is the schema. The other piece is the range of values that are valid for a particular property; this is the controlled vocabulary. For many information models, including the Common Information Model (CIM), these two pieces are managed and versioned separately.

ESMF implements the appropriate schema internally; it translates the Attributes as specified in the Attribute packages into the correct format based on the convention and purpose as specified in arguments to most Attribute functions. The controlled vocabularies, or Attribute values, however, are not controlled or validated within ESMF.

### 39.1.2 The Common Information Model (CIM)

The CIM is a formal model of the climate modeling process developed by the European Union's METAFOR project. The Earth System - Documentation (ES-DOC) project is an evolution of the METAFOR project, and they provide a detailed description of the CIM here.

ESMF is currently implementing only a subset of version 1.5 of the CIM, though this representation is expected to grow.

Mapping Attributes to the CIM

The ESMF Attribute packages provide a structure for the Attributes that are useful for climate modelers. When the ESMF_AttributeWrite() function is called with "CIM" XML specified as the target, ESMF translates these package structures into a format defined by the CIM schema. The package descriptions in the following sections provide a mapping from the ESMF Attribute name to the CIM schema field.

For example, in the CIM Main Attribute Package, the Attribute named "LongName" is mapped to the CIM schema field, "software:SoftwareComponent:longName":

 Name Definition Controlled Vocabulary CIM Schema Field (::) LongName A version of the component name with all acronyms spelled out. N/A software:SoftwareComponent:longName

There are 3 parts to this mapping:

• <CIM section> = "software"
• <Entity> = "SoftwareComponent"
• <Field> = "longName"

The CIM section refers to the categories, or subsections, of the CIM mentioned above. In this example, the CIM section is "software". To find this section in the CIM schema repository, go to the CIM repository and then select the "software" drop down (see Figure 33 ).

You can view the schema graphically in a UML diagram by selecting the software.png file and then visually search the picture for the SoftwareComponent entity. However, this view does not provide field details, such as type and description. Alternatively, you can select the software.xsd file, and then search the XML for the entity, "SoftwareComponent," and the field, "longName," which will provide the details for this field (see Figure 34 ).

As the ES-DOC team continues its work, more tools will be provided to support CIM implementations. Currently, a more user-friendly way to view the CIM schema is available through the CONCIM'' sections on this page.

### 39.1.3 The ESMF approach to Attributes

ESMF's approach to Attributes can be summarized as follows:

• Implement community standards where they exist.
• Associate Attributes with the ESMF object they describe. Currently, the following ESMF objects can have Attributes:
• CplComp
• GridComp
• State
• FieldBundle
• Field
• ArrayBundle
• Array
• Grid
• DistGrid
• Establish pre-defined Attribute packages (see Section 39.2) to make Attribute creation easier for the user.
• Allow for user-defined custom Attribute packages (see Section 39.2.7).
• Enable the nesting of Attribute packages (see Section 39.3) including Custom packages.
• Enable complex Attribute hierarchies (see Section 39.1.4.
• Export Attributes in more than one format (see Section 39.4).
• Ensure that all Attributes are consistent across the entire virtual machine of the object to which they are attached.

### 39.1.4 Attribute hierarchies

Of the ESMF objects with Attributes, only some can link their Attributes together in an Attribute hierarchy. These objects are:

• CplComp
• GridComp
• State
• FieldBundle
• Field
• ArrayBundle
• Array

Every ESMF deep object is given a root Attribute on creation. These root Attributes serve as the attachment point for all metadata that is stored on a particular ESMF object, including all Attributes and Attribute packages. The root Attributes can also be connected together via the ESMF_AttributeLink() functionality. This happens automatically in most cases, such as when a Field is added to a FieldBundle, and results in the formation of an Attribute hierarchy which mirrors the structure of the underlying object hierarchy.

When two Attribute hierarchies are linked together the objects are given read-only access to each other's Attributes. To ensure consistency across a distributed system, there can only ever be one set of Attributes associated with each ESMF object. This implies that a copy operation on an ESMF object Attribute hierarchy can use a value copy for all Attributes which are owned by the object being copied, but must use a reference copy for all Attributes which the object can access (through links) but does NOT own. See section 39.9.6 for more details on this concept.

The most common use for this hierarchy capability is for linking the Attributes of a Field to the FieldBundle which holds it, which is then linked to the State that is used to transport all of the data for a Component. All of these links, with the exception of the link between the Component and the State, are automatically handled by ESMF. Additionally, the State will automatically set a VariableIntent Attribute for Field when that Field is added to the State. VariableIntent will be set to either Export or Import.

## 39.2 Attribute Packages

At this time, all ESMF objects which are enabled to contain Attributes can also contain Attribute packages, which are groupings of individual Attributes. Every Attribute package is specified by a unique set of identifiers. These are called the convention and purpose of the Attribute package, such as "CF" and "General" (see below). These are used to validate ESMF Attribute packages against existing metadata conventions. The attPackInstanceName can be used to differentiate between Attributes of the same name within a package.

The user can choose to use an ESMF pre-defined Attribute package, specify their own Attribute package, or add customized Attributes to any of the ESMF pre-defined Attribute packages. Currently, the creation and setting of Attribute packages is quite involved, but future development with I/O will allow for a more automated approach to populating Attribute packages from a file. This is already possible via ESMF_AttributeRead() for the ESMF/CF Attribute packages supplied by ESMF, as well as for custom individual Attributes not in a package.

The standard Attribute packages supplied by ESMF exist for the following ESMF objects:

• CplComp
• GridComp
• State
• Field
• Array
• Grid

The packages described in this section are grouped by the ESMF object they apply to. The creation of custom attributes and custom attribute packages is also possible and is discussed in Section 39.2.7. In some cases it is possible to nest custom packages on top of ESMF packages. Attribute package nesting is described separately in Section 39.3.

Some Attributes come with a controlled vocabulary. A controlled vocabulary is a list of options that can be selected as the value of the attribute. The controlled vocabularies listed in this documentation represent those chosen by the community. They are not exhaustive and users may set these Attributes to a different value if they so choose. The primary consequence of doing so is that the resulting output may not be recognized by any of the online tools being developed with respect to this controlled vocabulary.

### 39.2.1 Component Attribute packages

There are many attributes that are used to describe components. There are currently 4 predefined component-level Attribute packages, with sub-packages defined for the 2nd:

1. Earth System Modeling Framework (ESMF) General
2. Common Information Model (CIM) Main
1. Common Information Model (CIM) Platform
2. International Organization for Standardization (ISO) Responsible Party
3. International Organization for Standardization (ISO) Citation
3. Common Information Model (CIM) Scientific Properties
4. Common Information Model (CIM) Component Properties

1. Earth System Modeling Framework (ESMF) General Attribute Package

• Specify with:
• convention = "ESMF"
• purpose = "General"
• Output Options:
• Simple XML
• Description: This package contains several Attributes used to describe model components within the Earth System Modeling Framework (ESMF) ontology.

 Name Definition Controlled Vocabulary Agency An administrative unit of government. DoD, DOE, DOI, NASA, NOAA, NSF Author The person who created the content of a book, article, or other source. N/A CodingLanguage The computer language in which a unit of software is written. C, C++, F77, F90, Java ComponentLongName The name of a model, model component, simulation, experiment, or dataset with all acronyms spelled out. N/A ComponentShortName A version of the component name that contains acronyms. N/A Discipline A subject, theme, category, or general area of interest. Aerosol, Fisheries, Climate, Carbon Cycle, Hydrology, Land, Ocean, Polar, Sediment, Storm Surge, Turbulence, Weather, Wave, Weather Prediction Institution An organization associated with a model component, simulation, or dataset. N/A ModelComponentFramework The software package or mechanism used to transfer and transform data between model components. CCA, ESMF, Flume, FMS, OASIS, SWMF PhysicalDomain A description of the geographic range being simulated. Atmosphere, Earth System, Ice, Lake, Land Ocean, River Version A specific form or variation of an artifact, i.e. a unit of software or metadata. N/A

2. Common Information Model (CIM) Main Attribute Package

• Specify with:
• convention = "CIM 1.5"
• purpose = "ModelComp"
• CIM Version: CIM 1.5
• CIM URL: http://metaforclimate.eu/trac/browser/CIM/tags/version-1.5/
• Includes:
• CIM Platform
• ISO Responsible Party (1 or more - user specifiable)
• ISO Citation (1 or more - user specifiable)
• Output Options:
• CIM XML
• Description: The CIM Main Package contains several standalone properties used to describe components. It also serves as the anchor to which other CIM packages are nested. Presently, these additional CIM packages (described further below) can only be created if the CIM Main Package is created. In the future, these packages will be decoupled, so that users may select subsections of the CIM to create and use. This package nests three of the packages below within it; this is described in Section 39.3.

 Name Definition Controlled Vocabulary CIM Schema Field (::) Description A multi-line description of the component. N/A software:SoftwareComponent:description LongName A version of the component name with all acronyms spelled out. N/A software:SoftwareComponent:longName MetadataVersion*** The version number of the simulation metadata. N/A software:modelComponent:metadataVersion ModelType* A short string describing the discipline of a model component. Advection, Aerosol3D-Sources etc. software:ModelComponent:type PreviousVersion** Name of the previous version of a model or model component. N/A shared:Reference:name PreviousVersionDescription** A short note about the previous version of the model or model component. N/A shared:Relationship:description ReleaseDate The date a model component was issued. N/A software:SoftwareComponent:releaseDate ShortName* A version of the component name that contains acronyms. N/A software:SoftwareComponent:shortName SimulationDuration The length of time a simulation runs. N/A activity:SimulationRun:dateRange SimulationEndDate The date in simulated time of the end of a model simulation. N/A activity:SimulationRun:dateRange SimulationEnsembleID The reference name or number of the ensemble to which a simulation belongs. N/A activity:EnsembleMember:ensembleMemberID SimulationLongName The name of the simulation with any acronyms spelled out. N/A activity:NumericalActivity:longName SimulationNumberOfProcessing Elements The number of PEs used in the simulation. N/A software:Parallelization:processes SimulationProjectName A campaign, such as a model intercomparison project, that may involve multiple groups and experiments. N/A activity:Activity:project SimulationRationale The reason for performing a simulation. N/A activity:Activity:rationale SimulationShortName The name of the simulation. N/A activity:NumericalActivity:shortName SimulationStartDate* The date in simulated time of the start of a model simulation. N/A activity:SimulationRun:dateRange URL A URL associated with a model component. N/A shared:CI_OnlineResource:linkage Version Version number of the component. N/A appended to software:SoftwareComponent:shortName
* Attribute required to be set to produce valid CIM XML output.
** If PreviousVersionDescription is set, PreviousVersion must also be set, to produce valid CIM XML output.
*** If not set, defaults to 1.0

2.1. CIM Platform Attribute Package

• Specify with:
• convention = "CIM 1.5"
• purpose = "Platform"
• CIM Version: CIM 1.5
• CIM URL: http://metaforclimate.eu/trac/browser/CIM/tags/version-1.5/
• Output Options:
• CIM XML
• Description: This package describes the platform a particular simulation is run on. It must be created in conjunction with the CIM Main Package (see above). This package is nested within the CIM Main Package (above); see the description in Section 39.3.

 Name Definition Controlled Vocabulary CIM Schema Field (::) CompilerName** The brand of the software that takes source code and turns it into an executable. Absoft, Default, Intel, Lahey, NAG, Pathscale, PGI, PGIGCC, XLF, XLFGCC shared:Compiler:compilerName CompilerVersion** The specific configuration value of the software used to take source code and turn it into executable code. N/A shared:Compiler:compilerVersion MachineCoresPerProcessor The number of sub-divided elements or mini-chips on a computer chip. N/A shared:Machine:machineCoresPerProcessor MachineDescription A short note about the machine. N/A shared:Machine:machineDescription MachineInterconnectType The technology used to associate each node in a supercomputer with every other node. Cray Interconnect, Fat Tree, Gigabit Ethernet, Infiniband, Mixed, Myrinet, Numalink, Quadrics, SP Switch shared:Machine:machineInterconnect MachineMaximumProcessors The highest number of computer chips on a computer system. N/A shared:Machine:machineMaximumProcessors MachineName* The name given to a computer by its system administrators. This is not the brand name of the system. N/A shared:Machine:machineName MachineOperatingSystem The software that is responsible for the management and coordination of activities and the sharing of resources of a computer. Aix, Darwin, Irix64, Linux, SUNOS, Unicos shared:Machine:machineOperatingSystem MachineProcessorType The type of computer chip used in a particular computer platform. Altix, AMD x86-64, Bluegene, G4, G5, Intel EM64T, Intel IA-64, Itanium, NEC, Opteron, Origin3800, Pentium 3, Pentium 4, SP, SPARC, X1, Xeon, XT3-4, ZX6000 shared:Machine:machineProcessorType MachineSystem The type of computer system (e.g. vector, parallel, cluster, etc.). Beowulf, Parallel, Vector shared:Machine:machineSystem MachineVendor The brand name of a computer system. ACS, Action, Appro International, Bull SA, Cray Inc, Dalco AG Switzerland, Dawning, Dell, Fujitsu, Hitachi, HP, IBM, Intel, Koi Computers, Lenovo, Mac, NEC, NEC SUN, NUDT, PC, Pyramid Computer, Raytheon-Aspen Systems, Self Made, SGI, Sun Microsystems, T-platforms shared:Machine:machineVendor
* Attribute required to be set to produce valid CIM XML output.
** Both CompilerName and CompilerVersion are required to be set, or else neither one, to produce valid CIM XML output; setting one without the other will produce invalid CIM XML output.

2.2. ISO Responsible Party Attribute Package

• Specify with:
• convention = "ISO 19115"
• purpose = "RespParty"
• Output Options:
• CIM XML
• Description: This package is used to describe contacts, authors, institutions, and funding agencies. This package is nested, with one or more user-specifiable instances, within the CIM Main Package(above); see the description in Section 39.3.
• Usage: The Responsible Party package is unique in that the user should first select the type of Responsible Party they wish to define. This is done via the ResponsiblePartyRole attribute within the package. Then the package's main value is set using the Name attribute.

* Attribute required to be set, when any other attributes in this package are set, to produce valid CIM XML output. It is valid to set none of the attributes in this package. In that case, no corresponding CIM XML output will appear for that Responsible Party package instance, although there may be other populated instances, which, because they have attributes set, will appear in the output.

2.3. ISO Citation Attribute Package

• Specify with:
• convention = "ISO 19115"
• purpose = "Citation"
• Output Options:
• CIM XML
• Description: This package is used to describe references. Examples include a URL or a scientific reference. This package is nested, with one or more user-specifiable instances, within the CIM Main Package (above); see the description in Section 39.3.

 Name Definition Controlled Vocabulary CIM Schema Field (::) Date* The date of the citation. N/A shared:CI_Citation:Date DOI The assigned Digital Object Identifier (DOI) of the citation. N/A shared:CI_Citation:otherCitationDetails LongTitle The text of the citation or pointer (e.g. URL) that further describes a model component or simulation. N/A shared:CI_Citation:collectiveTitle PresentationForm A description of the type of citation. documentDigital, documentHardcopy, imageDigital, imageHardcopy, mapDigital, mapHardcopy, modelDigital, modelHardcopy, profileDigital, profileHardcopy, tableDigital, tableHardcopy, videoDigital, videoHardcopy shared:CI_Citation:presentationForm ShortTitle* An abbreviation for the citation. This could be the short scientific citation (e.g. Murphy, 2009) or the title of a web page. N/A shared:CI_Citation:title URL Website associated with the citation. N/A appended to shared:CI_Citation:collectiveTitle
* Attribute required to be set, when any other attributes in this package are set, to produce valid CIM XML output. It is valid to set none of the attributes in this package. In that case, no corresponding CIM XML output will appear for that Citation package instance, although there may be other populated instances, which, because they have attributes set, will appear in the output.

3. Common Information Model (CIM) Scientific Properties Package

 Name Definition Controlled Vocabulary CIM Schema Field (::) . METAFOR mindmap files. software:SoftwareComponent: scientificProperties

4. Common Information Model (CIM) Component Properties Package

• Specify with:
• convention = "CIM 1.5"
• purpose = "CompProp"
• CIM Version: CIM 1.5
• CIM URL: http://metaforclimate.eu/trac/browser/CIM/tags/version-1.5/
• Output Options:
• CIM XML
• Description: This package is used to specify any number of custom, user-defined attributes of a component and have them output in valid CIM XML format. This differs from the scientific properties package above in that the names and values are custom, not part of any controlled vocabulary. It also differs from a custom attribute package (see Section 39.2.7) in that this package has a standard convention and purpose, which is used to control the output of the user-defined attributes in standard CIM XML format. One or more values can be set (via an array) for an attribute name.

 Name Definition Controlled Vocabulary CIM Schema Field (::) . N/A software:SoftwareComponent: componentProperties

### 39.2.2 State Attribute packages

There is currently only 1 predefined State-level Attribute package:

1. ESMF General

1. ESMF General State Attribute Package

• Specify with:
• convention = "ESMF"
• purpose = "General"
• Output Options:
• Tab-delimited
• Simple XML
• Description: This package is used to define whether an ESMF State object is an Import State or Export State.

 Name Definition Controlled Vocabulary Intent An indication of whether a state is imported into or exported from a particular model component. This refers to coupling, and not history output. Export,Import

### 39.2.3 Field Attribute packages

Several standards exist to describe fields. There are currently 4 predefined Field-level Attribute packages:

1. Common Information Model (CIM) Inputs
2. Earth System Modeling Framework (ESMF) General
3. Climate Forecast (CF) Convention Extended
4. Climate Forecast (CF) Convention General

1. Common Information Model (CIM) Inputs

• Specify with:
• convention = "CIM 1.5"
• purpose = "Inputs"
• CIM Version: CIM 1.5
• CIM URL: http://metaforclimate.eu/trac/browser/CIM/tags/version-1.5/
• Includes:
• ESMF General
• CF Extended
• CF General
• Output Options:
• CIM XML
• Description: This package is used to describe a simulation and the input (initial and boundary) conditions used in that simulation. It is also used to describe any ancillary data sets that contain input condition variables. This package should not be used to describe the variables in an unconfigured model component. A pre-defined Attribute package for that case will be implemented in a future release of ESMF. This package nests the ESMF General, CF Extended, and CF General Field packages (below) within it; this is described in Section 39.3. The attribute values within these ESMF and CF nested packages currently appear in the Component Properties section of the CIM output file. A separate Component Properties package may be developed for this purpose in a future ESMF release.

 Name Definition Controlled Vocabulary CIM Schema Field (::) CouplingPurpose* The form of the input condition (e.g. initial condition or boundary condition). Ancillary, Boundary, Initial software:Coupling:purpose CouplingSource* The component the input condition is coming from. N/A software:Coupling:couplingSource CouplingTarget* The component the input condition is going to. N/A software:Coupling:couplingTarget Description A multi-line description of the input. N/A software:Coupling:description Frequency The frequency (e.g. 2 months or 5 days) that a field from one component is input to another. n Seconds, n Minutes, n Hours, n Days, n Months, n Years, n Decades, n Centuries software:Timing:rate SpatialRegriddingMethod Method used to interpolate a field from one grid (source grid) to another (target grid). Linear, Near-Neighbor, Cubic, Conservative-First-Order, Conservative-Second-Order, Conservative, Non-Conservative software:SpatialRegridding: spatialRegriddingStandardMethod SpatialRegriddingDimension Dimension of the regridding method. 1D, 2D, 3D software:SpatialRegridding: spatialRegriddingDimension Technique The software package or mechanism used to transfer and transform data between model components. CCSM Flux Coupler, ESMF, Files, FMS, MCT, OASIS3, Shared N/A TimeTransformationType Temporal transformation performed on the input field before or after regridding onto the target grid. Exact, None, Time Accumulation, Time Average, Time Interpolation software:TimeTransformation:mappingType
* Attribute required to be set, when any other attributes in this package are set, to produce valid CIM XML output. It is valid to set none of the attributes in this package. In that case, no corresponding CIM XML output will appear for that Inputs package.

2. Earth System Modeling Framework (ESMF) Field

• Specify with:
• convention = "ESMF"
• purpose = "General"
• Includes:
• CF Extended
• CF General
• Output Options:
• Tab-delimited
• Simple XML
• CIM XML (when part of the CIM Inputs package)
• Description: This package nests the CF Extended and CF General packages (below) within it; this is described in Section 39.3.

 Name Definition Controlled Vocabulary Intent An indication of whether a variable is exported or imported. This refers to coupling and not history output. Export,Import

3. Climate Forecast (CF) Convention Extended

• Specify with:
• convention = "CF"
• purpose = "Extended"
• Includes:
• CF General
• Output Options:
• Tab-delimited
• Simple XML
• CIM XML (when part of the CIM Inputs package)
• Description: The CF standard for fields contains an optional standard_name Attribute. Standard names are controlled vocabularies and not every variable in the earth system sciences contains a standard name. Because of this, ESMF implemented this optional Attribute in its own package. This package nests the CF General package (below) within it; this is described in Section 39.3.

 Name Definition Controlled Vocabulary StandardName The approved CF standard name for a variable if it exists. N/A

4. Climate Forecast (CF) Convention General

• Specify with:
• convention = "CF"
• purpose = "General"
• Output Options:
• Tab-delimited
• Simple XML
• CIM XML (when part of the CIM Inputs package)
• Description: The climate and forecast (CF) convention contains metadata that is designed to promote the processing and sharing of files created with the NetCDF API. The CF conventions are increasingly gaining acceptance and have been adopted by a number of projects and groups as a primary standard. The conventions define metadata that provide a definitive description of what the data in each variable represents, and the spatial and temporal properties of the data. This enables users of data from different sources to decide which quantities are comparable, and facilitates building applications with powerful extraction, regridding, and display capabilities. The ESMF CF Attribute package contains the three mandatory Attributes required to describe fields.

 Name Definition Controlled Vocabulary LongName An ad-hoc long descriptive name which may, for example, be used for labeling plots N/A ShortName* The short_name is technically not part of the CF standard but is commonly the name of the variable on the output file and so is distinct from the long_name N/A Units The value of the units attribute is a string that can be recognized by UNIDATA's Udunits package N/A

* Attribute required to be set, if any attributes are set within this package, the CF/Extended, or ESMF/General package, to produce valid CIM XML output. It is valid to set none of the attributes in this package, the CF/Extended, or ESMF/General package, in which case no field CIM output will be produced.

### 39.2.4 Array Attribute packages

At this time the Array packages are the same as the Field packages.

### 39.2.5 Grid Attribute packages

There are 2 grid attribute packages in ESMF.

1. CIM 1.5.1 grids
2. ESMF Grid

1. grids

• Specify with:
• convention = "CIM 1.5.1"
• purpose = "grids"
• CIM Version: CIM 1.5.1
• CIM Schema URL: http://metaforclimate.eu/trac/browser/CIM/tags/version-1.5.1/
• Output Options:
• Simple XML
• This package can be used to create a CIM 1.5.1 compliant grids XML file.
• Description: This package contains the the information necessary to create a CIM 1.5.1 compliant grids XML file. The Attributes in this package are populated entirely by internal ESMF Grid information, no user intervention beyond the addition of the package is needed to create this package.

 Name Definition Controlled Vocabulary id A unique name used to identify this Grid, this is taken from the internal name of the Grid object N/A isLeaf A boolean value used to describe whether there are any nested mosaics inside of this mosaic true, false gridType A text description of the the type of the grid cubed_sphere, displaced_pole, icosahedral_geodesic, reduced_gaussian, regular_lat_lon, spectral_gaussian, tripolar, yin_yang, composite, other numTiles The number of tiles in this Grid N/A shortName A short name to identify this Grid N/A longName A long name describing this Grid in detail N/A gridTile The specific number for this tile of the Grid N/A discretizationType The type of discretization that is used in this Grid logically_rectangular, structured_rectangular, unstructured_rectangular, pixel_based_catchment, unstructured_polygonal, spherical_harmonics, other geometryType The type of geometry that best describes this Grid ellipsoid, plane, sphere numDims The number of dimensions in this Grid N/A xcoords The x (or longitude) coordinates of this Grid N/A ycoords The y (or latitude) coordinates of the Grid N/A

2. ESMF Grid

• Specify with:
• convention = "ESMF"
• purpose = "General"
• Description: This package is used by ESMF to track internal ESMF Grid information.

 Name Definition Controlled Vocabulary RegDecompX The number of DEs in X a particular grid is decomposed into. N/A RegDecompY The number of DEs in Y a particular grid is decomposed into. N/A

### 39.2.6 Table of available Attributes

The following is an alphabetical list of all the attributes implemented in ESMF, their definitions, and which packages they are contained within.

### 39.2.7 Custom Attribute packages

ESMF allows for the creation of custom attribute packages, each of which has a user-defined convention and purpose, as well as a set of user-defined attributes. This can be done to augment one of the pre-defined packages (via package nesting 39.3) or to create a suite of attributes unique to the user. A custom attribute package currently outputs only in simple XML format, when used as a stand-alone package (not when used to augment a pre-defined package). Examples of how to create such custom packages are contained in Sections 39.7.2 and 39.7.3.

## 39.3 Attribute Packages Nesting

Nesting is a way of creating larger Attribute packages out of smaller ones and allows users to add the attributes they want to an existing package. It is very useful when combining a custom package with a pre-defined package. One or more child Attribute packages can be nested within a parent package, and this can be repeated multiple times, allowing a full Attribute tree (hierarchical) structure to be created. Breaking Attributes up into smaller packages that are then nested also allows for the construction of complex attribute trees where certain structures repeat themselves, allowing for Attribute package reusability.

Several of the ESMF pre-defined packages, when added to an ESMF object, are created with nested packages:

CIM Main - Component package - is a nest with three child packages:

1. CIM Platform
2. CIM Responsible Party (one or more - user specifiable)
3. CIM Citation (one or more - user specifiable)

CIM Inputs - Field package - is a nest with one child package:

1. ESMF General (with CF Extended and CF General packages nested within it)

ESMF General - Field package - is a nest with one child package:

1. CF Extended (with a CF General package nested within it)

CF Extended - Field package - is a nest with one child package:

1. CF General

## 39.4 Export Formats

The ESMF_AttributeWrite() interface is used to write the contents of an Attribute package to a file. This routine can be called on any ESMF object that is capable of holding Attribute packages. It can also write out all Attributes in Attribute packages with the same convention and purpose throughout an entire ESMF object hierarchy.

There are three primary ways of exporting Attributes:

1. Tab-delimited ASCII
2. Simple XML
3. CIM XML

The flag that is used in the ESMF_AttributeWrite() interface to determine which format for writing the Attribute packages is called the ESMF_AttWriteFlag, with values as described below. The resulting file will be placed in the execution directory after it is written and closed.

### 39.4.1 Tab-delimited ASCII

When ESMF_AttWriteFlag is set to ESMF_ATTWRITE_TAB (the default), a tab-delimited ascii file containing name-value pairs of attributes in the packages will be written. The file will be named for the name of the ESMF object from which ESMF_AttributeWrite() is called. The suffix will be .stdout.

### 39.4.2 Simple XML

When ESMF_AttWriteFlag is set to ESMF_ATTWRITE_XML, an XML file containing name-value pairs of attributes in the packages will be written. The file will be named for the name of the ESMF object from which ESMF_AttributeWrite() is called. The suffix will be .xml.

### 39.4.3 CIM XML

When the ESMF object from which ESMF_AttributeWrite() is called is a Component, and the Attribute package convention="CIM1.5", and the purpose="ModelComp", and ESMF_AttWriteFlag is set to ESMF_ATTWRITE_XML, an XML file conforming to the CIM standard will be written. The file will contain Attributes from the entire Component tree and their contained Fields. The file will be named for the name of the ESMF Component object from which ESMF_AttributeWrite() is called, and the suffix will be .xml.

There is a deviation from the standard CIM in the ESMF code: if the top-level object is not a component, or the proper convention ("CIM 1.5") or purpose ("ModelComp") are not used, then the simple XML logic will be followed, and elements such as, "variable_set" and "variable" may be found in the exported XML.

### 39.4.4 CIM 1.5.1 grids XML

** This is a prototype capability.

When the ESMF object from which ESMF_AttributeWrite() is called is a Grid (or it contains a Grid), and the Attribute package convention="CIM 1.5.1", and the purpose="grids", and ESMF_AttWriteFlag is set to ESMF_ATTWRITE_XML, an XML file conforming to the CIM 1.5.1 grids standard will be written. The file will be named for the name of the ESMF Component object from which ESMF_AttributeWrite() is called, and the suffix will be .xml. This file is written by pulling internal information out of the Grid object. It is currently functional for one- and two-dimensional Grids.

## 39.5 Accessing object information through Attribute

Internal ESMF class information can be retrieved through the Attribute class with the ESMF_AttributeGet() interface. The Grid class is the prototype for this capability. Internal information is retrieved by specifying the name in ESMF_AttributeGet() as the keyword of the desired argument from one of the ESMF_GridGet()interfaces. The value' of the Attribute must be of the corresponding type that is required to retrieve the desired piece of information. There are a few pieces of information that cannot be retrieved from the Grid through the Attribute interface at this time, see Tables 14 - 16 to determine what is currently available.

The name of an Attribute that represents internal class information must have ESMF:' prepended. This is to indicate that the information should be retrieved directly from class methods. The input arguments must not have the ESMF:' string prepended, and they should be specified as a character string with the name and value separated by an equal sign. For example, the localDe=0 would be specified like this: localDe=0'.

Note: Attribute access to internal class information does not have the normal Attribute restriction that the values of the Attributes must be consistent across the current VM.

There is an example of how to use this capability in Section 39.7.5.

The name, type, input arguments and original Grid interface for each of the pieces of internal Grid information that can be retrieved through the Attribute class are listed in Tables 14 - 16. The name of the Attribute is specified by the character strings in the first column, and the type of the output is specified in the second column. The third column specifies which input information is required (or optional) to retrieve the information and the fourth column gives a link to a detailed description of the input arguments.

Note: The following pieces of Grid information cannot be retrieved with this method: distgrid, coordDimMap, arbIndexList, and coord.

 Name Type Input arguments Original Interface arbDim integer ESMF_GridGet() arbDimCount integer ESMF_GridGet() arbIndexCount integer localDe ESMF_GridGet() computationalCount integer(:) staggerloc, localDe ESMF_GridGet() computationalLBound integer(:) staggerloc, localDe ESMF_GridGet() computationalUBound integer(:) staggerloc, localDe ESMF_GridGet() coordDimCount integer(:) ESMF_GridGet() coordTypeKind ESMF_TypeKind_Flag ESMF_GridGet() dimCount integer ESMF_GridGet() distgridToGridMap integer(:) ESMF_GridGet() exclusiveCount integer(:) staggerloc, localDe ESMF_GridGet() exclusiveLBound integer(:) staggerloc, localDe ESMF_GridGet() exclusiveUBound integer(:) staggerloc, localDe ESMF_GridGet() gridEdgeLWidth integer(:) ESMF_GridGet() gridEdgeUWidth integer(:) ESMF_GridGet() gridAlign integer(:) ESMF_GridGet() indexflag ESMF_Index_Flag ESMF_GridGet() isLBound logical localDe ESMF_GridGet() isUBound logical localDe ESMF_GridGet() localDECount integer ESMF_GridGet() maxIndex integer(:) tile, staggerloc ESMF_GridGet() minIndex integer(:) tile, staggerloc ESMF_GridGet() name character ESMF_GridGet() rank integer ESMF_GridGet() staggerlocCount integer ESMF_GridGet() status ESMF_GridStatus_Flag ESMF_GridGet() tileCount integer ESMF_GridGet()

 Name Type Input arguments Original Interface farrayPtr integer(:) coordDim, (optional) staggerloc, (optional) localDe ESMF_GridGetCoord() computationalCount integer(:) coordDim, (optional) staggerloc, (optional) localDe ESMF_GridGetCoord() computationalLBound integer(:) coordDim, (optional) staggerloc, (optional) localDe ESMF_GridGetCoord() computationalUBound integer(:) coordDim, (optional) staggerloc, (optional) localDe ESMF_GridGetCoord() exclusiveCount integer(:) coordDim, (optional) staggerloc, (optional) localDe ESMF_GridGetCoord() exclusiveLBound integer(:) coordDim, (optional) staggerloc, (optional) localDe ESMF_GridGetCoord() exclusiveUBound integer(:) coordDim, (optional) staggerloc, (optional) localDe ESMF_GridGetCoord() totalCount integer(:) coordDim, (optional) staggerloc, (optional) localDe ESMF_GridGetCoord() totalLBound integer(:) coordDim, (optional) staggerloc, (optional) localDe ESMF_GridGetCoord() totalUBound integer(:) coordDim, (optional) staggerloc, (optional) localDe ESMF_GridGetCoord()

 Name Type Input arguments Original Interface computationalCount integer(:) itemflag, (optional) staggerloc, (optional) localDe ESMF_GridGetItem() computationalLBound integer(:) itemflag, (optional) staggerloc, (optional) localDe ESMF_GridGetItem() computationalUBound integer(:) itemflag, (optional) staggerloc, (optional) localDe ESMF_GridGetItem() exclusiveCount integer(:) itemflag, (optional) staggerloc, (optional) localDe ESMF_GridGetItem() exclusiveLBound integer(:) itemflag, (optional) staggerloc, (optional) localDe ESMF_GridGetItem() exclusiveUBound integer(:) itemflag, (optional) staggerloc, (optional) localDe ESMF_GridGetItem() totalCount integer(:) itemflag, (optional) staggerloc, (optional) localDe ESMF_GridGetItem() totalLBound integer(:) itemflag, (optional) staggerloc, (optional) localDe ESMF_GridGetItem() totalUBound integer(:) itemflag, (optional) staggerloc, (optional) localDe ESMF_GridGetItem()

## 39.6 Constants

### 39.6.1 ESMF_ATTCOPY

DESCRIPTION:
Indicates which type of copy behavior is used when copying ESMF Attribute objects.

The type of this flag is:

type(ESMF_AttCopy_Flag)

The valid values are:

ESMF_ATTCOPY_REFERENCE
The destination Attribute hierarchy becomes a reference copy of the Attribute hierarchy of the source object. Any further changes to one will also be reflected in the other.
ESMF_ATTCOPY_VALUE
All of the Attributes and Attribute packages of the source object will be copied by value to the destination object. None of the Attribute links to the Attribute hierarchies of other objects are copied to the destination object.
ESMF_ATTCOPY_HYBRID
All of the Attributes and Attribute packages of the source object will be copied by value to the destination object. The Attribute links to the Attribute hierarchies of other objects are copied by reference.

### 39.6.2 ESMF_ATTGETCOUNT

DESCRIPTION:
Indicates which type of Attribute object count to return.

The type of this flag is:

type(ESMF_AttGetCountFlag)

The valid values are:

ESMF_ATTGETCOUNT_ATTRIBUTE
This option will allow the routine to return the number of single Attributes.
ESMF_ATTGETCOUNT_ATTPACK
This option will allow the routine to return the number of Attribute packages.
This option will allow the routine to return the number of Attribute links.
ESMF_ATTGETCOUNT_TOTAL
This option will allow the routine to return the total number of Attributes.

### 39.6.3 ESMF_ATTWRITE

DESCRIPTION:
Indicates which file format to use in the write operation.

The type of this flag is:

type(ESMF_AttWriteFlag)

The valid values are:

ESMF_ATTWRITE_XML
This option will allow the routine to write in xml format.
ESMF_ATTWRITE_TAB
This option will allow the routine to write in tab-delimited format.

## 39.7 Use and Examples

This section describes the use of the Attribute class. There are eight examples that follow, which outline the use of Attributes at three increasing levels of difficulty. The first example covers basic Attribute manipulations on the gridded Component. The second example covers the Attribute package capabilities, including Attribute package nesting and Attribute hierarchy linking. The third example covers Attribute management in a distributed environment and the I/O utilities. These examples will be best understood if followed in an ascending order from basic to advanced. The fourth example shows how to use the CIM Attribute packages. The last four examples cover setting of Attribute packages and custom Attributes from an XML file.

### 39.7.1 Basic Attribute usage

This example illustrates the most basic usage of the Attribute class. This demonstration of Attribute manipulation is limited to the gridded Component, but the same principles apply to the coupler Component, State, Grid, FieldBundle, Field, ArrayBundle and Array. The functionality that is demonstrated includes setting and getting Attributes, working with Attributes with different types and lists, removing Attributes, and getting default Attributes. Various other uses of ESMF_AttributeGet() is covered in detail in the last section. The first thing we must do is declare variables and initialize ESMF.

      ! Use ESMF framework module
use ESMF
use ESMF_TestMod
implicit none

! Local variables
integer                 :: rc, finalrc, petCount, localPet, &
itemCount, count, result
type(ESMF_VM)           :: vm
type(ESMF_GridComp)     :: gridcomp
character(ESMF_MAXSTR)  :: name
type(ESMF_TypeKind_Flag)     :: tk

integer(ESMF_KIND_I4)                :: inI4
integer(ESMF_KIND_I4), dimension(3)  :: inI4l
integer(ESMF_KIND_I8)                :: inI8
integer(ESMF_KIND_I8), dimension(3)  :: inI8l
real(ESMF_KIND_R4)                   :: inR4
real(ESMF_KIND_R4), dimension(3)     :: inR4l
real(ESMF_KIND_R8)                   :: inR8
real(ESMF_KIND_R8), dimension(3)     :: inR8l
character(ESMF_MAXSTR)               :: inChar
character(ESMF_MAXSTR), dimension(3) :: inCharl, &
defaultCharl, dfltoutCharl
character(ESMF_MAXSTR), dimension(8) :: outCharl
logical                              :: inLog
logical, dimension(3)                :: inLogl, value
character(ESMF_MAXSTR)               :: testname
character(ESMF_MAXSTR)               :: failMsg



! initialize ESMF
finalrc = ESMF_SUCCESS
call ESMF_Initialize(vm=vm, defaultlogfilename="AttributeEx.Log", &
logkindflag=ESMF_LOGKIND_MULTI, rc=rc)



! get the vm
call ESMF_VMGet(vm, petCount=petCount, localPet=localPet, rc=rc)


We will construct the gridded Component which will be responsible for all of the Attributes we will be manipulating.

      if (petCount<4) then
gridcomp = ESMF_GridCompCreate(name="gridcomp", &
petList=(/0/), rc=rc)
else
gridcomp = ESMF_GridCompCreate(name="gridcomp", &
petList=(/0,1,2,3/), rc=rc)
endif


We can set Attributes using the ESMF_AttributeSet() command. Attributes can be any of several different types, all of which are demonstrated here.

      inI4 = 4
inI4l = (/1,2,3/)
inI8 = 4
inI8l = (/1,2,3/)
inR4 = 4
inR4l = (/1,2,3/)
inR8 = 4
inR8l = (/1,2,3/)
inChar = "Character string 4"
inCharl = (/ "Character string 1", &
"Character string 2", &
"Character string 3" /)
inLog = .true.
inLogl = (/.true., .false., .true. /)

call ESMF_AttributeSet(gridcomp, name="ESMF_I4name", value=inI4, rc=rc)


      call ESMF_AttributeSet(gridcomp, name="ESMF_I4namelist", &
valueList=inI4l, rc=rc)


      call ESMF_AttributeSet(gridcomp, name="ESMF_I8name", value=inI8,  rc=rc)


      call ESMF_AttributeSet(gridcomp, name="ESMF_I8namelist", &
valueList=inI8l, rc=rc)


      call ESMF_AttributeSet(gridcomp, name="ESMF_R4name", value=inR4, rc=rc)


      call ESMF_AttributeSet(gridcomp, name="ESMF_R4namelist", &
valueList=inR4l, rc=rc)


      call ESMF_AttributeSet(gridcomp, name="ESMF_R8name", value=inR8, rc=rc)


      call ESMF_AttributeSet(gridcomp, name="ESMF_R8namelist", &
valueList=inR8l, rc=rc)


      call ESMF_AttributeSet(gridcomp, name="Character_name", &
value=inChar, rc=rc)


      call ESMF_AttributeSet(gridcomp, name="Character_namelist", &
valueList=inCharl, rc=rc)


      call ESMF_AttributeSet(gridcomp, name="Logical_name", value=inLog, rc=rc)


      call ESMF_AttributeSet(gridcomp, name="Logical_namelist", &
valueList=inLogl, rc=rc)


We can retrieve Attributes by issuing the ESMF_AttributeGet() command. This command can also be used with an optional default value (or value list) so that if the Attribute is not found a value is returned without an error code. Removal of Attributes is also possible, and is demonstrated here as well. One of the Attributes previously created will be retrieved, then removed, then retrieved again using a default return value. In order to use the default return value capabilites, we must first set up a default parameter.

      defaultCharl = (/ "Character string 4", &
"Character string 5", &
"Character string 6" /)

itemCount=3
call ESMF_AttributeGet(gridcomp, name="Character_namelist", &
valueList=outCharl(1:5), itemCount=itemCount, rc=rc)



call ESMF_AttributeRemove(gridcomp, name="Character_namelist", rc=rc)



call ESMF_AttributeGet(gridcomp, name="Character_namelist", &
valueList=dfltoutCharl, defaultvalueList=defaultCharl,rc=rc)


There are more overloaded instances of ESMF_AttributeGet() which allow the retrieval of Attribute information by name or index number, or a query for the count of the Attributes on a certain object. These capabilities are demonstrated here by first retrieving the name of an Attribute using the index number, keep in mind that these index numbers start from 1. Then the name that is retrieved is used to get other information about the Attribute, such as the typekind, and the number of items in the value of the Attribute. This information is then used to actually retrieve the Attribute value. Then the count of the number of Attributes on the object will be retrieved.

      call ESMF_AttributeGet(gridcomp, attributeIndex=11 , name=name, rc=rc)



call ESMF_AttributeGet(gridcomp, name=name, typekind=tk, &
itemCount=itemCount, rc=rc)



if (tk==ESMF_TYPEKIND_Logical .AND. itemCount==3) then
call ESMF_AttributeGet(gridcomp, name=name, valueList=value, rc=rc)


      endif

call ESMF_AttributeGet(gridcomp, count=count, rc=rc)


### 39.7.2 Attribute packages

This example is slightly more complex than the example presented in section 39.7.1 and illustrates the use of the Attribute class to create Attribute hierarchies using Attribute packages. A gridded Component is used in conjunction with two States, a FieldBundle, and various realistic Fields to create an Attribute hierarchy and copy it from one State to another. Attribute packages are created on the Component and Fields, and the standard Attributes in each package are used in the Attribute hierarchy. The Attribute package nesting capability is demonstrated by nesting the standard ESMF supplied packages for the Fields inside a user specified Attribute package with a customized convention.

We must construct the ESMF objects that will be responsible for the Attributes we will be manipulating. These objects include the gridded Component, two States, a FieldBundle, and 10 Fields. In this trivial example we are constructing empty Fields with no underlying Grid.

      if (petCount<4) then
gridcomp = ESMF_GridCompCreate(name="gridded_comp_ex2", &
petList=(/0/), rc=rc)
else
gridcomp = ESMF_GridCompCreate(name="gridded_comp_ex2", &
petList=(/0,1,2,3/), rc=rc)
endif


      importState = ESMF_StateCreate(name="importState",  &
stateintent=ESMF_STATEINTENT_IMPORT, rc=rc)


      exportState = ESMF_StateCreate(name="exportState",  &
stateintent=ESMF_STATEINTENT_EXPORT, rc=rc)


      DPEDT = ESMF_FieldEmptyCreate(name='DPEDT', rc=rc)


      DTDT = ESMF_FieldEmptyCreate(name='DTDT', rc=rc)


      DUDT = ESMF_FieldEmptyCreate(name='DUDT', rc=rc)


      DVDT = ESMF_FieldEmptyCreate(name='DVDT', rc=rc)


      PHIS = ESMF_FieldEmptyCreate(name='PHIS', rc=rc)


      QTR = ESMF_FieldEmptyCreate(name='QTR', rc=rc)


      CNV = ESMF_FieldEmptyCreate(name='CNV', rc=rc)


      CONVCPT = ESMF_FieldEmptyCreate(name='CONVCPT', rc=rc)


      CONVKE = ESMF_FieldEmptyCreate(name='CONVKE', rc=rc)


      CONVPHI = ESMF_FieldEmptyCreate(name='CONVPHI', rc=rc)


      fbundle = ESMF_FieldBundleCreate(name="fbundle", rc=rc)


Now we can add Attribute packages to all of the appropriate objects. We will use the ESMF supplied Attribute packages for the Fields and the Component. On the Fields, we will first use ESMF_AttributeAdd() to create standard Attribute packages, then we will nest customized Attribute packages around the ESMF standard Attribute packages. In this simple example the purpose for the Attribute packages will be specified as "General" in all cases.

      convESMF = 'ESMF'
convCC = 'CustomConvention'
purpGen = 'General'

attrList(1) = 'Coordinates'

! DPEDT
rc=rc)


      call ESMF_AttributeAdd(DPEDT, convention=convCC, purpose=purpGen,   &
attrList=attrList, nestConvention=convESMF, nestPurpose=purpGen,  &
rc=rc)


... and so on for the other 9 Fields.

The standard Attribute package currently supplied by ESMF for Field contains 6 Attributes, 2 of which are set automatically. The remaining 4 Attributes in the standard Field Attribute package must be set manually by the user. We must also set the Attributes of our own custom Attribute package, which is built around the ESMF standard Attribute package.

      name1 = 'ShortName'
name2 = 'StandardName'
name3 = 'LongName'
name4 = 'Units'

! DPEDT
value1 = 'DPEDT'
value2 = 'tendency_of_air_pressure'
value3 = 'Edge pressure tendency'
value4 = 'Pa s-1'
! Custom Attributes

! retrieve Attribute package
call ESMF_AttributeGetAttPack(DPEDT, convCC, purpGen, &
attpack=attpack, rc=rc)


      call ESMF_AttributeSet(DPEDT, name='Coordinates', value='latlon', &
convention=convCC, purpose=purpGen, rc=rc)


      call ESMF_AttributeSet(DPEDT, name='Mask', value='yes', &
convention=convCC, purpose=purpGen, rc=rc)


      ! ESMF Attributes

! retrieve Attribute package
call ESMF_AttributeGetAttPack(DPEDT, convESMF, purpGen, &
attpack=attpack, rc=rc)


      call ESMF_AttributeSet(DPEDT, name2, value2, &
convention=convESMF, purpose=purpGen, rc=rc)


      call ESMF_AttributeSet(DPEDT, name3, value3, &
convention=convESMF, purpose=purpGen, rc=rc)


      call ESMF_AttributeSet(DPEDT, name4, value4, &
convention=convESMF, purpose=purpGen, rc=rc)


... and so on for the other 9 Fields.

The standard Attribute package currently supplied by ESMF for Component contains 10 Attributes. These Attributes conform to both the ESG and CF conventions, and must be set manually.

    ! retrieve Attribute package
call ESMF_AttributeGetAttPack(gridcomp, convESMF, purpGen, attpack=attpack, rc=rc)


    call ESMF_AttributeSet(gridcomp, 'Agency', 'NASA', &
convention=convESMF, purpose=purpGen, rc=rc)


    call ESMF_AttributeSet(gridcomp, 'Author', 'Max Suarez', &
convention=convESMF, purpose=purpGen, rc=rc)


    call ESMF_AttributeSet(gridcomp, 'CodingLanguage', &
'Fortran 90', convention=convESMF, purpose=purpGen, rc=rc)


    call ESMF_AttributeSet(gridcomp, 'Discipline', &
'Atmosphere', convention=convESMF, purpose=purpGen, rc=rc)


    call ESMF_AttributeSet(gridcomp, 'ComponentLongName', &
'Goddard Earth Observing System Version 5 Finite Volume Dynamical Core', &
convention=convESMF, purpose=purpGen, rc=rc)


    call ESMF_AttributeSet(gridcomp, 'ModelComponentFramework', &
'ESMF', convention=convESMF, purpose=purpGen, rc=rc)


    call ESMF_AttributeSet(gridcomp, 'ComponentShortName', &
'GEOS-5 FV dynamical core', &
convention=convESMF, purpose=purpGen, rc=rc)


    call ESMF_AttributeSet(gridcomp, 'PhysicalDomain', &
'Earth system', convention=convESMF, purpose=purpGen, rc=rc)


    call ESMF_AttributeSet(gridcomp, 'Version', &
'GEOSagcm-EROS-beta7p12', convention=convESMF, purpose=purpGen, rc=rc)


Adding the Fields to the FieldBundle will automatically link" the Attribute hierarchies. The same type of link will be generated when adding a FieldBundle to a State.

      call ESMF_FieldBundleAdd(fbundle, (/DPEDT/), rc=rc)


      call ESMF_FieldBundleAdd(fbundle, (/DTDT/), rc=rc)


      call ESMF_FieldBundleAdd(fbundle, (/DUDT/), rc=rc)


      call ESMF_FieldBundleAdd(fbundle, (/DVDT/), rc=rc)


      call ESMF_FieldBundleAdd(fbundle, (/PHIS/), rc=rc)


      call ESMF_FieldBundleAdd(fbundle, (/QTR/), rc=rc)


      call ESMF_FieldBundleAdd(fbundle, (/CNV/), rc=rc)


      call ESMF_FieldBundleAdd(fbundle, (/CONVCPT/), rc=rc)


      call ESMF_FieldBundleAdd(fbundle, (/CONVKE/), rc=rc)


      call ESMF_FieldBundleAdd(fbundle, (/CONVPHI/), rc=rc)


      call ESMF_StateAdd(exportState, fieldbundleList=(/fbundle/), rc=rc)


The link between a State and the Component of interest must be set manually.

      call ESMF_AttributeLink(gridcomp, exportState, rc=rc)


There are currently two different formats available for writing the contents of the Attribute packages in an Attribute hierarchy. There is an XML formatted write, which generates an .xml file in the execution directory with the contents of the write. There is also a tab-delimited write which writes to standard out, a file generated in the execution directory with the extension .stdout. Either of the ESMF_AttributeWrite() formats can be called on any of the objects which are capable of manipulating Attributes, but only from objects in an Attribute hierarchy which contain ESMF standard Attribute packages can it be confirmed that any relevant information be written. The ESMF_AttributeWrite() capability is only functional for single-item Attributes at this point, it will be more robust in future releases. A flag is used to specify which format to write, the default is tab-delimited.

      call ESMF_AttributeWrite(gridcomp,convESMF,purpGen, &
attwriteflag=ESMF_ATTWRITE_XML,rc=rc)


      call ESMF_AttributeWrite(gridcomp,convESMF,purpGen,rc=rc)


### 39.7.3 Custom Attribute package

This example illustrates how to create a user-defined, custom Attribute package. The package is created on a gridded Component with three custom Attributes.

We must construct the ESMF gridded Component object that will be responsible for the custom Attribute package we will be manipulating.

      if (petCount<4) then
gridcomp = ESMF_GridCompCreate(name="gridded_comp_ex3", &
petList=(/0/), rc=rc)
else
gridcomp = ESMF_GridCompCreate(name="gridded_comp_ex3", &
petList=(/0,1,2,3/), rc=rc)
endif


Now we can add a custom Attribute package to the gridded Component object.

      customConv = 'CustomConvention'
customPurp = 'CustomPurpose'

customAttrList(1) = 'CustomAttrName1'
customAttrList(2) = 'CustomAttrName2'
customAttrList(3) = 'CustomAttrName3'

purpose=customPurp, attrList=customAttrList, rc=rc)


We must set the Attribute values of our custom Attribute package.

    call ESMF_AttributeSet(gridcomp, 'CustomAttrName1', 'CustomAttrValue1', &
convention=customConv, purpose=customPurp, rc=rc)


    call ESMF_AttributeSet(gridcomp, 'CustomAttrName2', 'CustomAttrValue2', &
convention=customConv, purpose=customPurp, rc=rc)


    call ESMF_AttributeSet(gridcomp, 'CustomAttrName3', 'CustomAttrValue3', &
convention=customConv, purpose=customPurp, rc=rc)


Write out the contents of our custom Attribute package to an XML file, which is generated with a .xml file extension in the execution directory.

      call ESMF_AttributeWrite(gridcomp,customConv,customPurp, &
attwriteflag=ESMF_ATTWRITE_XML,rc=rc)


### 39.7.4 Updating Attributes in a distributed environment

This advanced example illustrates the proper methods of Attribute manipulation in a distributed environment to ensure consistency of metadata across the VM. This example is much more complicated than the previous two because we will be following the flow of control of a typical model run with two gridded Components and one coupling Component. We will start out in the application driver, declaring Components, States, and the routines used to initialize, run and finalize the user's model Components. Then we will follow the control flow into the actual Component level through initialize, run, and finalize examining how Attributes are used to organize the metadata.

This example follows a simple user model with two gridded Components and one coupling Component. The initialize routines are used to set up the application data and the run routines are used to manipulate the data. Accordingly, most of the Attribute manipulation will take place in the initialize phase of each of the three Components. The two gridded Components will be running on exclusive pieces of the VM and the coupler Component will encompass the entire VM so that it can handle the Attribute communications.

The control flow of this example will start in the application driver, after which it will complete three cycles through the three Components. The first cycle will be through the initialize routines, from the first gridded Component to the second gridded Component to the coupler Component. The second cycle will go through the run routines, from the first gridded Component to the coupler Component to the second Gridded component. The third cycle will be through the finalize routines in the same order as the first cycle.

In the application driver, we must now construct some ESMF objects, such as the gridded Components, the coupler Component, and the States. This is also where it is determined which subsets of the PETs of the VM the Components will be using to run their initialize, run, and finalize routines.

        gridcomp1 = ESMF_GridCompCreate(name="gridcomp1", &
petList=(/0,1/), rc=rc)


        gridcomp2 = ESMF_GridCompCreate(name="gridcomp2", &
petList=(/2,3/), rc=rc)


        cplcomp = ESMF_CplCompCreate(name="cplcomp", &
petList=(/0,1,2,3/), rc=rc)


      endif

c1exp = ESMF_StateCreate(name="Comp1 exportState", &
stateintent=ESMF_STATEINTENT_EXPORT, rc=rc)


Before the individual components are initialized, run, and finalized Attributes should be set at the Component level. Here we are going to use the ESG Attribute package on the first gridded Component. The Attribute package is added, and then each of the Attributes is set. The Attribute hierarchy of the Component is then linked to the Attribute hierarchy of the export State in a manual fashion.

      convESMF = 'ESMF'
purpGen = 'General'
convention=convESMF, purpose=purpGen, attpack=attpack, &
rc=rc)


    call ESMF_AttributeSet(gridcomp1, 'Agency', 'NASA', attpack, rc=rc)


    call ESMF_AttributeSet(gridcomp1, 'Author', 'Max Suarez', &
convention=convESMF, purpose=purpGen, rc=rc)


    call ESMF_AttributeSet(gridcomp1, 'CodingLanguage', &
'Fortran 90', convention=convESMF, purpose=purpGen, rc=rc)


    call ESMF_AttributeSet(gridcomp1, 'Discipline', &
'Atmosphere', convention=convESMF, purpose=purpGen, rc=rc)


    call ESMF_AttributeSet(gridcomp1, 'ComponentLongName', &
'Goddard Earth Observing System Version 5 Finite Volume Dynamical Core', &
convention=convESMF, purpose=purpGen, rc=rc)


    call ESMF_AttributeSet(gridcomp1, 'ModelComponentFramework', &
'ESMF', &
convention=convESMF, purpose=purpGen, rc=rc)


    call ESMF_AttributeSet(gridcomp1, 'ComponentShortName', &
'GEOS-5 FV dynamical core', convention=convESMF, purpose=purpGen, rc=rc)


    call ESMF_AttributeSet(gridcomp1, 'PhysicalDomain', &
'Earth system', convention=convESMF, purpose=purpGen, rc=rc)


    call ESMF_AttributeSet(gridcomp1, 'Version', &
'GEOSagcm-EROS-beta7p12', convention=convESMF, purpose=purpGen, rc=rc)


    call ESMF_AttributeLink(gridcomp1, c1exp, rc=rc)


    call ESMF_AttributeLinkRemove(gridcomp1, c1exp, rc=rc)


Now the individual Components will be run. First we will initialize the two gridded Components, then we will initialize the coupler Component. During each of these Component initialize routines Attribute packages will be added, and the Attributes set. The Attribute hierarchies will also be linked (unlinking also demonstrated). As the gridded Components will be running on exclusive portions of the VM, the Attributes will need to be made available across the VM using an ESMF_StateReconcile() call in the coupler Component. The majority of the work with Attributes will take place in this portion of the model run, as metadata rarely needs to be changed during run time.

What follows are the calls from the driver code that run the initialize, run, and finalize routines for each of the Components. After these calls we will step through the first cycle as explained in the introduction, through the initialize routines of gridded Component 1 to gridded Component 2 to the coupler Component.

      call ESMF_GridCompInitialize(gridcomp1, exportState=c1exp, rc=rc)
call ESMF_GridCompInitialize(gridcomp2, importState=c2imp, rc=rc)
call ESMF_CplCompInitialize(cplcomp, importState=c1exp, &
exportState=c2imp, rc=rc)


      call ESMF_GridCompRun(gridcomp1, exportState=c1exp, rc=rc)


      call ESMF_CplCompRun(cplcomp, importState=c1exp, &
exportState=c2imp, userRc=urc, rc=rc)


      call ESMF_GridCompRun(gridcomp2, importState=c2imp, rc=rc)


      call ESMF_GridCompFinalize(gridcomp1, exportState=c1exp, rc=rc)


      call ESMF_GridCompFinalize(gridcomp2, importState=c2imp, rc=rc)


      call ESMF_CplCompFinalize(cplcomp, importState=c1exp, &
exportState=c2imp, rc=rc)


In the first gridded Component initialize routine we need to create some Attribute packages and set all of the Attributes. These Attributes will be attached to realistic Fields, containing a Grid, which are contained in a FieldBundle. The first thing to do is declare variables and make the Grid.

        type(ESMF_AttPack)       :: attpack
type(ESMF_VM)            :: vm
integer                  :: petCount, status, myPet
character(ESMF_MAXSTR)   :: name1,name2,name3,name4,value1,value2, &
value3,value4,convESMF,purpGen,convCC
type(ESMF_ArraySpec)     :: arrayspec
type(ESMF_Grid)          :: grid
type(ESMF_Field)         :: DPEDT,DTDT,DUDT,DVDT,PHIS,QTR,CNV,CONVCPT, &
CONVKE,CONVPHI
type(ESMF_FieldBundle)   :: fieldbundle
character(ESMF_MAXSTR),dimension(2)   :: attrList

rc = ESMF_SUCCESS

call ESMF_GridCompGet(comp, vm=vm, rc=status)
call ESMF_VMGet(vm, petCount=petCount, localPet=myPet, rc=status)

call ESMF_ArraySpecSet(arrayspec, typekind=ESMF_TYPEKIND_R8, rank=2, &
rc=rc)
grid = ESMF_GridCreateNoPeriDim(minIndex=(/1,1/), maxIndex=(/100,150/), &
regDecomp=(/1,petCount/), &
gridEdgeLWidth=(/0,0/), gridEdgeUWidth=(/0,0/), &
indexflag=ESMF_INDEX_GLOBAL, rc=rc)


At this point the Fields will need to have Attribute packages attached to them, and the Attributes will be set with appropriate values.

    convCC = 'CustomConvention'
convESMF = 'ESMF'
purpGen = 'General'
name1 = 'ShortName'
name2 = 'StandardName'
name3 = 'LongName'
name4 = 'Units'

value1 = 'DPEDT'
value2 = 'tendency_of_air_pressure'
value3 = 'Edge pressure tendency'
value4 = 'Pa s-1'

DPEDT = ESMF_FieldCreate(grid, arrayspec=arrayspec, &
staggerloc=ESMF_STAGGERLOC_CENTER, rc=status)
attpack=attpack, rc=status)
call ESMF_AttributeSet(DPEDT, name=name1, value=value1, &
attpack=attpack, rc=status)
call ESMF_AttributeSet(DPEDT, name=name2, value=value2, &
attpack=attpack, rc=status)
call ESMF_AttributeSet(DPEDT, name=name3, value=value3, &
attpack=attpack, rc=status)
call ESMF_AttributeSet(DPEDT, name=name4, value=value4, &
attpack=attpack, rc=status)


... and so on for the other 9 Fields.

Now the Fields will be added to the FieldBundle, at which point the Attribute hierarchies of the Fields will also be attached to the Attribute hierarchy of the FieldBundle. After that, the FieldBundle will be attached to the export State, again at which time the Attribute hierarchy of the FieldBundle will be attached to the Attribute hierarchy of the export State.

    fieldbundle = ESMF_FieldBundleCreate(name="fieldbundle", rc=status)
call ESMF_FieldBundleSet(fieldbundle, grid=grid, rc=status)



At this point, the driver of the model run will transfer control to the initialize phase of the second gridded Component.

In the second gridded Component initialize routine we don't have anything to do. The data that was created in the initialize routine of the first gridded Component will be passed to this Component through the coupler Component. The data will not be used in this Component until the run phase of the model. So now the application driver transfers control to the initialize phase of the coupler Component.

In the coupler Component initialize routine all that is required is to ensure consistent data across the VM. The data created in the first gridded Component on one set of the PETs in the VM is intended to be read and manipulated by the second gridded Component which runs on an exclusive set of the PETs of the VM for this application. We need to first make that data consistent across the entire VM with the ESMF_StateReconcile() call. This State level call handles both the data - Fields and FieldBundles, and the metadata - Attribute and Attribute packages. There is a flag in this call to allow the user to specify whether they want the metadata to be reconciled or not.

    type(ESMF_VM)         :: vm

rc = ESMF_SUCCESS

call ESMF_CplCompGet(comp, vm=vm, rc=rc)
call ESMF_StateReconcile(importState, vm=vm, &
attreconflag=ESMF_ATTRECONCILE_ON, rc=rc)
call ESMF_StateReconcile(exportState, vm=vm, &
attreconflag=ESMF_ATTRECONCILE_ON, rc=rc)


At this point, the driver of the model run will transfer control to the run phase of the first gridded Component.

In the run phase of the first gridded Component is typically where the data contained in the Fields is manipulated. For this simple example we will do no actual data manipulation because all we are interested in at this point is the metadata. What we will do is add a nested Attribute package inside the currently existing Attribute package on each Field. We will also change the value of one of the Attributes in the original Attribute package, and remove another of the Attributes from the original Attribute package on each of the Fields. The first thing is to declare variables and get the Component, VM, State, and FieldBundle.

        type(ESMF_AttPack)          :: attpack, attpackGen
type(ESMF_VM)               :: vm
integer                     :: petCount, status, myPet, k
character(ESMF_MAXSTR)      :: name2,value2,convESMF,purpGen,purp2,name3
character(ESMF_MAXSTR),dimension(2) :: attrList
type(ESMF_Field)            :: field(10)
type(ESMF_FieldBundle)      :: fieldbundle
type(ESMF_Grid)             :: grid

rc = ESMF_SUCCESS

convESMF = 'ESMF'
purpGen = 'General'
name2 = 'StandardName'
value2 = 'default_standard_name'
name3 = 'LongName'

purp2 = 'Extended'
attrList(1) = 'Coordinates'

call ESMF_GridCompGet(comp, vm=vm, rc=status)
call ESMF_VMGet(vm, petCount=petCount, localPet=myPet, rc=status)

call ESMF_StateGet(exportState, "fieldbundle", fieldbundle, rc=rc)
if (rc .ne. ESMF_SUCCESS) return
call ESMF_FieldBundleGet(fieldbundle, grid=grid, rc=rc)
if (rc .ne. ESMF_SUCCESS) return


At this point we will extract each of the Fields in the FieldBundle in turn and change the value of one Attribute in the original Attribute package, add a nested Attribute package, and delete one other of the Attributes in the original Attribute package. These three changes represent, respectively, a value change and two structural changes to the Attribute hierarchy during run time, which must be reconciled across the VM before the second gridded Component can be allowed to further manipulate the Attribute hierarchy.

    call ESMF_FieldBundleGet(fieldbundle, fieldList=field, rc=rc)
if (rc .ne. ESMF_SUCCESS) return
do k = 1, 10
call ESMF_AttributeGetAttPack(field(k), convESMF, purpGen, &
attpack=attpackGen, rc=rc)
if (rc .ne. ESMF_SUCCESS) return
call ESMF_AttributeSet(field(k), name=name2, value=value2, &
attpack=attpackGen, rc=status)
if (rc .ne. ESMF_SUCCESS) return
convention=convESMF, purpose=purp2, &
nestConvention=convESMF, nestPurpose=purpGen, &
attpack=attpack, rc=rc)
if (rc .ne. ESMF_SUCCESS) return
call ESMF_AttributeSet(field(k), name='Coordinates', value='Latlon', &
attpack=attpack, rc=rc)
if (rc .ne. ESMF_SUCCESS) return
attpack=attpack, rc=rc)
if (rc .ne. ESMF_SUCCESS) return
call ESMF_AttributeRemove(field(k), name=name3, &
attpack=attpackGen, rc=status)
if (rc .ne. ESMF_SUCCESS) return
enddo


At this point, the driver of the model run will transfer control to the run phase of the coupler Component.

In the run phase of the coupler Component we must now ensure that the entire VM again has a consistent view of the Attribute hierarchy. This is different from the communication done in the initialize phase of the model run because the only structural change that has occurred is in the Attribute hierarchy. Therefore an ESMF_AttributeUpdate() call can be used at this point to reconcile these changes. It should be noted that the ESMF_AttributeUpdate() call will reconcile value changes to the Attribute hierarchy as well as structural changes.

The first thing to do is to retrieve the Component, VM, and States. Then ESMF_AttributeUpdate() will be called on the import State to accomplish a VM wide communication. Afterwards, the Attribute hierarchy can be transferred, in a local sense, from the import State to the export State using an ESMF_AttributeCopy() call.

    type(ESMF_VM)               :: vm
integer                     :: myPet

integer, dimension(2)       :: rootList

rc = ESMF_SUCCESS

call ESMF_CplCompGet(comp, vm=vm, rc=rc)

call ESMF_VMGet(vm, localPet=myPet, rc=rc)

call ESMF_StateGet(importState, rc=rc)
call ESMF_StateGet(exportState, rc=rc)

rootList = (/0,1/)
call ESMF_AttributeUpdate(importState, vm, rootList=rootList, rc=rc)

call ESMF_AttributeCopy(importState, exportState, &
attcopy=ESMF_ATTCOPY_REFERENCE, rc=rc)


At this point the entire VM has a consistent view of the Attribute hierarchy that was recently modified during run time in the first gridded component and the driver of the model run will transfer control to the run phase of the second gridded Component.

In the run phase of the second gridded Component is normally where a user model would again manipulate the data it was given. In this simple example we are only dealing with the metadata, which has already been ensured for consistency across the VM, including the exclusive piece of which is being used in this Component. Therefore we are free to use the metadata as we wish, considering only that any changes we make to it during run time will have to first be reconciled before other parts of the VM can use them. However, this is not our concern at this point because we will now explore the capabilities of ESMF_AttributeWrite().

First we will get the Component and VM. Then we will write out the Attribute hierarchy to an .xml file, after which we will write out the Attribute hierarchy to a more reader friendly tab-delimited format. Both of these write calls will output their respective data into files in the execution directory, in either a .xml or .stdout file.

    type(ESMF_VM)               :: vm
integer                     :: petCount, status, myPet
character(ESMF_MAXSTR)      :: convESMF,purpGen

rc = ESMF_SUCCESS

call ESMF_GridCompGet(comp, vm=vm, rc=status)
if (status .ne. ESMF_SUCCESS) return
call ESMF_VMGet(vm, petCount=petCount, localPet=myPet, rc=status)
if (status .ne. ESMF_SUCCESS) return

convESMF = 'ESMF'
purpGen = 'General'

if (myPet .eq. 2) then
call ESMF_AttributeWrite(importState,convESMF,purpGen, &
attwriteflag=ESMF_ATTWRITE_XML, rc=rc)
call ESMF_AttributeWrite(importState,convESMF,purpGen,rc=rc)
if (rc .ne. ESMF_SUCCESS) return
endif


At this point the driver of the model run would normally transfer control to the finalize phase of the first gridded Component. However, there is not much of interest as far as metadata is concerned in this portion of the model run. So with that we will conclude this example.

### 39.7.5 Accessing object information through Attribute

This example demonstrates the ability to access object information through the Attribute class. This capability is enabled only in the Grid class at this point. Internal Grid information is retrieved through the ESMF_AttributeGet() interface by specifying the name as a character string holding the keyword of the desired piece of Grid information. Information that requires input arguments is retrieved by specifying the input argument in a character array.

Some examples of this capability are given in this section. The first shows how to get the name of a Grid, and the second shows how to get a more complex parameter which requires inputs. First, we must initialize ESMF, declare some variables, and create a Grid:

      ! Use ESMF framework module
use ESMF
use ESMF_TestMod
implicit none

! Local variables
integer                 :: rc, finalrc, petCount, localPet, result
type(ESMF_VM)           :: vm
type(ESMF_Grid)         :: grid
type(ESMF_DistGrid)     :: distgrid
character(ESMF_MAXSTR)  :: name
character(ESMF_MAXSTR),dimension(3) :: inputList
integer(ESMF_KIND_I4)  :: exclusiveLBound(2), exclusiveUBound(2)
integer(ESMF_KIND_I4)  :: exclusiveCount(2)

character(ESMF_MAXSTR)               :: testname
character(ESMF_MAXSTR)               :: failMsg


      ! initialize ESMF
finalrc = ESMF_SUCCESS
call ESMF_Initialize(vm=vm, &
defaultlogfilename="AttributeInternalInfoEx.Log", &
logkindflag=ESMF_LOGKIND_MULTI, rc=rc)

distgrid=ESMF_DistGridCreate(minIndex=(/1,1/),maxIndex=(/10,10/), rc=rc)


      grid=ESMF_GridCreate(distgrid=distgrid, &
coordTypeKind=ESMF_TYPEKIND_I4, &
name="AttributeTestGrid", rc=rc)


This first call shows how to retrieve the name of a Grid. The return value is a character string in this case, which must be provided as the argument to 'value'. The 'name' of the Attribute is specified as a character string whose value is the keyword of the piece of Grid information to retrieve preceded by a special tag. This tag, 'ESMF:', tells the ESMF_AttributeGet() routine that it should be looking for class information, rather than an Attribute that was previously created with the ESMF_AttributeSet() call.

  call ESMF_AttributeGet(grid, name="ESMF:name", value=name, rc=rc)


This second call demonstrates how to retrieve the exclusiveCount from a Grid. As before, the 'name' of the Attribute is specified as the keyword of the information to retrieve, preceded by the 'ESMF:' tag. The value is an integer array, which must be allocated to a sufficient size to hold all of the requested information. The exclusiveCount of a Grid requires three pieces of input information: localDe, itemflag, and staggerloc. These are specified in an array of character strings. The name of the input parameter is separated from the value by a ':'.

  inputList(:) = ''
inputList(1) = 'localDe:0'
inputList(3) = 'staggerloc:ESMF_STAGGERLOC_CENTER'
call ESMF_AttributeGet(grid, name="ESMF:exclusiveCount", &
valueList=exclusiveCount, inputList=inputList, rc=rc)


That all there is to it! Now we just have to Finalize ESMF:

    call ESMF_Finalize(rc=rc)


### 39.7.6 CIM Attribute packages

This example illustrates the use of the Metafor CIM Attribute packages, supplied by ESMF, to create an Attribute hierarchy on an ESMF object tree. Gridded, coupler and science Components are used together with a State and a realistic Field to create a simple ESMF object tree. CIM Attributes packages are created on the Components and Field, and then the individual Attributes within the packages are populated with values. Finally, all the Attributes are written to a CIM-formatted XML file. For a more comprehensive example, see the ESMF_AttributeCIM system test.

      ! Use ESMF framework module
use ESMF
use ESMF_TestMod
implicit none

! Local variables
integer                 :: rc, finalrc, petCount, localPet, result
type(ESMF_AttPack)      :: attpack
type(ESMF_VM)           :: vm
type(ESMF_Field)        :: ozone
type(ESMF_State)        :: exportState
type(ESMF_CplComp)      :: cplcomp
type(ESMF_GridComp)     :: gridcomp
type(ESMF_SciComp)      :: scicomp
character(ESMF_MAXSTR)  :: convCIM, purpComp, purpProp, purpSci
character(ESMF_MAXSTR)  :: purpField, purpPlatform
character(ESMF_MAXSTR)  :: convISO, purpRP, purpCitation
character(ESMF_MAXSTR), dimension(2)  :: compPropAtt
character(ESMF_MAXSTR)  :: testname
character(ESMF_MAXSTR)  :: failMsg


      ! initialize ESMF
finalrc = ESMF_SUCCESS
call ESMF_Initialize(vm=vm, defaultlogfilename="AttributeCIMEx.Log", &
logkindflag=ESMF_LOGKIND_MULTI, rc=rc)
if (rc /= ESMF_SUCCESS) call ESMF_Finalize(endflag=ESMF_END_ABORT)

! get the vm
call ESMF_VMGet(vm, petCount=petCount, localPet=localPet, rc=rc)
if (rc /= ESMF_SUCCESS) call ESMF_Finalize(endflag=ESMF_END_ABORT)


Create the ESMF objects that will hold the CIM Attributes. These objects include all three Component types (coupler, gridded, and science Components) as well as a State, and a Field. In this example we are constructing empty Fields without an underlying Grid.

      ! Create top-level Coupler Component
cplcomp = ESMF_CplCompCreate(name="coupler_component", &
petList=(/0/), rc=rc)


      ! Create Gridded Component as a child of the Coupler Component
gridcomp = ESMF_GridCompCreate(name="gridded_component", &
petList=(/0/), rc=rc)



      ! Create Science Component as a child of the Gridded Component
scicomp = ESMF_SciCompCreate(name="science_component", rc=rc)



      ! Create State
exportState = ESMF_StateCreate(name="exportState",  &
stateintent=ESMF_STATEINTENT_EXPORT, rc=rc)


      ! Create Field
ozone = ESMF_FieldEmptyCreate(name='ozone', rc=rc)


      convCIM = 'CIM 1.5'
purpComp = 'ModelComp'
purpProp = 'CompProp'
purpSci = 'SciProp'
purpField = 'Inputs'
purpPlatform = 'Platform'

convISO = 'ISO 19115'
purpRP = 'RespParty'
purpCitation = 'Citation'


Add CIM Component package and Attributes to the Coupler Component.

      call ESMF_AttributeAdd(cplcomp,  &
convention=convCIM, purpose=purpComp, rc=rc)

call ESMF_AttributeSet(cplcomp, "ShortName", "Driver", &
convention=convCIM, purpose=purpComp, rc=rc)
call ESMF_AttributeSet(cplcomp, "LongName", &
"Model Driver", &
convention=convCIM, purpose=purpComp, rc=rc)
call ESMF_AttributeSet(cplcomp, "ModelType", &
"climate", &
convention=convCIM, purpose=purpComp, rc=rc)


      ! Simulation run attributes
call ESMF_AttributeSet(cplcomp, 'SimulationShortName', &
'SMS.f09_g16.X.hector', &
convention=convCIM, purpose=purpComp, rc=rc)

call ESMF_AttributeSet(cplcomp, 'SimulationLongName', &
'EarthSys - Earth System Modeling Framework Earth System Model 1.0', &
convention=convCIM, purpose=purpComp, rc=rc)

call ESMF_AttributeSet(cplcomp, 'SimulationRationale', &
'EarthSys-ESMF simulation run in respect to CMIP5 core experiment 1.1 ()', &
convention=convCIM, purpose=purpComp, rc=rc)

call ESMF_AttributeSet(cplcomp, 'SimulationStartDate', &
'1960-01-01T00:00:00Z', &
convention=convCIM, purpose=purpComp, rc=rc)

call ESMF_AttributeSet(cplcomp, 'SimulationDuration', 'P10Y', &
convention=convCIM, purpose=purpComp, rc=rc)

call ESMF_AttributeSet(cplcomp, &
'SimulationNumberOfProcessingElements', '16', &
convention=convCIM, purpose=purpComp, rc=rc)


      call ESMF_AttributeGetAttPack(cplcomp, convCIM, purpPlatform, &
attpack=attpack, rc=rc)

call ESMF_AttributeSet(cplcomp, 'MachineName', 'HECToR', &
convention=convCIM, purpose=purpPlatform, rc=rc)


Now add CIM Attribute packages and Attributes to the Gridded Component and Field. Also, add a CIM Component Properties package, to contain two custom attributes.

      ! Add CIM Attribute package to the gridded Component
purpose=purpComp, rc=rc)


      ! Specify the gridded Component to have a Component Properties
! package with two custom attributes, with user-specified names
compPropAtt(1) = 'SimulationType'
compPropAtt(2) = 'SimulationURL'
attrList=compPropAtt, rc=rc)


      ! Add CIM Attribute package to the Field
rc=rc)


The standard Attribute package supplied by ESMF for a CIM Component contains several Attributes, grouped into sub-packages. These Attributes conform to the CIM convention as defined by Metafor and their values are set individually.

      !
! Top-level model component attributes, set on gridded component
!
call ESMF_AttributeSet(gridcomp, 'ShortName', 'EarthSys_Atmos', &
convention=convCIM, purpose=purpComp, rc=rc)


      call ESMF_AttributeSet(gridcomp, 'LongName', &
'Earth System High Resolution Global Atmosphere Model', &
convention=convCIM, purpose=purpComp, rc=rc)


      call ESMF_AttributeSet(gridcomp, 'Description', &
'EarthSys brings together expertise from the global ' // &
'community in a concerted effort to develop coupled ' // &
'climate models with increased horizontal resolutions.  ' // &
'Increasing the horizontal resolution of coupled climate ' // &
'models will allow us to capture climate processes and ' // &
'weather systems in much greater detail.', &
convention=convCIM, purpose=purpComp, rc=rc)


      call ESMF_AttributeSet(gridcomp, 'Version', '2.0', &
convention=convCIM, purpose=purpComp, rc=rc)


      call ESMF_AttributeSet(gridcomp, 'ReleaseDate', '2009-01-01T00:00:00Z', &
convention=convCIM, purpose=purpComp, rc=rc)


      call ESMF_AttributeSet(gridcomp, 'ModelType', 'aerosol', &
convention=convCIM, purpose=purpComp, rc=rc)


      call ESMF_AttributeSet(gridcomp, 'URL', &
'www.earthsys.org', convention=convCIM, purpose=purpComp, rc=rc)


      call ESMF_AttributeSet(gridcomp, 'MetadataVersion', '1.1', &
convention=convCIM, purpose=purpComp, rc=rc)


      ! Document genealogy
call ESMF_AttributeSet(gridcomp, 'PreviousVersion', &
'EarthSys1 Atmosphere', &
convention=convCIM, purpose=purpComp, rc=rc)


      call ESMF_AttributeSet(gridcomp, 'PreviousVersionDescription', &
'Horizontal resolution increased to 1.20 x 0.80 degrees; ' // &
'Timestep reduced from 30 minutes to 15 minutes.', &
convention=convCIM, purpose=purpComp, rc=rc)


      call ESMF_AttributeGetAttPack(gridcomp, convCIM, purpPlatform, &
attpack=attpack, rc=rc)

! Platform description attributes
call ESMF_AttributeSet(gridcomp, 'CompilerName', 'Pathscale', &
convention=convCIM, purpose=purpPlatform, rc=rc)


      call ESMF_AttributeSet(gridcomp, 'CompilerVersion', '3.0', &
convention=convCIM, purpose=purpPlatform, rc=rc)


      call ESMF_AttributeSet(gridcomp, 'MachineName', 'HECToR', &
convention=convCIM, purpose=purpPlatform, rc=rc)


      call ESMF_AttributeSet(gridcomp, 'MachineDescription', &
'HECToR (Phase 2a) is currently an integrated system known ' // &
'as Rainier, which includes a scalar MPP XT4 system, a vector ' // &
'system known as BlackWidow, and storage systems.', &
convention=convCIM, purpose=purpPlatform, rc=rc)


      call ESMF_AttributeSet(gridcomp, 'MachineSystem', 'Parallel', &
convention=convCIM, purpose=purpPlatform, rc=rc)
call ESMF_AttributeSet(gridcomp, 'MachineOperatingSystem', 'Unicos', &
convention=convCIM, purpose=purpPlatform, rc=rc)
call ESMF_AttributeSet(gridcomp, 'MachineVendor', 'Cray Inc', &
convention=convCIM, purpose=purpPlatform, rc=rc)
call ESMF_AttributeSet(gridcomp, 'MachineInterconnectType', &
'Cray Interconnect', &
convention=convCIM, purpose=purpPlatform, rc=rc)


      call ESMF_AttributeSet(gridcomp, 'MachineMaximumProcessors', '22656', &
convention=convCIM, purpose=purpPlatform, rc=rc)


      call ESMF_AttributeSet(gridcomp, 'MachineCoresPerProcessor', '4', &
convention=convCIM, purpose=purpPlatform, rc=rc)


      call ESMF_AttributeSet(gridcomp, 'MachineProcessorType', 'AMD X86_64', &
convention=convCIM, purpose=purpPlatform, rc=rc)


      call ESMF_AttributeGetAttPack(gridcomp, convCIM, purpProp, &
attpack=attpack, rc=rc)

! Component Properties: custom attributes
call ESMF_AttributeSet(gridcomp, 'SimulationType', 'branch', &
convention=convCIM, purpose=purpProp, rc=rc)


      call ESMF_AttributeSet(gridcomp, 'SimulationURL', &
'http://earthsys.org/simulations', &
convention=convCIM, purpose=purpProp, rc=rc)


Set the attribute values of the Responsible Party sub-package, created above for the gridded Component in the ESMF_AttributeAdd(gridcomp, ...) call.

      call ESMF_AttributeGetAttPack(gridcomp, convISO, purpRP, &
attpack=attpack, rc=rc)

! Responsible party attributes (for Principal Investigator)
call ESMF_AttributeSet(gridcomp, 'Name', 'John Doe', &
convention=convISO, purpose=purpRP, rc=rc)
call ESMF_AttributeSet(gridcomp, 'Abbreviation', 'JD', &
convention=convISO, purpose=purpRP, rc=rc)
'Department of Meteorology, University of ABC', &
convention=convISO, purpose=purpRP, rc=rc)
'john.doe@earthsys.org', &
convention=convISO, purpose=purpRP, rc=rc)
call ESMF_AttributeSet(gridcomp, 'ResponsiblePartyRole', 'PI', &
convention=convISO, purpose=purpRP, rc=rc)


      call ESMF_AttributeSet(gridcomp, 'URL', 'www.earthsys.org', &
convention=convISO, purpose=purpRP, rc=rc)


Set the attribute values of the Citation sub-package, created above for the gridded Component in the ESMF_AttributeAdd(gridcomp, ...) call.

      call ESMF_AttributeGetAttPack(gridcomp, convISO, purpCitation, &
attpack=attpack, rc=rc)

! Citation attributes
call ESMF_AttributeSet(gridcomp, 'ShortTitle', 'Doe_2009', &
convention=convISO, purpose=purpCitation, rc=rc)
call ESMF_AttributeSet(gridcomp, 'LongTitle', &
'Doe, J.A.; Norton, A.B.; ' // &
'Clark, G.H.; Davies, I.J.. 2009 EarthSys: ' // &
'The Earth System High Resolution Global Atmosphere Model - Model ' // &
'description and basic evaluation. Journal of Climate, 15 (2). ' // &
'1261-1296.', &
convention=convISO, purpose=purpCitation, rc=rc)


      call ESMF_AttributeSet(gridcomp, 'Date', '2010-03-15', &
convention=convISO, purpose=purpCitation, rc=rc)


      call ESMF_AttributeSet(gridcomp, 'PresentationForm', 'Online Refereed', &
convention=convISO, purpose=purpCitation, rc=rc)


      call ESMF_AttributeSet(gridcomp, 'DOI', 'doi:17.1035/2009JCLI4508.1', &
convention=convISO, purpose=purpCitation, rc=rc)


      call ESMF_AttributeSet(gridcomp, 'URL', &
'http://www.earthsys.org/publications', &
convention=convISO, purpose=purpCitation, rc=rc)


Add Component attributes to the Science Component and then add scientific properties to it.

      call ESMF_AttributeAdd(scicomp,  &
convention=convCIM, purpose=purpComp, rc=rc)

convention=convCIM, purpose=purpComp, rc=rc)
call ESMF_AttributeSet(scicomp, "LongName", &
convention=convCIM, purpose=purpComp, rc=rc)
call ESMF_AttributeSet(scicomp, "ModelType", &
convention=convCIM, purpose=purpComp, rc=rc)


      rad_sciPropAtt(1) = 'LongwaveSchemeType'

convention=convCIM, purpose=purpSci, &

call ESMF_AttributeSet(scicomp, &
'LongwaveSchemeType', &
'wide-band model', &
convention=convCIM, purpose=purpSci, rc=rc)
call ESMF_AttributeSet(scicomp, &
'LongwaveSchemeMethod', &
'two-stream', &
convention=convCIM, purpose=purpSci, rc=rc)


The standard Attribute package currently supplied by ESMF for CIM Fields contains a standard CF-Extended package nested within it.

      call ESMF_AttributeGetAttPack(ozone, convCIM, purpField, &
attpack=attpack, rc=rc)

! ozone CF-Extended Attributes
call ESMF_AttributeSet(ozone, 'ShortName', 'Global_O3_mon', &
convention=convCIM, purpose=purpField, rc=rc)
call ESMF_AttributeSet(ozone, 'StandardName', 'ozone', &
convention=convCIM, purpose=purpField, rc=rc)
call ESMF_AttributeSet(ozone, 'LongName', 'ozone', &
convention=convCIM, purpose=purpField, rc=rc)
call ESMF_AttributeSet(ozone, 'Units', 'unknown', &
convention=convCIM, purpose=purpField, rc=rc)


      ! ozone CIM Attributes
call ESMF_AttributeSet(ozone, 'CouplingPurpose', 'Boundary', &
convention=convCIM, purpose=purpField, rc=rc)


      call ESMF_AttributeSet(ozone, 'CouplingSource', 'EarthSys_Atmos', &
convention=convCIM, purpose=purpField, rc=rc)


      call ESMF_AttributeSet(ozone, 'CouplingTarget', &
'EarthSys_AtmosDynCore', convention=convCIM, &
purpose=purpField, rc=rc)


      call ESMF_AttributeSet(ozone, 'Description', &
'Global Ozone concentration ' // &
'monitoring in the atmosphere.', &
convention=convCIM, purpose=purpField, rc=rc)


      call ESMF_AttributeSet(ozone, 'SpatialRegriddingMethod', &
'Conservative-First-Order', &
convention=convCIM, purpose=purpField, rc=rc)


      call ESMF_AttributeSet(ozone, 'SpatialRegriddingDimension', '3D', &
convention=convCIM, purpose=purpField, rc=rc)


      call ESMF_AttributeSet(ozone, 'Frequency', '15 Minutes', &
convention=convCIM, purpose=purpField, rc=rc)


      call ESMF_AttributeSet(ozone, 'TimeTransformationType', &
'TimeInterpolation', &
convention=convCIM, purpose=purpField, rc=rc)


Adding the Field to the State will automatically link the Attribute hierarchies from the State to the Field

      ! Add the Field directly to the State


The Attribute link between a Component and a State must be set manually.

      ! Link the State to the gridded Component


Write the entire CIM Attribute hierarchy, beginning at the gridded Component (the top), to an XML file formatted to conform to CIM specifications. The CIM output tree structure differs from the internal Attribute hierarchy in that it has all the attributes of the fields within its top-level <modelComponent> record. The filename used, gridded_component.xml, is derived from the name of the gridded Component, given as an input argument in the ESMF_GridCompCreate() call above. The file is written to the examples execution directory.

      call ESMF_AttributeWrite(cplcomp, convCIM, purpComp, &
attwriteflag=ESMF_ATTWRITE_XML,rc=rc)


      call ESMF_StateDestroy(exportState, rc=rc)


      call ESMF_SciCompDestroy(scicomp, rc=rc)
call ESMF_GridCompDestroy(gridcomp, rc=rc)
call ESMF_CplCompDestroy(cplcomp, rc=rc)


      call ESMF_Finalize(rc=rc)


### 39.7.7 Read an XML file-based ESG Attribute package for a Gridded Component

This example shows how to read an ESG Attribute Package for a Gridded Component from an XML file. The XML file contains Attribute values filled-in by the user. The standard ESG Component Attribute Package is supplied with ESMF and is defined in an XSD file, which is used to validate the XML file. See
ESMF_DIR/src/Superstructure/Component/etc/esmf_gridcomp.xml (Attribute Package values) and
ESMF_DIR/src/Superstructure/Component/etc/esmf_comp.xsd (Attribute Package definition).

      ! ESMF Framework module
use ESMF
use ESMF_TestMod
implicit none

! local variables
type(ESMF_GridComp)    :: gridcomp
type(ESMF_AttPack)   :: attpack
character(ESMF_MAXSTR) :: attrvalue
type(ESMF_VM)          :: vm
integer                :: rc, petCount, localPet


      ! initialize ESMF
logkindflag=ESMF_LOGKIND_MULTI, rc=rc)


      ! get the vm
call ESMF_VMGet(vm, petCount=petCount, localPet=localPet, rc=rc)


      if (petCount<4) then
gridcomp = ESMF_GridCompCreate(name="gridcomp", &
petList=(/0/), rc=rc)
else
gridcomp = ESMF_GridCompCreate(name="gridcomp", &
petList=(/0,1,2,3/), rc=rc)
endif


      ! Read an XML file to populate the ESG Attribute package of a GridComp.
! The file is validated against an internal, ESMF-supplied XSD file
! defining the standard ESG Component Attribute package (see file
! pathnames above).
rc=rc)


      ! Get ESG "ComponentShortName" Attribute from a GridComp
call ESMF_AttributeGet(gridcomp, name='ComponentShortName', &
value=attrValue, &
convention='ESG', purpose='General', rc=rc)


      ! Get ESG "ComponentLongName" Attribute from a GridComp
call ESMF_AttributeGet(gridcomp, name='ComponentLongName', &
value=attrValue, &
convention='ESG', purpose='General', rc=rc)


      ! Get ESG "Agency" Attribute from a GridComp
call ESMF_AttributeGet(gridcomp, name='Agency', value=attrValue, &
convention='ESG', purpose='General', rc=rc)


      ! Get ESG "Institution" Attribute from a GridComp
call ESMF_AttributeGet(gridcomp, name='Institution', value=attrValue, &
convention='ESG', purpose='General', rc=rc)


      ! Get ESG "Version" Attribute from a GridComp
call ESMF_AttributeGet(gridcomp, name='Version', value=attrValue, &
convention='ESG', purpose='General', rc=rc)


      ! Get ESG "Author" Attribute from a GridComp
call ESMF_AttributeGet(gridcomp, name='Author', value=attrValue, &
convention='ESG', purpose='General', rc=rc)


      ! Get ESG "Discipline" Attribute from a GridComp
call ESMF_AttributeGet(gridcomp, name='Discipline', value=attrValue, &
convention='ESG', purpose='General', rc=rc)


      ! Get ESG "PhysicalDomain" Attribute from a GridComp
call ESMF_AttributeGet(gridcomp, name='PhysicalDomain', &
value=attrValue, convention='ESG', &
purpose='General', rc=rc)


      ! Get ESG "CodingLanguage" Attribute from a GridComp Test
call ESMF_AttributeGet(gridcomp, name='CodingLanguage', &
value=attrValue,  convention='ESG', &
purpose='General', rc=rc)


      ! Get ESG "ModelComponentFramework" Attribute from a GridComp
call ESMF_AttributeGet(gridcomp, name='ModelComponentFramework', &
value=attrValue, &
convention='ESG', purpose='General', rc=rc)


      call ESMF_GridCompDestroy(gridcomp, rc=rc)


      ! finalize ESMF framework
call ESMF_Finalize(rc=rc)


### 39.7.8 Read an XML file-based CF Attribute package for a Field

This example shows how to read a CF Attribute Package for a Field from an XML file. The XML file contains Attribute values filled-in by the user. The standard CF Attribute Package is supplied with ESMF and is defined in an XSD file, which is used to validate the XML file. See
ESMF_DIR/src/Infrastructure/Field/etc/esmf_field.xml (Attribute Package values) and
ESMF_DIR/src/Infrastructure/Field/etc/esmf_field.xsd (Attribute Package definition).

      ! ESMF Framework module
use ESMF
use ESMF_TestMod
implicit none

! local variables
type(ESMF_Field)       :: field
type(ESMF_AttPack)   :: attpack, attpack_extended
character(ESMF_MAXSTR) :: attrvalue
type(ESMF_VM)          :: vm
integer                :: rc


      ! initialize ESMF
logkindflag=ESMF_LOGKIND_MULTI, rc=rc)


      ! Create a field
field = ESMF_FieldEmptyCreate(name="field", rc=rc)


      ! Read an XML file to populate the CF Attribute package of a Field.
! The file is validated against an internal, ESMF-supplied XSD file
! defining the standard CF Attribute package (see file pathnames above).


      ! Get CF "ShortName" Attribute from a Field
call ESMF_AttributeGet(field, name='ShortName', value=attrValue, &
convention='CF', purpose='General', rc=rc)


      ! Get CF "StandardName" Attribute from a Field
call ESMF_AttributeGet(field, name='StandardName', &
value=attrValue, &
convention='CF', purpose='Extended', rc=rc)


      ! Get CF "LongName" Attribute from a Field
call ESMF_AttributeGet(field, name='LongName', value=attrValue, &
convention='CF', purpose='General', rc=rc)


      ! Get CF "Units" Attribute from a Field
call ESMF_AttributeGet(field, name='Units', value=attrValue, &
convention='CF', purpose='General', rc=rc)


      call ESMF_FieldDestroy(field, rc=rc)


      ! finalize ESMF framework
call ESMF_Finalize(rc=rc)


### 39.7.9 Read and validate an XML file-based set of user-defined Attributes for a Coupler Component

This example shows how to read and validate, from an XML and XSD file, respectively, a set of user-defined custom Attributes for a Coupler Component. See
ESMF_DIR/src/Superstructure/Component/etc/custom_cplcomp.xml (Attribute values) and
ESMF_DIR/src/Superstructure/Component/etc/custom_cplcomp.xsd (Attribute definitions)

      ! ESMF Framework module
use ESMF
use ESMF_TestMod
implicit none

! local variables
type(ESMF_CplComp)     :: cplcomp
character(ESMF_MAXSTR) :: attrvalue
type(ESMF_VM)          :: vm
integer                :: rc, petCount, localPet


      ! initialize ESMF
call ESMF_Initialize(vm=vm, &
logkindflag=ESMF_LOGKIND_MULTI, rc=rc)


      ! get the vm
call ESMF_VMGet(vm, petCount=petCount, localPet=localPet, rc=rc)


      if (petCount<4) then
cplcomp = ESMF_CplCompCreate(name="cplcomp", &
petList=(/0/), rc=rc)
else
cplcomp = ESMF_CplCompCreate(name="cplcomp", &
petList=(/0,1,2,3/), rc=rc)
endif


      ! Read an XML file to decorate a Coupler Component with custom,
! user-defined attributes, and validate them against a corresponding
! XSD schema file (see file pathnames above).
schemaFileName="custom_cplcomp.xsd", rc=rc)


      ! Get custom "MyAttribute1" from CplComp
call ESMF_AttributeGet(cplcomp, name='MyAttribute1', value=attrValue, &
rc=rc)


      ! Get custom "MyAttribute2" from CplComp
call ESMF_AttributeGet(cplcomp, name='MyAttribute2', value=attrValue, &
rc=rc)


      ! Get custom "MyAttribute3" from CplComp
call ESMF_AttributeGet(cplcomp, name='MyAttribute3', value=attrValue, &
rc=rc)


      ! Get custom "MyAttribute4" from CplComp
call ESMF_AttributeGet(cplcomp, name='MyAttribute4', value=attrValue, &
rc=rc)


      ! Get custom "MyAttribute5" from CplComp
call ESMF_AttributeGet(cplcomp, name='MyAttribute5', value=attrValue, &
rc=rc)


      call ESMF_CplCompDestroy(cplcomp, rc=rc)


      ! finalize ESMF framework
call ESMF_Finalize(rc=rc)


## 39.8 Restrictions and Future Work

### 39.8.1 Attributes

• Case insensitive Attribute names, conventions, purposes, and values will be enabled in a future release.

### 39.8.2 Attribute packages

• A future capability may be to automatically create default object Attribute packages upon ESMF object creation, this is being prototyped with the CIM 1.5.1 grids package in the present release.
• The implementation of Grids is still in flux within the CIM. In particular, this will affect the final appearance of the CIM 1.5.1 grids package in ESMF.
• A CIM Scientific Property Attribute Package will be added. For CMIP5, hundreds of Scientific Properties have been identified. All of these will be added to ESMF.
• The Attribute packages ISO Responsible Party, ISO Citation, and CIM Platform can only be created automatically within a CIM Main component Attribute package. In a future release, it will be possible to create these within other CIM Attribute packages as required, or as separate, standalone packages.

### 39.8.3 Attribute hierarchies

• The option of "deep" copies of an Attribute hierarchy will be added.

### 39.8.4 Attribute import and export

• The CIM XML output in this release validates against the official CIM v1.5 release. CIM development is continuing, with further releases expected. ESMF, in its future releases, will conform to these future CIM releases.
• CIM Attribute packages can only be output (to CIM XML); they may be inputtable (via XML) in a future release.

## 39.9 Design and Implementation Notes

This section covers Attribute memory deallocation, the use of ESMF_AttributeGet(), Attribute package nesting capabilities, issues with Attributes in a distributed environment, and reading/writing of Attributes via XML files. Issues and procedures dealing with Attribute memory deallocation, using ESMF_AttributeGet() to retrieve Attribute lists, and nested Attribute package capabilities are discussed to help avoid misuse. The limitations with Attributes in a distributed environment are also discussed, with an outline of the future work to be done in this area.

### 39.9.1 Attribute memory deallocation

The Attribute class presents a somewhat different paradigm with respect to memory deallocation than other ESMF objects. The ESMF_AttributeRemove() call can be issued to remove any Attribute from an ESMF object or an Attribute package on an ESMF object. This call is also enabled to remove entire Attribute packages with one call, which would remove any nested Attribute packages as well. The user is not required to remove all Attributes that are used in a model run. The entire Attribute hierarchy will be removed automatically by ESMF, provided the ESMF objects which contain them are properly destroyed.

The decision to remove either an Attribute or an Attribute package is made by calling ESMF_AttributeRemove() with the correct optional arguments. If an Attribute which is not associated with any Attribute package should be removed, then the call must be issued without a convention or purpose argument. If an Attribute in an Attribute package is to be removed, then the call should be issued with all three of name, convention, and purpose. Finally, if an entire Attribute package is to be removed the call should be issued with a convention and purpose, but no Attribute name.

### 39.9.2 Using ESMF_AttributeGet() to retrieve Attribute lists

The behavior of the ESMF_AttributeGet() routine, when retrieving an Attribute containing a value list, follows a slightly different convention than other similar ESMF routines. This routine requires the input of a Fortran array as a place to store the retrieved values of the Attribute list. If the array that is given is longer that the list of Attribute values, the first part of the array will be filled, leaving the extra space untouched. If, however, the array passed in is shorter than the number of Attribute values, the routine will exit with a return code which is not equal to ESMF_SUCCESS. It is suggested that if it is required by the user to use a Fortran array that is longer than the number of Attribute values returned, only the indices of the array which the user desires to be filled with retrieved Attribute values should be passed into the routine.

Similar behavior is exhibited with the defaultvalueList argument in the ESMF_AttributeGet() routine. The difference here is that if the valueList is shorter than the defaultvalueList only the appropriate values will be filed in, and the routine will exit without error. Likewise, if the valueList is longer than the defaultvalueList then the entire valueList will be populated with the beginning section of the defaultvalueList that is given.

### 39.9.3 Using Attribute package nesting capabilites

There is a recommended practice to organizing metadata conventions when using nested Attribute packages. The most general Attribute packages should always be added first (innermost parts of the tree), followed by the more specific ones (encompassing tree branches). For instance, when adding Attribute packages to a Field, it is recommended that the CF convention be added first, followed by the ESMF convention, followed by any additional customized Attribute packages.

At this time there are several ESMF supplied Attribute packages, with a convention of ESMF and a purpose of General. These Attribute packages are generated by calling ESMF_AttributeAdd() with the appropriate convention and purpose. The ESMF standard Attribute packages can be customized by nesting a custom Attribute package around them.

Another consideration when using nested Attribute packages is to remember that when a nested Attribute package is removed every nested Attribute package below the point of removal will also be removed (like pruning a tree branch). Thus, by removing the ESMF Attribute package on a Field, the CF Attribute package contained within it will also be removed.

### 39.9.4 Attributes in a distributed environment

This section discusses the methods of building a consistent view of the metadata across the VM of a model run. To better explain the ESMF capabilities for ensuring the integrity of Attributes in a distributed environment three types of changes to an Attribute hierarchy need to be specified, these are: 1. link changes are structural links created when two separate Attribute hierarchies are linked, 2. structural changes are changes which occur when Attributes or Attribute packages are added or removed within a single level of an Attribute hierarchy, and 3. value changes occur when the value portion of any single Attribute is modified. These definitions will help to describe how ESMF_StateReconcile() and ESMF_AttributeUpdate() can be effectively used to ensure a consistent view of the metadata throughout a model run.

The ESMF_StateReconcile() call is used to create a consistent view of ESMF objects over the entire VM in the initialization phase of a model run. All Attributes that are attached to an ESMF object contained in the State, i.e. an object that is being reconciled, can also be reconciled. This is done by setting a flag in the ESMF_StateReconcile() call, see the State documentation for details. This means that, at the conclusion of ESMF_StateReconcile() there is a one-to-one correspondence between Attribute hierarchies and the ESMF objects they represent. This is the only place where link changes in an Attribute hierarchy can be resolved.

The ESMF_AttributeUpdate() call can be used any time during the run phase of a model to insure that either structural or value changes made to an Attribute hierarchy on a subset of the VM are consistently represented across the remainder of the VM. At this time, link changes cannot be resolved by ESMF_AttributeUpdate() as this would represent a departure from the one-to-one correspondence between the Attribute hierarchy and the ESMF objects it represents. This means that ESMF_AttributeUpdate() will only work if it is called after ESMF_StateReconcile() when link changes have been made.

ESMF_AttributeUpdate() is similar to ESMF_StateReconcile() in that it must be called from a location that has a view of the entire VM across which to update the Attribute hierarchy, such as a coupler Component. The main difference is that ESMF_AttributeUpdate() operates only on the underlying Attribute hierarchy of the given ESMF object. The Attribute hierarchy may be updated as many times as necessary.

The specification of a list of PETs that are to be used as the basis for the update is a key feature of this interface. This allows a many-to-many communication, as well as the direct specification of which PETs are to be updated and which are to be used as the "real" values. The information is basically transported from the Attributes on the PETs specified in the rootList to their counterparts on the PETs which are not specified in the rootList. This means that care must be taken to ensure that the data on the PETs in the rootList is consistent.

Simultaneous changes or addition of the same Attributes in different order on both the source and destination PETs can result in inefficient and/or undefined behavior if the reconcile flag is not used. The reconcile flag will completely replace all Attributes on the destination PETs with those of the source PETs. The reconcile flag is a good way to ensure a consistent Attribute hierarchy when using ESMF_AttributeUpdate() for the first-pass metadata update in a situation where either ESMF_StateReconcile() is not available or some unusual state has arisen within the Attribute hierarchy.

### 39.9.5 Writing Attribute packages to file

The ESMF_AttributeWrite() interface is in limited form at the present time, as it can only be used reliably on the ESMF standard Attribute packages. Chances are that it will perform as expected for most Attribute packages, but for now it is only guaranteed for the ESMF standard Attribute packages. This routine is also not yet enabled to handle multi-valued Attributes. One thing to remember when using this interface is that if you are writing an Attribute package that contains nested Attribute packages then all Attribute nested below the top level Attribute package will be written.

### 39.9.6 Copying Attribute hierarchies

The ESMF_AttributeCopy() routine can be used to locally copy an Attribute hierarchy between Components, States, FieldBundles, Fields or Grids. It is important to note that this is a local copy, and no inter-PET communication is carried out. Another thing to note is that when this functionality is based on a reference copy any further changes made to some portions of the original Attribute hierarchy will also affect the new Attribute hierarchy.

The ESMF_AttCopy_Flag is used to specify which type of copy is desired. The default behavior is represented by ESMF_ATTCOPY_VALUE . This will copy by value (deep copy) only the first level of an Attribute hierarchy (i.e. Attributes and Attribute packages but none of the Attribute hierarchies that are linked by other objects). There is a reference copy represented by ESMF_ATTCOPY_REFERENCE, which is a strict shallow copy. Any changes to one Attribute hierarchy after the copy will also affect the other. A third type of copy can be done by setting the ESMF_AttCopy_Flag to ESMF_ATTCOPY_HYBRID. This is a hybrid approach of reference and value copies. Attributes and Attribute packates are copied by value, and links to Attribute hierarchies of other objects are copied by reference.

### 39.9.7 Reading and writing Attributes from XML files

The Xerces C++ library, v3.1.0 or newer, is used to read XML files. More specifically, the SAX2 API is currently used, although future releases may also use the DOM API. The Xerces C++ website is http://xerces.apache.org/xerces-c/. For more details, see the "ESMF Users Guide", "Building and Installing the ESMF, Third Party Libraries, Xerces". Also please see the section on Attribute I/O, 37.2. Writing Attribute XML files is performed with the standard C++ output file stream facility.

### 39.9.8 Attribute duplicates

The Attribute class has three different types of Attributes, they are: 1. regular Attributes, 2. Attribute packages, and 3. Attribute links. Each of these types of Attributes have different behavior with respect to duplicates.

With regular Attributes a duplicate Attribute is replaced by the new value, sometimes resulting in a change in the type of the Attribute. This behavior also applies to the individual Attributes inside an Attribute package.

The second type, Attribute packages (Attpacks), are groups of Attributes identified and organized by a "convention" and "purpose"; i.e. the name of an Attpack is just one of the three pieces of identifying information: 1. name, 2. convention, and 3. purpose. If a duplicate Attpack is created (this is a common use case for some users) a fourth piece of identifying information is created by ESMF to separate the two Attpacks. The user can query for this fourth piece of identifying information, called an attPackInstanceName, either at the time of creation or later in the runtime.

The third type, Attribute links, are used to link the Attribute trees of two objects. Duplicates of Attribute links are required for some of the operations within the ESMF containers, and therefore they are enabled. However, because there is little demand for duplicate links on the user level, they cannot be deleted in any order other than the order in which they were added.

## 39.10 Object Model

Each Attribute contains a name-value pair in which the value can be any of several numeric, character, and logical types. Each value type is implemented as a vector, and can hold one or several values. The available ESMF Attribute value types include:

• ESMF_TYPEKIND_I4
• ESMF_TYPEKIND_I8
• ESMF_TYPEKIND_R4
• ESMF_TYPEKIND_R8
• ESMF_TYPEKIND_Logical
• EMSF_TYPEKIND_Character

The other members of the Attribute class can be seen in Figure 35 below, which shows a UML representation of the ESMF Attribute class.

In addition to a name, all Attributes within an Attribute package are identified by a convention, purpose, and the ESMF object type with which they are associated. These are additional strings that are initialized as empty until specified.

Also, all Attributes contain three vectors of pointers to other Attributes, which are empty until specified otherwise. These vectors of Attribute pointers hold the Attributes, Attribute packages, and Attribute links. This feature is what allows the Attribute class to self assemble complex structures for representing and organizing the metadata of an ESMF object hierarchy.

For a more detailed view of how Attribute packages and hierarchies are formed, see Figures 36 and 37, respectively.

## 39.11 Class API

INTERFACE:

   ! Private name; call using ESMF_AttributeAdd()
subroutine ESMF_AttAddPackStd(<object>, convention, purpose, attpack, rc)

ARGUMENTS:
   <object>, see below for supported values
character (len = *), intent(in) :: convention
character (len = *), intent(in) :: purpose
type(ESMF_AttPack), intent(inout), optional :: attpack
integer, intent(out), optional :: rc

DESCRIPTION:

Add an ESMF standard Attribute package. See Section 39.2 for a description of Attribute packages.

Supported values for <object> are:

type(ESMF_Array), intent(inout) :: array
type(ESMF_CplComp), intent(inout) :: comp
type(ESMF_GridComp), intent(inout) :: comp
type(ESMF_SciComp), intent(inout) :: comp
type(ESMF_Field), intent(inout) :: field
type(ESMF_Grid), intent(inout) :: grid
type(ESMF_State), intent(inout) :: state

The arguments are:

<object>
An ESMF object.
convention
The convention of the new Attribute package.
purpose
The purpose of the new Attribute package.
[attpack]
An optional handle to the Attribute package that is to be created.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 39.11.2 ESMF_AttributeAdd - Add an ESMF standard Attribute package containing nested standard Attribute packages

INTERFACE:

   ! Private name; call using ESMF_AttributeAdd()
nestConvention, nestPurpose, nestAttPackInstanceCountList, &
nestAttPackInstanceNameList, nestCount, &
nestAttPackInstanceNameCount, attpack, rc)

ARGUMENTS:
   <object>, see below for supported values
character (len = *), intent(in) :: convention
character (len = *), intent(in) :: purpose
character (len = *), intent(in) :: nestConvention(:)
character (len = *), intent(in) :: nestPurpose(:)
integer, intent(in) :: nestAttPackInstanceCountList(:)
character (len = *), intent(out) :: nestAttPackInstanceNameList(:)
integer, intent(in), optional :: nestCount
integer, intent(out), optional :: nestAttPackInstanceNameCount
type(ESMF_AttPack), intent(inout), optional :: attpack
integer, intent(out), optional :: rc

DESCRIPTION:

Add an ESMF standard Attribute package which contains a user-specified number of nested standard Attribute packages. ESMF generates and returns default instance names for the nested Attribute packages. These names can be used later to distinguish among multiple nested Attribute packages of the same type in calls to ESMF_AttributeGet(), ESMF_AttributeSet(), and ESMF_AttributeRemove(). See Section 39.2 for a description of Attribute packages.

Supported values for <object> are:

type(ESMF_CplComp), intent(inout) :: comp
type(ESMF_GridComp), intent(inout) :: comp
type(ESMF_SciComp), intent(inout) :: comp

The arguments are:

<object>
An ESMF object.
convention
The convention of the new Attribute package.
purpose
The purpose of the new Attribute package.
nestConvention
The convention(s) of the standard Attribute package(s) around which to nest the new Attribute package.
nestPurpose
The purpose(s) of the standard Attribute package(s) around which to nest the new Attribute package.
nestAttPackInstanceCountList
The desired number of nested Attribute package instances for each nested (nestConvention, nestPurpose) package type. Note: if only one of each nested package type is desired, then the ESMF_AttributeAdd() overloaded method ESMF_AttAddPackStd() should be used.
nestAttPackInstanceNameList
The name(s) of the nested Attribute package instances, generated by ESMF, used to distinguish between multiple instances of the same convention and purpose.
[nestCount]
The count of the number of nested Attribute package types to add to the new Attribute package.
[nestAttPackInstanceNameCount]
The number of nested Attribute package instance names.
[attpack]
An optional handle to the Attribute package that is to be created.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 39.11.3 ESMF_AttributeAdd - Add a custom Attribute package or modify an existing Attribute package

INTERFACE:

   ! Private name; call using ESMF_AttributeAdd()
attrList, count, redundant, attpack, rc)

ARGUMENTS:
   <object>, see below for supported values
character (len = *), intent(in) :: convention
character (len = *), intent(in) :: purpose
character (len = *), intent(in) :: attrList(:)
integer, intent(in), optional :: count
logical, intent(in), optional :: redundant
type(ESMF_AttPack), intent(inout), optional :: attpack
integer, intent(out), optional :: rc

DESCRIPTION:

Add a custom Attribute package to <object>, or add Attributes to an existing Attribute package. The redundant flag can be set to .true. to create redundant Attribute packages. Otherwise, Attributes will be added to an existing package. The attpack will be used instead of convention and purpose if both are present. See Section 39.2 for a description of Attribute packages.

Supported values for <object> are:

type(ESMF_Array), intent(inout) :: array
type(ESMF_ArrayBundle), intent(inout) :: arraybundle
type(ESMF_CplComp), intent(inout) :: comp
type(ESMF_GridComp), intent(inout) :: comp
type(ESMF_SciComp), intent(inout) :: comp
type(ESMF_DistGrid), intent(inout) :: distgrid
type(ESMF_Field), intent(inout) :: field
type(ESMF_FieldBundle), intent(inout) :: fieldbundle
type(ESMF_Grid), intent(inout) :: grid
type(ESMF_State), intent(inout) :: state

The arguments are:

<object>
An ESMF object.
convention
The convention of the Attribute package.
purpose
The purpose of the Attribute package.
attrList
The list of Attribute names to specify the custom Attribute package.
[count]
The number of Attributes to add to the custom Attribute package.
[redundant]
A flag to determine whether or not to create redundant Attribute packages. If an Attribute package already exists with the specified convention and purpose and redundant is set to .true. then a redundant Attribute package will be created. The default value is .false..
[attpack]
The handle to the Attribute package that was created. This can also be used as an input parameter to indicate the Attribute package to which additional Attributes should be added.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 39.11.4 ESMF_AttributeAdd - Add a custom Attribute package with nested Attribute packages

INTERFACE:

   ! Private name; call using ESMF_AttributeAdd()
attrList, count, nestConvention, nestPurpose, nestCount, attpack, rc)

ARGUMENTS:
   <object>, see below for supported values
character (len = *), intent(in) :: convention
character (len = *), intent(in) :: purpose
character (len = *), intent(in), optional :: attrList(:)
integer, intent(in), optional :: count
character (len = *), intent(in) :: nestConvention(:)
character (len = *), intent(in) :: nestPurpose(:)
integer, intent(in), optional :: nestCount
type(ESMF_AttPack), intent(inout), optional :: attpack
integer, intent(out), optional :: rc

DESCRIPTION:

Add a custom Attribute package, with one or more nested Attribute packages, to <object>. Allows for building full multiple-child Attribute hierarchies (multi-child trees). See Section 39.2 for a description of Attribute packages.

Supported values for <object> are:

type(ESMF_Array), intent(inout) :: array
type(ESMF_ArrayBundle), intent(inout) :: arraybundle
type(ESMF_CplComp), intent(inout) :: comp
type(ESMF_GridComp), intent(inout) :: comp
type(ESMF_SciComp), intent(inout) :: comp
type(ESMF_DistGrid), intent(inout) :: distgrid
type(ESMF_Field), intent(inout) :: field
type(ESMF_FieldBundle), intent(inout) :: fieldbundle
type(ESMF_Grid), intent(inout) :: grid
type(ESMF_State), intent(inout) :: state

The arguments are:

<object>
An ESMF object.
convention
The convention of the Attribute package.
purpose
The purpose of the Attribute package.
[attrList]
The list of Attribute names to specify the custom Attribute package.
[count]
The number of Attributes to add to the custom Attribute package.
nestConvention
The convention(s) of the Attribute package(s) around which to nest the new Attribute package.
nestPurpose
The purpose(s) of the Attribute package(s) around which to nest the new Attribute package.
[nestCount]
The number of nested Attribute packages to add to the custom Attribute package.
[attpack]
An optional handle to the Attribute package that is to be created.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 39.11.5 ESMF_AttributeAdd - Add a custom Attribute package with a single nested Attribute package

INTERFACE:

   ! Private name; call using ESMF_AttributeAdd()
attrList, count, nestConvention, nestPurpose, attpack, rc)

ARGUMENTS:
   <object>, see below for supported values
character (len = *), intent(in) :: convention
character (len = *), intent(in) :: purpose
character (len = *), intent(in), optional :: attrList(:)
integer, intent(in), optional :: count
character (len = *), intent(in) :: nestConvention
character (len = *), intent(in) :: nestPurpose
type(ESMF_AttPack), intent(inout), optional :: attpack
integer, intent(out), optional :: rc

DESCRIPTION:

Add a custom Attribute package, with a single nested Attribute package, to <object>. Allows for building single-child Attribute hierarchies (single-child trees). See Section 39.2 for a description of Attribute packages.

Supported values for <object> are:

type(ESMF_Array), intent(inout) :: array
type(ESMF_ArrayBundle), intent(inout) :: arraybundle
type(ESMF_CplComp), intent(inout) :: comp
type(ESMF_GridComp), intent(inout) :: comp
type(ESMF_SciComp), intent(inout) :: comp
type(ESMF_DistGrid), intent(inout) :: distgrid
type(ESMF_Field), intent(inout) :: field
type(ESMF_FieldBundle), intent(inout) :: fieldbundle
type(ESMF_Grid), intent(inout) :: grid
type(ESMF_State), intent(inout) :: state

The arguments are:

<object>
An ESMF object.
convention
The convention of the Attribute package.
purpose
The purpose of the Attribute package.
[attrList]
The list of Attribute names to specify the custom Attribute package.
[count]
The number of Attributes to add to the custom Attribute package.
nestConvention
The convention of the Attribute package around which to nest the new Attribute package.
nestPurpose
The purpose of the Attribute package around which to nest the new Attribute package.
[attpack]
An optional handle to the Attribute package that is to be created.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 39.11.6 ESMF_AttributeCopy - Copy an Attribute hierarchy

INTERFACE:

   ! Private name; call using ESMF_AttributeCopy()
subroutine ESMF_AttributeCopy(<object1>, <object2>, attcopy, rc)

ARGUMENTS:
   <object1>, see below for supported values
<object2>, see below for supported values
type(ESMF_AttCopy_Flag),intent(in) optional :: attcopy
integer, intent(out), optional :: rc

DESCRIPTION:

Copy an Attribute hierarchy from <object1> to <object2>. The default behavior is to ignore (instead of replace) values on pre-existing Attributes.

Supported values for <object1> are:

type(ESMF_CplComp), intent(in) :: comp1
type(ESMF_GridComp), intent(in) :: comp1
type(ESMF_SciComp), intent(in) :: comp1
type(ESMF_Field), intent(inout) :: field1
type(ESMF_FieldBundle), intent(inout) :: fieldbundle1
type(ESMF_Grid), intent(inout) :: grid1
type(ESMF_State), intent(in) :: state

Supported values for <object2> are:

type(ESMF_CplComp), intent(inout) :: comp2
type(ESMF_GridComp), intent(inout) :: comp2
type(ESMF_SciComp), intent(inout) :: comp2
type(ESMF_Field), intent(inout) :: field2
type(ESMF_FieldBundle), intent(inout) :: fieldbundle2
type(ESMF_Grid), intent(inout) :: grid2
type(ESMF_State), intent(inout) :: state

NOTE: Copies between different ESMF object types are not possible at this time.

The arguments are:

<object1>
An Attribute-bearing ESMF object.
<object2>
An Attribute-bearing ESMF object.
[attcopy]
A flag to determine if the copy is to be by reference, value, or hybrid. This flag is documented in section 39.6.1. The default is to copy by value.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 39.11.7 ESMF_AttributeGet - Get an Attribute from an ESMF_AttPack

INTERFACE:

   subroutine ESMF_AttributeGet(<object>, name, attpack, <value> &
<defaultvalue>, attnestflag, isPresent, rc)

ARGUMENTS:
   <object>, see below for supported values
character (len = *), intent(in) :: name
type(ESMF_AttPack), intent(inout) :: attpack
<value>, see below for supported values
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
<defaultvalue>, see below for supported values
type(ESMF_AttNest_Flag),intent(in), optional :: attnestflag
logical, intent(out), optional :: isPresent
integer, intent(out), optional :: rc

DESCRIPTION:

Return an Attribute value from the <object>, or from an Attribute package on the <object>, specified by attpack. Internal information can also be retrieved from Grid objects by prepending 'ESMF:' to the name of the piece of information that is requested. See Section 39.5 for more information on which pieces of Grid data can be retrieved through this interface. A defaultvalue argument may be given if a return code is not desired when the Attribute is not found. See Section 39.2 for a description of Attribute packages.

Supported values for <object> are:

type(ESMF_Array), intent(in) :: array
type(ESMF_ArrayBundle), intent(in) :: arraybundle
type(ESMF_CplComp), intent(in) :: comp
type(ESMF_GridComp), intent(in) :: comp
type(ESMF_SciComp), intent(in) :: comp
type(ESMF_DistGrid), intent(in) :: distgrid
type(ESMF_Field), intent(in) :: field
type(ESMF_FieldBundle), intent(in) :: fieldbundle
type(ESMF_Grid), intent(in) :: grid
type(ESMF_State), intent(in) :: state

Supported values for <value> are:

integer(ESMF_KIND_I4), intent(out) :: value
integer(ESMF_KIND_I8), intent(out) :: value
real (ESMF_KIND_R4), intent(out) :: value
real (ESMF_KIND_R8), intent(out) :: value
logical, intent(out) :: value
character (len = *), intent(out) :: value

Supported values for <defaultvalue> are:

integer(ESMF_KIND_I4), intent(in), optional :: defaultvalue
integer(ESMF_KIND_I8), intent(in), optional :: defaultvalue
real (ESMF_KIND_R4), intent(in), optional :: defaultvalue
real (ESMF_KIND_R8), intent(in), optional :: defaultvalue
logical, intent(in), optional :: defaultvalue
character (len = *), intent(in), optional :: defaultvalue

The arguments are:

<object>
An ESMF object.
name
The name of the Attribute to retrieve.
attpack
A handle to the Attribute package.
<value>
The value of the named Attribute.
[<defaultvalue>]
The default value of the named Attribute.
[attnestflag]
A flag to determine whether to descend the Attribute hierarchy when looking for this Attribute, the default is ESMF_ATTNEST_ON. This flag is documented in section 52.5.
[isPresent]
A logical flag to tell if this Attribute is present or not.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 39.11.8 ESMF_AttributeGet - Get an Attribute pointing to internal class information from an ESMF_AttPack

INTERFACE:

   subroutine ESMF_AttributeGet(<object>, name, attpack, <value>, &
<defaultvalue>, inputList, attnestflag, isPresent, rc)

ARGUMENTS:
   <object>, see below for supported values
character (len = *), intent(in) :: name
type(ESMF_AttPack), intent(inout) :: attpack
<value>, see below for supported values
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
<defaultvalue>, see below for supported values
character (len = *), intent(in), optional :: inputList(:)
type(ESMF_AttNest_Flag),intent(in), optional :: attnestflag
logical, intent(out), optional :: isPresent
integer, intent(out), optional :: rc

DESCRIPTION:

Return an Attribute value from the <object>, or from an Attribute package on the <object>, specified by attpack. Internal class information can be retrieved by prepending 'ESMF:' to the name of the piece of information that is requested. See Section 39.5 for more information on this capability. A defaultvalue argument may be given if a return code is not desired when the Attribute is not found. See Section 39.2 for a description of Attribute packages.

Supported values for <object> are:

type(ESMF_Grid), intent(in) :: grid

Supported values for <value> are:

integer(ESMF_KIND_I4), intent(out) :: value
character (len = *), intent(out) :: value

Supported values for <defaultvalue> are:

integer(ESMF_KIND_I4), intent(in), optional :: defaultvalue
character (len = *), intent(in), optional :: defaultvalue

The arguments are:

<object>
An ESMF object.
name
The name of the Attribute to retrieve.
attpack
A handle to the Attribute package.
<value argument>
The value of the named Attribute.
[<defaultvalue argument>]
The default value of the named Attribute.
[inputList]
A list of the input parameters required to retrieve internal info.
[attnestflag]
A flag to determine whether to descend the Attribute hierarchy when looking for this Attribute, the default is ESMF_ATTNEST_ON. This flag is documented in section 52.5.
[isPresent]
A logical flag to tell if this Attribute is present or not.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 39.11.9 ESMF_AttributeGet - Get an Attribute from an ESMF_AttPack

INTERFACE:

   subroutine ESMF_AttributeGet(<object>, name, attpack, <valueList>, &
<defaultvalueList>, attnestflag, itemCount, &
isPresent, rc)

ARGUMENTS:
   <object>, see below for supported values
character (len = *), intent(in) :: name
type(ESMF_AttPack), intent(inout) :: attpack
<valueList>, see below for supported values
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
<defaultvalueList>, see below for supported values
type(ESMF_AttNest_Flag),intent(in), optional :: attnestflag
integer, intent(out), optional :: itemCount
logical, intent(out), optional :: isPresent
integer, intent(out), optional :: rc

DESCRIPTION:

Return an Attribute valueList from the <object>, or from an Attribute package on the <object>, specified by attpack. Internal information can also be retrieved from Grid objects by prepending 'ESMF:' to the name of the piece of information that is requested. See Section 39.5 for more information on which pieces of Grid data can be retrieved through this interface. A defaultvalueList list argument may be given if a return code is not desired when the Attribute is not found. See Section 39.2 for a description of Attribute packages.

Supported values for <object> are:

type(ESMF_Array), intent(in) :: array
type(ESMF_ArrayBundle), intent(in) :: arraybundle
type(ESMF_CplComp), intent(in) :: comp
type(ESMF_GridComp), intent(in) :: comp
type(ESMF_SciComp), intent(in) :: comp
type(ESMF_DistGrid), intent(in) :: distgrid
type(ESMF_Field), intent(in) :: field
type(ESMF_FieldBundle), intent(in) :: fieldbundle
type(ESMF_Grid), intent(in) :: grid
type(ESMF_State), intent(in) :: state

Supported values for <valueList> are:

integer(ESMF_KIND_I4), intent(out) :: valueList(:)
integer(ESMF_KIND_I8), intent(out) :: valueList(:)
real (ESMF_KIND_R4), intent(out) :: valueList(:)
real (ESMF_KIND_R8), intent(out) :: valueList(:)
logical, intent(out) :: valueList(:)
character (len = *), intent(out) :: valueList(:)

Supported values for <defaultvalueList> are:

integer(ESMF_KIND_I4), intent(in), optional :: defaultvalueList(:)
integer(ESMF_KIND_I8), intent(in), optional :: defaultvalueList(:)
real (ESMF_KIND_R4), intent(in), optional :: defaultvalueList(:)
real (ESMF_KIND_R8), intent(in), optional :: defaultvalueList(:)
logical, intent(in), optional :: defaultvalueList(:)
character (len = *), intent(in), optional :: defaultvalueList(:)

The arguments are:

<object>
An ESMF object.
name
The name of the Attribute to retrieve.
attpack
A handle to the Attribute package.
<valueList>
The valueList of the named Attribute.
[<defaultvalueList>]
The default value list of the named Attribute.
[attnestflag]
A flag to determine whether to descend the Attribute hierarchy when looking for this Attribute, the default is ESMF_ATTNEST_ON. This flag is documented in section 52.5.
[itemCount]
The number of items in a multi-valued Attribute.
[isPresent]
A logical flag to tell if this Attribute is present or not.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 39.11.10 ESMF_AttributeGet - Get an Attribute pointing to internal class information from an ESMF_AttPack

INTERFACE:

   subroutine ESMF_AttributeGet(<object>, name, attpack, <valueList>, &
<defaultvalueList>, inputList, attnestflag, &
itemCount, isPresent, rc)

ARGUMENTS:
   <object>, see below for supported values
character (len = *), intent(in) :: name
type(ESMF_AttPack), intent(inout) :: attpack
<valueList>, see below for supported values
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
<defaultvalueList>, see below for supported values
character (len = *), intent(in), optional :: inputList(:)
type(ESMF_AttNest_Flag),intent(in), optional :: attnestflag
integer, intent(out), optional :: itemCount
logical, intent(out), optional :: isPresent
integer, intent(out), optional :: rc

DESCRIPTION:

Return an Attribute valueList from the <object>, or from an Attribute package on the <object>, specified by attpack. Internal class information can be retrieved by prepending 'ESMF:' to the name of the piece of information that is requested. See Section 39.5 for more information on this capability. A defaultvalueList list argument may be given if a return code is not desired when the Attribute is not found. See Section 39.2 for a description of Attribute packages.

Supported values for <object> are:

type(ESMF_Grid), intent(in) :: grid

Supported values for <valueList> are:

integer(ESMF_KIND_I4), intent(out) :: valueList(:)
real (ESMF_KIND_R8), intent(out) :: valueList(:)
logical, intent(out) :: valueList(:)

Supported values for <defaultvalueList> are:

integer(ESMF_KIND_I4), intent(in), optional :: defaultvalueList(:)
real (ESMF_KIND_R8), intent(in), optional :: defaultvalueList(:)
logical, intent(in), optional :: defaultvalueList(:)

The arguments are:

<object>
An ESMF object.
name
The name of the Attribute to retrieve.
attpack
A handle to the Attribute package.
<valueList>
The valueList of the named Attribute.
[<defaultvalueList>]
The default value list of the named Attribute.
[inputList]
A list of the input parameters required to retrieve internal info.
[attnestflag]
A flag to determine whether to descend the Attribute hierarchy when looking for this Attribute, the default is ESMF_ATTNEST_ON. This flag is documented in section 52.5.
[itemCount]
The number of items in a multi-valued Attribute.
[isPresent]
A logical flag to tell if this Attribute is present or not.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 39.11.11 ESMF_AttributeGet - Get an Attribute

INTERFACE:

   subroutine ESMF_AttributeGet(<object>, name, <value>, <defaultvalue>, &
convention, purpose, attPackInstanceName, attnestflag, isPresent, rc)

ARGUMENTS:
   <object>, see below for supported values
character (len = *), intent(in) :: name
<value>, see below for supported values
<defaultvalue>, see below for supported values
character (len = *), intent(in), optional :: convention
character (len = *), intent(in), optional :: purpose
character (len = *), intent(in), optional :: attPackInstanceName
type(ESMF_AttNest_Flag),intent(in), optional :: attnestflag
logical, intent(out), optional :: isPresent
integer, intent(out), optional :: rc

DESCRIPTION:

Return an Attribute value from the <object>, or from an Attribute package on the <object>, specified by convention, purpose, and attPackInstanceName. Internal information can also be retrieved from Grid objects by prepending 'ESMF:' to the name of the piece of information that is requested. See Section 39.5 for more information on which pieces of Grid data can be retrieved through this interface. A defaultvalue argument may be given if a return code is not desired when the Attribute is not found. See Section 39.2 for a description of Attribute packages.

Supported values for <object> are:

type(ESMF_Array), intent(in) :: array
type(ESMF_ArrayBundle), intent(in) :: arraybundle
type(ESMF_CplComp), intent(in) :: comp
type(ESMF_GridComp), intent(in) :: comp
type(ESMF_SciComp), intent(in) :: comp
type(ESMF_DistGrid), intent(in) :: distgrid
type(ESMF_Field), intent(in) :: field
type(ESMF_FieldBundle), intent(in) :: fieldbundle
type(ESMF_Grid), intent(in) :: grid
type(ESMF_State), intent(in) :: state

Supported values for <value> are:

integer(ESMF_KIND_I4), intent(out) :: value
integer(ESMF_KIND_I8), intent(out) :: value
real (ESMF_KIND_R4), intent(out) :: value
real (ESMF_KIND_R8), intent(out) :: value
logical, intent(out) :: value
character (len = *), intent(out) :: value

Supported values for <defaultvalue> are:

integer(ESMF_KIND_I4), intent(in), optional :: defaultvalue
integer(ESMF_KIND_I8), intent(in), optional :: defaultvalue
real (ESMF_KIND_R4), intent(in), optional :: defaultvalue
real (ESMF_KIND_R8), intent(in), optional :: defaultvalue
logical, intent(in), optional :: defaultvalue
character (len = *), intent(in), optional :: defaultvalue

The arguments are:

<object>
An ESMF object.
name
The name of the Attribute to retrieve.
<value>
The value of the named Attribute.
[<defaultvalue>]
The default value of the named Attribute.
[convention]
The convention of the Attribute package.
[purpose]
The purpose of the Attribute package.
[attPackInstanceName]
The name of an Attribute package instance, specifying which one of multiple Attribute package instances of the same convention and purpose, within a nest. If not specified, defaults to the first instance.
[attnestflag]
A flag to determine whether to descend the Attribute hierarchy when looking for this Attribute, the default is ESMF_ATTNEST_ON. This flag is documented in section 52.5.
[isPresent]
A logical flag to tell if this Attribute is present or not.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 39.11.12 ESMF_AttributeGet - Get an Attribute pointing to internal class information

INTERFACE:

   subroutine ESMF_AttributeGet(<object>, name, <value>, <defaultvalue>, &
inputList, convention, purpose, attPackInstanceName, attnestflag, &
isPresent, rc)

ARGUMENTS:
   <object>, see below for supported values
character (len = *), intent(in) :: name
<value>, see below for supported values
<defaultvalue>, see below for supported values
character (len = *), intent(in), optional :: inputList(:)
character (len = *), intent(in), optional :: convention
character (len = *), intent(in), optional :: purpose
character (len = *), intent(in), optional :: attPackInstanceName
type(ESMF_AttNest_Flag),intent(in), optional :: attnestflag
logical, intent(out), optional :: isPresent
integer, intent(out), optional :: rc

DESCRIPTION:

Return an Attribute value from the <object>, or from an Attribute package on the <object>, specified by convention, purpose, and attPackInstanceName. Internal class information can be retrieved by prepending 'ESMF:' to the name of the piece of information that is requested. See Section 39.5 for more information on this capability. A defaultvalue argument may be given if a return code is not desired when the Attribute is not found. See Section 39.2 for a description of Attribute packages.

Supported values for <object> are:

type(ESMF_Grid), intent(in) :: grid

Supported values for <value> are:

integer(ESMF_KIND_I4), intent(out) :: value
character (len = *), intent(out) :: value

Supported values for <defaultvalue> are:

integer(ESMF_KIND_I4), intent(in), optional :: defaultvalue
character (len = *), intent(in), optional :: defaultvalue

The arguments are:

<object>
An ESMF object.
name
The name of the Attribute to retrieve.
<value argument>
The value of the named Attribute.
[<defaultvalue argument>]
The default value of the named Attribute.
[inputList]
A list of the input parameters required to retrieve internal info.
[convention]
The convention of the Attribute package.
[purpose]
The purpose of the Attribute package.
[attPackInstanceName]
The name of an Attribute package instance, specifying which one of multiple Attribute package instances of the same convention and purpose, within a nest. If not specified, defaults to the first instance.
[attnestflag]
A flag to determine whether to descend the Attribute hierarchy when looking for this Attribute, the default is ESMF_ATTNEST_ON. This flag is documented in section 52.5.
[isPresent]
A logical flag to tell if this Attribute is present or not.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 39.11.13 ESMF_AttributeGet - Get an Attribute

INTERFACE:

   subroutine ESMF_AttributeGet(<object>, name, <valueList>, &
<defaultvalueList>, convention, purpose, attPackInstanceName, &
attnestflag, itemCount, isPresent, rc)

ARGUMENTS:
   <object>, see below for supported values
character (len = *), intent(in) :: name
<valueList>, see below for supported values
<defaultvalueList>, see below for supported values
character (len = *), intent(in), optional :: convention
character (len = *), intent(in), optional :: purpose
character (len = *), intent(in), optional :: attPackInstanceName
type(ESMF_AttNest_Flag),intent(in), optional :: attnestflag
integer, intent(out), optional :: itemCount
logical, intent(out), optional :: isPresent
integer, intent(out), optional :: rc

DESCRIPTION:

Return an Attribute valueList from the <object>, or from an Attribute package on the <object>, specified by convention, purpose, and attPackInstanceName. Internal information can also be retrieved from Grid objects by prepending 'ESMF:' to the name of the piece of information that is requested. See Section 39.5 for more information on which pieces of Grid data can be retrieved through this interface. A defaultvalueList list argument may be given if a return code is not desired when the Attribute is not found. See Section 39.2 for a description of Attribute packages.

Supported values for <object> are:

type(ESMF_Array), intent(in) :: array
type(ESMF_ArrayBundle), intent(in) :: arraybundle
type(ESMF_CplComp), intent(in) :: comp
type(ESMF_GridComp), intent(in) :: comp
type(ESMF_SciComp), intent(in) :: comp
type(ESMF_DistGrid), intent(in) :: distgrid
type(ESMF_Field), intent(in) :: field
type(ESMF_FieldBundle), intent(in) :: fieldbundle
type(ESMF_Grid), intent(in) :: grid
type(ESMF_State), intent(in) :: state

Supported values for <valueList> are:

integer(ESMF_KIND_I4), intent(out) :: valueList(:)
integer(ESMF_KIND_I8), intent(out) :: valueList(:)
real (ESMF_KIND_R4), intent(out) :: valueList(:)
real (ESMF_KIND_R8), intent(out) :: valueList(:)
logical, intent(out) :: valueList(:)
character (len = *), intent(out) :: valueList(:)

Supported values for <defaultvalueList> are:

integer(ESMF_KIND_I4), intent(in), optional :: defaultvalueList(:)
integer(ESMF_KIND_I8), intent(in), optional :: defaultvalueList(:)
real (ESMF_KIND_R4), intent(in), optional :: defaultvalueList(:)
real (ESMF_KIND_R8), intent(in), optional :: defaultvalueList(:)
logical, intent(in), optional :: defaultvalueList(:)
character (len = *), intent(in), optional :: defaultvalueList(:)

The arguments are:

<object>
An ESMF object.
name
The name of the Attribute to retrieve.
<valueList>
The valueList of the named Attribute.
[<defaultvalueList>]
The default value list of the named Attribute.
[convention]
The convention of the Attribute package.
[purpose]
The purpose of the Attribute package.
[attPackInstanceName]
The name of an Attribute package instance, specifying which one of multiple Attribute package instances of the same convention and purpose, within a nest. If not specified, defaults to the first instance.
[attnestflag]
A flag to determine whether to descend the Attribute hierarchy when looking for this Attribute, the default is ESMF_ATTNEST_ON. This flag is documented in section 52.5.
[itemCount]
The number of items in a multi-valued Attribute.
[isPresent]
A logical flag to tell if this Attribute is present or not.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 39.11.14 ESMF_AttributeGet - Get an Attribute pointing to internal class information

INTERFACE:

   subroutine ESMF_AttributeGet(<object>, name, <valueList>, &
<defaultvalueList>, inputList, convention, purpose, attPackInstanceName, &
attnestflag, itemCount, isPresent, rc)

ARGUMENTS:
   <object>, see below for supported values
character (len = *), intent(in) :: name
<valueList>, see below for supported values
<defaultvalueList>, see below for supported values
character (len = *), intent(in), optional :: inputList(:)
character (len = *), intent(in), optional :: convention
character (len = *), intent(in), optional :: purpose
character (len = *), intent(in), optional :: attPackInstanceName
type(ESMF_AttNest_Flag),intent(in), optional :: attnestflag
integer, intent(out), optional :: itemCount
logical, intent(out), optional :: isPresent
integer, intent(out), optional :: rc

DESCRIPTION:

Return an Attribute valueList from the <object>, or from an Attribute package on the <object>, specified by convention, purpose, and attPackInstanceName. Internal class information can be retrieved by prepending 'ESMF:' to the name of the piece of information that is requested. See Section 39.5 for more information on this capability. A defaultvalueList list argument may be given if a return code is not desired when the Attribute is not found. See Section 39.2 for a description of Attribute packages.

Supported values for <object> are:

type(ESMF_Grid), intent(in) :: grid

Supported values for <valueList> are:

integer(ESMF_KIND_I4), intent(out) :: valueList(:)
real (ESMF_KIND_R8), intent(out) :: valueList(:)
logical, intent(out) :: valueList(:)

Supported values for <defaultvalueList> are:

integer(ESMF_KIND_I4), intent(in), optional :: defaultvalueList(:)
real (ESMF_KIND_R8), intent(in), optional :: defaultvalueList(:)
logical, intent(in), optional :: defaultvalueList(:)

The arguments are:

<object>
An ESMF object.
name
The name of the Attribute to retrieve.
<valueList>
The valueList of the named Attribute.
[<defaultvalueList>]
The default value list of the named Attribute.
[inputList]
A list of the input parameters required to retrieve internal info.
[convention]
The convention of the Attribute package.
[purpose]
The purpose of the Attribute package.
[attPackInstanceName]
The name of an Attribute package instance, specifying which one of multiple Attribute package instances of the same convention and purpose, within a nest. If not specified, defaults to the first instance.
[attnestflag]
A flag to determine whether to descend the Attribute hierarchy when looking for this Attribute, the default is ESMF_ATTNEST_ON. This flag is documented in section 52.5.
[itemCount]
The number of items in a multi-valued Attribute.
[isPresent]
A logical flag to tell if this Attribute is present or not.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 39.11.15 ESMF_AttributeGet - Get the Attribute count from an ESMF_AttPack

INTERFACE:

   ! Private name; call using ESMF_AttributeGet()
subroutine ESMF_AttributeGetCount(<object>, attpack, count, &
attcountflag, attnestflag, rc)

ARGUMENTS:
   <object>, see below for supported values
type(ESMF_AttPack), intent(inout) :: attpack
integer, intent(out) :: count
type(ESMF_AttGetCountFlag), intent(in), optional :: attcountflag
type(ESMF_AttNest_Flag), intent(in), optional :: attnestflag
integer, intent(out), optional :: rc

DESCRIPTION:

Return the Attribute count for <object>.

Supported values for <object> are:

type(ESMF_Array), intent(in) :: array
type(ESMF_ArrayBundle), intent(in) :: arraybundle
type(ESMF_CplComp), intent(in) :: comp
type(ESMF_GridComp), intent(in) :: comp
type(ESMF_SciComp), intent(in) :: comp
type(ESMF_DistGrid), intent(in) :: distgrid
type(ESMF_Field), intent(in) :: field
type(ESMF_FieldBundle), intent(in) :: fieldbundle
type(ESMF_Grid), intent(in) :: grid
type(ESMF_State), intent(in) :: state

The arguments are:

<object>
An ESMF object.
attpack
A handle to the Attribute package.
count
The number of all existing Attributes of the type designated in the attcountflag, not just Attribute that have been set.
[attcountflag]
The flag to specify which attribute count to return, the default is ESMF_ATTGETCOUNT_ATTRIBUTE. This flag is documented in section 39.6.2.
[attnestflag]
A flag to determine whether to descend the Attribute hierarchy when looking for this Attribute, the default is ESMF_ATTNEST_ON. This flag is documented in section 52.5.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

EOP!---------------------------------------

### 39.11.16 ESMF_AttributeGet - Get the Attribute count

INTERFACE:

   ! Private name; call using ESMF_AttributeGet()
subroutine ESMF_AttributeGetCount(<object>, count, &
convention, purpose, attPackInstanceName, &
attcountflag, attnestflag, rc)

ARGUMENTS:
   <object>, see below for supported values
integer, intent(out) :: count
character (len=*), intent(in), optional :: convention
character (len=*), intent(in), optional :: purpose
character (len=*), intent(in), optional :: attPackInstanceName
type(ESMF_AttGetCountFlag), intent(in), optional :: attcountflag
type(ESMF_AttNest_Flag), intent(in), optional :: attnestflag
integer, intent(out), optional :: rc

DESCRIPTION:

Return the Attribute count for <object>.

Supported values for <object> are:

type(ESMF_Array), intent(in) :: array
type(ESMF_ArrayBundle), intent(in) :: arraybundle
type(ESMF_CplComp), intent(in) :: comp
type(ESMF_GridComp), intent(in) :: comp
type(ESMF_SciComp), intent(in) :: comp
type(ESMF_DistGrid), intent(in) :: distgrid
type(ESMF_Field), intent(in) :: field
type(ESMF_FieldBundle), intent(in) :: fieldbundle
type(ESMF_Grid), intent(in) :: grid
type(ESMF_State), intent(in) :: state

The arguments are:

<object>
An ESMF object.
count
The number of all existing Attributes of the type designated in the attcountflag, not just Attribute that have been set.
[convention]
The convention of the Attribute package.
[purpose]
The purpose of the Attribute package.
[attPackInstanceName]
The name of an Attribute package instance, specifying which one of multiple Attribute package instances of the same convention and purpose, within a nest. If not specified, defaults to the first instance.
[attcountflag]
The flag to specify which attribute count to return, the default is ESMF_ATTGETCOUNT_ATTRIBUTE. This flag is documented in section 39.6.2.
[attnestflag]
A flag to determine whether to descend the Attribute hierarchy when looking for this Attribute, the default is ESMF_ATTNEST_ON. This flag is documented in section 52.5.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 39.11.17 ESMF_AttributeGet - Get Attribute info by name from an ESMF_AttPack

INTERFACE:

   ! Private name; call using ESMF_AttributeGet()
subroutine ESMF_AttributeGetInfoByNamAP(<object>, name, attpack, &
attnestflag, typekind, itemCount, isPresent, rc)

ARGUMENTS:
   <object>, see below for supported values
character (len = *), intent(in) :: name
type(ESMF_AttPack), intent(inout) :: attpack
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
type(ESMF_AttNest_Flag), intent(in), optional :: attnestflag
type(ESMF_TypeKind_Flag), intent(out), optional :: typekind
integer, intent(out), optional :: itemCount
logical, intent(out), optional :: isPresent
integer, intent(out), optional :: rc

DESCRIPTION:

Return information associated with an Attribute in an Attribute package, including typekind and itemCount.

Supported values for <object> are:

type(ESMF_Array), intent(in) :: array
type(ESMF_ArrayBundle), intent(in) :: arraybundle
type(ESMF_CplComp), intent(in) :: comp
type(ESMF_GridComp), intent(in) :: comp
type(ESMF_SciComp), intent(in) :: comp
type(ESMF_DistGrid), intent(in) :: distgrid
type(ESMF_Field), intent(in) :: field
type(ESMF_FieldBundle), intent(in) :: fieldbundle
type(ESMF_Grid), intent(in) :: grid
type(ESMF_State), intent(in) :: state

The arguments are:

<object>
An ESMF object.
name
The name of the Attribute to query.
attpack
A handle to the Attribute package.
[attnestflag]
A flag to determine whether to descend the Attribute hierarchy when looking for this Attribute, the default is ESMF_ATTNEST_ON. This flag is documented in section 52.5.
[typekind]
The typekind of the Attribute. This flag is documented in section 52.58.
[itemCount]
The number of items in this Attribute.
[isPresent]
A logical flag to tell if this Attribute is present or not.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 39.11.18 ESMF_AttributeGet - Get Attribute info by name

INTERFACE:

   ! Private name; call using ESMF_AttributeGet()
subroutine ESMF_AttributeGetInfoByNam(<object>, name, &
convention, purpose, attPackInstanceName, &
attnestflag, typekind, itemCount, isPresent, rc)

ARGUMENTS:
   <object>, see below for supported values
character (len = *), intent(in) :: name
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
character (len=*), intent(in), optional :: convention
character (len=*), intent(in), optional :: purpose
character (len=*), intent(in), optional :: attPackInstanceName
type(ESMF_AttNest_Flag), intent(in), optional :: attnestflag
type(ESMF_TypeKind_Flag), intent(out), optional :: typekind
integer, intent(out), optional :: itemCount
logical, intent(out), optional :: isPresent
integer, intent(out), optional :: rc

DESCRIPTION:

Return information associated with the named Attribute, including typekind and itemCount.

Supported values for <object> are:

type(ESMF_Array), intent(in) :: array
type(ESMF_ArrayBundle), intent(in) :: arraybundle
type(ESMF_CplComp), intent(in) :: comp
type(ESMF_GridComp), intent(in) :: comp
type(ESMF_SciComp), intent(in) :: comp
type(ESMF_DistGrid), intent(in) :: distgrid
type(ESMF_Field), intent(in) :: field
type(ESMF_FieldBundle), intent(in) :: fieldbundle
type(ESMF_Grid), intent(in) :: grid
type(ESMF_State), intent(in) :: state

The arguments are:

<object>
An ESMF object.
name
The name of the Attribute to query.
[convention]
The convention of the Attribute package.
[purpose]
The purpose of the Attribute package.
[attPackInstanceName]
The name of an Attribute package instance, specifying which one of multiple Attribute package instances of the same convention and purpose, within a nest. If not specified, defaults to the first instance.
[attnestflag]
A flag to determine whether to descend the Attribute hierarchy when looking for this Attribute, the default is ESMF_ATTNEST_ON. This flag is documented in section 52.5.
[typekind]
The typekind of the Attribute. This flag is documented in section 52.58.
[itemCount]
The number of items in this Attribute.
[isPresent]
A logical flag to tell if this Attribute is present or not.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 39.11.19 ESMF_AttributeGet - Get Attribute info by index number from an ESMF_AttPack

INTERFACE:

   ! Private name; call using ESMF_AttributeGet()
subroutine ESMF_AttributeGetInfoByNum(<object>, attributeIndex, &
name, attpack, attnestflag, typekind, itemcount, isPresent, rc)

ARGUMENTS:
   <object>, see below for supported values
integer, intent(in) :: attributeIndex
character (len = *), intent(out) :: name
type(ESMF_AttPack), intent(inout) :: attpack
type(ESMF_AttNest_Flag), intent(in), optional :: attnestflag
type(ESMF_TypeKind_Flag), intent(out), optional :: typekind
integer, intent(out), optional :: itemCount
logical, intent(out), optional :: isPresent
integer, intent(out), optional :: rc

DESCRIPTION:

Returns information associated with the indexed Attribute, including name, typekind and itemCount. Keep in mind that these indices start from 1, as expected in a Fortran API.

Supported values for <object> are:

type(ESMF_Array), intent(in) :: array
type(ESMF_ArrayBundle), intent(in) :: arraybundle
type(ESMF_CplComp), intent(in) :: comp
type(ESMF_GridComp), intent(in) :: comp
type(ESMF_SciComp), intent(in) :: comp
type(ESMF_DistGrid), intent(in) :: distgrid
type(ESMF_Field), intent(in) :: field
type(ESMF_FieldBundle), intent(in) :: fieldbundle
type(ESMF_Grid), intent(in) :: grid
type(ESMF_State), intent(in) :: state

The arguments are:

<object>
An ESMF object.
attributeIndex
The index number of the Attribute to query.
name
The name of the Attribute.
attpack
A handle to the Attribute package.
[attnestflag]
A flag to determine whether to descend the Attribute hierarchy when looking for this Attribute, the default is ESMF_ATTNEST_ON. This flag is documented in section 52.5.
[typekind]
The typekind of the Attribute. This flag is documented in section 52.58.
[itemCount]
The number of items in this Attribute.
[isPresent]
A logical flag to tell if this Attribute is present or not.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 39.11.20 ESMF_AttributeGet - Get Attribute info by index number

INTERFACE:

   ! Private name; call using ESMF_AttributeGet()
subroutine ESMF_AttributeGetInfoByNum(<object>, attributeIndex, &
name, convention, purpose, attPackInstanceName, attnestflag, &
typekind, itemcount, isPresent, rc)

ARGUMENTS:
   <object>, see below for supported values
integer, intent(in) :: attributeIndex
character (len = *), intent(out) :: name
character (len = *), intent(in), optional :: convention
character (len = *), intent(in), optional :: purpose
character (len = *), intent(in), optional :: attPackInstanceName
type(ESMF_AttNest_Flag), intent(in), optional :: attnestflag
type(ESMF_TypeKind_Flag), intent(out), optional :: typekind
integer, intent(out), optional :: itemCount
logical, intent(out), optional :: isPresent
integer, intent(out), optional :: rc

DESCRIPTION:

Returns information associated with the indexed Attribute, including name, typekind and itemCount. Keep in mind that these indices start from 1, as expected in a Fortran API.

Supported values for <object> are:

type(ESMF_Array), intent(in) :: array
type(ESMF_ArrayBundle), intent(in) :: arraybundle
type(ESMF_CplComp), intent(in) :: comp
type(ESMF_GridComp), intent(in) :: comp
type(ESMF_SciComp), intent(in) :: comp
type(ESMF_DistGrid), intent(in) :: distgrid
type(ESMF_Field), intent(in) :: field
type(ESMF_FieldBundle), intent(in) :: fieldbundle
type(ESMF_Grid), intent(in) :: grid
type(ESMF_State), intent(in) :: state

The arguments are:

<object>
An ESMF object.
attributeIndex
The index number of the Attribute to query.
name
The name of the Attribute.
[convention]
The convention of the Attribute package.
[purpose]
The purpose of the Attribute package.
[attPackInstanceName]
The name of an Attribute package instance, specifying which one of multiple Attribute package instances of the same convention and purpose, within a nest. If not specified, defaults to the first instance.
[attnestflag]
A flag to determine whether to descend the Attribute hierarchy when looking for this Attribute, the default is ESMF_ATTNEST_ON. This flag is documented in section 52.5.
[typekind]
The typekind of the Attribute. This flag is documented in section 52.58.
[itemCount]
The number of items in this Attribute.
[isPresent]
A logical flag to tell if this Attribute is present or not.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 39.11.21 ESMF_AttributeGet - Get Attribute package instance names from an ESMF_AttPack

INTERFACE:

   ! Private name; call using ESMF_AttributeGet()
subroutine ESMF_AttributeGetAPinstNamesAP(<object>, attpack, &
attPackInstanceNameList, attPackInstanceNameCount, &
attnestflag, rc)

ARGUMENTS:
   <object>, see below for supported values
type(ESMF_AttPack), intent(inout) :: attpack
character (len = *), intent(out) :: attPackInstanceNameList(:)
integer, intent(out) :: attPackInstanceNameCount
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
type(ESMF_AttNest_Flag), intent(in), optional :: attnestflag
integer, intent(out), optional :: rc

DESCRIPTION:

Get the Attribute package instance names of the ESMF_AttPack. Also get the number of such names. See Section 39.2 for a description of Attribute packages.

Supported values for <object> are:

type(ESMF_CplComp), intent(in) :: comp
type(ESMF_GridComp), intent(in) :: comp
type(ESMF_SciComp), intent(in) :: comp

The arguments are:

<object>
An ESMF object.
attpack
A handle to the Attribute package.
attPackInstanceNameList
The name(s) of the Attribute package instances of the given convention and purpose.
attPackInstanceNameCount
The number of Attribute package instance names.
[attnestflag]
A flag to determine whether to descend the Attribute hierarchy when searching for this Attribute package, the default is ESMF_ATTNEST_ON. This flag is documented in section 52.5.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 39.11.22 ESMF_AttributeGet - Get Attribute package instance names

INTERFACE:

   ! Private name; call using ESMF_AttributeGet()
subroutine ESMF_AttributeGetAPinstNames(<object>, convention, purpose, &
attPackInstanceNameList, attPackInstanceNameCount, attnestflag, rc)

ARGUMENTS:
   <object>, see below for supported values
character (len = *), intent(in), :: convention
character (len = *), intent(in), :: purpose
character (len = *), intent(out) :: attPackInstanceNameList(:)
integer, intent(out) :: attPackInstanceNameCount
type(ESMF_AttNest_Flag), intent(in), optional :: attnestflag
integer, intent(out), optional :: rc

DESCRIPTION:

Get the Attribute package instance names of the specified convention and purpose. Also get the number of such names. See Section 39.2 for a description of Attribute packages and their conventions, purposes, and object types.

Supported values for <object> are:

type(ESMF_CplComp), intent(in) :: comp
type(ESMF_GridComp), intent(in) :: comp
type(ESMF_SciComp), intent(in) :: comp

The arguments are:

<object>
An ESMF object.
convention
The convention of the Attribute package instances.
purpose
The purpose of the Attribute package instances.
attPackInstanceNameList
The name(s) of the Attribute package instances of the given convention and purpose.
attPackInstanceNameCount
The number of Attribute package instance names.
[attnestflag]
A flag to determine whether to descend the Attribute hierarchy when searching for this Attribute package, the default is ESMF_ATTNEST_ON. This flag is documented in section 52.5.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 39.11.23 ESMF_AttributeGetAttPack - Get an ESMF Attribute package object and/or query for presence

INTERFACE:

   ! Private name; call using ESMF_AttributeGetAttPack()
subroutine ESMF_AttGetAttPack(<object>, convention, purpose, &
attPackInstanceName, attpack, attnestflag, isPresent, rc)

ARGUMENTS:
   <object>, see below for supported values
character (len = *), intent(in) :: convention
character (len = *), intent(in) :: purpose
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
character (len = *), intent(in), optional :: attPackInstanceName
type(ESMF_AttPack), intent(inout), optional :: attpack
type(ESMF_AttNest_Flag), intent(in), optional :: attnestflag
logical, intent(out), optional :: isPresent
integer, intent(out), optional :: rc

DESCRIPTION:

Get an ESMF Attribute package object. If there are redundant Attribute packages on this object then the most recently created one will be retrieved. See Section 39.2 for a description of Attribute packages.

Supported values for <object> are:

type(ESMF_Array), intent(inout) :: array
type(ESMF_ArrayBundle), intent(inout) :: arraybundle
type(ESMF_CplComp), intent(inout) :: comp
type(ESMF_GridComp), intent(inout) :: comp
type(ESMF_SciComp), intent(inout) :: comp
type(ESMF_DistGrid), intent(inout) :: distgrid
type(ESMF_Field), intent(inout) :: field
type(ESMF_FieldBundle), intent(inout) :: fieldbundle
type(ESMF_Grid), intent(inout) :: grid
type(ESMF_State), intent(inout) :: state

The arguments are:

<object>
An ESMF object.
convention
The convention of the Attribute package.
purpose
The purpose of the Attribute package.
[attPackInstanceName]
The name of an Attribute package instance, specifying which one of multiple Attribute package instances of the same convention and purpose, within a nest. If not specified, defaults to the first instance.
[attpack]
A handle to the Attribute package.
[attnestflag]
A flag to determine whether to descend the Attribute hierarchy when searching for this Attribute package, the default is ESMF_ATTNEST_ON. This flag is documented in section 52.5.
[isPresent]
A logical flag to tell if this Attribute package is present or not.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 39.11.24 ESMF_AttributeLink - Link a Component Attribute hierarchy to that of a Component or State

INTERFACE:

   ! Private name; call using ESMF_AttributeLink()

ARGUMENTS:
   <object1>, see below for supported values
<object2>, see below for supported values
integer, intent(out), optional :: rc

DESCRIPTION:

Attach a CplComp, GridComp, or SciComp Attribute hierarchy to the hierarchy of a CplComp, GridComp, SciComp, or State.

Supported values for the <object1> are:

type(ESMF_CplComp), intent(inout) :: comp1
type(ESMF_GridComp), intent(inout) :: comp1
type(ESMF_SCiComp), intent(inout) :: comp1

Supported values for the <object2> are:

type(ESMF_CplComp), intent(in) :: comp2
type(ESMF_GridComp), intent(in) :: comp2
type(ESMF_SciComp), intent(in) :: comp2
type(ESMF_State), intent(in) :: state

The arguments are:

<object1>
The parent object in the Attribute hierarchy link.
<object2>
The child object in the Attribute hierarchy link.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 39.11.25 ESMF_AttributeLink - Link a State Attribute hierarchy with the hierarchy of an Array, ArrayBundle, Field, FieldBundle, or State

INTERFACE:

   ! Private name; call using ESMF_AttributeLink()

ARGUMENTS:
   type(ESMF_State), intent(inout) :: state
<object>, see below for supported values
integer, intent(out), optional :: rc

DESCRIPTION:

Attach a State Attribute hierarchy to the hierarchy of a Fieldbundle, Field, or another State.

Supported values for the <object> are:

type(ESMF_Array), intent(in) :: array
type(ESMF_ArrayBundle), intent(in) :: arraybundle
type(ESMF_Field), intent(in) :: field
type(ESMF_FieldBundle), intent(in) :: fieldbundle
type(ESMF_State), intent(in) :: state

The arguments are:

state
An ESMF_State object.
<object>
The object with which to link hierarchies.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

INTERFACE:

   ! Private name; call using ESMF_AttributeLink()

ARGUMENTS:
   type(ESMF_FieldBundle), intent(inout) :: fieldbundle
type(ESMF_Field), intent(in) :: field
integer, intent(out), optional :: rc

DESCRIPTION:

Attach a FieldBundle Attribute hierarchy to the hierarchy of a Field.

The arguments are:

fieldbundle
An ESMF_FieldBundle object.
field
An ESMF_Field object.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

INTERFACE:

   ! Private name; call using ESMF_AttributeLink()

ARGUMENTS:
   type(ESMF_Field), intent(inout) :: field
type(ESMF_Grid), intent(in) :: grid
integer, intent(out), optional :: rc

DESCRIPTION:

Attach a Field Attribute hierarchy to the hierarchy of a Grid.

The arguments are:

field
An ESMF_Field object.
grid
An ESMF_Grid object.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

INTERFACE:

   ! Private name; call using ESMF_AttributeLink()

ARGUMENTS:
   type(ESMF_ArrayBundle), intent(inout) :: arraybundle
type(ESMF_Array), intent(in) :: array
integer, intent(out), optional :: rc

DESCRIPTION:

Attach an ArrayBundle Attribute hierarchy to the hierarchy of an Array.

The arguments are:

arraybundle
An ESMF_ArrayBundle object.
array
An ESMF_Array object.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 39.11.29 ESMF_AttributeLinkRemove - Unlink a Component Attribute hierarchy from that of a Component or State

INTERFACE:

   ! Private name; call using ESMF_AttributeLinkRemove()

ARGUMENTS:
   <object1>, see below for supported values
<object2>, see below for supported values
integer, intent(out), optional :: rc

DESCRIPTION:

Unattach a CplComp, GridComp, or SciComp Attribute hierarchy from the hierarchy of a CplComp, GridComp, SciComp, or State.

Supported values for the <object1> are:

type(ESMF_CplComp), intent(inout) :: comp1
type(ESMF_GridComp), intent(inout) :: comp1
type(ESMF_SciComp), intent(inout) :: comp1

Supported values for the <object2> are:

type(ESMF_CplComp), intent(in) :: comp2
type(ESMF_GridComp), intent(in) :: comp2
type(ESMF_SciComp), intent(in) :: comp2
type(ESMF_State), intent(in) :: state

The arguments are:

<object1>
The parent object in the Attribute hierarchy link.
<object2>
The child object in the Attribute hierarchy link.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 39.11.30 ESMF_AttributeLinkRemove - Unlink a State Attribute hierarchy from the hierarchy of an Array, ArrayBundle, Field, FieldBundle, or State

INTERFACE:

   ! Private name; call using ESMF_AttributeLinkRemove()

ARGUMENTS:
   type(ESMF_State), intent(inout) :: state
<object>, see below for supported values
integer, intent(out), optional :: rc

DESCRIPTION:

Unattach a State Attribute hierarchy from the hierarchy of a Fieldbundle, Field, or another State.

Supported values for the <object> are:

type(ESMF_Array), intent(in) :: array
type(ESMF_ArrayBundle), intent(in) :: arraybundle
type(ESMF_Field), intent(in) :: field
type(ESMF_FieldBundle), intent(in) :: fieldbundle
type(ESMF_State), intent(in) :: state

The arguments are:

state
An ESMF_State object.
<object>
The object with which to unlink hierarchies.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

INTERFACE:

   ! Private name; call using ESMF_AttributeLinkRemove()

ARGUMENTS:
   type(ESMF_FieldBundle), intent(inout) :: fieldbundle
type(ESMF_Field), intent(in) :: field
integer, intent(out), optional :: rc

DESCRIPTION:

Unattach a FieldBundle Attribute hierarchy from the hierarchy of a Field.

The arguments are:

fieldbundle
An ESMF_FieldBundle object.
field
An ESMF_Field object.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

INTERFACE:

   ! Private name; call using ESMF_AttributeLinkRemove()

ARGUMENTS:
   type(ESMF_Field), intent(inout) :: field
type(ESMF_Grid), intent(in) :: grid
integer, intent(out), optional :: rc

DESCRIPTION:

Unattach a Field Attribute hierarchy from the hierarchy of a Grid.

The arguments are:

field
An ESMF_Field object.
grid
An ESMF_Grid object.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

INTERFACE:

   ! Private name; call using ESMF_AttributeLinkRemove()

ARGUMENTS:
   type(ESMF_ArrayBundle), intent(inout) :: arraybundle
type(ESMF_Array), intent(in) :: array
integer, intent(out), optional :: rc

DESCRIPTION:

Unattach an ArrayBundle Attribute hierarchy from the hierarchy of an Array.

The arguments are:

arraybundle
An ESMF_ArrayBundle object.
array
An ESMF_Array object.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

INTERFACE:

   subroutine ESMF_AttributeRead(<object>, fileName, schemaFileName, rc)

ARGUMENTS:
   <object>, see below for supported values
character (len = *), intent(in), optional :: fileName
character (len = *), intent(in), optional :: schemaFileName
integer, intent(out), optional :: rc

DESCRIPTION:

Read Attributes for <object> from fileName, whose format is XML. schemaFileName format is XSD. If present, the schemaFileName is used to validate the contents of fileName. schemaFileName must be specified for a fileName containing custom, user-defined Attributes.

Requires the third-party Xerces C++ XML Parser library to be installed, v3.1.0 or newer. For more details, see the "ESMF Users Guide", "Building and Installing the ESMF, Third Party Libraries, Xerces" and the website
"http://xerces.apache.org/xerces-c". Also please see the section on Attribute I/O, 37.2.

Supported values for <object> are:

type(ESMF_Array), intent(inout) :: array ! not yet implemented
type(ESMF_ArrayBundle), intent(inout) :: arrayBundle ! not yet implemented
type(ESMF_CplComp), intent(inout) :: cplComp
type(ESMF_GridComp), intent(inout) :: gridComp
type(ESMF_SciComp), intent(inout) :: gridComp
type(ESMF_Field), intent(inout) :: field
type(ESMF_FieldBundle), intent(inout) :: fieldbundle ! not yet implemented
type(ESMF_Grid), intent(inout) :: grid
type(ESMF_DistGrid), intent(inout) :: distGrid ! not yet implemented

The arguments are:

<object>
The ESMF object onto which the read Attributes will be placed.
[fileName]
The name of the XML file to read.
[schemaFileName]
The name of the XSD file to validate the contents of fileName.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 39.11.35 ESMF_AttributeRemove - Remove an Attribute or Attribute package using an ESMF_AttPack

INTERFACE:

   subroutine ESMF_AttributeRemove(<object>, name, &
attpack, rc)

ARGUMENTS:
   <object>, see below for supported values
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
character (len = *), intent(in), optional :: name
type(ESMF_AttPack), intent(inout) :: attpack
integer, intent(out), optional :: rc

DESCRIPTION:

Remove an Attribute, or Attribute package on <object>. See Section 39.2 for a description of Attribute packages and their conventions, purposes, and object types.

Supported values for <object> are:

type(ESMF_Array), intent(inout) :: array
type(ESMF_ArrayBundle), intent(inout) :: arraybundle
type(ESMF_CplComp), intent(inout) :: comp
type(ESMF_GridComp), intent(inout) :: comp
type(ESMF_SciComp), intent(inout) :: comp
type(ESMF_DistGrid), intent(inout) :: distgrid
type(ESMF_Field), intent(inout) :: field
type(ESMF_FieldBundle), intent(inout) :: fieldbundle
type(ESMF_Grid), intent(inout) :: grid
type(ESMF_State), intent(inout) :: state

The arguments are:

<object>
An ESMF object.
[name]
The name of the Attribute to remove.
attpack
A handle to the Attribute package.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

NOTE: An entire Attribute package can be removed by specifying attpack only, without name. By specifying attpack an Attribute will be removed from the corresponding Attribute package, if it exists. An Attribute can be removed directly from <object> by specifying name, without attpack.

### 39.11.36 ESMF_AttributeRemove - Remove an Attribute or Attribute package

INTERFACE:

   subroutine ESMF_AttributeRemove(<object>, name, convention, purpose, &
attPackInstanceName, rc)

ARGUMENTS:
   <object>, see below for supported values
character (len = *), intent(in), optional :: name
character (len = *), intent(in), optional :: convention
character (len = *), intent(in), optional :: purpose
character (len = *), intent(in), optional :: attPackInstanceName
integer, intent(out), optional :: rc

DESCRIPTION:

Remove an Attribute, or Attribute package on <object>. See Section 39.2 for a description of Attribute packages and their conventions, purposes, and object types.

Supported values for <object> are:

type(ESMF_Array), intent(inout) :: array
type(ESMF_ArrayBundle), intent(inout) :: arraybundle
type(ESMF_CplComp), intent(inout) :: comp
type(ESMF_GridComp), intent(inout) :: comp
type(ESMF_SciComp), intent(inout) :: comp
type(ESMF_DistGrid), intent(inout) :: distgrid
type(ESMF_Field), intent(inout) :: field
type(ESMF_FieldBundle), intent(inout) :: fieldbundle
type(ESMF_Grid), intent(inout) :: grid
type(ESMF_State), intent(inout) :: state

The arguments are:

<object>
An ESMF object.
[name]
The name of the Attribute to remove.
[convention]
The convention of the Attribute package.
[purpose]
The purpose of the Attribute package.
[attPackInstanceName]
The name of an Attribute package instance, specifying which one of multiple Attribute package instances of the same convention and purpose, within a nest. If not specified, defaults to the first instance.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

NOTE: An entire Attribute package can be removed by specifying convention, purpose, and attPackInstanceName only, without name. An Attribute can be removed directly from <object> by specifying name, without convention, purpose, and attPackInstanceName.

### 39.11.37 ESMF_AttributeSet - Set an Attribute in an ESMF_AttPack

INTERFACE:

   subroutine ESMF_AttributeSet(<object>, name, <value>, attpack, &
rc)

ARGUMENTS:
   <object>, see below for supported values
character (len = *), intent(in) :: name
<value>, see below for supported values
type(ESMF_AttPack), intent(inout) :: attpack
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer, intent(out), optional :: rc

DESCRIPTION:

Attach an Attribute to <object>, or set an Attribute in an Attribute package. The Attribute has a name and value, and, if in an Attribute package, a attpack. See Section 39.2 for a description of Attribute packages.

Supported values for <object> are:

type(ESMF_Array), intent(inout) :: array
type(ESMF_ArrayBundle), intent(inout) :: arraybundle
type(ESMF_CplComp), intent(inout) :: comp
type(ESMF_GridComp), intent(inout) :: comp
type(ESMF_SciComp), intent(inout) :: comp
type(ESMF_DistGrid), intent(inout) :: distgrid
type(ESMF_Field), intent(inout) :: field
type(ESMF_FieldBundle), intent(inout) :: fieldbundle
type(ESMF_Grid), intent(inout) :: grid
type(ESMF_State), intent(inout) :: state

Supported values for the <value> are:

integer(ESMF_KIND_I4), intent(in) :: value
integer(ESMF_KIND_I8), intent(in) :: value
real (ESMF_KIND_R4), intent(in) :: value
real (ESMF_KIND_R8), intent(in) :: value
logical, intent(in) :: value
character (len = *), intent(in) :: value

The arguments are:

<object>
An ESMF object.
name
The name of the Attribute to set.
<value argument>
The value of the Attribute to set.
attpack
A handle to the Attribute package.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 39.11.38 ESMF_AttributeSet - Set an Attribute to point to internal class information in an ESMF_AttPack

INTERFACE:

   subroutine ESMF_AttributeSet(<object>, name, <value>, attpack, &
inputList, rc)

ARGUMENTS:
   <object>, see below for supported values
character (len = *), intent(in) :: name
<value>, see below for supported values
type(ESMF_AttPack), intent(inout) :: attpack
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
character (len = *), intent(in), optional :: inputList(:)
integer, intent(out), optional :: rc

DESCRIPTION:

Attach an Attribute to <object>, or set an Attribute in an Attribute package. The Attribute has a name and value, and, if in an Attribute package, a attpack. See Section 39.2 for a description of Attribute packages. The Attribute can also be set to be a pointer to internal class information. See Section 39.5 for a description of this capability.

Supported values for <object> are:

type(ESMF_Grid), intent(inout) :: grid

Supported values for the <value> are:

character (len = *), intent(in), :: value

The arguments are:

<object>
An ESMF object.
name
The name of the Attribute to set.
<value argument>
The value of the Attribute to set.
attpack
A handle to the Attribute package.
[inputList]
A list of the input parameters required to set internal info.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 39.11.39 ESMF_AttributeSet - Set an Attribute in an ESMF_AttPack

INTERFACE:

   subroutine ESMF_AttributeSet(<object>, name, <valueList>, attpack, &
itemCount, rc)

ARGUMENTS:
   <object>, see below for supported values
character (len = *), intent(in) :: name
<valueList>, see below for supported values
type(ESMF_AttPack), intent(in) :: attpack
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer, intent(in), optional :: itemCount
integer, intent(out), optional :: rc

DESCRIPTION:

Attach an Attribute to <object>, or set an Attribute in an Attribute package. The Attribute has a name and a valueList, with an itemCount, and, if in an Attribute package, a attpack. See Section 39.2 for a description of Attribute packages.

Supported values for <object> are:

type(ESMF_Array), intent(inout) :: array
type(ESMF_ArrayBundle), intent(inout) :: arraybundle
type(ESMF_CplComp), intent(inout) :: comp
type(ESMF_GridComp), intent(inout) :: comp
type(ESMF_SciComp), intent(inout) :: comp
type(ESMF_DistGrid), intent(inout) :: distgrid
type(ESMF_Field), intent(inout) :: field
type(ESMF_FieldBundle), intent(inout) :: fieldbundle
type(ESMF_Grid), intent(inout) :: grid
type(ESMF_State), intent(inout) :: state

Supported values for the <valueList> are:

integer(ESMF_KIND_I4), intent(in) :: valueList(:)
integer(ESMF_KIND_I8), intent(in) :: valueList(:)
real (ESMF_KIND_R4), intent(in) :: valueList(:)
real (ESMF_KIND_R8), intent(in) :: valueList(:)
logical, intent(in) :: valueList(:)
character (len = *), intent(in) :: valueList(:)

The arguments are:

<object>
An ESMF object.
name
The name of the Attribute to set.
<valueList argument>
The valueList of the Attribute to set.
attpack
A handle to the Attribute package.
[itemCount]
The number of items in a multi-valued Attribute.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 39.11.40 ESMF_AttributeSet - Set an Attribute

INTERFACE:

   subroutine ESMF_AttributeSet(<object>, name, <value>, &
convention, purpose, attPackInstanceName, rc)

ARGUMENTS:
   <object>, see below for supported values
character (len = *), intent(in) :: name
<value>, see below for supported values
character (len = *), intent(in), optional :: convention
character (len = *), intent(in), optional :: purpose
character (len = *), intent(in), optional :: attPackInstanceName
integer, intent(out), optional :: rc

DESCRIPTION:

Attach an Attribute to <object>, or set an Attribute in an Attribute package. The Attribute has a name and value, and, if in an Attribute package, convention, purpose, and attPackInstanceName. See Section 39.2 for a description of Attribute packages.

Supported values for <object> are:

type(ESMF_Array), intent(inout) :: array
type(ESMF_ArrayBundle), intent(inout) :: arraybundle
type(ESMF_CplComp), intent(inout) :: comp
type(ESMF_GridComp), intent(inout) :: comp
type(ESMF_SciComp), intent(inout) :: comp
type(ESMF_DistGrid), intent(inout) :: distgrid
type(ESMF_Field), intent(inout) :: field
type(ESMF_FieldBundle), intent(inout) :: fieldbundle
type(ESMF_Grid), intent(inout) :: grid
type(ESMF_State), intent(inout) :: state

Supported values for the <value> are:

integer(ESMF_KIND_I4), intent(in) :: value
integer(ESMF_KIND_I8), intent(in) :: value
real (ESMF_KIND_R4), intent(in) :: value
real (ESMF_KIND_R8), intent(in) :: value
logical, intent(in) :: value
character (len = *), intent(in) :: value

The arguments are:

<object>
An ESMF object.
name
The name of the Attribute to set.
<value argument>
The value of the Attribute to set.
[convention]
The convention of the Attribute package.
[purpose]
The purpose of the Attribute package.
[attPackInstanceName]
The name of an Attribute package instance, specifying which one of multiple Attribute package instances of the same convention and purpose, within a nest. If not specified, defaults to the first instance. (Not implemented yet)
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 39.11.41 ESMF_AttributeSet - Set an Attribute to point to internal class information

INTERFACE:

   subroutine ESMF_AttributeSet(<object>, name, <value>, inputList,
convention, purpose, attPackInstanceName, rc)

ARGUMENTS:
   <object>, see below for supported values
character (len = *), intent(in) :: name
<value>, see below for supported values
character (len = *), intent(in), optional :: inputList(:)
character (len = *), intent(in), optional :: convention
character (len = *), intent(in), optional :: purpose
character (len = *), intent(in), optional :: attPackInstanceName
integer, intent(out), optional :: rc

DESCRIPTION:

Attach an Attribute to <object>, or set an Attribute in an Attribute package. The Attribute has a name and value, and, if in an Attribute package, convention, purpose, and attPackInstanceName. See Section 39.2 for a description of Attribute packages. The Attribute can also be set to be a pointer to internal class information. See Section 39.5 for a description of this capability.

Supported values for <object> are:

type(ESMF_Grid), intent(inout) :: grid

Supported values for the <value> are:

character (len = *), intent(in), :: value

The arguments are:

<object>
An ESMF object.
name
The name of the Attribute to set.
<value argument>
The value of the Attribute to set.
[inputList]
A list of the input parameters required to set internal info.
[convention]
The convention of the Attribute package.
[purpose]
The purpose of the Attribute package.
[attPackInstanceName]
The name of an Attribute package instance, specifying which one of multiple Attribute package instances of the same convention and purpose, within a nest. If not specified, defaults to the first instance. (Not implemented yet)
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 39.11.42 ESMF_AttributeSet - Set an Attribute

INTERFACE:

   subroutine ESMF_AttributeSet(<object>, name, <valueList>, &
convention, purpose, attPackInstanceName, itemCount, rc)

ARGUMENTS:
   <object>, see below for supported values
character (len = *), intent(in) :: name
<valueList>, see below for supported values
character (len = *), intent(in), optional :: convention
character (len = *), intent(in), optional :: purpose
character (len = *), intent(in), optional :: attPackInstanceName
integer, intent(in), optional :: itemCount
integer, intent(out), optional :: rc

DESCRIPTION:

Attach an Attribute to <object>, or set an Attribute in an Attribute package. The Attribute has a name and a valueList, with an itemCount, and, if in an Attribute package, convention, purpose, and attPackInstanceName. See Section 39.2 for a description of Attribute packages.

Supported values for <object> are:

type(ESMF_Array), intent(inout) :: array
type(ESMF_ArrayBundle), intent(inout) :: arraybundle
type(ESMF_CplComp), intent(inout) :: comp
type(ESMF_GridComp), intent(inout) :: comp
type(ESMF_SciComp), intent(inout) :: comp
type(ESMF_DistGrid), intent(inout) :: distgrid
type(ESMF_Field), intent(inout) :: field
type(ESMF_FieldBundle), intent(inout) :: fieldbundle
type(ESMF_Grid), intent(inout) :: grid
type(ESMF_State), intent(inout) :: state

Supported values for the <valueList> are:

integer(ESMF_KIND_I4), intent(in) :: valueList(:)
integer(ESMF_KIND_I8), intent(in) :: valueList(:)
real (ESMF_KIND_R4), intent(in) :: valueList(:)
real (ESMF_KIND_R8), intent(in) :: valueList(:)
logical, intent(in) :: valueList(:)
character (len = *), intent(in) :: valueList(:)

The arguments are:

<object>
An ESMF object.
name
The name of the Attribute to set.
<valueList argument>
The valueList of the Attribute to set.
[convention]
The convention of the Attribute package.
[purpose]
The purpose of the Attribute package.
[attPackInstanceName]
The name of an Attribute package instance, specifying which one of multiple Attribute package instances of the same convention and purpose, within a nest. If not specified, defaults to the first instance. (Not implemented yet)
[itemCount]
The number of items in a multi-valued Attribute.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 39.11.43 ESMF_AttributeUpdate - Update an Attribute hierarchy

INTERFACE:

   subroutine ESMF_AttributeUpdate(<object>, vm, rootList, reconcile, rc)

ARGUMENTS:
   <object>, see below for supported values
type(ESMF_VM), intent(in) :: vm
integer, intent(in) :: rootList(:)
logical, intent(in), optional :: reconcile
integer, intent(out), optional :: rc

DESCRIPTION:

Update an Attribute hierarchy during runtime. The information from the PETs in the rootList is transferred to the PETs that are not in the rootList. Care should be taken to ensure that the information contained in the Attributes on the PETs in the rootList is consistent. If changes have been made to the underlying object hierarchy then either ESMF_StateReconcile() or the reconcile flag must be used to resolve them. The same applies if changes are made to both PETs and in the rootList and PETs outside of the rootList, or if the same changes are made in a different order.

Supported values for <object> are:

type(ESMF_Array), intent(inout) :: array
type(ESMF_ArrayBundle), intent(inout) :: arraybundle
type(ESMF_CplComp), intent(inout) :: comp
type(ESMF_GridComp), intent(inout) :: comp
type(ESMF_SciComp), intent(inout) :: comp
type(ESMF_Field), intent(inout) :: field
type(ESMF_FieldBundle), intent(inout) :: fieldbundle
type(ESMF_State), intent(inout) :: state

The arguments are:

<object>
An ESMF object.
vm
The virtual machine over which this Attribute hierarchy should be updated.
rootList
The list of PETs that are to be used as the source of the update.
[reconcile]
A logical flag used to indicate whether to use reconcile behavior or normal update behavior. If reconcile is set to .true. then the values of the root PETs will be sent to the nonroot PETs without exception. Otherwise, an algorithm that is optimized to use minimal memory will be used to update only the modified parts of the Attribute hierarchy on the nonroot PETs. The default value is .false..
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 39.11.44 ESMF_AttributeWrite - Write an Attribute package

INTERFACE:

   subroutine ESMF_AttributeWrite(<object>, convention, purpose, &
attwriteflag, rc)

ARGUMENTS:
   <object>, see below for supported values
character (len = *), intent(in), optional :: convention
character (len = *), intent(in), optional :: purpose
type(ESMF_AttWriteFlag), intent(in), optional :: attwriteflag
integer, intent(out), optional :: rc

DESCRIPTION:

Write the Attribute package for <object>. The Attribute package defines the convention, purpose, and object type of the associated Attributes. Either tab-delimited or xml format is achieved by using attwriteflag. Currently, only ESMF/ESG/CF Field Attribute packages can be written in tab-delimited format. See Section 39.2 for a description of Attribute packages and their conventions, purposes, and object types.

This call is collective across the current VM.

Writing Attribute XML files is performed with the standard C++ output file stream facility.

Note: For an object type of ESMF_GridComp, convention='WaterML', purpose='TimeSeries', and
attwriteflag=ESMF_ATTWRITE_XML, an XML file conforming to a hydrologic standard called WaterML will be written. See the following for more information:

"http://his.cuahsi.org/wofws.html"
"http://www.earthsystemcurator.org/projects/waterml.shtml"

An ESMF Use Test Case is available which showcases an example of how to write a WaterML file; please see

"http://esmf.cvs.sourceforge.net/viewvc/esmf/use_test_cases/ESMF_WaterML"

Supported values for <object> are:

type(ESMF_Array), intent(in) :: array
type(ESMF_ArrayBundle), intent(in) :: arraybundle
type(ESMF_CplComp), intent(in) :: comp
type(ESMF_GridComp), intent(in) :: comp
type(ESMF_SciComp), intent(in) :: comp
type(ESMF_DistGrid), intent(in) :: distgrid
type(ESMF_Field), intent(in) :: field
type(ESMF_FieldBundle), intent(in) :: fieldbundle
type(ESMF_Grid), intent(in) :: grid
type(ESMF_State), intent(in) :: state

The arguments are:

<object>
An ESMF object.
[convention]
The convention of the Attribute package.
[purpose]
The purpose of the Attribute package.
[attwriteflag]
The flag to specify which format is desired for the write, the default is ESMF_ATTWRITE_TAB. This flag is documented in section 39.6.3.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

# 40 Time Manager Utility

The ESMF Time Manager utility includes software for time and date representation and calculations, model time advancement, and the identification of unique and periodic events. Since multi-component geophysical applications often require synchronization across the time management schemes of the individual components, the Time Manager's standard calendars and consistent time representation promote component interoperability.

 Key Features Drift-free timekeeping through an integer-based internal time representation. Both integers and reals can be specified at the interface. The ability to represent time as a rational fraction, to support exact timekeeping in applications that involve grid refinement. Support for many calendar kinds, including user-customized calendars. Support for both concurrent and sequential modes of component execution. Support for varying and negative time steps.

## 40.1 Time Manager Classes

There are five ESMF classes that represent time concepts:
• Calendar A Calendar can be used to keep track of the date as an ESMF Gridded Component advances in time. Standard calendars (such as Gregorian and 360-day) and user-specified calendars are supported. Calendars can be queried for quantities such as seconds per day, days per month, and days per year.
• Time A Time represents a time instant in a particular calendar, such as November 28, 1964, at 7:31pm EST in the Gregorian calendar. The Time class can be used to represent the start and stop time of a time integration.
• TimeInterval TimeIntervals represent a period of time, such as 300 milliseconds. Time steps can be represented using TimeIntervals.
• Clock Clocks collect the parameters and methods used for model time advancement into a convenient package. A Clock can be queried for quantities such as start time, stop time, current time, and time step. Clock methods include incrementing the current time, and determining if it is time to stop.
• Alarm Alarms identify unique or periodic events by ringing'' - returning a true value - at specified times. For example, an Alarm might be set to ring on the day of the year when leaves start falling from the trees in a climate model.

In the remainder of this section, we briefly summarize the functionality that the Time Manager classes provide. Detailed descriptions and usage examples precede the API listing for each class.

## 40.2 Calendar

An ESMF Calendar can be queried for seconds per day, days per month and days per year. The flexible definition of Calendars allows them to be defined for planetary bodies other than Earth. The set of supported calendars includes:
Gregorian
The standard Gregorian calendar.
no-leap
The Gregorian calendar with no leap years.
Julian
The standard Julian date calendar.
Julian Day
The standard Julian days calendar.
Modified Julian Day
The Modified Julian days calendar.
360-day
A 30-day-per-month, 12-month-per-year calendar.
no calendar
Tracks only elapsed model time in hours, minutes, seconds.
See Section 41.1 for more details on supported standard calendars, and how to create a customized ESMF Calendar.

## 40.3 Time Instants and TimeIntervals

TimeIntervals and Time instants (simply called Times) are the computational building blocks of the Time Manager utility. TimeIntervals support operations such as add, subtract, compare size, reset value, copy value, and subdivide by a scalar. Times, which are moments in time associated with specific Calendars, can be incremented or decremented by TimeIntervals, compared to determine which of two Times is later, differenced to obtain the TimeInterval between two Times, copied, reset, and manipulated in other useful ways. Times support a host of different queries, both for values of individual Time components such as year, month, day, and second, and for derived values such as day of year, middle of current month and Julian day. It is also possible to retrieve the value of the hardware realtime clock in the form of a Time. See Sections 42.1 and 43.1, respectively, for use and examples of Times and TimeIntervals.

Since climate modeling, numerical weather prediction and other Earth and space applications have widely varying time scales and require different sorts of calendars, Times and TimeIntervals must support a wide range of time specifiers, spanning nanoseconds to years. The interfaces to these time classes are defined so that the user can specify a time using a combination of units selected from the list shown in Table 40.4.

## 40.4 Clocks and Alarms

Although it is possible to repeatedly step a Time forward by a TimeInterval using arithmetic on these basic types, it is useful to identify a higher-level concept to represent this function. We refer to this capability as a Clock, and include in its required features the ability to store the start and stop times of a model run, to check when time advancement should cease, and to query the value of quantities such as the current time and the time at the previous time step. The Time Manager includes a class with methods that return a true value when a periodic or unique event has taken place; we refer to these as Alarms. Applications may contain temporary or multiple Clocks and Alarms. Sections 44.1 and 45.1 describe the use of Clocks and Alarms in detail.

 Unit Meaning Year. mm Month of the year. dd Day of the month. Julian or Modified Julian day. Hour. Minute. Second. Millisecond. Microsecond. Nanosecond. O Time zone offset in integer number of hours and minutes. Numerator for times of the form s , where s is seconds and s, sN, and sD are integers. This format provides a mechanism for supporting exact behavior.

## 40.5 Design and Implementation Notes

1. Base TimeIntervals and Times on the same integer representation. It is useful to allow both TimeIntervals and Times to inherit from a single class, BaseTime. In C++, this can be implemented by using inheritance. In Fortran, it can be implemented by having the derived types TimeIntervals and Times contain a derived type BaseTime. In both cases, the BaseTime class can be made private and invisible to the user.

The result of this strategy is that Time Intervals and Times gain a consistent core representation of time as well a set of basic methods.

The BaseTime class can be designed with a minimum number of elements to represent any required time. The design is based on the idea used in the real-time POSIX 1003.1b-1993 standard. That is, to represent time simply as a pair of integers: one for seconds (whole) and one for nanoseconds (fractional). These can then be converted at the interface level to any desired format.

For ESMF, this idea can be modified and extended, in order to handle the requirements for a large time range (> 200,000 years) and to exactly represent any rational fraction, not just nanoseconds. To handle the large time range, a 64-bit or greater integer is used for whole seconds. Any rational fractional second is expressed using two additional integers: a numerator and a denominator. Both the whole seconds and fractional numerator are signed to handle negative time intervals and instants. For arithmetic consistency both must carry the same sign (both positive or both negative), except, of course, for zero values. The fractional seconds element (numerator) is bounded with respect to whole seconds. If the absolute value of the numerator becomes greater than or equal to the denominator, whole seconds are incremented or decremented accordingly and the numerator is reset to the remainder. Conversions are performed upon demand by interface methods within the TimeInterval and Time classes. This is done because different applications require different representations of time intervals and time instances. Floating point values as well as integers can be specified for the various time units in the interfaces, see Table 40.4. Floating point values are represented internally as integer-based rational fractions.

The BaseTime class defines increment and decrement methods for basic TimeInterval calculations between Time instants. It is done here rather than in the Calendar class because it can be done with simple second-based arithmetic that is calendar independent.

Comparison methods can also be defined in the BaseTime class. These perform equality/inequality, less than, and greater than comparisons between any two TimeIntervals or Times. These methods capture the common comparison logic between TimeIntervals and Times and hence are defined here for sharing.

2. The Time class depends on a calendar. The Time class contains an internal Calendar class. Upon demand by a user, the results of an increment or decrement operation are converted to user units, which may be calendar-dependent, via methods obtained from their internal Calendar.

## 40.6 Object Model

The following is a simplified UML diagram showing the structure of the Time Manager utility. See Appendix A, A Brief Introduction to UML, for a translation table that lists the symbols in the diagram and their meaning.

# 41 Calendar Class

## 41.1 Description

The Calendar class represents the standard calendars used in geophysical modeling: Gregorian, Julian, Julian Day, Modified Julian Day, no-leap, 360-day, and no-calendar. It also supports a user-customized calendar. Brief descriptions are provided for each calendar below. For more information on standard calendars, see [25] and [21].

## 41.2 Constants

### 41.2.1 ESMF_CALKIND

DESCRIPTION:
Supported calendar kinds.

The type of this flag is:

type(ESMF_CalKind_Flag)

The valid values are:

ESMF_CALKIND_360DAY
Valid range: machine limits
In the 360-day calendar, there are 12 months, each of which has 30 days. Like the no-leap calendar, this is a simple approximation to the Gregorian calendar sometimes used by modelers.

ESMF_CALKIND_CUSTOM
Valid range: machine limits
The user can set calendar parameters in the generic calendar.

ESMF_CALKIND_GREGORIAN
Valid range: 3/1/4801 BC to 10/29/292,277,019,914
The Gregorian calendar is the calendar currently in use throughout Western countries. Named after Pope Gregory XIII, it is a minor correction to the older Julian calendar. In the Gregorian calendar every fourth year is a leap year in which February has 29 and not 28 days; however, years divisible by 100 are not leap years unless they are also divisible by 400. As in the Julian calendar, days begin at midnight.

ESMF_CALKIND_JULIAN
Valid range: 3/1/4713 BC to 4/24/292,271,018,333
The Julian calendar was introduced by Julius Caesar in 46 B.C., and reached its final form in 4 A.D. The Julian calendar differs from the Gregorian only in the determination of leap years, lacking the correction for years divisible by 100 and 400 in the Gregorian calendar. In the Julian calendar, any year is a leap year if divisible by 4. Days are considered to begin at midnight.

ESMF_CALKIND_JULIANDAY
Valid range: +/- 1x10
Julian days simply enumerate the days and fraction of a day which have elapsed since the start of the Julian era, defined as beginning at noon on Monday, 1st January of year 4713 B.C. in the Julian calendar. Julian days, unlike the dates in the Julian and Gregorian calendars, begin at noon.

ESMF_CALKIND_MODJULIANDAY
Valid range: +/- 1x10
The Modified Julian Day (MJD) was introduced by space scientists in the late 1950's. It is defined as an offset from the Julian Day (JD):

MJD = JD - 2400000.5

The half day is subtracted so that the day starts at midnight.

ESMF_CALKIND_NOCALENDAR
Valid range: machine limits
The no-calendar option simply tracks the elapsed model time in seconds.

ESMF_CALKIND_NOLEAP
Valid range: machine limits
The no-leap calendar is the Gregorian calendar with no leap years - February is always assumed to have 28 days. Modelers sometimes use this calendar as a simple, close approximation to the Gregorian calendar.

## 41.3 Use and Examples

In most multi-component Earth system applications, the timekeeping in each component must refer to the same standard calendar in order for the components to properly synchronize. It therefore makes sense to create as few ESMF Calendars as possible, preferably one per application. A typical strategy would be to create a single Calendar at the start of an application, and use that Calendar in all subsequent calls that accept a Calendar, such as ESMF_TimeSet.

The following example shows how to set up an ESMF Calendar.

! !PROGRAM: ESMF_CalendarEx - Calendar creation examples
!
! !DESCRIPTION:
!
! This program shows examples of how to create different calendar kinds
!-----------------------------------------------------------------------------
#include "ESMF.h"

! ESMF Framework module
use ESMF
use ESMF_TestMod
implicit none

! instantiate calendars
type(ESMF_Calendar) :: gregorianCalendar
type(ESMF_Calendar) :: julianDayCalendar
type(ESMF_Calendar) :: marsCalendar

! local variables for Get methods
integer :: sols
integer(ESMF_KIND_I8) :: dl
type(ESMF_Time) :: time, marsTime
type(ESMF_TimeInterval) :: marsTimeStep

! return code
integer:: rc


      ! initialize ESMF framework
call ESMF_Initialize(defaultlogfilename="CalendarEx.Log", &
logkindflag=ESMF_LOGKIND_MULTI, rc=rc)


### 41.3.1 Calendar creation

This example shows how to create three ESMF_Calendars.

      ! create a Gregorian calendar
gregorianCalendar = ESMF_CalendarCreate(ESMF_CALKIND_GREGORIAN, &
name="Gregorian", rc=rc)


      ! create a Julian Day calendar
julianDayCalendar = ESMF_CalendarCreate(ESMF_CALKIND_JULIANDAY, &
name="JulianDay", rc=rc)


      ! create a Custom calendar for the planet Mars
! 1 Mars solar day = 24 hours, 39 minutes, 35 seconds = 88775 seconds
! 1 Mars solar year = 668.5921 Mars solar days = 668 5921/10000 sols/year
! http://www.giss.nasa.gov/research/briefs/allison_02
! http://www.giss.nasa.gov/tools/mars24/help/notes.html
marsCalendar = ESMF_CalendarCreate(secondsPerDay=88775, &
daysPerYear=668, &
daysPerYearDn=5921, &
daysPerYearDd=10000, &
name="MarsCalendar", rc=rc)


### 41.3.2 Calendar comparison

This example shows how to compare an ESMF_Calendar with a known calendar kind.

      ! compare calendar kind against a known type
if (gregorianCalendar == ESMF_CALKIND_GREGORIAN) then
print *, "gregorianCalendar is of type ESMF_CALKIND_GREGORIAN."
else
print *, "gregorianCalendar is not of type ESMF_CALKIND_GREGORIAN."
end if


### 41.3.3 Time conversion between Calendars

This example shows how to convert a time from one ESMF_Calendar to another.

      call ESMF_TimeSet(time, yy=2004, mm=4, dd=17, &
calendar=gregorianCalendar, rc=rc)


      ! switch time's calendar to perform conversion
call ESMF_TimeSet(time, calendar=julianDayCalendar, rc=rc)


      call ESMF_TimeGet(time, d_i8=dl, rc=rc)
print *, "Gregorian date 2004/4/17 is ", dl, &
" days in the Julian Day calendar."


### 41.3.4 Add a time interval to a time on a Calendar

This example shows how to increment a time using a custom ESMF_Calendar.

      ! Set a time to Mars solar year 3, sol 100
call ESMF_TimeSet(marsTime, yy=3, d=100, &
calendar=marsCalendar, rc=rc)


      ! Set a 1 solar year time step
call ESMF_TimeIntervalSet(marsTimeStep, yy=1, rc=rc)


      ! Perform the increment
marsTime = marsTime + marsTimeStep


      ! Get the result in sols (2774 = (3+1)*668.5921 + 100)
call ESMF_TimeGet(marsTime, d=sols, rc=rc)
print *, "For Mars, 3 solar years, 100 sols + 1 solar year = ", &
sols, "sols."


### 41.3.5 Calendar destruction

This example shows how to destroy three ESMF_Calendars.

      call ESMF_CalendarDestroy(julianDayCalendar, rc=rc)


      call ESMF_CalendarDestroy(gregorianCalendar, rc=rc)


      call ESMF_CalendarDestroy(marsCalendar, rc=rc)


      ! finalize ESMF framework
call ESMF_Finalize(rc=rc)


      end program ESMF_CalendarEx


## 41.4 Restrictions and Future Work

1. Months per year set to 12. Due to the requirement of only Earth modeling, the number of months per year is hard-coded at 12. However, for easy modification, this is implemented via a C preprocessor #define MONTHS_PER_YEAR in ESMCI_Calendar.h.

2. Calendar date conversions. Date conversions are currently defined between the Gregorian, Julian, Julian Day, and Modified Julian Day calendars. Further research and work would need to be done to determine conversion algorithms with and between the other calendars: No Leap, 360 Day, and Custom.

3. ESMF_CALKIND_CUSTOM. Currently, there is no provision for a custom calendar to define a leap year rule, so ESMF_CalendarIsLeapYear() will always return .false. in this case. However, the arguments daysPerYear, daysPerYearDn, and daysPerYearDd in ESMF_CalendarCreate() and ESMF_CalendarSet() can be used to set a fractional number of days per year, for example, 365.25 = 365 25/100. Also, if further timekeeping precision is required, fractional and/or floating point secondsPerDay and secondsPerYear could be added to the interfaces ESMF_CalendarCreate(), ESMF_CalendarSet(), and ESMF_CalendarGet() and implemented.

## 41.5 Class API

### 41.5.1 ESMF_CalendarAssignment(=) - Assign a Calendar to another Calendar

INTERFACE:

       interface assignment(=)
calendar1 = calendar2

ARGUMENTS:
       type(ESMF_Calendar) :: calendar1
type(ESMF_Calendar) :: calendar2

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Assign calendar1 as an alias to the same ESMF_Calendar object in memory as calendar2. If calendar2 is invalid, then calendar1 will be equally invalid after the assignment.

The arguments are:

calendar1
The ESMF_Calendar object on the left hand side of the assignment.
calendar2
The ESMF_Calendar object on the right hand side of the assignment.

### 41.5.2 ESMF_CalendarOperator(==) - Test if Calendar argument 1 is equal to Calendar argument 2

INTERFACE:

       interface operator(==)
if (<calendar argument 1> == <calendar argument 2>) then ... endif
OR
result = (<calendar argument 1> == <calendar argument 2>)

RETURN VALUE:
       logical :: result

ARGUMENTS:
       <calendar argument 1>, see below for supported values
<calendar argument 2>, see below for supported values

DESCRIPTION:

Overloads the (==) operator for the ESMF_Calendar class. Compare an ESMF_Calendar object or ESMF_CalKind_Flag with another calendar object or calendar kind for equality. Return .true. if equal, .false. otherwise. Comparison is based on calendar kind, which is a property of a calendar object.

If both arguments are ESMF_Calendar objects, and both are of type ESMF_CALKIND_CUSTOM, then all the calendar's properties, except name, are compared.

If both arguments are ESMF_Calendar objects, and either of them is not in the ESMF_INIT_CREATED status, an error will be logged. However, this does not affect the return value, which is .true. when both arguments are in the same status, and .false. otherwise.

If one argument is an ESMF_Calendar object, and the other is an ESMF_CalKind_Flag, and the calendar object is not in the ESMF_INIT_CREATED status, an error will be logged and .false. will be returned.

Supported values for <calendar argument 1> are:

type(ESMF_Calendar), intent(in) :: calendar1
type(ESMF_CalKind_Flag), intent(in) :: calkindflag1
Supported values for <calendar argument 2> are:
type(ESMF_Calendar), intent(in) :: calendar2
type(ESMF_CalKind_Flag), intent(in) :: calkindflag2

The arguments are:

<calendar argument 1>
The ESMF_Calendar object or ESMF_CalKind_Flag on the left hand side of the equality operation.
<calendar argument 2>
The ESMF_Calendar object or ESMF_CalKind_Flag on the right hand side of the equality operation.

### 41.5.3 ESMF_CalendarOperator(/=) - Test if Calendar argument 1 is not equal to Calendar argument 2

INTERFACE:

       interface operator(/=)
if (<calendar argument 1> /= <calendar argument 2>) then ... endif
OR
result = (<calendar argument 1> /= <calendar argument 2>)

RETURN VALUE:
       logical :: result

ARGUMENTS:
       <calendar argument 1>, see below for supported values
<calendar argument 2>, see below for supported values

DESCRIPTION:

Overloads the (/=) operator for the ESMF_Calendar class. Compare a ESMF_Calendar object or ESMF_CalKind_Flag with another calendar object or calendar kind for inequality. Return .true. if not equal, .false. otherwise. Comparison is based on calendar kind, which is a property of a calendar object.

If both arguments are ESMF_Calendar objects, and both are of type ESMF_CALKIND_CUSTOM, then all the calendar's properties, except name, are compared.

If both arguments are ESMF_Calendar objects, and either of them is not in the ESMF_INIT_CREATED status, an error will be logged. However, this does not affect the return value, which is .true. when both arguments are not in the same status, and .false. otherwise.

If one argument is an ESMF_Calendar object, and the other is an ESMF_CalKind_Flag, and the calendar object is not in the ESMF_INIT_CREATED status, an error will be logged and .true. will be returned.

Supported values for <calendar argument 1> are:

type(ESMF_Calendar), intent(in) :: calendar1
type(ESMF_CalKind_Flag), intent(in) :: calkindflag1
Supported values for <calendar argument 2> are:
type(ESMF_Calendar), intent(in) :: calendar2
type(ESMF_CalKind_Flag), intent(in) :: calkindflag2

The arguments are:

<calendar argument 1>
The ESMF_Calendar object or ESMF_CalKind_Flag on the left hand side of the non-equality operation.
<calendar argument 2>
The ESMF_Calendar object or ESMF_CalKind_Flag on the right hand side of the non-equality operation.

### 41.5.4 ESMF_CalendarCreate - Create a new ESMF Calendar of built-in type

INTERFACE:

       ! Private name; call using ESMF_CalendarCreate()
function ESMF_CalendarCreateBuiltIn(calkindflag, &
name, rc)

RETURN VALUE:
       type(ESMF_Calendar) :: ESMF_CalendarCreateBuiltIn

ARGUMENTS:
       type(ESMF_CalKind_Flag), intent(in)            :: calkindflag
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
character (len=*),       intent(in),  optional :: name
integer,                 intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Creates and sets a calendar to the given built-in ESMF_CalKind_Flag.

The arguments are:

calkindflag
The built-in ESMF_CalKind_Flag. Valid values are:
ESMF_CALKIND_360DAY,
ESMF_CALKIND_GREGORIAN,
ESMF_CALKIND_JULIAN,
ESMF_CALKIND_JULIANDAY,
ESMF_CALKIND_MODJULIANDAY,
ESMF_CALKIND_NOCALENDAR,
and ESMF_CALKIND_NOLEAP.
See Section 41.2 for a description of each calendar kind.
[name]
The name for the newly created calendar. If not specified, a default unique name will be generated: "CalendarNNN" where NNN is a unique sequence number from 001 to 999.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 41.5.5 ESMF_CalendarCreate - Create a copy of an ESMF Calendar

INTERFACE:

       ! Private name; call using ESMF_CalendarCreate()
function ESMF_CalendarCreateCopy(calendar, rc)

RETURN VALUE:
       type(ESMF_Calendar) :: ESMF_CalendarCreateCopy

ARGUMENTS:
       type(ESMF_Calendar), intent(in)            :: calendar
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,             intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Creates a complete (deep) copy of a given ESMF_Calendar.

The arguments are:

calendar
The ESMF_Calendar to copy.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 41.5.6 ESMF_CalendarCreate - Create a new custom ESMF Calendar

INTERFACE:

       ! Private name; call using ESMF_CalendarCreate()
function ESMF_CalendarCreateCustom(&
daysPerMonth, secondsPerDay, &
daysPerYear, daysPerYearDn, daysPerYearDd, name, rc)

RETURN VALUE:
       type(ESMF_Calendar) :: ESMF_CalendarCreateCustom

ARGUMENTS:
 -- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,               intent(in),  optional :: daysPerMonth(:)
integer(ESMF_KIND_I4), intent(in),  optional :: secondsPerDay
integer(ESMF_KIND_I4), intent(in),  optional :: daysPerYear
integer(ESMF_KIND_I4), intent(in),  optional :: daysPerYearDn
integer(ESMF_KIND_I4), intent(in),  optional :: daysPerYearDd
character (len=*),     intent(in),  optional :: name
integer,               intent(out), optional :: rc

DESCRIPTION:

Creates a custom ESMF_Calendar and sets its properties.

The arguments are:

[daysPerMonth]
Integer array of days per month, for each month of the year. The number of months per year is variable and taken from the size of the array. If unspecified, months per year = 0, with the days array undefined.
[secondsPerDay]
Integer number of seconds per day. Defaults to 0 if not specified.
[daysPerYear]
Integer number of days per year. Use with daysPerYearDn and daysPerYearDd (see below) to specify a days-per-year calendar for any planetary body. Default = 0.
[daysPerYearDn]
Integer numerator portion of fractional number of days per year (daysPerYearDn/daysPerYearDd). Use with daysPerYear (see above) and daysPerYearDd (see below) to specify a days-per-year calendar for any planetary body. Default = 0.
[daysPerYearDd]
Integer denominator portion of fractional number of days per year (daysPerYearDn/daysPerYearDd). Use with daysPerYear and daysPerYearDn (see above) to specify a days-per-year calendar for any planetary body. Default = 1.
[name]
The name for the newly created calendar. If not specified, a default unique name will be generated: "CalendarNNN" where NNN is a unique sequence number from 001 to 999.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 41.5.7 ESMF_CalendarDestroy - Release resources associated with a Calendar

INTERFACE:

       subroutine ESMF_CalendarDestroy(calendar, rc)

ARGUMENTS:
       type(ESMF_Calendar), intent(inout)          :: calendar
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,             intent(out),  optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Releases resources associated with this ESMF_Calendar.

The arguments are:

calendar
Release resources associated with this ESMF_Calendar and mark the object as invalid. It is an error to pass this object into any other routines after being destroyed.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 41.5.8 ESMF_CalendarGet - Get Calendar properties

INTERFACE:

       subroutine ESMF_CalendarGet(calendar, &
name, calkindflag, daysPerMonth, monthsPerYear, &
secondsPerDay, secondsPerYear, &
daysPerYear, daysPerYearDn, daysPerYearDd, rc)

ARGUMENTS:
       type(ESMF_Calendar),    intent(in)            :: calendar
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
type(ESMF_CalKind_Flag),intent(out), optional :: calkindflag
integer,                intent(out), optional :: daysPerMonth(:)
integer,                intent(out), optional :: monthsPerYear
integer(ESMF_KIND_I4),  intent(out), optional :: secondsPerDay
integer(ESMF_KIND_I4),  intent(out), optional :: secondsPerYear
integer(ESMF_KIND_I4),  intent(out), optional :: daysPerYear
integer(ESMF_KIND_I4),  intent(out), optional :: daysPerYearDn
integer(ESMF_KIND_I4),  intent(out), optional :: daysPerYearDd
character (len=*),      intent(out), optional :: name
integer,                intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Gets one or more of an ESMF_Calendar's properties.

The arguments are:

calendar
The object instance to query.
[calkindflag]
The CalKind_Flag ESMF_CALKIND_GREGORIAN, ESMF_CALKIND_JULIAN, etc.
[daysPerMonth]
Integer array of days per month, for each month of the year.
[monthsPerYear]
Integer number of months per year; the size of the daysPerMonth array.
[secondsPerDay]
Integer number of seconds per day.
[secondsPerYear]
Integer number of seconds per year.
[daysPerYear]
Integer number of days per year. For calendars with intercalations, daysPerYear is the number of days for years without an intercalation. For other calendars, it is the number of days in every year.
[daysPerYearDn]
Integer fractional number of days per year (numerator). For calendars with intercalations, daysPerYearDn/daysPerYearDd is the average fractional number of days per year (e.g. 25/100 for Julian 4-year intercalation). For other calendars, it is zero.
[daysPerYearDd]
Integer fractional number of days per year (denominator). See daysPerYearDn above.
[name]
The name of this calendar.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 41.5.9 ESMF_CalendarIsCreated - Check whether a Calendar object has been created

INTERFACE:

   function ESMF_CalendarIsCreated(calendar, rc)

RETURN VALUE:
     logical :: ESMF_CalendarIsCreated

ARGUMENTS:
     type(ESMF_Calendar), intent(in)            :: calendar
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,             intent(out), optional :: rc

DESCRIPTION:

Return .true. if the calendar has been created. Otherwise return .false.. If an error occurs, i.e. rc /= ESMF_SUCCESS is returned, the return value of the function will also be .false..

The arguments are:

calendar
ESMF_Calendar queried.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 41.5.10 ESMF_CalendarIsLeapYear - Determine if given year is a leap year

INTERFACE:

       ! Private name; call using ESMF_CalendarIsLeapYear()
function ESMF_CalendarIsLeapYear<kind>(calendar, yy, rc)

RETURN VALUE:
       logical :: ESMF_CalendarIsLeapYear<kind>

ARGUMENTS:
       type(ESMF_Calendar),       intent(in)            :: calendar
integer(ESMF_KIND_<kind>), intent(in)            :: yy
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,                   intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Returns .true. if the given year is a leap year within the given calendar, and .false. otherwise. Custom calendars do not define leap years, so .false. will always be returned in this case; see Section 41.4. See also ESMF_TimeIsLeapYear().

The arguments are:

calendar
ESMF_Calendar to determine leap year within.
yy
Year to check for leap year. The type is integer and the <kind> can be either I4 or I8: ESMF_KIND_I4 or ESMF_KIND_I8.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 41.5.11 ESMF_CalendarPrint - Print Calendar information

INTERFACE:

       subroutine ESMF_CalendarPrint(calendar, options, rc)

ARGUMENTS:
       type(ESMF_Calendar), intent(in)            :: calendar
character (len=*),   intent(in),  optional :: options
integer,             intent(out), optional :: rc

DESCRIPTION:

Prints out an ESMF_Calendar's properties to stdio, in support of testing and debugging. The options control the type of information and level of detail.

The arguments are:

calendar
ESMF_Calendar to be printed out.
[options]
Print options. If none specified, prints all calendar property values.
"calkindflag" - print the calendar's type (e.g. ESMF_CALKIND_GREGORIAN).
"daysPerMonth" - print the array of number of days for each month.
"daysPerYear" - print the number of days per year (integer and fractional parts).
"monthsPerYear" - print the number of months per year.
"name" - print the calendar's name.
"secondsPerDay" - print the number of seconds in a day.
"secondsPerYear" - print the number of seconds in a year.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 41.5.12 ESMF_CalendarSet - Set a Calendar to a built-in type

INTERFACE:

       ! Private name; call using ESMF_CalendarSet()
subroutine ESMF_CalendarSetBuiltIn(calendar, calkindflag, &
name, rc)

ARGUMENTS:
       type(ESMF_Calendar),     intent(inout)         :: calendar
type(ESMF_CalKind_Flag), intent(in)            :: calkindflag
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
character (len=*),       intent(in),  optional :: name
integer,                 intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Sets calendar to the given built-in ESMF_CalKind_Flag.

The arguments are:

calendar
The object instance to initialize.
calkindflag
The built-in CalKind_Flag. Valid values are:
ESMF_CALKIND_360DAY,
ESMF_CALKIND_GREGORIAN,
ESMF_CALKIND_JULIAN,
ESMF_CALKIND_JULIANDAY,
ESMF_CALKIND_MODJULIANDAY,
ESMF_CALKIND_NOCALENDAR,
and ESMF_CALKIND_NOLEAP.
See Section 41.2 for a description of each calendar kind.
[name]
The new name for this calendar.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 41.5.13 ESMF_CalendarSet - Set properties of a custom Calendar

INTERFACE:

       ! Private name; call using ESMF_CalendarSet()
subroutine ESMF_CalendarSetCustom(calendar, &
daysPerMonth, secondsPerDay, &
daysPerYear, daysPerYearDn, daysPerYearDd, name, rc)

ARGUMENTS:
       type(ESMF_Calendar),  intent(inout)         :: calendar
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,              intent(in),  optional :: daysPerMonth(:)
integer(ESMF_KIND_I4),intent(in),  optional :: secondsPerDay
integer(ESMF_KIND_I4),intent(in),  optional :: daysPerYear
integer(ESMF_KIND_I4),intent(in),  optional :: daysPerYearDn
integer(ESMF_KIND_I4),intent(in),  optional :: daysPerYearDd
character (len=*),    intent(in),  optional :: name
integer,              intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Sets properties in a custom ESMF_Calendar.

The arguments are:

calendar
The object instance to initialize.
[daysPerMonth]
Integer array of days per month, for each month of the year. The number of months per year is variable and taken from the size of the array. If unspecified, months per year = 0, with the days array undefined.
[secondsPerDay]
Integer number of seconds per day. Defaults to 0 if not specified.
[daysPerYear]
Integer number of days per year. Use with daysPerYearDn and daysPerYearDd (see below) to specify a days-per-year calendar for any planetary body. Default = 0.
[daysPerYearDn]
Integer numerator portion of fractional number of days per year (daysPerYearDn/daysPerYearDd). Use with daysPerYear (see above) and daysPerYearDd (see below) to specify a days-per-year calendar for any planetary body. Default = 0.
[daysPerYearDd]
Integer denominator portion of fractional number of days per year (daysPerYearDn/daysPerYearDd). Use with daysPerYear and daysPerYearDn (see above) to specify a days-per-year calendar for any planetary body. Default = 1.
[name]
The new name for this calendar.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 41.5.14 ESMF_CalendarSetDefault - Set the default Calendar kind

INTERFACE:

       ! Private name; call using ESMF_CalendarSetDefault()
subroutine ESMF_CalendarSetDefaultKind(calkindflag, rc)

ARGUMENTS:
       type(ESMF_CalKind_Flag), intent(in)            :: calkindflag
integer,                 intent(out), optional :: rc

DESCRIPTION:

Sets the default calendar to the given type. Subsequent Time Manager operations requiring a calendar where one isn't specified will use the internal calendar of this type.

The arguments are:

calkindflag
The calendar kind to be the default.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 41.5.15 ESMF_CalendarSetDefault - Set the default Calendar

INTERFACE:

       ! Private name; call using ESMF_CalendarSetDefault()
subroutine ESMF_CalendarSetDefaultCal(calendar, rc)

ARGUMENTS:
       type(ESMF_Calendar),     intent(in)            :: calendar
integer,                 intent(out), optional :: rc

DESCRIPTION:

Sets the default calendar to the one given. Subsequent Time Manager operations requiring a calendar where one isn't specified will use this calendar.

The arguments are:

calendar
The object instance to be the default.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 41.5.16 ESMF_CalendarValidate - Validate a Calendar's properties

INTERFACE:

       subroutine ESMF_CalendarValidate(calendar, rc)

ARGUMENTS:
       type(ESMF_Calendar), intent(in)            :: calendar
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,             intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Checks whether a calendar is valid. Must be one of the defined calendar kinds. daysPerMonth, daysPerYear, secondsPerDay must all be greater than or equal to zero.

The arguments are:

calendar
ESMF_Calendar to be validated.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

# 42 Time Class

## 42.1 Description

A Time represents a specific point in time. In order to accommodate the range of time scales in Earth system applications, Times in the ESMF can be specified in many different ways, from years to nanoseconds. The Time interface is designed so that you select one or more options from a list of time units in order to specify a Time. The options for specifying a Time are shown in Table 40.4.

There are Time methods defined for setting and getting a Time, incrementing and decrementing a Time by a TimeInterval, taking the difference between two Times, and comparing Times. Special quantities such as the middle of the month and the day of the year associated with a particular Time can be retrieved. There is a method for returning the Time value as a string in the ISO 8601 format YYYY-MM-DDThh:mm:ss [18].

A Time that is specified in hours, minutes, seconds, or subsecond intervals does not need to be associated with a standard calendar; a Time whose specification includes time units of a day and greater must be. The ESMF representation of a calendar, the Calendar class, is described in Section 41.1. The ESMF_TimeSet method is used to initialize a Time as well as associate it with a Calendar. If a Time method is invoked in which a Calendar is necessary and one has not been set, the ESMF method will return an error condition.

In the ESMF the TimeInterval class is used to represent time periods. This class is frequently used in combination with the Time class. The Clock class, for example, advances model time by incrementing a Time with a TimeInterval.

## 42.2 Use and Examples

Times are most frequently used to represent start, stop, and current model times. The following examples show how to create, initialize, and manipulate Time.

! !PROGRAM: ESMF_TimeEx - Time initialization and manipulation examples
!
! !DESCRIPTION:
!
! This program shows examples of Time initialization and manipulation
!-----------------------------------------------------------------------------
#include "ESMF.h"

! ESMF Framework module
use ESMF
use ESMF_TestMod
implicit none

! instantiate two times
type(ESMF_Time) :: time1, time2

type(ESMF_VM) :: vm

! instantiate a time interval
type(ESMF_TimeInterval) :: timeinterval1

! local variables for Get methods
integer :: YY, MM, DD, H, M, S

! return code
integer:: rc


      ! initialize ESMF framework
call ESMF_Initialize(vm=vm, defaultCalKind=ESMF_CALKIND_GREGORIAN, &
defaultlogfilename="TimeEx.Log", &
logkindflag=ESMF_LOGKIND_MULTI, rc=rc)


### 42.2.1 Time initialization

This example shows how to initialize an ESMF_Time.

      ! initialize time1 to 2/28/2000 2:24:45
call ESMF_TimeSet(time1, yy=2000, mm=2, dd=28, h=2, m=24, s=45, rc=rc)


      print *, "Time1 = "
call ESMF_TimePrint(time1, options="string", rc=rc)


### 42.2.2 Time increment

This example shows how to increment an ESMF_Time by an ESMF_TimeInterval.

      ! initialize a time interval to 2 days, 8 hours, 36 minutes, 15 seconds
call ESMF_TimeIntervalSet(timeinterval1, d=2, h=8, m=36, s=15, rc=rc)


      print *, "Timeinterval1 = "
call ESMF_TimeIntervalPrint(timeinterval1, options="string", rc=rc)


      ! increment time1 with timeinterval1
time2 = time1 + timeinterval1

call ESMF_TimeGet(time2, yy=YY, mm=MM, dd=DD, h=H, m=M, s=S, rc=rc)
print *, "time2 = time1 + timeinterval1 = ", YY, "/", MM, "/", DD, &
" ",  H, ":", M, ":", S


### 42.2.3 Time comparison

This example shows how to compare two ESMF_Times.

      if (time2 > time1) then
print *, "time2 is larger than time1"
else
print *, "time1 is smaller than or equal to time2"
endif


      ! finalize ESMF framework
call ESMF_Finalize(rc=rc)


      end program ESMF_TimeEx


## 42.3 Restrictions and Future Work

1. Limits on size and resolution of Time. The limits on the size and resolution of the time representation are based on the 64-bit integer types used. For seconds, a signed 64-bit integer will have a range of +/- -1, or +/- 9,223,372,036,854,775,807. This corresponds to a maximum size of +/- (-1)/(86400 * 365.25) or +/- 292,271,023,045 years.

For fractional seconds, a signed 64-bit integer will handle a resolution of +/- -1, or +/- 9,223,372,036,854,775,807 parts of a second.

## 42.4 Class API

### 42.4.1 ESMF_TimeAssignment(=) - Assign a Time to another Time

INTERFACE:

       interface assignment(=)
time1 = time2

ARGUMENTS:
       type(ESMF_Time) :: time1
type(ESMF_Time) :: time2

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Set time1 equal to time2. This is the default Fortran assignment, which creates a complete, independent copy of time2 as time1. If time2 is an invalid ESMF_Time object then time1 will be equally invalid after the assignment.

The arguments are:

time1
The ESMF_Time to be set.
time2
The ESMF_Time to be copied.

### 42.4.2 ESMF_TimeOperator(+) - Increment a Time by a TimeInterval

INTERFACE:

       interface operator(+)
time2 = time1 + timeinterval

RETURN VALUE:
       type(ESMF_Time) :: time2

ARGUMENTS:
       type(ESMF_Time),         intent(in) :: time1
type(ESMF_TimeInterval), intent(in) :: timeinterval

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Overloads the (+) operator for the ESMF_Time class to increment time1 with timeinterval and return the result as an ESMF_Time.

The arguments are:

time1
The ESMF_Time to increment.
timeinterval
The ESMF_TimeInterval to add to the given ESMF_Time.

### 42.4.3 ESMF_TimeOperator(-) - Decrement a Time by a TimeInterval

INTERFACE:

       interface operator(-)
time2 = time1 - timeinterval

RETURN VALUE:
       type(ESMF_Time) :: time2

ARGUMENTS:
       type(ESMF_Time),         intent(in) :: time1
type(ESMF_TimeInterval), intent(in) :: timeinterval

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Overloads the (-) operator for the ESMF_Time class to decrement time1 with timeinterval, and return the result as an ESMF_Time.

The arguments are:

time1
The ESMF_Time to decrement.
timeinterval
The ESMF_TimeInterval to subtract from the given ESMF_Time.

### 42.4.4 ESMF_TimeOperator(-) - Return the difference between two Times

INTERFACE:

       interface operator(-)
timeinterval = time1 - time2

RETURN VALUE:
       type(ESMF_TimeInterval) :: timeinterval

ARGUMENTS:
       type(ESMF_Time),         intent(in) :: time1
type(ESMF_Time),         intent(in) :: time2

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Overloads the (-) operator for the ESMF_Time class to return the difference between time1 and time2 as an ESMF_TimeInterval. It is assumed that time1 is later than time2; if not, the resulting ESMF_TimeInterval will have a negative value.

The arguments are:

time1
The first ESMF_Time in comparison.
time2
The second ESMF_Time in comparison.

### 42.4.5 ESMF_TimeOperator(==) - Test if Time 1 is equal to Time 2

INTERFACE:

       interface operator(==)
if (time1 == time2) then ... endif
OR
result = (time1 == time2)

RETURN VALUE:
       logical :: result

ARGUMENTS:
       type(ESMF_Time), intent(in) :: time1
type(ESMF_Time), intent(in) :: time2

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Overloads the (==) operator for the ESMF_Time class to return .true. if time1 and time2 represent the same instant in time, and .false. otherwise.

The arguments are:

time1
First ESMF_Time in comparison.
time2
Second ESMF_Time in comparison.

### 42.4.6 ESMF_TimeOperator(/=) - Test if Time 1 is not equal to Time 2

INTERFACE:

       interface operator(/=)
if (time1 /= time2) then ... endif
OR
result = (time1 /= time2)

RETURN VALUE:
       logical :: result

ARGUMENTS:
       type(ESMF_Time), intent(in) :: time1
type(ESMF_Time), intent(in) :: time2

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Overloads the (/=) operator for the ESMF_Time class to return .true. if time1 and time2 do not represent the same instant in time, and .false. otherwise.

The arguments are:

time1
First ESMF_Time in comparison.
time2
Second ESMF_Time in comparison.

### 42.4.7 ESMF_TimeOperator(<) - Test if Time 1 is less than Time 2

INTERFACE:

       interface operator(<)
if (time1 < time2) then ... endif
OR
result = (time1 < time2)

RETURN VALUE:
       logical :: result

ARGUMENTS:
       type(ESMF_Time), intent(in) :: time1
type(ESMF_Time), intent(in) :: time2

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Overloads the (<) operator for the ESMF_Time class to return .true. if time1 is earlier in time than time2, and .false. otherwise.

The arguments are:

time1
First ESMF_Time in comparison.
time2
Second ESMF_Time in comparison.

### 42.4.8 ESMF_TimeOperator(<=) - Test if Time 1 is less than or equal to Time 2

INTERFACE:

       interface operator(<=)
if (time1 <= time2) then ... endif
OR
result = (time1 <= time2)

RETURN VALUE:
       logical :: result

ARGUMENTS:
       type(ESMF_Time), intent(in) :: time1
type(ESMF_Time), intent(in) :: time2

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Overloads the (<=) operator for the ESMF_Time class to return .true. if time1 is earlier in time or the same time as time2, and .false. otherwise.

The arguments are:

time1
First ESMF_Time in comparison.
time2
Second ESMF_Time in comparison.

### 42.4.9 ESMF_TimeOperator(>) - Test if Time 1 is greater than Time 2

INTERFACE:

       interface operator(>)
if (time1 > time2) then ... endif
OR
result = (time1 > time2)

RETURN VALUE:
       logical :: result

ARGUMENTS:
       type(ESMF_Time), intent(in) :: time1
type(ESMF_Time), intent(in) :: time2

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Overloads the (>) operator for the ESMF_Time class to return .true. if time1 is later in time than time2, and .false. otherwise.

The arguments are:

time1
First ESMF_Time in comparison.
time2
Second ESMF_Time in comparison.

### 42.4.10 ESMF_TimeOperator(>=) - Test if Time 1 is greater than or equal to Time 2

INTERFACE:

       interface operator(>=)
if (time1 >= time2) then ... endif
OR
result = (time1 >= time2)

RETURN VALUE:
       logical :: result

ARGUMENTS:
       type(ESMF_Time), intent(in) :: time1
type(ESMF_Time), intent(in) :: time2

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Overloads the (>=) operator for the ESMF_Time class to return .true. if time1 is later in time or the same time as time2, and .false. otherwise.

The arguments are:

time1
First ESMF_Time in comparison.
time2
Second ESMF_Time in comparison.

### 42.4.11 ESMF_TimeGet - Get a Time value

INTERFACE:

       subroutine ESMF_TimeGet(time, &
yy, yy_i8, &
mm, dd, &
d, d_i8, &
h, m, &
s, s_i8, &
ms, us, ns, &
d_r8, h_r8, m_r8, s_r8, &
ms_r8, us_r8, ns_r8, &
sN, sN_i8, sD, sD_i8, &
calendar, calkindflag, timeZone, &
timeString, timeStringISOFrac, &
dayOfWeek, midMonth, &
dayOfYear,  dayOfYear_r8, &
dayOfYear_intvl, rc)

ARGUMENTS:
       type(ESMF_Time),         intent(in)            :: time
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer(ESMF_KIND_I4),   intent(out), optional :: yy
integer(ESMF_KIND_I8),   intent(out), optional :: yy_i8
integer,                 intent(out), optional :: mm
integer,                 intent(out), optional :: dd
integer(ESMF_KIND_I4),   intent(out), optional :: d
integer(ESMF_KIND_I8),   intent(out), optional :: d_i8
integer(ESMF_KIND_I4),   intent(out), optional :: h
integer(ESMF_KIND_I4),   intent(out), optional :: m
integer(ESMF_KIND_I4),   intent(out), optional :: s
integer(ESMF_KIND_I8),   intent(out), optional :: s_i8
integer(ESMF_KIND_I4),   intent(out), optional :: ms
integer(ESMF_KIND_I4),   intent(out), optional :: us
integer(ESMF_KIND_I4),   intent(out), optional :: ns
real(ESMF_KIND_R8),      intent(out), optional :: d_r8
real(ESMF_KIND_R8),      intent(out), optional :: h_r8
real(ESMF_KIND_R8),      intent(out), optional :: m_r8
real(ESMF_KIND_R8),      intent(out), optional :: s_r8
real(ESMF_KIND_R8),      intent(out), optional :: ms_r8
real(ESMF_KIND_R8),      intent(out), optional :: us_r8
real(ESMF_KIND_R8),      intent(out), optional :: ns_r8
integer(ESMF_KIND_I4),   intent(out), optional :: sN
integer(ESMF_KIND_I8),   intent(out), optional :: sN_i8
integer(ESMF_KIND_I4),   intent(out), optional :: sD
integer(ESMF_KIND_I8),   intent(out), optional :: sD_i8
type(ESMF_Calendar),     intent(out), optional :: calendar
type(ESMF_CalKind_Flag), intent(out), optional :: calkindflag
integer,                 intent(out), optional :: timeZone ! not imp
character (len=*),       intent(out), optional :: timeString
character (len=*),       intent(out), optional :: timeStringISOFrac
integer,                 intent(out), optional :: dayOfWeek
type(ESMF_Time),         intent(out), optional :: midMonth
integer(ESMF_KIND_I4),   intent(out), optional :: dayOfYear
real(ESMF_KIND_R8),      intent(out), optional :: dayOfYear_r8
type(ESMF_TimeInterval), intent(out), optional :: dayOfYear_intvl
integer,                 intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Gets the value of time in units specified by the user via Fortran optional arguments. See ESMF_TimeSet() above for a description of time units and calendars.

The ESMF Time Manager represents and manipulates time internally with integers to maintain precision. Hence, user-specified floating point values are converted internally from integers. For example, if a time value is 5 and 3/8 seconds (s=5, sN=3, sD=8), and you want to get it as floating point seconds, you would get 5.375 (s_r8=5.375).

Units are bound (normalized) by the next larger unit specified. For example, if a time is defined to be 2:00 am on February 2, 2004, then ESMF_TimeGet(dd=day, h=hours, s=seconds) would return day = 2, hours = 2, seconds = 0, whereas ESMF_TimeGet(dd = day, s=seconds) would return day = 2, seconds = 7200. Note that hours and seconds are bound by a day. If bound by a month, ESMF_TimeGet(mm=month, h=hours, s=seconds) would return month = 2, hours = 26, seconds = 0, and ESMF_TimeGet(mm = month, s=seconds) would return month = 2, seconds = 93600 (26 * 3600). Similarly, if bound to a year, ESMF_TimeGet(yy=year, h=hours, s=seconds) would return year = 2004, hours = 770 (32*24 + 2), seconds = 0, and ESMF_TimeGet(yy = year, s=seconds) would return year = 2004, seconds = 2772000 (770 * 3600).

For timeString, timeStringISOFrac, dayOfWeek, midMonth, dayOfYear, dayOfYear_intvl, and dayOfYear_r8 described below, valid calendars are Gregorian, Julian, No Leap, 360 Day and Custom calendars. Not valid for Julian Day, Modified Julian Day, or No Calendar.

For timeString and timeStringISOFrac, YYYY format returns at least 4 digits; years <= 999 are padded on the left with zeroes and years >= 10000 return the number of digits required.

For timeString, convert ESMF_Time's value into partial ISO 8601 format YYYY-MM-DDThh:mm:ss[:n/d]. See [18] and [5]. See also method ESMF_TimePrint().

For timeStringISOFrac, convert ESMF_Time's value into full ISO 8601 format YYYY-MM-DDThh:mm:ss[.f]. See [18] and [5]. See also method ESMF_TimePrint().

For dayOfWeek, gets the day of the week the given ESMF_Time instant falls on. ISO 8601 standard: Monday = 1 through Sunday = 7. See [18] and [5].

For midMonth, gets the middle time instant of the month that the given ESMF_Time instant falls on.

For dayOfYear, gets the day of the year that the given ESMF_Time instant falls on. See range discussion in argument list below. Return as an integer value.

For dayOfYear_r8, gets the day of the year the given ESMF_Time instant falls on. See range discussion in argument list below. Return as floating point value; fractional part represents the time of day.

For dayOfYear_intvl, gets the day of the year the given ESMF_Time instant falls on. Return as an ESMF_TimeInterval.

The arguments are:

time
The object instance to query.
[yy]
Integer year (32-bit).
[yy_i8]
Integer year (large, 64-bit).
[mm]
Integer month.
[dd]
Integer day of the month.
[d]
Integer Julian date, or Modified Julian date (32-bit).
[d_i8]
Integer Julian date, or Modified Julian date (large, 64-bit).
[h]
Integer hour.
[m]
Integer minute.
[s]
Integer second (32-bit).
[s_i8]
Integer second (large, 64-bit).
[ms]
Integer millisecond.
[us]
Integer microsecond.
[ns]
Integer nanosecond.
[d_r8]
Double precision day.
[h_r8]
Double precision hour.
[m_r8]
Double precision minute.
[s_r8]
Double precision second.
[ms_r8]
Double precision millisecond.
[us_r8]
Double precision microsecond.
[ns_r8]
Double precision nanosecond.
[sN]
Integer numerator of fractional second (sN/sD).
[sN_i8]
Integer numerator of fractional second (sN_i8/sD_i8) (large, <= 64-bit).
[sD]
Integer denominator of fractional second (sN/sD).
[sD_i8]
Integer denominator of fractional second (sN_i8/sD_i8) (large, <= 64-bit).
[calendar]
Associated Calendar.
[calkindflag]
Associated CalKind_Flag.
[timeZone]
Associated timezone (hours offset from UCT, e.g. EST = -5). (Not implemented yet).
[timeString]
Convert time value to format string YYYY-MM-DDThh:mm:ss[:n/d], where n/d is numerator/denominator of any fractional seconds and all other units are in ISO 8601 format. See [18] and  [5]. See also method ESMF_TimePrint().
[timeStringISOFrac]
Convert time value to strict ISO 8601 format string YYYY-MM-DDThh:mm:ss[.f], where f is decimal form of any fractional seconds. See [18] and [5]. See also method ESMF_TimePrint().
[dayOfWeek]
The time instant's day of the week [1-7].
[MidMonth]
The given time instant's middle-of-the-month time instant.
[dayOfYear]
The ESMF_Time instant's integer day of the year. [1-366] for Gregorian and Julian calendars, [1-365] for No-Leap calendar. [1-360] for 360-Day calendar. User-defined range for Custom calendar.
[dayOfYear_r8]
The ESMF_Time instant's floating point day of the year. [1.x-366.x] for Gregorian and Julian calendars, [1.x-365.x] for No-Leap calendar. [1.x-360.x] for 360-Day calendar. User-defined range for Custom calendar.
[dayOfYear_intvl]
The ESMF_Time instant's day of the year as an ESMF_TimeInterval.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 42.4.12 ESMF_TimeIsLeapYear - Determine if a Time is in a leap year

INTERFACE:

       function ESMF_TimeIsLeapYear(time, rc)

RETURN VALUE:
       logical :: ESMF_TimeIsLeapYear

ARGUMENTS:
       type(ESMF_Time), intent(in)            :: time
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,         intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Returns .true. if given time is in a leap year, and .false. otherwise. See also ESMF_CalendarIsLeapYear().

The arguments are:

time
The ESMF_Time to check for leap year.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 42.4.13 ESMF_TimeIsSameCalendar - Compare Calendars of two Times

INTERFACE:

       function ESMF_TimeIsSameCalendar(time1, time2, rc)

RETURN VALUE:
       logical :: ESMF_TimeIsSameCalendar

ARGUMENTS:
       type(ESMF_Time), intent(in)            :: time1
type(ESMF_Time), intent(in)            :: time2
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,         intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Returns .true. if the Calendars in these Times are the same, .false. otherwise.

The arguments are:

time1
The first ESMF_Time in comparison.
time2
The second ESMF_Time in comparison.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 42.4.14 ESMF_TimePrint - Print Time information

INTERFACE:

       subroutine ESMF_TimePrint(time, options, preString, unit, rc)

ARGUMENTS:
       type(ESMF_Time),   intent(in)            :: time
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
character (len=*), intent(in),  optional :: options
character(*),      intent(in),  optional :: preString
character(*),      intent(out), optional :: unit
integer,           intent(out), optional :: rc

DESCRIPTION:

Prints out the contents of an ESMF_Time to stdout, in support of testing and debugging. The options control the type of information and level of detail. For options "string" and "string isofrac", YYYY format returns at least 4 digits; years <= 999 are padded on the left with zeroes and years >= 10000 return the number of digits required.

The arguments are:

time
The ESMF_Time to be printed out.
[options]
Print options. If none specified, prints all Time property values.
"string" - prints time's value in ISO 8601 format for all units through seconds. For any non-zero fractional seconds, prints in integer rational fraction form n/d. Format is YYYY-MM-DDThh:mm:ss[:n/d], where [:n/d] is the integer numerator and denominator of the fractional seconds value, if present. See [18] and  [5]. See also method ESMF_TimeGet(..., timeString= , ...)
"string isofrac" - prints time's value in strict ISO 8601 format for all units, including any fractional seconds part. Format is YYYY-MM-DDThh:mm:ss[.f] where [.f] represents fractional seconds in decimal form, if present. See [18] and [5]. See also method ESMF_TimeGet(..., timeStringISOFrac= , ...)
[preString]
Optionally prepended string. Default to empty string.
[unit]
Internal unit, i.e. a string. Default to printing to stdout.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 42.4.15 ESMF_TimeSet - Initialize or set a Time

INTERFACE:

       subroutine ESMF_TimeSet(time, &
yy, yy_i8, &
mm, dd, &
d, d_i8, &
h, m, &
s, s_i8, &
ms, us, ns, &
d_r8, h_r8, m_r8, s_r8, &
ms_r8, us_r8, ns_r8, &
sN, sN_i8, sD, sD_i8, &
calendar, calkindflag, &
timeZone, rc)

ARGUMENTS:
       type(ESMF_Time),         intent(inout)         :: time
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer(ESMF_KIND_I4),   intent(in),  optional :: yy
integer(ESMF_KIND_I8),   intent(in),  optional :: yy_i8
integer,                 intent(in),  optional :: mm
integer,                 intent(in),  optional :: dd
integer(ESMF_KIND_I4),   intent(in),  optional :: d
integer(ESMF_KIND_I8),   intent(in),  optional :: d_i8
integer(ESMF_KIND_I4),   intent(in),  optional :: h
integer(ESMF_KIND_I4),   intent(in),  optional :: m
integer(ESMF_KIND_I4),   intent(in),  optional :: s
integer(ESMF_KIND_I8),   intent(in),  optional :: s_i8
integer(ESMF_KIND_I4),   intent(in),  optional :: ms
integer(ESMF_KIND_I4),   intent(in),  optional :: us
integer(ESMF_KIND_I4),   intent(in),  optional :: ns
real(ESMF_KIND_R8),      intent(in),  optional :: d_r8
real(ESMF_KIND_R8),      intent(in),  optional :: h_r8
real(ESMF_KIND_R8),      intent(in),  optional :: m_r8
real(ESMF_KIND_R8),      intent(in),  optional :: s_r8
real(ESMF_KIND_R8),      intent(in),  optional :: ms_r8
real(ESMF_KIND_R8),      intent(in),  optional :: us_r8
real(ESMF_KIND_R8),      intent(in),  optional :: ns_r8
integer(ESMF_KIND_I4),   intent(in),  optional :: sN
integer(ESMF_KIND_I8),   intent(in),  optional :: sN_i8
integer(ESMF_KIND_I4),   intent(in),  optional :: sD
integer(ESMF_KIND_I8),   intent(in),  optional :: sD_i8
type(ESMF_Calendar),     intent(in),  optional :: calendar
type(ESMF_CalKind_Flag), intent(in),  optional :: calkindflag
integer,                 intent(in),  optional :: timeZone ! not imp
integer,                 intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Initializes an ESMF_Time with a set of user-specified units via Fortran optional arguments.

The range of valid values for mm and dd depend on the calendar used. For Gregorian, Julian, and No-Leap calendars, mm is [1-12] and dd is [1-28,29,30, or 31], depending on the value of mm and whether yy or yy_i8 is a leap year. For the 360-day calendar, mm is [1-12] and dd is [1-30]. For Julian Day, Modified Julian Day, and No-Calendar, yy, yy_i8, mm, and dd are invalid inputs, since these calendars do not define them. When valid, the yy and yy_i8 arguments should be fully specified, e.g. 2003 instead of 03. yy and yy_i8 ranges are only limited by machine word size, except for the Gregorian and Julian calendars, where the lowest (proleptic) date limits are 3/1/-4800 and 3/1/-4712, respectively. This is a limitation of the Gregorian date-to-Julian day and Julian date-to-Julian day conversion algorithms used to convert Gregorian and Julian dates to the internal representation of seconds. See [14] for a description of the Gregorian date-to-Julian day algorithm and [17] for a description of the Julian date-to-Julian day algorithm. The Custom calendar will have user-defined values for yy, yy_i8, mm, and dd.

The Julian day specifier, d or d_i8, can only be used with the Julian Day and Modified Julian Day calendars, and has a valid range depending on the word size. For a signed 32-bit d, the range for Julian day is [+/- 24855]. For a signed 64-bit d_i8, the valid range for Julian day is [+/- 106,751,991,167,300]. The Julian day number system adheres to the conventional standard where the reference day of d=0 corresponds to 11/24/-4713 in the proleptic Gregorian calendar and 1/1/-4712 in the proleptic Julian calendar. See [22] and  [1].

The Modified Julian Day system, introduced by space scientists in the late 1950's, is defined as Julian Day - 2400000.5. See [27].

Note that d and d_i8 are not valid for the No-Calendar. To remain consistent with non-Earth calendars added to ESMF in the future, ESMF requires a calendar to be planet-specific. Hence the No-Calendar does not know what a day is; it cannot assume an Earth day of 86400 seconds.

Hours, minutes, seconds, and sub-seconds can be used with any calendar, since they are standardized units that are the same for any planet.

Time manager represents and manipulates time internally with integers to maintain precision. Hence, user-specified floating point values are converted internally to integers. Sub-second values are represented internally with an integer numerator and denominator fraction (sN/sD). The smallest required resolution is nanoseconds (denominator). For example, pi can be represented as s=3, sN=141592654, sD=1000000000. However, via sN_i8 and sD_i8, larger values can be used. If specifying a constant floating point value, be sure to provide at least 16 digits to take full advantage of double precision, for example s_r8=2.718281828459045d0 for 'e' seconds.

The arguments are:

time
The object instance to initialize.
[yy]
Integer year (32-bit). Default = 0.
[yy_i8]
Integer year (large, 64-bit). Default = 0.
[mm]
Integer month. Default = 1.
[dd]
Integer day of the month. Default = 1.
[d]
Integer Julian Day, or Modified Julian Day (32-bit). Must not be specified with Gregorian calendars. Default = 0.
[d_i8]
Integer Julian Day, or Modified Julian Day (large, 64-bit). Must not be specified with Gregorian calendars. Default = 0.
[h]
Integer hour. Default = 0.
[m]
Integer minute. Default = 0.
[s]
Integer second (32-bit). Default = 0.
[s_i8]
Integer second (large, 64-bit). Default = 0.
[ms]
Integer millisecond. Default = 0.
[us]
Integer microsecond. Default = 0.
[ns]
Integer nanosecond. Default = 0.
[d_r8]
Double precision day. Default = 0.0.
[h_r8]
Double precision hour. Default = 0.0.
[m_r8]
Double precision minute. Default = 0.0.
[s_r8]
Double precision second. Default = 0.0.
[ms_r8]
Double precision millisecond. Default = 0.0.
[us_r8]
Double precision microsecond. Default = 0.0.
[ns_r8]
Double precision nanosecond. Default = 0.0.
[sN]
Integer numerator of fractional second (sN/sD). Default = 0.
[sN_i8]
Integer numerator of fractional second (sN_i8/sD_i8) (large, 64-bit). Default = 0.
[sD]
Integer denominator of fractional second (sN/sD). Default = 1.
[sD_i8]
Integer denominator of fractional second (sN_i8/sD_i8) (large, 64-bit). Default = 1.
[calendar]
Associated Calendar. Defaults to calendar ESMF_CALKIND_NOCALENDAR or default specified in ESMF_Initialize() or ESMF_CalendarSetDefault(). Alternate to, and mutually exclusive with, calkindflag below. Primarily for specifying a custom calendar kind.
[calkindflag]
Alternate to, and mutually exclusive with, calendar above. More convenient way of specifying a built-in calendar kind.
[timeZone]
Associated timezone (hours offset from UTC, e.g. EST = -5). Default = 0 (UTC). (Not implemented yet).
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 42.4.16 ESMF_TimeSyncToRealTime - Get system real time (wall clock time)

INTERFACE:

       subroutine ESMF_TimeSyncToRealTime(time, rc)

ARGUMENTS:
       type(ESMF_Time), intent(inout) :: time
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer, intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Gets the system real time (wall clock time), and returns it as an ESMF_Time. Accurate to the nearest second.

The arguments are:

time
The object instance to receive the real time.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 42.4.17 ESMF_TimeValidate - Validate a Time

INTERFACE:

       subroutine ESMF_TimeValidate(time, options, rc)

ARGUMENTS:
       type(ESMF_Time),   intent(in)            :: time
character (len=*), intent(in),  optional :: options
integer,           intent(out), optional :: rc

DESCRIPTION:

Checks whether an ESMF_Time is valid. Must be a valid date/time on a valid calendar. The options control the type of validation.

The arguments are:

time
ESMF_Time instant to be validated.
[options]
Validation options. If none specified, validates all time property values.
"calendar" - validate only the time's calendar.
"timezone" - validate only the time's timezone.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

# 43 TimeInterval Class

## 43.1 Description

A TimeInterval represents a period between time instants. It can be either positive or negative. Like the Time interface, the TimeInterval interface is designed so that you can choose one or more options from a list of time units in order to specify a TimeInterval. See Section 40.3, Table 40.4 for the available options.

There are TimeInterval methods defined for setting and getting a TimeInterval, for incrementing and decrementing a TimeInterval by another TimeInterval, and for multiplying and dividing TimeIntervals by integers, reals, fractions and other TimeIntervals. Methods are also defined to take the absolute value and negative absolute value of a TimeInterval, and for comparing the length of two TimeIntervals.

The class used to represent time instants in ESMF is Time, and this class is frequently used in operations along with TimeIntervals. For example, the difference between two Times is a TimeInterval.

When a TimeInterval is used in calculations that involve an absolute reference time, such as incrementing a Time with a TimeInterval, calendar dependencies may be introduced. The length of the time period that the TimeInterval represents will depend on the reference Time and the standard calendar that is associated with it. The calendar dependency becomes apparent when, for example, adding a TimeInterval of 1 day to the Time of February 28, 1996, at 4:00pm EST. In a 360 day calendar, the resulting date would be February 29, 1996, at 4:00pm EST. In a no-leap calendar, the result would be March 1, 1996, at 4:00pm EST.

TimeIntervals are used by other parts of the ESMF timekeeping system, such as Clocks (Section 44.1) and Alarms (Section 45.1).

## 43.2 Use and Examples

A typical use for a TimeInterval in a geophysical model is representation of the time step by which the model is advanced. Some models change the size of their time step as the model run progresses; this could be done by incrementing or decrementing the original time step by another TimeInterval, or by dividing or multiplying the time step by an integer value. An example of advancing model time using a TimeInterval representation of a time step is shown in Section 44.1.

The following brief example shows how to create, initialize and manipulate TimeInterval.

! !PROGRAM: ESMF_TimeIntervalEx - Time Interval initialization and
!                                 manipulation examples
!
! !DESCRIPTION:
!
! This program shows examples of Time Interval initialization and manipulation
!-----------------------------------------------------------------------------
#include "ESMF.h"

! ESMF Framework module
use ESMF
use ESMF_TestMod
implicit none

! instantiate some time intervals
type(ESMF_TimeInterval) :: timeinterval1, timeinterval2, timeinterval3

! local variables
integer :: d, h, m, s

! return code
integer:: rc


      ! initialize ESMF framework
call ESMF_Initialize(defaultCalKind=ESMF_CALKIND_GREGORIAN, &
defaultlogfilename="TimeIntervalEx.Log", &
logkindflag=ESMF_LOGKIND_MULTI, rc=rc)


### 43.2.1 TimeInterval initialization

This example shows how to initialize two ESMF_TimeIntervals.

      ! initialize time interval1 to 1 day
call ESMF_TimeIntervalSet(timeinterval1, d=1, rc=rc)


      call ESMF_TimeIntervalPrint(timeinterval1, options="string", rc=rc)


      ! initialize time interval2 to 4 days, 1 hour, 30 minutes, 10 seconds
call ESMF_TimeIntervalSet(timeinterval2, d=4, h=1, m=30, s=10, rc=rc)


      call ESMF_TimeIntervalPrint(timeinterval2, options="string", rc=rc)


### 43.2.2 TimeInterval conversion

This example shows how to convert ESMF_TimeIntervals into different units.

      call ESMF_TimeIntervalGet(timeinterval1, s=s, rc=rc)
print *, "Time Interval1 = ", s, " seconds."


      call ESMF_TimeIntervalGet(timeinterval2, h=h, m=m, s=s, rc=rc)
print *, "Time Interval2 = ", h, " hours, ", m, " minutes, ", &
s, " seconds."


### 43.2.3 TimeInterval difference

This example shows how to calculate the difference between two ESMF_TimeIntervals.

      ! difference between two time intervals
timeinterval3 = timeinterval2 - timeinterval1
call ESMF_TimeIntervalGet(timeinterval3, d=d, h=h, m=m, s=s, rc=rc)
print *, "Difference between TimeInterval2 and TimeInterval1 = ", &
d, " days, ", h, " hours, ", m, " minutes, ", s, " seconds."


### 43.2.4 TimeInterval multiplication

This example shows how to multiply an ESMF_TimeInterval.

      ! multiply time interval by an integer
timeinterval3 = timeinterval2 * 3
call ESMF_TimeIntervalGet(timeinterval3, d=d, h=h, m=m, s=s, rc=rc)
print *, "TimeInterval2 multiplied by 3 = ", d, " days, ", h, &
" hours, ", m, " minutes, ", s, " seconds."


### 43.2.5 TimeInterval comparison

This example shows how to compare two ESMF_TimeIntervals.

      ! comparison
if (timeinterval1 < timeinterval2) then
print *, "TimeInterval1 is smaller than TimeInterval2"
else
print *, "TimeInterval1 is larger than or equal to TimeInterval2"
end if


      end program ESMF_TimeIntervalEx


## 43.3 Restrictions and Future Work

1. Limits on time span. The limits on the time span that can be represented are based on the 64-bit integer types used. For seconds, a signed 64-bit integer will have a range of +/- -1, or +/- 9,223,372,036,854,775,807. This corresponds to a range of +/- (-1)/(86400 * 365.25) or +/- 292,271,023,045 years.

For fractional seconds, a signed 64-bit integer will handle a resolution of +/- -1, or +/- 9,223,372,036,854,775,807 parts of a second.

## 43.4 Class API

### 43.4.1 ESMF_TimeIntervalAssignment(=) - Assign a TimeInterval to another TimeInterval

INTERFACE:

       interface assignment(=)
timeinterval1 = timeinterval2

ARGUMENTS:
       type(ESMF_TimeInterval) :: timeinterval1
type(ESMF_TimeInterval) :: timeinterval2

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Set timeinterval1 equal to timeinterval2. This is the default Fortran assignment, which creates a complete, independent copy of timeinterval2 as timeinterval1. If timeinterval2 is an invalid ESMF_TimeInterval object then timeinterval1 will be equally invalid after the assignment.

The arguments are:

timeinterval1
The ESMF_TimeInterval to be set.
timeinterval2
The ESMF_TimeInterval to be copied.

### 43.4.2 ESMF_TimeIntervalOperator(+) - Add two TimeIntervals

INTERFACE:

       interface operator(+)
sum = timeinterval1 + timeinterval2

RETURN VALUE:
       type(ESMF_TimeInterval) :: sum

ARGUMENTS:
       type(ESMF_TimeInterval), intent(in) :: timeinterval1
type(ESMF_TimeInterval), intent(in) :: timeinterval2

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Overloads the (+) operator for the ESMF_TimeInterval class to add timeinterval1 to timeinterval2 and return the sum as an ESMF_TimeInterval.

The arguments are:

timeinterval1
The augend.
timeinterval2

### 43.4.3 ESMF_TimeIntervalOperator(-) - Subtract one TimeInterval from another

INTERFACE:

       interface operator(-)
difference = timeinterval1 - timeinterval2

RETURN VALUE:
       type(ESMF_TimeInterval) :: difference

ARGUMENTS:
       type(ESMF_TimeInterval), intent(in) :: timeinterval1
type(ESMF_TimeInterval), intent(in) :: timeinterval2

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Overloads the (-) operator for the ESMF_TimeInterval class to subtract timeinterval2 from timeinterval1 and return the difference as an ESMF_TimeInterval.

The arguments are:

timeinterval1
The minuend.
timeinterval2
The subtrahend.

### 43.4.4 ESMF_TimeIntervalOperator(-) - Perform unary negation on a TimeInterval

INTERFACE:

       interface operator(-)
timeinterval = -timeinterval

RETURN VALUE:
       type(ESMF_TimeInterval) :: -timeInterval

ARGUMENTS:
       type(ESMF_TimeInterval), intent(in) :: timeinterval

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Overloads the (-) operator for the ESMF_TimeInterval class to perform unary negation on timeinterval and return the result.

The arguments are:

timeinterval
The time interval to be negated.

### 43.4.5 ESMF_TimeIntervalOperator(/) - Divide two TimeIntervals, return double precision quotient

INTERFACE:

       interface operator(/)
quotient = timeinterval1 / timeinterval2

RETURN VALUE:
       real(ESMF_KIND_R8) :: quotient

ARGUMENTS:
       type(ESMF_TimeInterval), intent(in) :: timeinterval1
type(ESMF_TimeInterval), intent(in) :: timeinterval2

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Overloads the (/) operator for the ESMF_TimeInterval class to return timeinterval1 divided by timeinterval2 as a double precision quotient.

The arguments are:

timeinterval1
The dividend.
timeinterval2
The divisor.

### 43.4.6 ESMF_TimeIntervalOperator(/) - Divide a TimeInterval by an integer, return TimeInterval quotient

INTERFACE:

       interface operator(/)
quotient = timeinterval / divisor

RETURN VALUE:
       type(ESMF_TimeInterval) :: quotient

ARGUMENTS:
       type(ESMF_TimeInterval), intent(in) :: timeinterval
integer(ESMF_KIND_I4),   intent(in) :: divisor

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Overloads the (/) operator for the ESMF_TimeInterval class to divide a timeinterval by an integer divisor, and return the quotient as an ESMF_TimeInterval.

The arguments are:

timeinterval
The dividend.
divisor
Integer divisor.

### 43.4.7 ESMF_TimeIntervalFunction(MOD) - Divide two TimeIntervals, return TimeInterval remainder

INTERFACE:

       interface MOD
function MOD(timeinterval1, timeinterval2)

RETURN VALUE:
       type(ESMF_TimeInterval) :: MOD

ARGUMENTS:
       type(ESMF_TimeInterval), intent(in) :: timeinterval1
type(ESMF_TimeInterval), intent(in) :: timeinterval2

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Overloads the Fortran intrinsic MOD() function for the ESMF_TimeInterval class to return the remainder of timeinterval1 divided by timeinterval2 as an ESMF_TimeInterval.

The arguments are:

timeinterval1
The dividend.
timeinterval2
The divisor.

### 43.4.8 ESMF_TimeIntervalOperator(*) - Multiply a TimeInterval by an integer

INTERFACE:

       interface operator(*)
product = timeinterval * multiplier
OR
product = multiplier * timeinterval

RETURN VALUE:
       type(ESMF_TimeInterval) :: product

ARGUMENTS:
       type(ESMF_TimeInterval), intent(in) :: timeinterval
integer(ESMF_KIND_I4),   intent(in) :: multiplier

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Overloads the (*) operator for the ESMF_TimeInterval class to multiply a timeinterval by an integer multiplier, and return the product as an ESMF_TimeInterval.

The arguments are:

timeinterval
The multiplicand.
multiplier
The integer multiplier.

### 43.4.9 ESMF_TimeIntervalOperator(==) - Test if TimeInterval 1 is equal to TimeInterval 2

INTERFACE:

       interface operator(==)
if (timeinterval1 == timeinterval2) then ... endif
OR
result = (timeinterval1 == timeinterval2)

RETURN VALUE:
       logical :: result

ARGUMENTS:
       type(ESMF_TimeInterval), intent(in) :: timeinterval1
type(ESMF_TimeInterval), intent(in) :: timeinterval2

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Overloads the (==) operator for the ESMF_TimeInterval class to return .true. if timeinterval1 and timeinterval2 represent an equal duration of time, and .false. otherwise.

The arguments are:

timeinterval1
First ESMF_TimeInterval in comparison.
timeinterval2
Second ESMF_TimeInterval in comparison.

### 43.4.10 ESMF_TimeIntervalOperator(/=) - Test if TimeInterval 1 is not equal to TimeInterval 2

INTERFACE:

       interface operator(/=)
if (timeinterval1 /= timeinterval2) then ... endif
OR
result = (timeinterval1 /= timeinterval2)

RETURN VALUE:
       logical :: result

ARGUMENTS:
       type(ESMF_TimeInterval), intent(in) :: timeinterval1
type(ESMF_TimeInterval), intent(in) :: timeinterval2

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Overloads the (/=) operator for the ESMF_TimeInterval class to return .true. if timeinterval1 and timeinterval2 do not represent an equal duration of time, and .false. otherwise.

The arguments are:

timeinterval1
First ESMF_TimeInterval in comparison.
timeinterval2
Second ESMF_TimeInterval in comparison.

### 43.4.11 ESMF_TimeIntervalOperator(<) - Test if TimeInterval 1 is less than TimeInterval 2

INTERFACE:

       interface operator(<)
if (timeinterval1 < timeinterval2) then ... endif
OR
result = (timeinterval1 < timeinterval2)

RETURN VALUE:
       logical :: result

ARGUMENTS:
       type(ESMF_TimeInterval), intent(in) :: timeinterval1
type(ESMF_TimeInterval), intent(in) :: timeinterval2

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Overloads the (<) operator for the ESMF_TimeInterval class to return .true. if timeinterval1 is a lesser duration of time than timeinterval2, and .false. otherwise.

The arguments are:

timeinterval1
First ESMF_TimeInterval in comparison.
timeinterval2
Second ESMF_TimeInterval in comparison.

### 43.4.12 ESMF_TimeIntervalOperator(<=) - Test if TimeInterval 1 is less than or equal to TimeInterval 2

INTERFACE:

       interface operator(<=)
if (timeinterval1 <= timeinterval2) then ... endif
OR
result = (timeinterval1 <= timeinterval2)

RETURN VALUE:
       logical :: result

ARGUMENTS:
       type(ESMF_TimeInterval), intent(in) :: timeinterval1
type(ESMF_TimeInterval), intent(in) :: timeinterval2

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Overloads the (<=) operator for the ESMF_TimeInterval class to return .true. if timeinterval1 is a lesser or equal duration of time than timeinterval2, and .false. otherwise.

The arguments are:

timeinterval1
First ESMF_TimeInterval in comparison.
timeinterval2
Second ESMF_TimeInterval in comparison.

### 43.4.13 ESMF_TimeIntervalOperator(>) - Test if TimeInterval 1 is greater than TimeInterval 2

INTERFACE:

       interface operator(>)
if (timeinterval1 > timeinterval2) then ... endif
OR
result = (timeinterval1 > timeinterval2)

RETURN VALUE:
       logical :: result

ARGUMENTS:
       type(ESMF_TimeInterval), intent(in) :: timeinterval1
type(ESMF_TimeInterval), intent(in) :: timeinterval2

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Overloads the (>) operator for the ESMF_TimeInterval class to return .true. if timeinterval1 is a greater duration of time than timeinterval2, and .false. otherwise.

The arguments are:

timeinterval1
First ESMF_TimeInterval in comparison.
timeinterval2
Second ESMF_TimeInterval in comparison.

### 43.4.14 ESMF_TimeIntervalOperator(>=) - Test if TimeInterval 1 is greater than or equal to TimeInterval 2

INTERFACE:

       interface operator(>=)
if (timeinterval1 >= timeinterval2) then ... endif
OR
result = (timeinterval1 >= timeinterval2)

RETURN VALUE:
       logical :: result

ARGUMENTS:
       type(ESMF_TimeInterval), intent(in) :: timeinterval1
type(ESMF_TimeInterval), intent(in) :: timeinterval2

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Overloads the (>=) operator for the ESMF_TimeInterval class to return .true. if timeinterval1 is a greater or equal duration of time than timeinterval2, and .false. otherwise.

The arguments are:

timeinterval1
First ESMF_TimeInterval in comparison.
timeinterval2
Second ESMF_TimeInterval in comparison.

### 43.4.15 ESMF_TimeIntervalAbsValue - Get the absolute value of a TimeInterval

INTERFACE:

       function ESMF_TimeIntervalAbsValue(timeinterval)

RETURN VALUE:
       type(ESMF_TimeInterval) :: ESMF_TimeIntervalAbsValue

ARGUMENTS:
       type(ESMF_TimeInterval), intent(in) :: timeinterval

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Returns the absolute value of timeinterval.

The argument is:

timeinterval
The object instance to take the absolute value of. Absolute value is returned as the value of the function.

### 43.4.16 ESMF_TimeIntervalGet - Get a TimeInterval value

INTERFACE:

       ! Private name; call using ESMF_TimeIntervalGet()
subroutine ESMF_TimeIntervalGetDur(timeinterval, &
yy, yy_i8, &
mm, mm_i8, &
d, d_i8, &
h, m, &
s, s_i8, &
ms, us, ns, &
d_r8, h_r8, m_r8, s_r8, &
ms_r8, us_r8, ns_r8, &
sN, sN_i8, sD, sD_i8, &
startTime, calendar, calkindflag, &
timeString, timeStringISOFrac, rc)

ARGUMENTS:
       type(ESMF_TimeInterval), intent(in)            :: timeinterval
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer(ESMF_KIND_I4),   intent(out), optional :: yy
integer(ESMF_KIND_I8),   intent(out), optional :: yy_i8
integer(ESMF_KIND_I4),   intent(out), optional :: mm
integer(ESMF_KIND_I8),   intent(out), optional :: mm_i8
integer(ESMF_KIND_I4),   intent(out), optional :: d
integer(ESMF_KIND_I8),   intent(out), optional :: d_i8
integer(ESMF_KIND_I4),   intent(out), optional :: h
integer(ESMF_KIND_I4),   intent(out), optional :: m
integer(ESMF_KIND_I4),   intent(out), optional :: s
integer(ESMF_KIND_I8),   intent(out), optional :: s_i8
integer(ESMF_KIND_I4),   intent(out), optional :: ms
integer(ESMF_KIND_I4),   intent(out), optional :: us
integer(ESMF_KIND_I4),   intent(out), optional :: ns
real(ESMF_KIND_R8),      intent(out), optional :: d_r8
real(ESMF_KIND_R8),      intent(out), optional :: h_r8
real(ESMF_KIND_R8),      intent(out), optional :: m_r8
real(ESMF_KIND_R8),      intent(out), optional :: s_r8
real(ESMF_KIND_R8),      intent(out), optional :: ms_r8
real(ESMF_KIND_R8),      intent(out), optional :: us_r8
real(ESMF_KIND_R8),      intent(out), optional :: ns_r8
integer(ESMF_KIND_I4),   intent(out), optional :: sN
integer(ESMF_KIND_I8),   intent(out), optional :: sN_i8
integer(ESMF_KIND_I4),   intent(out), optional :: sD
integer(ESMF_KIND_I8),   intent(out), optional :: sD_i8
type(ESMF_Time),         intent(out), optional :: startTime
type(ESMF_Calendar),     intent(out), optional :: calendar
type(ESMF_CalKind_Flag), intent(out), optional :: calkindflag
character (len=*),       intent(out), optional :: timeString
character (len=*),       intent(out), optional :: timeStringISOFrac
integer,                 intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Gets the value of timeinterval in units specified by the user via Fortran optional arguments.

The ESMF Time Manager represents and manipulates time internally with integers to maintain precision. Hence, user-specified floating point values are converted internally from integers.

Units are bound (normalized) to the next larger unit specified. For example, if a time interval is defined to be one day, then ESMF_TimeIntervalGet(d = days, s = seconds) would return days = 1, seconds = 0, whereas ESMF_TimeIntervalGet(s = seconds) would return seconds = 86400.

For timeString, converts ESMF_TimeInterval's value into partial ISO 8601 format PyYmMdDThHmMs[:n/d]S. See [18] and  [5]. See also method ESMF_TimeIntervalPrint().

For timeStringISOFrac, converts ESMF_TimeInterval's value into full ISO 8601 format PyYmMdDThHmMs[.f]S. See [18] and  [5]. See also method ESMF_TimeIntervalPrint().

The arguments are:

timeinterval
The object instance to query.
[yy]
Integer year (32-bit).
[yy_i8]
Integer year (large, 64-bit).
[mm]
Integer month (32-bit).
[mm_i8]
Integer month (large, 64-bit).
[d]
Integer Julian day, or Modified Julian day (32-bit).
[d_i8]
Integer Julian day, or Modified Julian day (large, 64-bit).
[h]
Integer hour.
[m]
Integer minute.
[s]
Integer second (32-bit).
[s_i8]
Integer second (large, 64-bit).
[ms]
Integer millisecond.
[us]
Integer microsecond.
[ns]
Integer nanosecond.
[d_r8]
Double precision day.
[h_r8]
Double precision hour.
[m_r8]
Double precision minute.
[s_r8]
Double precision second.
[ms_r8]
Double precision millisecond.
[us_r8]
Double precision microsecond.
[ns_r8]
Double precision nanosecond.
[sN]
Integer numerator of fractional second (sN/sD).
[sN_i8]
Integer numerator of fractional second (sN_i8/sD_i8) (large, 64-bit).
[sD]
Integer denominator of fractional second (sN/sD).
[sD_i8]
Integer denominator of fractional second (sN_i8/sD_i8) (large, 64-bit).
[startTime]
Starting time, if set, of an absolute calendar interval (yy, mm, and/or d).
[calendar]
Associated Calendar, if any.
[calkindflag]
Associated CalKind_Flag, if any.
[timeString]
Convert time interval value to format string PyYmMdDThHmMs[:n/d]S, where n/d is numerator/denominator of any fractional seconds and all other units are in ISO 8601 format. See [18] and  [5]. See also method ESMF_TimeIntervalPrint().
[timeStringISOFrac]
Convert time interval value to strict ISO 8601 format string PyYmMdDThHmMs[.f], where f is decimal form of any fractional seconds. See [18] and [5]. See also method ESMF_TimeIntervalPrint().
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 43.4.17 ESMF_TimeIntervalGet - Get a TimeInterval value

INTERFACE:

       ! Private name; call using ESMF_TimeIntervalGet()
subroutine ESMF_TimeIntervalGetDurStart(timeinterval, startTimeIn, &
&
yy, yy_i8, &
mm, mm_i8, &
d, d_i8, &
h, m, &
s, s_i8, &
ms, us, ns, &
d_r8, h_r8, m_r8, s_r8, &
ms_r8, us_r8, ns_r8, &
sN, sN_i8, sD, sD_i8, &
startTime, &
calendar, calkindflag, &
timeString, timeStringISOFrac, rc)

ARGUMENTS:
       type(ESMF_TimeInterval), intent(in)            :: timeinterval
type(ESMF_Time),         intent(in)            :: startTimeIn ! Input
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer(ESMF_KIND_I4),   intent(out), optional :: yy
integer(ESMF_KIND_I8),   intent(out), optional :: yy_i8
integer(ESMF_KIND_I4),   intent(out), optional :: mm
integer(ESMF_KIND_I8),   intent(out), optional :: mm_i8
integer(ESMF_KIND_I4),   intent(out), optional :: d
integer(ESMF_KIND_I8),   intent(out), optional :: d_i8
integer(ESMF_KIND_I4),   intent(out), optional :: h
integer(ESMF_KIND_I4),   intent(out), optional :: m
integer(ESMF_KIND_I4),   intent(out), optional :: s
integer(ESMF_KIND_I8),   intent(out), optional :: s_i8
integer(ESMF_KIND_I4),   intent(out), optional :: ms
integer(ESMF_KIND_I4),   intent(out), optional :: us
integer(ESMF_KIND_I4),   intent(out), optional :: ns
real(ESMF_KIND_R8),      intent(out), optional :: d_r8
real(ESMF_KIND_R8),      intent(out), optional :: h_r8
real(ESMF_KIND_R8),      intent(out), optional :: m_r8
real(ESMF_KIND_R8),      intent(out), optional :: s_r8
real(ESMF_KIND_R8),      intent(out), optional :: ms_r8
real(ESMF_KIND_R8),      intent(out), optional :: us_r8
real(ESMF_KIND_R8),      intent(out), optional :: ns_r8
integer(ESMF_KIND_I4),   intent(out), optional :: sN
integer(ESMF_KIND_I8),   intent(out), optional :: sN_i8
integer(ESMF_KIND_I4),   intent(out), optional :: sD
integer(ESMF_KIND_I8),   intent(out), optional :: sD_i8
type(ESMF_Time),         intent(out), optional :: startTime
type(ESMF_Calendar),     intent(out), optional :: calendar
type(ESMF_CalKind_Flag), intent(out), optional :: calkindflag
character (len=*),       intent(out), optional :: timeString
character (len=*),       intent(out), optional :: timeStringISOFrac
integer,                 intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Gets the value of timeinterval in units specified by the user via Fortran optional arguments.

The ESMF Time Manager represents and manipulates time internally with integers to maintain precision. Hence, user-specified floating point values are converted internally from integers.

Units are bound (normalized) to the next larger unit specified. For example, if a time interval is defined to be one day, then ESMF_TimeIntervalGet(d = days, s = seconds) would return days = 1, seconds = 0, whereas ESMF_TimeIntervalGet(s = seconds) would return seconds = 86400.

For timeString, converts ESMF_TimeInterval's value into partial ISO 8601 format PyYmMdDThHmMs[:n/d]S. See [18] and  [5]. See also method ESMF_TimeIntervalPrint().

For timeStringISOFrac, converts ESMF_TimeInterval's value into full ISO 8601 format PyYmMdDThHmMs[.f]S. See [18] and  [5]. See also method ESMF_TimeIntervalPrint().

The arguments are:

timeinterval
The object instance to query.
startTimeIn
INPUT argument: pins a calendar interval to a specific point in time to allow conversion between relative units (yy, mm, d) and absolute units (d, h, m, s). Overrides any startTime and/or endTime previously set. Mutually exclusive with endTimeIn and calendarIn.
[yy]
Integer year (32-bit).
[yy_i8]
Integer year (large, 64-bit).
[mm]
Integer month (32-bit).
[mm_i8]
Integer month (large, 64-bit).
[d]
Integer Julian day, or Modified Julian day (32-bit).
[d_i8]
Integer Julian day, or Modified Julian day (large, 64-bit).
[h]
Integer hour.
[m]
Integer minute.
[s]
Integer second (32-bit).
[s_i8]
Integer second (large, 64-bit).
[ms]
Integer millisecond.
[us]
Integer microsecond.
[ns]
Integer nanosecond.
[d_r8]
Double precision day.
[h_r8]
Double precision hour.
[m_r8]
Double precision minute.
[s_r8]
Double precision second.
[ms_r8]
Double precision millisecond.
[us_r8]
Double precision microsecond.
[ns_r8]
Double precision nanosecond.
[sN]
Integer numerator of fractional second (sN/sD).
[sN_i8]
Integer numerator of fractional second (sN_i8/sD_i8) (large, 64-bit).
[sD]
Integer denominator of fractional second (sN/sD).
[sD_i8]
Integer denominator of fractional second (sN_i8/sD_i8) (large, 64-bit).
[startTime]
Starting time, if set, of an absolute calendar interval (yy, mm, and/or d).
[calendar]
Associated Calendar, if any.
[calkindflag]
Associated CalKind_Flag, if any.
[timeString]
Convert time interval value to format string PyYmMdDThHmMs[:n/d]S, where n/d is numerator/denominator of any fractional seconds and all other units are in ISO 8601 format. See [18] and  [5]. See also method ESMF_TimeIntervalPrint().
[timeStringISOFrac]
Convert time interval value to strict ISO 8601 format string PyYmMdDThHmMs[.f], where f is decimal form of any fractional seconds. See [18] and [5]. See also method ESMF_TimeIntervalPrint().
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 43.4.18 ESMF_TimeIntervalGet - Get a TimeInterval value

INTERFACE:

       ! Private name; call using ESMF_TimeIntervalGet()
subroutine ESMF_TimeIntervalGetDurCal(timeinterval, calendarIn, &
&
yy, yy_i8, &
mm, mm_i8, &
d, d_i8, &
h, m, &
s, s_i8, &
ms, us, ns, &
d_r8, h_r8, m_r8, s_r8, &
ms_r8, us_r8, ns_r8, &
sN, sN_i8, sD, sD_i8, &
startTime, &
calendar, calkindflag, &
timeString, timeStringISOFrac, rc)

ARGUMENTS:
       type(ESMF_TimeInterval), intent(in)            :: timeinterval
type(ESMF_Calendar),     intent(in)            :: calendarIn ! Input
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer(ESMF_KIND_I4),   intent(out), optional :: yy
integer(ESMF_KIND_I8),   intent(out), optional :: yy_i8
integer(ESMF_KIND_I4),   intent(out), optional :: mm
integer(ESMF_KIND_I8),   intent(out), optional :: mm_i8
integer(ESMF_KIND_I4),   intent(out), optional :: d
integer(ESMF_KIND_I8),   intent(out), optional :: d_i8
integer(ESMF_KIND_I4),   intent(out), optional :: h
integer(ESMF_KIND_I4),   intent(out), optional :: m
integer(ESMF_KIND_I4),   intent(out), optional :: s
integer(ESMF_KIND_I8),   intent(out), optional :: s_i8
integer(ESMF_KIND_I4),   intent(out), optional :: ms
integer(ESMF_KIND_I4),   intent(out), optional :: us
integer(ESMF_KIND_I4),   intent(out), optional :: ns
real(ESMF_KIND_R8),      intent(out), optional :: d_r8
real(ESMF_KIND_R8),      intent(out), optional :: h_r8
real(ESMF_KIND_R8),      intent(out), optional :: m_r8
real(ESMF_KIND_R8),      intent(out), optional :: s_r8
real(ESMF_KIND_R8),      intent(out), optional :: ms_r8
real(ESMF_KIND_R8),      intent(out), optional :: us_r8
real(ESMF_KIND_R8),      intent(out), optional :: ns_r8
integer(ESMF_KIND_I4),   intent(out), optional :: sN
integer(ESMF_KIND_I8),   intent(out), optional :: sN_i8
integer(ESMF_KIND_I4),   intent(out), optional :: sD
integer(ESMF_KIND_I8),   intent(out), optional :: sD_i8
type(ESMF_Time),         intent(out), optional :: startTime
type(ESMF_Calendar),     intent(out), optional :: calendar
type(ESMF_CalKind_Flag), intent(out), optional :: calkindflag
character (len=*),       intent(out), optional :: timeString
character (len=*),       intent(out), optional :: timeStringISOFrac
integer,                 intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Gets the value of timeinterval in units specified by the user via Fortran optional arguments.

The ESMF Time Manager represents and manipulates time internally with integers to maintain precision. Hence, user-specified floating point values are converted internally from integers.

Units are bound (normalized) to the next larger unit specified. For example, if a time interval is defined to be one day, then ESMF_TimeIntervalGet(d = days, s = seconds) would return days = 1, seconds = 0, whereas ESMF_TimeIntervalGet(s = seconds) would return seconds = 86400.

For timeString, converts ESMF_TimeInterval's value into partial ISO 8601 format PyYmMdDThHmMs[:n/d]S. See [18] and  [5]. See also method ESMF_TimeIntervalPrint().

For timeStringISOFrac, converts ESMF_TimeInterval's value into full ISO 8601 format PyYmMdDThHmMs[.f]S. See [18] and  [5]. See also method ESMF_TimeIntervalPrint().

The arguments are:

timeinterval
The object instance to query.
calendarIn
INPUT argument: pins a calendar interval to a specific calendar to allow conversion between relative units (yy, mm, d) and absolute units (d, h, m, s). Mutually exclusive with startTimeIn and endTimeIn since they contain a calendar. Alternate to, and mutually exclusive with, calkindflagIn below. Primarily for specifying a custom calendar kind.
[yy]
Integer year (32-bit).
[yy_i8]
Integer year (large, 64-bit).
[mm]
Integer month (32-bit).
[mm_i8]
Integer month (large, 64-bit).
[d]
Integer Julian day, or Modified Julian day (32-bit).
[d_i8]
Integer Julian day, or Modified Julian day (large, 64-bit).
[h]
Integer hour.
[m]
Integer minute.
[s]
Integer second (32-bit).
[s_i8]
Integer second (large, 64-bit).
[ms]
Integer millisecond.
[us]
Integer microsecond.
[ns]
Integer nanosecond.
[d_r8]
Double precision day.
[h_r8]
Double precision hour.
[m_r8]
Double precision minute.
[s_r8]
Double precision second.
[ms_r8]
Double precision millisecond.
[us_r8]
Double precision microsecond.
[ns_r8]
Double precision nanosecond.
[sN]
Integer numerator of fractional second (sN/sD).
[sN_i8]
Integer numerator of fractional second (sN_i8/sD_i8) (large, 64-bit).
[sD]
Integer denominator of fractional second (sN/sD).
[sD_i8]
Integer denominator of fractional second (sN_i8/sD_i8) (large, 64-bit).
[startTime]
Starting time, if set, of an absolute calendar interval (yy, mm, and/or d).
[calendar]
Associated Calendar, if any.
[calkindflag]
Associated CalKind_Flag, if any.
[timeString]
Convert time interval value to format string PyYmMdDThHmMs[:n/d]S, where n/d is numerator/denominator of any fractional seconds and all other units are in ISO 8601 format. See [18] and  [5]. See also method ESMF_TimeIntervalPrint().
[timeStringISOFrac]
Convert time interval value to strict ISO 8601 format string PyYmMdDThHmMs[.f], where f is decimal form of any fractional seconds. See [18] and [5]. See also method ESMF_TimeIntervalPrint().
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 43.4.19 ESMF_TimeIntervalGet - Get a TimeInterval value

INTERFACE:

       ! Private name; call using ESMF_TimeIntervalGet()
subroutine ESMF_TimeIntervalGetDurCalTyp(timeinterval, calkindflagIn, &
&
yy, yy_i8, &
mm, mm_i8, &
d, d_i8, &
h, m, &
s, s_i8, &
ms, us, ns, &
d_r8, h_r8, m_r8, s_r8, &
ms_r8, us_r8, ns_r8, &
sN, sN_i8, sD, sD_i8, &
startTime, &
calendar, calkindflag, &
timeString, &
timeStringISOFrac, rc)

ARGUMENTS:
       type(ESMF_TimeInterval), intent(in)            :: timeinterval
type(ESMF_CalKind_Flag), intent(in)            :: calkindflagIn ! Input
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer(ESMF_KIND_I4),   intent(out), optional :: yy
integer(ESMF_KIND_I8),   intent(out), optional :: yy_i8
integer(ESMF_KIND_I4),   intent(out), optional :: mm
integer(ESMF_KIND_I8),   intent(out), optional :: mm_i8
integer(ESMF_KIND_I4),   intent(out), optional :: d
integer(ESMF_KIND_I8),   intent(out), optional :: d_i8
integer(ESMF_KIND_I4),   intent(out), optional :: h
integer(ESMF_KIND_I4),   intent(out), optional :: m
integer(ESMF_KIND_I4),   intent(out), optional :: s
integer(ESMF_KIND_I8),   intent(out), optional :: s_i8
integer(ESMF_KIND_I4),   intent(out), optional :: ms
integer(ESMF_KIND_I4),   intent(out), optional :: us
integer(ESMF_KIND_I4),   intent(out), optional :: ns
real(ESMF_KIND_R8),      intent(out), optional :: d_r8
real(ESMF_KIND_R8),      intent(out), optional :: h_r8
real(ESMF_KIND_R8),      intent(out), optional :: m_r8
real(ESMF_KIND_R8),      intent(out), optional :: s_r8
real(ESMF_KIND_R8),      intent(out), optional :: ms_r8
real(ESMF_KIND_R8),      intent(out), optional :: us_r8
real(ESMF_KIND_R8),      intent(out), optional :: ns_r8
integer(ESMF_KIND_I4),   intent(out), optional :: sN
integer(ESMF_KIND_I8),   intent(out), optional :: sN_i8
integer(ESMF_KIND_I4),   intent(out), optional :: sD
integer(ESMF_KIND_I8),   intent(out), optional :: sD_i8
type(ESMF_Time),         intent(out), optional :: startTime
type(ESMF_Calendar),     intent(out), optional :: calendar
type(ESMF_CalKind_Flag), intent(out), optional :: calkindflag
character (len=*),       intent(out), optional :: timeString
character (len=*),       intent(out), optional :: timeStringISOFrac
integer,                 intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Gets the value of timeinterval in units specified by the user via Fortran optional arguments.

The ESMF Time Manager represents and manipulates time internally with integers to maintain precision. Hence, user-specified floating point values are converted internally from integers.

Units are bound (normalized) to the next larger unit specified. For example, if a time interval is defined to be one day, then ESMF_TimeIntervalGet(d = days, s = seconds) would return days = 1, seconds = 0, whereas ESMF_TimeIntervalGet(s = seconds) would return seconds = 86400.

For timeString, converts ESMF_TimeInterval's value into partial ISO 8601 format PyYmMdDThHmMs[:n/d]S. See [18] and  [5]. See also method ESMF_TimeIntervalPrint().

For timeStringISOFrac, converts ESMF_TimeInterval's value into full ISO 8601 format PyYmMdDThHmMs[.f]S. See [18] and  [5]. See also method ESMF_TimeIntervalPrint().

The arguments are:

timeinterval
The object instance to query.
calkindflagIn
INPUT argument: Alternate to, and mutually exclusive with, calendarIn above. More convenient way of specifying a built-in calendar kind.
[yy]
Integer year (32-bit).
[yy_i8]
Integer year (large, 64-bit).
[mm]
Integer month (32-bit).
[mm_i8]
Integer month (large, 64-bit).
[d]
Integer Julian day, or Modified Julian day (32-bit).
[d_i8]
Integer Julian day, or Modified Julian day (large, 64-bit).
[h]
Integer hour.
[m]
Integer minute.
[s]
Integer second (32-bit).
[s_i8]
Integer second (large, 64-bit).
[ms]
Integer millisecond.
[us]
Integer microsecond.
[ns]
Integer nanosecond.
[d_r8]
Double precision day.
[h_r8]
Double precision hour.
[m_r8]
Double precision minute.
[s_r8]
Double precision second.
[ms_r8]
Double precision millisecond.
[us_r8]
Double precision microsecond.
[ns_r8]
Double precision nanosecond.
[sN]
Integer numerator of fractional second (sN/sD).
[sN_i8]
Integer numerator of fractional second (sN_i8/sD_i8) (large, 64-bit).
[sD]
Integer denominator of fractional second (sN/sD).
[sD_i8]
Integer denominator of fractional second (sN_i8/sD_i8) (large, 64-bit).
[startTime]
Starting time, if set, of an absolute calendar interval (yy, mm, and/or d).
[calendar]
Associated Calendar, if any.
[calkindflag]
Associated CalKind_Flag, if any.
[timeString]
Convert time interval value to format string PyYmMdDThHmMs[:n/d]S, where n/d is numerator/denominator of any fractional seconds and all other units are in ISO 8601 format. See [18] and  [5]. See also method ESMF_TimeIntervalPrint().
[timeStringISOFrac]
Convert time interval value to strict ISO 8601 format string PyYmMdDThHmMs[.f], where f is decimal form of any fractional seconds. See [18] and [5]. See also method ESMF_TimeIntervalPrint().
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 43.4.20 ESMF_TimeIntervalNegAbsValue - Return the negative absolute value of a TimeInterval

INTERFACE:

       function ESMF_TimeIntervalNegAbsValue(timeinterval)

RETURN VALUE:
       type(ESMF_TimeInterval) :: ESMF_TimeIntervalNegAbsValue

ARGUMENTS:
       type(ESMF_TimeInterval), intent(in) :: timeinterval

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Returns the negative absolute value of timeinterval.

The argument is:

timeinterval
The object instance to take the negative absolute value of. Negative absolute value is returned as the value of the function.

### 43.4.21 ESMF_TimeIntervalPrint - Print TimeInterval information

INTERFACE:

       subroutine ESMF_TimeIntervalPrint(timeinterval, options, rc)

ARGUMENTS:
       type(ESMF_TimeInterval), intent(in)            :: timeinterval
character (len=*),       intent(in),  optional :: options
integer,                 intent(out), optional :: rc

DESCRIPTION:

Prints out the contents of an ESMF_TimeInterval to stdout, in support of testing and debugging. The options control the type of information and level of detail.

The arguments are:

timeinterval
Time interval to be printed out.
[options]
Print options. If none specified, prints all timeinterval property values.
"string" - prints timeinterval's value in ISO 8601 format for all units through seconds. For any non-zero fractional seconds, prints in integer rational fraction form n/d. Format is PyYmMdDThHmMs[:n/d]S, where [:n/d] is the integer numerator and denominator of the fractional seconds value, if present. See [18] and [5]. See also method ESMF_TimeIntervalGet(..., timeString= , ...)
"string isofrac" - prints timeinterval's value in strict ISO 8601 format for all units, including any fractional seconds part. Format is PyYmMdDThHmMs[.f]S, where [.f] represents fractional seconds in decimal form, if present. See [18] and [5]. See also method ESMF_TimeIntervalGet(..., timeStringISOFrac= , ...)
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 43.4.22 ESMF_TimeIntervalSet - Initialize or set a TimeInterval

INTERFACE:

       ! Private name; call using ESMF_TimeIntervalSet()
subroutine ESMF_TimeIntervalSetDur(timeinterval, &
yy, yy_i8, &
mm, mm_i8, &
d, d_i8, &
h, m, &
s, s_i8, &
ms, us, ns, &
d_r8, h_r8, m_r8, s_r8, &
ms_r8, us_r8, ns_r8, &
sN, sN_i8, sD, sD_i8, rc)

ARGUMENTS:
       type(ESMF_TimeInterval), intent(inout)         :: timeinterval
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer(ESMF_KIND_I4),   intent(in),  optional :: yy
integer(ESMF_KIND_I8),   intent(in),  optional :: yy_i8
integer(ESMF_KIND_I4),   intent(in),  optional :: mm
integer(ESMF_KIND_I8),   intent(in),  optional :: mm_i8
integer(ESMF_KIND_I4),   intent(in),  optional :: d
integer(ESMF_KIND_I8),   intent(in),  optional :: d_i8
integer(ESMF_KIND_I4),   intent(in),  optional :: h
integer(ESMF_KIND_I4),   intent(in),  optional :: m
integer(ESMF_KIND_I4),   intent(in),  optional :: s
integer(ESMF_KIND_I8),   intent(in),  optional :: s_i8
integer(ESMF_KIND_I4),   intent(in),  optional :: ms
integer(ESMF_KIND_I4),   intent(in),  optional :: us
integer(ESMF_KIND_I4),   intent(in),  optional :: ns
real(ESMF_KIND_R8),      intent(in),  optional :: d_r8
real(ESMF_KIND_R8),      intent(in),  optional :: h_r8
real(ESMF_KIND_R8),      intent(in),  optional :: m_r8
real(ESMF_KIND_R8),      intent(in),  optional :: s_r8
real(ESMF_KIND_R8),      intent(in),  optional :: ms_r8
real(ESMF_KIND_R8),      intent(in),  optional :: us_r8
real(ESMF_KIND_R8),      intent(in),  optional :: ns_r8
integer(ESMF_KIND_I4),   intent(in),  optional :: sN
integer(ESMF_KIND_I8),   intent(in),  optional :: sN_i8
integer(ESMF_KIND_I4),   intent(in),  optional :: sD
integer(ESMF_KIND_I8),   intent(in),  optional :: sD_i8
integer,                 intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Sets the value of the ESMF_TimeInterval in units specified by the user via Fortran optional arguments.

The ESMF Time Manager represents and manipulates time internally with integers to maintain precision. Hence, user-specified floating point values are converted internally to integers.

Ranges are limited only by machine word size. Numeric defaults are 0, except for sD, which is 1.

The arguments are:

timeinterval
The object instance to initialize.
[yy]
Integer year (32-bit). Default = 0.
[yy_i8]
Integer year (large, 64-bit). Default = 0.
[mm]
Integer month (32-bit). Default = 0.
[mm_i8]
Integer month (large, 64-bit). Default = 0.
[d]
Integer Julian day, or Modified Julian day (32-bit). Default = 0.
[d_i8]
Integer Julian day, or Modified Julian day (large, 64-bit). Default = 0.
[h]
Integer hour. Default = 0.
[m]
Integer minute. Default = 0.
[s]
Integer second (32-bit). Default = 0.
[s_i8]
Integer second (large, 64-bit). Default = 0.
[ms]
Integer millisecond. Default = 0.
[us]
Integer microsecond. Default = 0.
[ns]
Integer nanosecond. Default = 0.
[d_r8]
Double precision day. Default = 0.0.
[h_r8]
Double precision hour. Default = 0.0.
[m_r8]
Double precision minute. Default = 0.0.
[s_r8]
Double precision second. Default = 0.0.
[ms_r8]
Double precision millisecond. Default = 0.0.
[us_r8]
Double precision microsecond. Default = 0.0.
[ns_r8]
Double precision nanosecond. Default = 0.0.
[sN]
Integer numerator of fractional second (sN/sD). Default = 0.
[sN_i8]
Integer numerator of fractional second (sN_i8/sD_i8) (large, 64-bit). Default = 0.
[sD]
Integer denominator of fractional second (sN/sD). Default = 1.
[sD_i8]
Integer denominator of fractional second (sN_i8/sD_i8) (large, 64-bit). Default = 1.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 43.4.23 ESMF_TimeIntervalSet - Initialize or set a TimeInterval

INTERFACE:

       ! Private name; call using ESMF_TimeIntervalSet()
subroutine ESMF_TimeIntervalSetDurStart(timeinterval, startTime, &
&
yy, yy_i8, &
mm, mm_i8, &
d, d_i8, &
h, m, &
s, s_i8, &
ms, us, ns, &
d_r8, h_r8, m_r8, s_r8, &
ms_r8, us_r8, ns_r8, &
sN, sN_i8, sD, sD_i8, &
rc)

ARGUMENTS:
       type(ESMF_TimeInterval), intent(inout)         :: timeinterval
type(ESMF_Time),         intent(in)            :: startTime
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer(ESMF_KIND_I4),   intent(in),  optional :: yy
integer(ESMF_KIND_I8),   intent(in),  optional :: yy_i8
integer(ESMF_KIND_I4),   intent(in),  optional :: mm
integer(ESMF_KIND_I8),   intent(in),  optional :: mm_i8
integer(ESMF_KIND_I4),   intent(in),  optional :: d
integer(ESMF_KIND_I8),   intent(in),  optional :: d_i8
integer(ESMF_KIND_I4),   intent(in),  optional :: h
integer(ESMF_KIND_I4),   intent(in),  optional :: m
integer(ESMF_KIND_I4),   intent(in),  optional :: s
integer(ESMF_KIND_I8),   intent(in),  optional :: s_i8
integer(ESMF_KIND_I4),   intent(in),  optional :: ms
integer(ESMF_KIND_I4),   intent(in),  optional :: us
integer(ESMF_KIND_I4),   intent(in),  optional :: ns
real(ESMF_KIND_R8),      intent(in),  optional :: d_r8
real(ESMF_KIND_R8),      intent(in),  optional :: h_r8
real(ESMF_KIND_R8),      intent(in),  optional :: m_r8
real(ESMF_KIND_R8),      intent(in),  optional :: s_r8
real(ESMF_KIND_R8),      intent(in),  optional :: ms_r8
real(ESMF_KIND_R8),      intent(in),  optional :: us_r8
real(ESMF_KIND_R8),      intent(in),  optional :: ns_r8
integer(ESMF_KIND_I4),   intent(in),  optional :: sN
integer(ESMF_KIND_I8),   intent(in),  optional :: sN_i8
integer(ESMF_KIND_I4),   intent(in),  optional :: sD
integer(ESMF_KIND_I8),   intent(in),  optional :: sD_i8
integer,                 intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Sets the value of the ESMF_TimeInterval in units specified by the user via Fortran optional arguments.

The ESMF Time Manager represents and manipulates time internally with integers to maintain precision. Hence, user-specified floating point values are converted internally to integers.

Ranges are limited only by machine word size. Numeric defaults are 0, except for sD, which is 1.

The arguments are:

timeinterval
The object instance to initialize.
startTime
Starting time of an absolute calendar interval (yy, mm, and/or d); pins a calendar interval to a specific point in time. If not set, and calendar also not set, calendar interval "floats" across all calendars and times.
[yy]
Integer year (32-bit). Default = 0.
[yy_i8]
Integer year (large, 64-bit). Default = 0.
[mm]
Integer month (32-bit). Default = 0.
[mm_i8]
Integer month (large, 64-bit). Default = 0.
[d]
Integer Julian day, or Modified Julian day (32-bit). Default = 0.
[d_i8]
Integer Julian day, or Modified Julian day (large, 64-bit). Default = 0.
[h]
Integer hour. Default = 0.
[m]
Integer minute. Default = 0.
[s]
Integer second (32-bit). Default = 0.
[s_i8]
Integer second (large, 64-bit). Default = 0.
[ms]
Integer millisecond. Default = 0.
[us]
Integer microsecond. Default = 0.
[ns]
Integer nanosecond. Default = 0.
[d_r8]
Double precision day. Default = 0.0.
[h_r8]
Double precision hour. Default = 0.0.
[m_r8]
Double precision minute. Default = 0.0.
[s_r8]
Double precision second. Default = 0.0.
[ms_r8]
Double precision millisecond. Default = 0.0.
[us_r8]
Double precision microsecond. Default = 0.0.
[ns_r8]
Double precision nanosecond. Default = 0.0.
[sN]
Integer numerator of fractional second (sN/sD). Default = 0.
[sN_i8]
Integer numerator of fractional second (sN_i8/sD_i8) (large, 64-bit). Default = 0.
[sD]
Integer denominator of fractional second (sN/sD). Default = 1.
[sD_i8]
Integer denominator of fractional second (sN_i8/sD_i8). (large, 64-bit). Default = 1.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 43.4.24 ESMF_TimeIntervalSet - Initialize or set a TimeInterval

INTERFACE:

       ! Private name; call using ESMF_TimeIntervalSet()
subroutine ESMF_TimeIntervalSetDurCal(timeinterval, calendar, &
&
yy, yy_i8, &
mm, mm_i8, &
d, d_i8, &
h, m, &
s, s_i8, &
ms, us, ns, &
d_r8, h_r8, m_r8, s_r8, &
ms_r8, us_r8, ns_r8, &
sN, sN_i8, sD, sD_i8, rc)

ARGUMENTS:
       type(ESMF_TimeInterval), intent(inout)         :: timeinterval
type(ESMF_Calendar),     intent(in)            :: calendar
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer(ESMF_KIND_I4),   intent(in),  optional :: yy
integer(ESMF_KIND_I8),   intent(in),  optional :: yy_i8
integer(ESMF_KIND_I4),   intent(in),  optional :: mm
integer(ESMF_KIND_I8),   intent(in),  optional :: mm_i8
integer(ESMF_KIND_I4),   intent(in),  optional :: d
integer(ESMF_KIND_I8),   intent(in),  optional :: d_i8
integer(ESMF_KIND_I4),   intent(in),  optional :: h
integer(ESMF_KIND_I4),   intent(in),  optional :: m
integer(ESMF_KIND_I4),   intent(in),  optional :: s
integer(ESMF_KIND_I8),   intent(in),  optional :: s_i8
integer(ESMF_KIND_I4),   intent(in),  optional :: ms
integer(ESMF_KIND_I4),   intent(in),  optional :: us
integer(ESMF_KIND_I4),   intent(in),  optional :: ns
real(ESMF_KIND_R8),      intent(in),  optional :: d_r8
real(ESMF_KIND_R8),      intent(in),  optional :: h_r8
real(ESMF_KIND_R8),      intent(in),  optional :: m_r8
real(ESMF_KIND_R8),      intent(in),  optional :: s_r8
real(ESMF_KIND_R8),      intent(in),  optional :: ms_r8
real(ESMF_KIND_R8),      intent(in),  optional :: us_r8
real(ESMF_KIND_R8),      intent(in),  optional :: ns_r8
integer(ESMF_KIND_I4),   intent(in),  optional :: sN
integer(ESMF_KIND_I8),   intent(in),  optional :: sN_i8
integer(ESMF_KIND_I4),   intent(in),  optional :: sD
integer(ESMF_KIND_I8),   intent(in),  optional :: sD_i8
integer,                 intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Sets the value of the ESMF_TimeInterval in units specified by the user via Fortran optional arguments.

The ESMF Time Manager represents and manipulates time internally with integers to maintain precision. Hence, user-specified floating point values are converted internally to integers.

Ranges are limited only by machine word size. Numeric defaults are 0, except for sD, which is 1.

The arguments are:

timeinterval
The object instance to initialize.
calendar
Calendar used to give better definition to calendar interval (yy, mm, and/or d) for arithmetic, comparison, and conversion operations. Allows calendar interval to "float" across all times on a specific calendar. Default = NULL; if startTime also not specified, calendar interval "floats" across all calendars and times. Mutually exclusive with startTime since it contains a calendar. Alternate to, and mutually exclusive with, calkindflag below. Primarily for specifying a custom calendar kind.
[yy]
Integer year (32-bit). Default = 0.
[yy_i8]
Integer year (large, 64-bit). Default = 0.
[mm]
Integer month (32-bit). Default = 0.
[mm_i8]
Integer month (large, 64-bit). Default = 0.
[d]
Integer Julian day, or Modified Julian day (32-bit). Default = 0.
[d_i8]
Integer Julian day, or Modified Julian day (large, 64-bit). Default = 0.
[h]
Integer hour. Default = 0.
[m]
Integer minute. Default = 0.
[s]
Integer second (32-bit). Default = 0.
[s_i8]
Integer second (large, 64-bit). Default = 0.
[ms]
Integer millisecond. Default = 0.
[us]
Integer microsecond. Default = 0.
[ns]
Integer nanosecond. Default = 0.
[d_r8]
Double precision day. Default = 0.0.
[h_r8]
Double precision hour. Default = 0.0.
[m_r8]
Double precision minute. Default = 0.0.
[s_r8]
Double precision second. Default = 0.0.
[ms_r8]
Double precision millisecond. Default = 0.0.
[us_r8]
Double precision microsecond. Default = 0.0.
[ns_r8]
Double precision nanosecond. Default = 0.0.
[sN]
Integer numerator of fractional second (sN/sD). Default = 0.
[sN_i8]
Integer numerator of fractional second (sN_i8/sD_i8). (large, 64-bit). Default = 0.
[sD]
Integer denominator of fractional second (sN/sD). Default = 1.
[sD_i8]
Integer denominator of fractional second (sN_i8/sD_i8). (large, 64-bit). Default = 1.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 43.4.25 ESMF_TimeIntervalSet - Initialize or set a TimeInterval

INTERFACE:

       ! Private name; call using ESMF_TimeIntervalSet()
subroutine ESMF_TimeIntervalSetDurCalTyp(timeinterval, calkindflag, &
&
yy, yy_i8, &
mm, mm_i8, &
d, d_i8, &
h, m, &
s, s_i8, &
ms, us, ns, &
d_r8, h_r8, m_r8, s_r8, &
ms_r8, us_r8, ns_r8, &
sN, sN_i8, sD, sD_i8, &
rc)

ARGUMENTS:
       type(ESMF_TimeInterval), intent(inout)         :: timeinterval
type(ESMF_CalKind_Flag), intent(in)            :: calkindflag
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer(ESMF_KIND_I4),   intent(in),  optional :: yy
integer(ESMF_KIND_I8),   intent(in),  optional :: yy_i8
integer(ESMF_KIND_I4),   intent(in),  optional :: mm
integer(ESMF_KIND_I8),   intent(in),  optional :: mm_i8
integer(ESMF_KIND_I4),   intent(in),  optional :: d
integer(ESMF_KIND_I8),   intent(in),  optional :: d_i8
integer(ESMF_KIND_I4),   intent(in),  optional :: h
integer(ESMF_KIND_I4),   intent(in),  optional :: m
integer(ESMF_KIND_I4),   intent(in),  optional :: s
integer(ESMF_KIND_I8),   intent(in),  optional :: s_i8
integer(ESMF_KIND_I4),   intent(in),  optional :: ms
integer(ESMF_KIND_I4),   intent(in),  optional :: us
integer(ESMF_KIND_I4),   intent(in),  optional :: ns
real(ESMF_KIND_R8),      intent(in),  optional :: d_r8
real(ESMF_KIND_R8),      intent(in),  optional :: h_r8
real(ESMF_KIND_R8),      intent(in),  optional :: m_r8
real(ESMF_KIND_R8),      intent(in),  optional :: s_r8
real(ESMF_KIND_R8),      intent(in),  optional :: ms_r8
real(ESMF_KIND_R8),      intent(in),  optional :: us_r8
real(ESMF_KIND_R8),      intent(in),  optional :: ns_r8
integer(ESMF_KIND_I4),   intent(in),  optional :: sN
integer(ESMF_KIND_I8),   intent(in),  optional :: sN_i8
integer(ESMF_KIND_I4),   intent(in),  optional :: sD
integer(ESMF_KIND_I8),   intent(in),  optional :: sD_i8
integer,                 intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Sets the value of the ESMF_TimeInterval in units specified by the user via Fortran optional arguments.

The ESMF Time Manager represents and manipulates time internally with integers to maintain precision. Hence, user-specified floating point values are converted internally to integers.

Ranges are limited only by machine word size. Numeric defaults are 0, except for sD, which is 1.

The arguments are:

timeinterval
The object instance to initialize.
calkindflag
Alternate to, and mutually exclusive with, calendar above. More convenient way of specifying a built-in calendar kind.
[yy]
Integer year (32-bit). Default = 0.
[yy_i8]
Integer year (large, 64-bit). Default = 0.
[mm]
Integer month (32-bit). Default = 0.
[mm_i8]
Integer month (large, 64-bit). Default = 0.
[d]
Integer Julian day, or Modified Julian day (32-bit). Default = 0.
[d_i8]
Integer Julian day, or Modified Julian day (large, 64-bit). Default = 0.
[h]
Integer hour. Default = 0.
[m]
Integer minute. Default = 0.
[s]
Integer second (32-bit). Default = 0.
[s_i8]
Integer second (large, 64-bit). Default = 0.
[ms]
Integer millisecond. Default = 0.
[us]
Integer microsecond. Default = 0.
[ns]
Integer nanosecond. Default = 0.
[d_r8]
Double precision day. Default = 0.0.
[h_r8]
Double precision hour. Default = 0.0.
[m_r8]
Double precision minute. Default = 0.0.
[s_r8]
Double precision second. Default = 0.0.
[ms_r8]
Double precision millisecond. Default = 0.0.
[us_r8]
Double precision microsecond. Default = 0.0.
[ns_r8]
Double precision nanoseconds. Default = 0.0.
[sN]
Integer numerator of fractional second (sN/sD). Default = 0.
[sN_i8]
Integer numerator of fractional second (sN_i8/sD_i8) (large, 64-bit). Default = 0.
[sD]
Integer denominator of fractional second (sN/sD). Default = 1.
[sD_i8]
Integer denominator of fractional second (sN_i8/sD_i8) (large, 64-bit). Default = 1.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 43.4.26 ESMF_TimeIntervalValidate - Validate a TimeInterval

INTERFACE:

       subroutine ESMF_TimeIntervalValidate(timeinterval, rc)

ARGUMENTS:
       type(ESMF_TimeInterval), intent(in)            :: timeinterval
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,                 intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Checks whether a timeinterval is valid. If fractional value, denominator must be non-zero.

The arguments are:

timeinterval
ESMF_TimeInterval to be validated.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

# 44 Clock Class

## 44.1 Description

The Clock class advances model time and tracks its associated date on a specified Calendar. It stores start time, stop time, current time, previous time, and a time step. It can also store a reference time, typically the time instant at which a simulation originally began. For a restart run, the reference time can be different than the start time, when the application execution resumes.

A user can call the ESMF_ClockSet method and reset the time step as desired.

A Clock also stores a list of Alarms, which can be set to flag events that occur at a specified time instant or at a specified time interval. See Section 45.1 for details on how to use Alarms.

There are methods for setting and getting the Times and Alarms associated with a Clock. Methods are defined for advancing the Clock's current time, checking if the stop time has been reached, reversing direction, and synchronizing with a real clock.

## 44.2 Constants

### 44.2.1 ESMF_DIRECTION

DESCRIPTION:
Specifies the time-stepping direction of a clock. Use with "direction" argument to methods ESMF_ClockSet() and ESMF_ClockGet(). Cannot be used with method ESMF_ClockCreate(), since it only initializes a clock in the default forward mode; a clock must be advanced (timestepped) at least once before reversing direction via ESMF_ClockSet(). This also holds true for negative timestep clocks which are initialized (created) with stopTime < startTime, since "forward" means timestepping from startTime towards stopTime (see ESMF_DIRECTION_FORWARD below).

"Forward" and "reverse" directions are distinct from positive and negative timesteps. "Forward" means timestepping in the direction established at ESMF_ClockCreate(), from startTime towards stopTime, regardless of the timestep sign. "Reverse" means timestepping in the opposite direction, back towards the clock's startTime, regardless of the timestep sign.

Clocks and alarms run in reverse in such a way that the state of a clock and its alarms after each time step is precisely replicated as it was in forward time-stepping mode. All methods which query clock and alarm state will return the same result for a given timeStep, regardless of the direction of arrival.

The type of this flag is:

type(ESMF_Direction_Flag)

The valid values are:

ESMF_DIRECTION_FORWARD
Upon calling ESMF_ClockAdvance(), the clock will timestep from its startTime toward its stopTime. This is the default direction. A user can use either ESMF_ClockIsStopTime() or ESMF_ClockIsDone() methods to determine when stopTime is reached. This forward behavior also holds for negative timestep clocks which are initialized (created) with stopTime < startTime.

ESMF_DIRECTION_REVERSE
Upon calling ESMF_ClockAdvance(), the clock will timestep backwards toward its startTime. Use method ESMF_ClockIsDone() to determine when startTime is reached. This reverse behavior also holds for negative timestep clocks which are initialized (created) with stopTime < startTime.

## 44.3 Use and Examples

The following is a typical sequence for using a Clock in a geophysical model.

At initialize:

• Set a Calendar.
• Set start time, stop time and time step as Times and Time Intervals.
• Create and Initialize a Clock using the start time, stop time and time step.
• Define Times and Time Intervals associated with special events, and use these to set Alarms.

At run:

• Advance the Clock, checking for ringing alarms as needed.
• Check if it is time to stop.

At finalize:

• Since Clocks and Alarms are deep classes, they need to be explicitly destroyed at finalization. Times and TimeIntervals are lightweight classes, so they don't need explicit destruction.

The following code example illustrates Clock usage.

! !PROGRAM: ESMF_ClockEx - Clock initialization and time-stepping
!
! !DESCRIPTION:
!
! This program shows an example of how to create, initialize, advance, and
! examine a basic clock
!-----------------------------------------------------------------------------
#include "ESMF.h"

! ESMF Framework module
use ESMF
use ESMF_TestMod
implicit none

! instantiate a clock
type(ESMF_Clock) :: clock

! instantiate time_step, start and stop times
type(ESMF_TimeInterval) :: timeStep
type(ESMF_Time) :: startTime
type(ESMF_Time) :: stopTime

! local variables for Get methods
type(ESMF_Time) :: currTime
integer :: YY, MM, DD, H, M, S

! return code
integer :: rc


      ! initialize ESMF framework
call ESMF_Initialize(defaultCalKind=ESMF_CALKIND_GREGORIAN, &
defaultlogfilename="ClockEx.Log", &
logkindflag=ESMF_LOGKIND_MULTI, rc=rc)


### 44.3.1 Clock creation

This example shows how to create and initialize an ESMF_Clock.

      ! initialize time interval to 2 days, 4 hours (6 timesteps in 13 days)
call ESMF_TimeIntervalSet(timeStep, d=2, h=4, rc=rc)


      ! initialize start time to 4/1/2003 2:24:00 ( 1/10 of a day )
call ESMF_TimeSet(startTime, yy=2003, mm=4, dd=1, h=2, m=24, rc=rc)


      ! initialize stop time to 4/14/2003 2:24:00 ( 1/10 of a day )
call ESMF_TimeSet(stopTime, yy=2003, mm=4, dd=14, h=2, m=24, rc=rc)


      ! initialize the clock with the above values
clock = ESMF_ClockCreate(timeStep, startTime, stopTime=stopTime, &
name="Clock 1", rc=rc)


This example shows how to time-step an ESMF_Clock.

      ! time step clock from start time to stop time
do while (.not.ESMF_ClockIsStopTime(clock, rc=rc))


        call ESMF_ClockPrint(clock, options="currTime string", rc=rc)


        call ESMF_ClockAdvance(clock, rc=rc)


      end do


### 44.3.3 Clock examination

This example shows how to examine an ESMF_Clock.

      ! get the clock's final current time
call ESMF_ClockGet(clock, currTime=currTime, rc=rc)


      call ESMF_TimeGet(currTime, yy=YY, mm=MM, dd=DD, h=H, m=M, s=S, rc=rc)
print *, "The clock's final current time is ", YY, "/", MM, "/", DD, &
" ", H, ":", M, ":", S


      ! get the number of times the clock was advanced


### 44.3.4 Clock reversal

This example shows how to time-step an ESMF_Clock in reverse mode.

      call ESMF_ClockSet(clock, direction=ESMF_DIRECTION_REVERSE, rc=rc)


      ! time step clock in reverse from stop time back to start time;
!  note use of ESMF_ClockIsDone() rather than ESMF_ClockIsStopTime()
do while (.not.ESMF_ClockIsDone(clock, rc=rc))


        call ESMF_ClockPrint(clock, options="currTime string", rc=rc)


        call ESMF_ClockAdvance(clock, rc=rc)


      end do


### 44.3.5 Clock destruction

This example shows how to destroy an ESMF_Clock.

      ! destroy clock
call ESMF_ClockDestroy(clock, rc=rc)


      ! finalize ESMF framework
call ESMF_Finalize(rc=rc)


      end program ESMF_ClockEx


## 44.4 Restrictions and Future Work

1. Alarm list allocation factor The alarm list within a clock is dynamically allocated automatically, 200 alarm references at a time. This constant is defined in both Fortran and C++ with a #define for ease of modification.

2. Clock variable timesteps in reverse In order for a clock with variable timesteps to be run in ESMF_DIRECTION_REVERSE, the user must supply those timesteps to ESMF_ClockAdvance(). Essentially, the user must save the timesteps while in forward mode. In a future release, the Time Manager will assume this responsibility by saving the clock state (including the timeStep) at every timestep while in forward mode.

## 44.5 Class API

### 44.5.1 ESMF_ClockAssignment(=) - Assign a Clock to another Clock

INTERFACE:

       interface assignment(=)
clock1 = clock2

ARGUMENTS:
       type(ESMF_Clock) :: clock1
type(ESMF_Clock) :: clock2

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Assign clock1 as an alias to the same ESMF_Clock object in memory as clock2. If clock2 is invalid, then clock1 will be equally invalid after the assignment.

The arguments are:

clock1
The ESMF_Clock object on the left hand side of the assignment.
clock2
The ESMF_Clock object on the right hand side of the assignment.

### 44.5.2 ESMF_ClockOperator(==) - Test if Clock 1 is equal to Clock 2

INTERFACE:

       interface operator(==)
if (clock1 == clock2) then ... endif
OR
result = (clock1 == clock2)

RETURN VALUE:
       logical :: result

ARGUMENTS:
       type(ESMF_Clock), intent(in) :: clock1
type(ESMF_Clock), intent(in) :: clock2

DESCRIPTION:

Overloads the (==) operator for the ESMF_Clock class. Compare two clocks for equality; return .true. if equal, .false. otherwise. Comparison is based on IDs, which are distinct for newly created clocks and identical for clocks created as copies.

If either side of the equality test is not in the ESMF_INIT_CREATED status an error will be logged. However, this does not affect the return value, which is .true. when both sides are in the same status, and .false. otherwise.

The arguments are:

clock1
The ESMF_Clock object on the left hand side of the equality operation.
clock2
The ESMF_Clock object on the right hand side of the equality operation.

### 44.5.3 ESMF_ClockOperator(/=) - Test if Clock 1 is not equal to Clock 2

INTERFACE:

       interface operator(/=)
if (clock1 /= clock2) then ... endif
OR
result = (clock1 /= clock2)

RETURN VALUE:
       logical :: result

ARGUMENTS:
       type(ESMF_Clock), intent(in) :: clock1
type(ESMF_Clock), intent(in) :: clock2

DESCRIPTION:

Overloads the (/=) operator for the ESMF_Clock class. Compare two clocks for inequality; return .true. if not equal, .false. otherwise. Comparison is based on IDs, which are distinct for newly created clocks and identical for clocks created as copies.

If either side of the equality test is not in the ESMF_INIT_CREATED status an error will be logged. However, this does not affect the return value, which is .true. when both sides are not in the same status, and .false. otherwise.

The arguments are:

clock1
The ESMF_Clock object on the left hand side of the non-equality operation.
clock2
The ESMF_Clock object on the right hand side of the non-equality operation.

### 44.5.4 ESMF_ClockAdvance - Advance a Clock's current time by one time step

INTERFACE:

       subroutine ESMF_ClockAdvance(clock, &
timeStep, ringingAlarmList, ringingAlarmCount, rc)

ARGUMENTS:
       type(ESMF_Clock),        intent(inout)         :: clock
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
type(ESMF_TimeInterval), intent(in),  optional :: timeStep
type(ESMF_Alarm),        intent(out), optional :: ringingAlarmList(:)
integer,                 intent(out), optional :: ringingAlarmCount
integer,                 intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Advances the clock's current time by one time step: either the clock's, or the passed-in timeStep (see below). When the clock is in ESMF_DIRECTION_FORWARD (default), this method adds the timeStep to the clock's current time. In ESMF_DIRECTION_REVERSE, timeStep is subtracted from the current time. In either case, timeStep can be positive or negative. See the "direction" argument in method ESMF_ClockSet(). ESMF_ClockAdvance() optionally returns a list and number of ringing ESMF_Alarms. See also method ESMF_ClockGetRingingAlarms().

The arguments are:

clock
[timeStep]
Time step is performed with given timeStep, instead of the ESMF_Clock's. Does not replace the ESMF_Clock's timeStep; use ESMF_ClockSet(clock, timeStep, ...) for this purpose. Supports applications with variable time steps. timeStep can be positive or negative.
[ringingAlarmList]
Returns the array of alarms that are ringing after the time step.
[ringingAlarmCount]
The number of alarms ringing after the time step.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 44.5.5 ESMF_ClockCreate - Create a new ESMF Clock

INTERFACE:

       ! Private name; call using ESMF_ClockCreate()
function ESMF_ClockCreateNew(timeStep, startTime, &
stopTime, runDuration, runTimeStepCount, refTime, name, rc)

RETURN VALUE:
       type(ESMF_Clock) :: ESMF_ClockCreateNew

ARGUMENTS:
       type(ESMF_TimeInterval), intent(in)            :: timeStep
type(ESMF_Time),         intent(in)            :: startTime
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
type(ESMF_Time),         intent(in),  optional :: stopTime
type(ESMF_TimeInterval), intent(in),  optional :: runDuration
integer,                 intent(in),  optional :: runTimeStepCount
type(ESMF_Time),         intent(in),  optional :: refTime
character (len=*),       intent(in),  optional :: name
integer,                 intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Creates and sets the initial values in a new ESMF_Clock.

The arguments are:

timeStep
The ESMF_Clock's time step interval, which can be positive or negative.
startTime
The ESMF_Clock's starting time. Can be less than or or greater than stopTime, depending on a positive or negative timeStep, respectively, and whether a stopTime is specified; see below.
[stopTime]
The ESMF_Clock's stopping time. Can be greater than or less than the startTime, depending on a positive or negative timeStep, respectively. If neither stopTime, runDuration, nor runTimeStepCount is specified, clock runs "forever"; user must use other means to know when to stop (e.g. ESMF_Alarm or ESMF_ClockGet(clock, currTime)). Mutually exclusive with runDuration and runTimeStepCount.
[runDuration]
Alternative way to specify ESMF_Clock's stopping time; stopTime = startTime + runDuration. Can be positive or negative, consistent with the timeStep's sign. Mutually exclusive with stopTime and runTimeStepCount.
[runTimeStepCount]
Alternative way to specify ESMF_Clock's stopping time; stopTime = startTime + (runTimeStepCount * timeStep). stopTime can be before startTime if timeStep is negative. Mutually exclusive with stopTime and runDuration.
[refTime]
The ESMF_Clock's reference time. Provides reference point for simulation time (see currSimTime in ESMF_ClockGet() below).
[name]
The name for the newly created clock. If not specified, a default unique name will be generated: "ClockNNN" where NNN is a unique sequence number from 001 to 999.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 44.5.6 ESMF_ClockCreate - Create a copy of an existing ESMF Clock

INTERFACE:

       ! Private name; call using ESMF_ClockCreate()
function ESMF_ClockCreateCopy(clock, rc)

RETURN VALUE:
       type(ESMF_Clock) :: ESMF_ClockCreateCopy

ARGUMENTS:
       type(ESMF_Clock), intent(in)            :: clock
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,          intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Creates a deep copy of a given ESMF_Clock, but does not copy its list of ESMF_Alarms (pointers), since an ESMF_Alarm can only be associated with one ESMF_Clock. Hence, the returned ESMF_Clock copy has no associated ESMF_Alarms, the same as with a newly created ESMF_Clock. If desired, new ESMF_Alarms must be created and associated with this copied ESMF_Clock via ESMF_AlarmCreate(), or existing ESMF_Alarms must be re-associated with this copied ESMF_Clock via ESMF_AlarmSet(...clock=...).

The arguments are:

clock
The ESMF_Clock to copy.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 44.5.7 ESMF_ClockDestroy - Release resources associated with a Clock

INTERFACE:

       subroutine ESMF_ClockDestroy(clock, rc)

ARGUMENTS:
       type(ESMF_Clock), intent(inout)          :: clock
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,          intent(out),  optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Releases resources associated with this ESMF_Clock. This releases the list of associated ESMF_Alarms (pointers), but not the ESMF_Alarms themselves; the user must explicitly call ESMF_AlarmDestroy() on each ESMF_Alarm to release its resources. ESMF_ClockDestroy() and corresponding ESMF_AlarmDestroy()s can be called in either order.

If ESMF_ClockDestroy() is called before ESMF_AlarmDestroy(), any ESMF_Alarms that were in the ESMF_Clock's list will no longer be associated with any ESMF_Clock. If desired, these "orphaned" ESMF_Alarms can be associated with a different ESMF_Clock via a call to ESMF_AlarmSet(...clock=...).

The arguments are:

clock
Release resources associated with this ESMF_Clock and mark the object as invalid. It is an error to pass this object into any other routines after being destroyed.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 44.5.8 ESMF_ClockGet - Get a Clock's properties

INTERFACE:

       subroutine ESMF_ClockGet(clock, &
timeStep, startTime, stopTime, &
runDuration, runTimeStepCount, refTime, currTime, prevTime, &
currSimTime, prevSimTime, calendar, calkindflag, timeZone, &

ARGUMENTS:
       type(ESMF_Clock),        intent(in)            :: clock
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
type(ESMF_TimeInterval), intent(out), optional :: timeStep
type(ESMF_Time),         intent(out), optional :: startTime
type(ESMF_Time),         intent(out), optional :: stopTime
type(ESMF_TimeInterval), intent(out), optional :: runDuration
real(ESMF_KIND_R8),      intent(out), optional :: runTimeStepCount
type(ESMF_Time),         intent(out), optional :: refTime
type(ESMF_Time),         intent(out), optional :: currTime
type(ESMF_Time),         intent(out), optional :: prevTime
type(ESMF_TimeInterval), intent(out), optional :: currSimTime
type(ESMF_TimeInterval), intent(out), optional :: prevSimTime
type(ESMF_Calendar),     intent(out), optional :: calendar
type(ESMF_CalKind_Flag), intent(out), optional :: calkindflag
integer,                 intent(out), optional :: timeZone
integer,                 intent(out), optional :: alarmCount
type(ESMF_Direction_Flag),    intent(out), optional :: direction
character (len=*),       intent(out), optional :: name
integer,                 intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Gets one or more of the properties of an ESMF_Clock.

The arguments are:

clock
The object instance to query.
[timeStep]
The ESMF_Clock's time step interval.
[startTime]
The ESMF_Clock's starting time.
[stopTime]
The ESMF_Clock's stopping time.
[runDuration]
Alternative way to get ESMF_Clock's stopping time; runDuration = stopTime - startTime.
[runTimeStepCount]
Alternative way to get ESMF_Clock's stopping time; runTimeStepCount = (stopTime - startTime) / timeStep.
[refTime]
The ESMF_Clock's reference time.
[currTime]
The ESMF_Clock's current time.
[prevTime]
The ESMF_Clock's previous time. Equals currTime at the previous time step.
[currSimTime]
The current simulation time (currTime - refTime).
[prevSimTime]
The previous simulation time. Equals currSimTime at the previous time step.
[calendar]
The Calendar on which all the Clock's times are defined.
[calkindflag]
The CalKind_Flag on which all the Clock's times are defined.
[timeZone]
The timezone within which all the Clock's times are defined.
The number of times the ESMF_Clock has been advanced. Increments in ESMF_DIRECTION_FORWARD and decrements in ESMF_DIRECTION_REVERSE; see "direction" argument below and in ESMF_ClockSet().
[alarmCount]
The number of ESMF_Alarms in the ESMF_Clock's ESMF_Alarm list.
[direction]
The ESMF_Clock's time stepping direction. See also ESMF_ClockIsReverse(), an alternative for convenient use in "if" and "do while" constructs.
[name]
The name of this clock.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 44.5.9 ESMF_ClockGetAlarm - Get an Alarm in a Clock's Alarm list

INTERFACE:

       subroutine ESMF_ClockGetAlarm(clock, alarmname, alarm, &
rc)

ARGUMENTS:
       type(ESMF_Clock),  intent(in)            :: clock
character (len=*), intent(in)            :: alarmname
type(ESMF_Alarm),  intent(out)           :: alarm
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,           intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Gets the alarm whose name is the value of alarmname in the clock's ESMF_Alarm list.

The arguments are:

clock
The object instance to get the ESMF_Alarm from.
alarmname
The name of the desired ESMF_Alarm.
alarm
The desired alarm.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 44.5.10 ESMF_ClockGetAlarmList - Get a list of Alarms from a Clock

INTERFACE:

       subroutine ESMF_ClockGetAlarmList(clock, alarmlistflag, &
timeStep, alarmList, alarmCount, rc)

ARGUMENTS:
       type(ESMF_Clock),          intent(in)            :: clock
type(ESMF_AlarmList_Flag), intent(in)            :: alarmlistflag
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
type(ESMF_TimeInterval),   intent(in),  optional :: timeStep
type(ESMF_Alarm),          intent(out), optional :: alarmList(:)
integer,                   intent(out), optional :: alarmCount
integer,                   intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Gets the clock's list of alarms and/or number of alarms.

The arguments are:

clock
The object instance from which to get an ESMF_Alarm list and/or count of ESMF_Alarms.
alarmlistflag
The kind of list to get:

ESMF_ALARMLIST_ALL : Returns the ESMF_Clock's entire list of alarms.

ESMF_ALARMLIST_NEXTRINGING : Return only those alarms that will ring upon the next clock time step. Can optionally specify argument timeStep (see below) to use instead of the clock's. See also method ESMF_AlarmWillRingNext() for checking a single alarm.

ESMF_ALARMLIST_PREVRINGING : Return only those alarms that were ringing on the previous ESMF_Clock time step. See also method ESMF_AlarmWasPrevRinging() for checking a single alarm.

ESMF_ALARMLIST_RINGING : Returns only those clock alarms that are currently ringing. See also method ESMF_ClockAdvance() for getting the list of ringing alarms subsequent to a time step. See also method ESMF_AlarmIsRinging() for checking a single alarm.

[timeStep]
Optional time step to be used instead of the clock's. Only used with ESMF_ALARMLIST_NEXTRINGING alarmlistflag (see above); ignored if specified with other alarmlistflags.
[alarmList]
The array of returned alarms. If given, the array must be large enough to hold the number of alarms of the specified alarmlistflag in the specified clock.
[alarmCount]
If specified, returns the number of ESMF_Alarms of the specified alarmlistflag in the specified clock.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 44.5.11 ESMF_ClockGetNextTime - Calculate a Clock's next time

INTERFACE:

       subroutine ESMF_ClockGetNextTime(clock, nextTime, &
timeStep, rc)

ARGUMENTS:
       type(ESMF_Clock),        intent(in)            :: clock
type(ESMF_Time),         intent(out)           :: nextTime
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
type(ESMF_TimeInterval), intent(in),  optional :: timeStep
integer,                 intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Calculates what the next time of the clock will be, based on the clock's current time step or an optionally passed-in timeStep.

The arguments are:

clock
The object instance for which to get the next time.
nextTime
The resulting ESMF_Clock's next time.
[timeStep]
The time step interval to use instead of the clock's.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 44.5.12 ESMF_ClockIsCreated - Check whether a Clock object has been created

INTERFACE:

   function ESMF_ClockIsCreated(clock, rc)

RETURN VALUE:
     logical :: ESMF_ClockIsCreated

ARGUMENTS:
     type(ESMF_Clock), intent(in)            :: clock
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,             intent(out), optional :: rc

DESCRIPTION:

Return .true. if the clock has been created. Otherwise return .false.. If an error occurs, i.e. rc /= ESMF_SUCCESS is returned, the return value of the function will also be .false..

The arguments are:

clock
ESMF_Clock queried.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 44.5.13 ESMF_ClockIsDone - Based on its direction, test if the Clock has reached or exceeded its stop time or start time

INTERFACE:

       function ESMF_ClockIsDone(clock, rc)

RETURN VALUE:
       logical :: ESMF_ClockIsDone

ARGUMENTS:
       type(ESMF_Clock), intent(in)            :: clock
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,          intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Returns true if currentTime is greater than or equal to stopTime in ESMF_DIRECTION_FORWARD, or if currentTime is less than or equal to startTime in ESMF_DIRECTION_REVERSE. It returns false otherwise.

The arguments are:

clock
The object instance to check.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 44.5.14 ESMF_ClockIsReverse - Test if the Clock is in reverse mode

INTERFACE:

       function ESMF_ClockIsReverse(clock, rc)

RETURN VALUE:
       logical :: ESMF_ClockIsReverse

ARGUMENTS:
       type(ESMF_Clock), intent(in)            :: clock
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,          intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Returns true if clock is in ESMF_DIRECTION_REVERSE, and false if in ESMF_DIRECTION_FORWARD. Allows convenient use in "if" and "do while" constructs. Alternative to ESMF_ClockGet(...direction=...).

The arguments are:

clock
The object instance to check.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 44.5.15 ESMF_ClockIsStopTime - Test if the Clock has reached or exceeded its stop time

INTERFACE:

       function ESMF_ClockIsStopTime(clock, rc)

RETURN VALUE:
       logical :: ESMF_ClockIsStopTime

ARGUMENTS:
       type(ESMF_Clock), intent(in)            :: clock
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,          intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Returns true if the clock has reached or exceeded its stop time, and false otherwise.

The arguments are:

clock
The object instance to check.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 44.5.16 ESMF_ClockIsStopTimeEnabled - Test if the Clock's stop time is enabled

INTERFACE:

       function ESMF_ClockIsStopTimeEnabled(clock, rc)

RETURN VALUE:
       logical :: ESMF_ClockIsStopTimeEnabled

ARGUMENTS:
       type(ESMF_Clock), intent(in)            :: clock
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,          intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Returns true if the clock's stop time is set and enabled, and false otherwise.

The arguments are:

clock
The object instance to check.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 44.5.17 ESMF_ClockPrint - Print Clock information

INTERFACE:

       subroutine ESMF_ClockPrint(clock, options, preString, unit, rc)

ARGUMENTS:
       type(ESMF_Clock),  intent(in)            :: clock
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
character (len=*), intent(in),  optional :: options
character(*),      intent(in),  optional :: preString
character(*),      intent(out), optional :: unit
integer,           intent(out), optional :: rc

DESCRIPTION:

Prints out an ESMF_Clock's properties to stdout, in support of testing and debugging. The options control the type of information and level of detail.

The arguments are:

clock
ESMF_Clock to be printed out.
[options]
Print options. If none specified, prints all clock property values.
"advanceCount" - print the number of times the clock has been advanced.
"alarmCount" - print the number of alarms in the clock's list.
"alarmList" - print the clock's alarm list.
"currTime" - print the current clock time.
"direction" - print the clock's timestep direction.
"name" - print the clock's name.
"prevTime" - print the previous clock time.
"refTime" - print the clock's reference time.
"startTime" - print the clock's start time.
"stopTime" - print the clock's stop time.
"timeStep" - print the clock's time step.
[preString]
Optionally prepended string. Default to empty string.
[unit]
Internal unit, i.e. a string. Default to printing to stdout.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 44.5.18 ESMF_ClockSet - Set one or more properties of a Clock

INTERFACE:

       subroutine ESMF_ClockSet(clock, &
timeStep, startTime, stopTime, &
runDuration, runTimeStepCount, refTime, currTime, advanceCount, &
direction, name, rc)

ARGUMENTS:
       type(ESMF_Clock),        intent(inout)         :: clock
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
type(ESMF_TimeInterval), intent(in),  optional :: timeStep
type(ESMF_Time),         intent(in),  optional :: startTime
type(ESMF_Time),         intent(in),  optional :: stopTime
type(ESMF_TimeInterval), intent(in),  optional :: runDuration
integer,                 intent(in),  optional :: runTimeStepCount
type(ESMF_Time),         intent(in),  optional :: refTime
type(ESMF_Time),         intent(in),  optional :: currTime
type(ESMF_Direction_Flag),    intent(in),  optional :: direction
character (len=*),       intent(in),  optional :: name
integer,                 intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Sets/resets one or more of the properties of an ESMF_Clock that was previously initialized via ESMF_ClockCreate().

The arguments are:

clock
The object instance to set.
[timeStep]
The ESMF_Clock's time step interval, which can be positive or negative. This is used to change a clock's timestep property for those applications that need variable timesteps. See ESMF_ClockAdvance() below for specifying variable timesteps that are NOT saved as the clock's internal time step property. See "direction" argument below for behavior with
t ESMF_DIRECTION_REVERSE direction.
[startTime]
The ESMF_Clock's starting time. Can be less than or or greater than stopTime, depending on a positive or negative timeStep, respectively, and whether a stopTime is specified; see below.
[stopTime]
The ESMF_Clock's stopping time. Can be greater than or less than the startTime, depending on a positive or negative timeStep, respectively. If neither stopTime, runDuration, nor runTimeStepCount is specified, clock runs "forever"; user must use other means to know when to stop (e.g. ESMF_Alarm or ESMF_ClockGet(clock, currTime)). Mutually exclusive with runDuration and runTimeStepCount.
[runDuration]
Alternative way to specify ESMF_Clock's stopping time; stopTime = startTime + runDuration. Can be positive or negative, consistent with the timeStep's sign. Mutually exclusive with stopTime and runTimeStepCount.
[runTimeStepCount]
Alternative way to specify ESMF_Clock's stopping time; stopTime = startTime + (runTimeStepCount * timeStep). stopTime can be before startTime if timeStep is negative. Mutually exclusive with stopTime and runDuration.
[refTime]
The ESMF_Clock's reference time. See description in ESMF_ClockCreate() above.
[currTime]
The current time.
The number of times the clock has been timestepped.
[direction]
Sets the clock's time-stepping direction. If called with ESMF_DIRECTION_REVERSE, sets the clock in "reverse" mode, causing it to timestep back towards its startTime. If called with ESMF_DIRECTION_FORWARD, sets the clock in normal, "forward" mode, causing it to timestep in the direction of its startTime to stopTime. This holds true for negative timestep clocks as well, which are initialized (created) with stopTime < startTime. The default mode is ESMF_DIRECTION_FORWARD, established at ESMF_ClockCreate(). timeStep can also be specified as an argument at the same time, which allows for a change in magnitude and/or sign of the clock's timeStep. If not specified with ESMF_DIRECTION_REVERSE, the clock's current timeStep is effectively negated. If timeStep is specified, its sign is used as specified; it is not negated internally. E.g., if the specified timeStep is negative and the clock is placed in ESMF_DIRECTION_REVERSE, subsequent calls to ESMF_ClockAdvance() will cause the clock's current time to be decremented by the new timeStep's magnitude.
[name]
The new name for this clock.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 44.5.19 ESMF_ClockStopTimeDisable - Disable a Clock's stop time

INTERFACE:

       subroutine ESMF_ClockStopTimeDisable(clock, rc)

ARGUMENTS:
       type(ESMF_Clock), intent(inout)         :: clock
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,          intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Disables a ESMF_Clock's stop time; ESMF_ClockIsStopTime() will always return false, allowing a clock to run past its stopTime.

The arguments are:

clock
The object instance whose stop time to disable.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 44.5.20 ESMF_ClockStopTimeEnable - Enable an Clock's stop time

INTERFACE:

       subroutine ESMF_ClockStopTimeEnable(clock, stopTime, rc)

ARGUMENTS:
       type(ESMF_Clock), intent(inout)         :: clock
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
type(ESMF_Time),  intent(in),  optional :: stopTime
integer,          intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Enables a ESMF_Clock's stop time, allowing ESMF_ClockIsStopTime() to respect the stopTime.

The arguments are:

clock
The object instance whose stop time to enable.
[stopTime]
The stop time to set or reset.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 44.5.21 ESMF_ClockSyncToRealTime - Set Clock's current time to wall clock time

INTERFACE:

       subroutine ESMF_ClockSyncToRealTime(clock, rc)

ARGUMENTS:
       type(ESMF_Clock), intent(inout)         :: clock
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,          intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Sets a clock's current time to the wall clock time. It is accurate to the nearest second.

The arguments are:

clock
The object instance to be synchronized with wall clock time.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 44.5.22 ESMF_ClockValidate - Validate a Clock's properties

INTERFACE:

       subroutine ESMF_ClockValidate(clock, rc)

ARGUMENTS:
       type(ESMF_Clock),  intent(in)            :: clock
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,           intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Checks whether a clock is valid. Must have a valid startTime and timeStep. If clock has a stopTime, its currTime must be within startTime to stopTime, inclusive; also startTime's and stopTime's calendars must be the same.

The arguments are:

clock
ESMF_Clock to be validated.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

# 45 Alarm Class

## 45.1 Description

The Alarm class identifies events that occur at specific Times or specific TimeIntervals by returning a true value at those times or subsequent times, and a false value otherwise.

## 45.2 Constants

### 45.2.1 ESMF_ALARMLIST

DESCRIPTION:
Specifies the characteristics of Alarms that populate a retrieved Alarm list.

The type of this flag is:

type(ESMF_AlarmList_Flag)

The valid values are:

ESMF_ALARMLIST_ALL
All alarms.

ESMF_ALARMLIST_NEXTRINGING
Alarms that will ring before or at the next timestep.

ESMF_ALARMLIST_PREVRINGING
Alarms that rang at or since the last timestep.

ESMF_ALARMLIST_RINGING
Only ringing alarms.

## 45.3 Use and Examples

Alarms are used in conjunction with Clocks (see Section 44.1). Multiple Alarms can be associated with a Clock. During the ESMF_ClockAdvance() method, a Clock iterates over its internal Alarms to determine if any are ringing. Alarms ring when a specified Alarm time is reached or exceeded, taking into account whether the time step is positive or negative. In ESMF_DIRECTION_REVERSE (see Section 44.1), alarms ring in reverse, i.e., they begin ringing when they originally ended, and end ringing when they originally began. On completion of the time advance call, the Clock optionally returns a list of ringing alarms.

Each ringing Alarm can then be processed using Alarm methods for identifying, turning off, disabling or resetting the Alarm.

Alarm methods are defined for obtaining the ringing state, turning the ringer on/off, enabling/disabling the Alarm, and getting/setting associated times.

The following example shows how to set and process Alarms.

! !PROGRAM: ESMF_AlarmEx - Alarm examples
!
! !DESCRIPTION:
!
! This program shows an example of how to create, initialize, and process
! alarms associated with a clock.
!-----------------------------------------------------------------------------
#include "ESMF.h"

! ESMF Framework module
use ESMF
use ESMF_TestMod
implicit none

! instantiate time_step, start, stop, and alarm times
type(ESMF_TimeInterval) :: timeStep, alarmInterval
type(ESMF_Time) :: alarmTime, startTime, stopTime

! instantiate a clock
type(ESMF_Clock) :: clock

! instantiate Alarm lists
integer, parameter :: NUMALARMS = 2
type(ESMF_Alarm) :: alarm(NUMALARMS)

! local variables for Get methods
integer :: ringingAlarmCount  ! at any time step (0 to NUMALARMS)

! name, loop counter, result code
character (len=ESMF_MAXSTR) :: name
integer :: i, rc, result


      ! initialize ESMF framework
call ESMF_Initialize(defaultCalKind=ESMF_CALKIND_GREGORIAN, &
defaultlogfilename="AlarmEx.Log", &
logkindflag=ESMF_LOGKIND_MULTI, rc=rc)


### 45.3.1 Clock initialization

This example shows how to create and initialize an ESMF_Clock.

      ! initialize time interval to 1 day
call ESMF_TimeIntervalSet(timeStep, d=1, rc=rc)


      ! initialize start time to 9/1/2003
call ESMF_TimeSet(startTime, yy=2003, mm=9, dd=1, rc=rc)


      ! initialize stop time to 9/30/2003
call ESMF_TimeSet(stopTime, yy=2003, mm=9, dd=30, rc=rc)


      ! create & initialize the clock with the above values
clock = ESMF_ClockCreate(timeStep, startTime, stopTime=stopTime, &
name="The Clock", rc=rc)


### 45.3.2 Alarm initialization

This example shows how to create and initialize two ESMF_Alarms and associate them with the clock.

      ! Initialize first alarm to be a one-shot on 9/15/2003 and associate
! it with the clock
call ESMF_TimeSet(alarmTime, yy=2003, mm=9, dd=15, rc=rc)


      alarm(1) = ESMF_AlarmCreate(clock, &
ringTime=alarmTime, name="Example alarm 1", rc=rc)


      ! Initialize second alarm to ring on a 1 week interval starting 9/1/2003
! and associate it with the clock
call ESMF_TimeSet(alarmTime, yy=2003, mm=9, dd=1, rc=rc)


      call ESMF_TimeIntervalSet(alarmInterval, d=7, rc=rc)


      ! Alarm gets default name "Alarm002"
alarm(2) = ESMF_AlarmCreate(clock=clock, ringTime=alarmTime, &
ringInterval=alarmInterval, rc=rc)


### 45.3.3 Clock advance and Alarm processing

This example shows how to advance an ESMF_Clock and process any resulting ringing alarms.

      ! time step clock from start time to stop time
do while (.not.ESMF_ClockIsStopTime(clock, rc=rc))


        ! perform time step and get the number of any ringing alarms
rc=rc)


        call ESMF_ClockPrint(clock, options="currTime string", rc=rc)


        ! check if alarms are ringing
if (ringingAlarmCount > 0) then
print *, "number of ringing alarms = ", ringingAlarmCount

do i = 1, NUMALARMS
if (ESMF_AlarmIsRinging(alarm(i), rc=rc)) then


              call ESMF_AlarmGet(alarm(i), name=name, rc=rc)
print *, trim(name), " is ringing!"


              ! after processing alarm, turn it off
call ESMF_AlarmRingerOff(alarm(i), rc=rc)


            end if ! this alarm is ringing
end do ! each ringing alarm
endif ! ringing alarms
end do ! timestep clock


### 45.3.4 Alarm and Clock destruction

This example shows how to destroy ESMF_Alarms and ESMF_Clocks.

      call ESMF_AlarmDestroy(alarm(1), rc=rc)


      call ESMF_AlarmDestroy(alarm(2), rc=rc)


      call ESMF_ClockDestroy(clock, rc=rc)


      ! finalize ESMF framework
call ESMF_Finalize(rc=rc)


      end program ESMF_AlarmEx


## 45.4 Restrictions and Future Work

1. Alarm list allocation factor The alarm list within a clock is dynamically allocated automatically, 200 alarm references at a time. This constant is defined in both Fortran and C++ with a #define for ease of modification.

2. Sticky alarm end times in reverse For sticky alarms, there is an implicit limitation that in order to properly reverse timestep through a ring end time, that time must have already been traversed in the forward direction. This is due to the fact that the Time Manager cannot predict when user code will call ESMF_AlarmRingerOff(). An error message will be logged when this limitation is not satisfied.

3. Sticky alarm ring interval in reverse For repeating sticky alarms, it is currently assumed that the ringInterval is constant, so that only the time of the last call to ESMF_AlarmRingerOff() is saved. In ESMF_DIRECTION_REVERSE, this information is used to turn sticky alarms back on. In a future release, ringIntervals will be allowed to be variable, by saving alarm state at every timestep.

## 45.5 Design and Implementation Notes

The Alarm class is designed as a deep, dynamically allocatable class, based on a pointer type. This allows for both indirect and direct manipulation of alarms. Indirect alarm manipulation is where ESMF_Alarm API methods, such as ESMF_AlarmRingerOff(), are invoked on alarm references (pointers) returned from ESMF_Clock queries such as "return ringing alarms." Since the method is performed on an alarm reference, the actual alarm held by the clock is affected, not just a user's local copy. Direct alarm manipulation is the more common case where alarm API methods are invoked on the original alarm objects created by the user.

For consistency, the ESMF_Clock class is also designed as a deep, dynamically allocatable class.

An additional benefit from this approach is that Clocks and Alarms can be created and used from anywhere in a user's code without regard to the scope in which they were created. In contrast, statically created Alarms and Clocks would disappear if created within a user's routine that returns, whereas dynamically allocated Alarms and Clocks will persist until explicitly destroyed by the user.

## 45.6 Class API

### 45.6.1 ESMF_AlarmAssignment(=) - Assign an Alarm to another Alarm

INTERFACE:

       interface assignment(=)
alarm1 = alarm2

ARGUMENTS:
       type(ESMF_Alarm) :: alarm1
type(ESMF_Alarm) :: alarm2

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Assign alarm1 as an alias to the same ESMF_Alarm object in memory as alarm2. If alarm2 is invalid, then alarm1 will be equally invalid after the assignment.

The arguments are:

alarm1
The ESMF_Alarm object on the left hand side of the assignment.
alarm2
The ESMF_Alarm object on the right hand side of the assignment.

### 45.6.2 ESMF_AlarmOperator(==) - Test if Alarm 1 is equal to Alarm 2

INTERFACE:

       interface operator(==)
if (alarm1 == alarm2) then ... endif
OR
result = (alarm1 == alarm2)

RETURN VALUE:
       logical :: result

ARGUMENTS:
       type(ESMF_Alarm), intent(in) :: alarm1
type(ESMF_Alarm), intent(in) :: alarm2

DESCRIPTION:

Overloads the (==) operator for the ESMF_Alarm class. Compare two alarms for equality; return .true. if equal, .false. otherwise. Comparison is based on IDs, which are distinct for newly created alarms and identical for alarms created as copies.

If either side of the equality test is not in the ESMF_INIT_CREATED status an error will be logged. However, this does not affect the return value, which is .true. when both sides are in the same status, and .false. otherwise.

The arguments are:

alarm1
The ESMF_Alarm object on the left hand side of the equality operation.
alarm2
The ESMF_Alarm object on the right hand side of the equality operation.

### 45.6.3 ESMF_AlarmOperator(/=) - Test if Alarm 1 is not equal to Alarm 2

INTERFACE:

       interface operator(/=)
if (alarm1 /= alarm2) then ... endif
OR
result = (alarm1 /= alarm2)

RETURN VALUE:
       logical :: result

ARGUMENTS:
       type(ESMF_Alarm), intent(in) :: alarm1
type(ESMF_Alarm), intent(in) :: alarm2

DESCRIPTION:

Overloads the (/=) operator for the ESMF_Alarm class. Compare two alarms for inequality; return .true. if not equal, .false. otherwise. Comparison is based on IDs, which are distinct for newly created alarms and identical for alarms created as copies.

If either side of the equality test is not in the ESMF_INIT_CREATED status an error will be logged. However, this does not affect the return value, which is .true. when both sides are not in the same status, and .false. otherwise.

The arguments are:

alarm1
The ESMF_Alarm object on the left hand side of the non-equality operation.
alarm2
The ESMF_Alarm object on the right hand side of the non-equality operation.

### 45.6.4 ESMF_AlarmCreate - Create a new ESMF Alarm

INTERFACE:

       ! Private name; call using ESMF_AlarmCreate()
function ESMF_AlarmCreateNew(clock, &
ringTime, ringInterval, stopTime, ringDuration, ringTimeStepCount, &
refTime, enabled, sticky, name, rc)

RETURN VALUE:
       type(ESMF_Alarm) :: ESMF_AlarmCreateNew

ARGUMENTS:
       type(ESMF_Clock),        intent(in)            :: clock
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
type(ESMF_Time),         intent(in),  optional :: ringTime
type(ESMF_TimeInterval), intent(in),  optional :: ringInterval
type(ESMF_Time),         intent(in),  optional :: stopTime
type(ESMF_TimeInterval), intent(in),  optional :: ringDuration
integer,                 intent(in),  optional :: ringTimeStepCount
type(ESMF_Time),         intent(in),  optional :: refTime
logical,                 intent(in),  optional :: enabled
logical,                 intent(in),  optional :: sticky
character (len=*),       intent(in),  optional :: name
integer,                 intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Creates and sets the initial values in a new ESMF_Alarm.

In ESMF_DIRECTION_REVERSE (see Section 44.1), alarms ring in reverse, i.e., they begin ringing when they originally ended, and end ringing when they originally began.

The arguments are:

clock
The clock with which to associate this newly created alarm.
[ringTime]
The ring time for a one-shot alarm or the first ring time for a repeating (interval) alarm. Must specify at least one of ringTime or ringInterval.
[ringInterval]
The ring interval for repeating (interval) alarms. If ringTime is not also specified (first ring time), it will be calculated as the clock's current time plus ringInterval. Must specify at least one of ringTime or ringInterval.
[stopTime]
The stop time for repeating (interval) alarms. If not specified, an interval alarm will repeat forever.
[ringDuration]
The absolute ring duration. If not sticky (see argument below), alarms rings for ringDuration, then turns itself off. Default is zero (unused). Mutually exclusive with ringTimeStepCount (below); used only if set to a non-zero duration and ringTimeStepCount is 1 (see below). See also ESMF_AlarmSticky(), ESMF_AlarmNotSticky().
[ringTimeStepCount]
The relative ring duration. If not sticky (see argument below), alarms rings for ringTimeStepCount, then turns itself off. Default is 1: a non-sticky alarm will ring for one clock time step. Mutually exclusive with ringDuration (above); used if ringTimeStepCount > 1. If ringTimeStepCount is 1 (default) and ringDuration is non-zero, ringDuration is used (see above), otherwise ringTimeStepCount is used. See also ESMF_AlarmSticky(), ESMF_AlarmNotSticky().
[refTime]
The reference (i.e. base) time for an interval alarm.
[enabled]
Sets the enabled state; default is on (true). If disabled, an alarm will not function at all. See also ESMF_AlarmEnable(), ESMF_AlarmDisable().
[sticky]
Sets the sticky state; default is on (true). If sticky, once an alarm is ringing, it will remain ringing until turned off manually via a user call to ESMF_AlarmRingerOff(). If not sticky, an alarm will turn itself off after a certain ring duration specified by either ringDuration or ringTimeStepCount (see above). There is an implicit limitation that in order to properly reverse timestep through a ring end time in ESMF_DIRECTION_REVERSE, that time must have already been traversed in the forward direction. This is due to the fact that the Time Manager cannot predict when user code will call ESMF_AlarmRingerOff(). An error message will be logged when this limitation is not satisfied. See also ESMF_AlarmSticky(), ESMF_AlarmNotSticky().
[name]
The name for the newly created alarm. If not specified, a default unique name will be generated: "AlarmNNN" where NNN is a unique sequence number from 001 to 999.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 45.6.5 ESMF_AlarmCreate - Create a copy of an existing ESMF Alarm

INTERFACE:

       ! Private name; call using ESMF_AlarmCreate()
function ESMF_AlarmCreateCopy(alarm, rc)

RETURN VALUE:
       type(ESMF_Alarm) :: ESMF_AlarmCreateCopy

ARGUMENTS:
       type(ESMF_Alarm), intent(in)            :: alarm
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,          intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Creates a complete (deep) copy of a given ESMF_Alarm. The returned ESMF_Alarm copy is associated with the same ESMF_Clock as the original ESMF_Alarm. If desired, use ESMF_AlarmSet(...clock=...) to re-associate the ESMF_Alarm copy with a different ESMF_Clock.

The arguments are:

alarm
The ESMF_Alarm to copy.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 45.6.6 ESMF_AlarmDestroy - Release resources associated with an Alarm

INTERFACE:

       subroutine ESMF_AlarmDestroy(alarm, rc)

ARGUMENTS:
       type(ESMF_Alarm), intent(inout)          :: alarm
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,          intent(out),  optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Releases resources associated with this ESMF_Alarm. Also removes this ESMF_Alarm from its associated ESMF_Clock's list of ESMF_Alarms (removes the ESMF_Alarm pointer from the list).

The arguments are:

alarm
Release resources associated with this ESMF_Alarm and mark the object as invalid. It is an error to pass this object into any other routines after being destroyed.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 45.6.7 ESMF_AlarmDisable - Disable an Alarm

INTERFACE:

       subroutine ESMF_AlarmDisable(alarm, rc)

ARGUMENTS:
       type(ESMF_Alarm), intent(inout)         :: alarm
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,          intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Disables an ESMF_Alarm.

The arguments are:

alarm
The object instance to disable.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 45.6.8 ESMF_AlarmEnable - Enable an Alarm

INTERFACE:

       subroutine ESMF_AlarmEnable(alarm, rc)

ARGUMENTS:
       type(ESMF_Alarm), intent(inout)         :: alarm
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,          intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Enables an ESMF_Alarm to function.

The arguments are:

alarm
The object instance to enable.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 45.6.9 ESMF_AlarmGet - Get Alarm properties

INTERFACE:

       subroutine ESMF_AlarmGet(alarm, &
clock, ringTime, prevRingTime, ringInterval, stopTime, ringDuration, &
ringTimeStepCount, timeStepRingingCount, ringBegin, ringEnd, &
refTime, ringing, ringingOnPrevTimeStep, enabled, sticky, name, rc)

ARGUMENTS:
       type(ESMF_Alarm),        intent(in)            :: alarm
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
type(ESMF_Clock),        intent(out), optional :: clock
type(ESMF_Time),         intent(out), optional :: ringTime
type(ESMF_Time),         intent(out), optional :: prevRingTime
type(ESMF_TimeInterval), intent(out), optional :: ringInterval
type(ESMF_Time),         intent(out), optional :: stopTime
type(ESMF_TimeInterval), intent(out), optional :: ringDuration
integer,                 intent(out), optional :: ringTimeStepCount
integer,                 intent(out), optional :: timeStepRingingCount
type(ESMF_Time),         intent(out), optional :: ringBegin
type(ESMF_Time),         intent(out), optional :: ringEnd
type(ESMF_Time),         intent(out), optional :: refTime
logical,                 intent(out), optional :: ringing
logical,                 intent(out), optional :: ringingOnPrevTimeStep
logical,                 intent(out), optional :: enabled
logical,                 intent(out), optional :: sticky
character (len=*),       intent(out), optional :: name
integer,                 intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Gets one or more of an ESMF_Alarm's properties.

The arguments are:

alarm
The object instance to query.
[clock]
The associated clock.
[ringTime]
The ring time for a one-shot alarm or the next repeating alarm.
[prevRingTime]
The previous ring time.
[ringInterval]
The ring interval for repeating (interval) alarms.
[stopTime]
The stop time for repeating (interval) alarms.
[ringDuration]
The ring duration. Mutually exclusive with ringTimeStepCount (see below).
[ringTimeStepCount]
The number of time steps comprising the ring duration. Mutually exclusive with ringDuration (see above).
[timeStepRingingCount]
The number of time steps for which the alarm has been ringing thus far. Used internally for tracking ringTimeStepCount ring durations (see above). Mutually exclusive with ringBegin (see below). Increments in ESMF_DIRECTION_FORWARD and decrements in ESMF_DIRECTION_REVERSE; see Section 44.1.
[ringBegin]
The time when the alarm began ringing. Used internally for tracking ringDuration (see above). Mutually exclusive with timeStepRingingCount (see above).
[ringEnd]
The time when the alarm ended ringing. Used internally for re-ringing alarm in ESMF_DIRECTION_REVERSE.
[refTime]
The reference (i.e. base) time for an interval alarm.
[ringing]
[ringingOnPrevTimeStep]
The ringing state upon the previous time step. Same as ESMF_AlarmWasPrevRinging().
[enabled]
[sticky]
[name]
The name of this alarm.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 45.6.10 ESMF_AlarmIsCreated - Check whether a Alarm object has been created

INTERFACE:

   function ESMF_AlarmIsCreated(alarm, rc)

RETURN VALUE:
     logical :: ESMF_AlarmIsCreated

ARGUMENTS:
     type(ESMF_Alarm), intent(in)            :: alarm
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,             intent(out), optional :: rc

DESCRIPTION:

Return .true. if the alarm has been created. Otherwise return .false.. If an error occurs, i.e. rc /= ESMF_SUCCESS is returned, the return value of the function will also be .false..

The arguments are:

alarm
ESMF_Alarm queried.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 45.6.11 ESMF_AlarmIsEnabled - Check if Alarm is enabled

INTERFACE:

       function ESMF_AlarmIsEnabled(alarm, rc)

RETURN VALUE:
       logical :: ESMF_AlarmIsEnabled

ARGUMENTS:
       type(ESMF_Alarm), intent(in)            :: alarm
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,          intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Check if ESMF_Alarm is enabled.

The arguments are:

alarm
The object instance to check for enabled state.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 45.6.12 ESMF_AlarmIsRinging - Check if Alarm is ringing

INTERFACE:

       function ESMF_AlarmIsRinging(alarm, rc)

RETURN VALUE:
       logical :: ESMF_AlarmIsRinging

ARGUMENTS:
       type(ESMF_Alarm), intent(in)            :: alarm
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,          intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Check if ESMF_Alarm is ringing.

See also method ESMF_ClockGetAlarmList(clock, ESMF_ALARMLIST_RINGING, ...) to get a list of all ringing alarms belonging to an ESMF_Clock.

The arguments are:

alarm
The alarm to check for ringing state.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 45.6.13 ESMF_AlarmIsSticky - Check if Alarm is sticky

INTERFACE:

       function ESMF_AlarmIsSticky(alarm, rc)

RETURN VALUE:
       logical :: ESMF_AlarmIsSticky

ARGUMENTS:
       type(ESMF_Alarm), intent(in)            :: alarm
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,          intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Check if alarm is sticky.

The arguments are:

alarm
The object instance to check for sticky state.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 45.6.14 ESMF_AlarmNotSticky - Unset an Alarm's sticky flag

INTERFACE:

       subroutine ESMF_AlarmNotSticky(alarm, &
ringDuration, ringTimeStepCount, rc)

ARGUMENTS:
       type(ESMF_Alarm),        intent(inout)         :: alarm
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
type(ESMF_TimeInterval), intent(in),  optional :: ringDuration
integer,                 intent(in),  optional :: ringTimeStepCount
integer,                 intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Unset an ESMF_Alarm's sticky flag; once alarm is ringing, it turns itself off after ringDuration.

The arguments are:

alarm
The object instance to unset sticky.
[ringDuration]
If not sticky, alarms rings for ringDuration, then turns itself off. Mutually exclusive with ringTimeStepCount (see below and full description in method ESMF_AlarmCreate() or ESMF_AlarmSet()).
[ringTimeStepCount]
If not sticky, alarms rings for ringTimeStepCount, then turns itself off. Mutually exclusive with ringDuration (see above and full description in method ESMF_AlarmCreate() or ESMF_AlarmSet()).
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 45.6.15 ESMF_AlarmPrint - Print Alarm information

INTERFACE:

       subroutine ESMF_AlarmPrint(alarm, options, rc)

ARGUMENTS:
       type(ESMF_Alarm),  intent(in)            :: alarm
character (len=*), intent(in),  optional :: options
integer,           intent(out), optional :: rc

DESCRIPTION:

Prints out an ESMF_Alarm's properties to stdout, in support of testing and debugging. The options control the type of information and level of detail.

The arguments are:

alarm
ESMF_Alarm to be printed out.
[options]
Print options. If none specified, prints all alarm property values.
"clock" - print the associated clock's name.
"enabled" - print the alarm's ability to ring.
"name" - print the alarm's name.
"prevRingTime" - print the alarm's previous ring time.
"ringBegin" - print time when the alarm actually begins to ring.
"ringDuration" - print how long this alarm is to remain ringing.
"ringEnd" - print time when the alarm actually ends ringing.
"ringing" - print the alarm's current ringing state.
"ringingOnPrevTimeStep" - print whether the alarm was ringing immediately after the previous clock time step.
"ringInterval" - print the alarm's periodic ring interval.
"ringTime" - print the alarm's next time to ring.
"ringTimeStepCount" - print how long this alarm is to remain ringing, in terms of a number of clock time steps.
"refTime" - print the alarm's interval reference (base) time.
"sticky" - print whether the alarm must be turned off manually.
"stopTime" - print when alarm intervals end.
"timeStepRingingCount" - print the number of time steps the alarm has been ringing thus far.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 45.6.16 ESMF_AlarmRingerOff - Turn off an Alarm

INTERFACE:

       subroutine ESMF_AlarmRingerOff(alarm, rc)

ARGUMENTS:
       type(ESMF_Alarm), intent(inout)         :: alarm
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,          intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Turn off an ESMF_Alarm; unsets ringing state. For a sticky alarm, this method must be called to turn off its ringing state. This is true for either ESMF_DIRECTION_FORWARD (default) or ESMF_DIRECTION_REVERSE. See Section 44.1.

The arguments are:

alarm
The object instance to turn off.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 45.6.17 ESMF_AlarmRingerOn - Turn on an Alarm

INTERFACE:

       subroutine ESMF_AlarmRingerOn(alarm, rc)

ARGUMENTS:
       type(ESMF_Alarm), intent(inout)         :: alarm
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,          intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Turn on an ESMF_Alarm; sets ringing state.

The arguments are:

alarm
The object instance to turn on.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 45.6.18 ESMF_AlarmSet - Set Alarm properties

INTERFACE:

       subroutine ESMF_AlarmSet(alarm, &
clock, ringTime, ringInterval, stopTime, ringDuration, &
ringTimeStepCount, refTime, ringing, enabled, sticky, name, rc)

ARGUMENTS:
       type(ESMF_Alarm),        intent(inout)         :: alarm
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
type(ESMF_Clock),        intent(in),  optional :: clock
type(ESMF_Time),         intent(in),  optional :: ringTime
type(ESMF_TimeInterval), intent(in),  optional :: ringInterval
type(ESMF_Time),         intent(in),  optional :: stopTime
type(ESMF_TimeInterval), intent(in),  optional :: ringDuration
integer,                 intent(in),  optional :: ringTimeStepCount
type(ESMF_Time),         intent(in),  optional :: refTime
logical,                 intent(in),  optional :: ringing
logical,                 intent(in),  optional :: enabled
logical,                 intent(in),  optional :: sticky
character (len=*),       intent(in),  optional :: name
integer,                 intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Sets/resets one or more of the properties of an ESMF_Alarm that was previously initialized via ESMF_AlarmCreate().

The arguments are:

alarm
The object instance to set.
[clock]
Re-associates this alarm with a different clock.
[ringTime]
The next ring time for a one-shot alarm or a repeating (interval) alarm.
[ringInterval]
The ring interval for repeating (interval) alarms.
[stopTime]
The stop time for repeating (interval) alarms.
[ringDuration]
The absolute ring duration. If not sticky (see argument below), alarms rings for ringDuration, then turns itself off. Default is zero (unused). Mutually exclusive with ringTimeStepCount (below); used only if set to a non-zero duration and ringTimeStepCount is 1 (see below). See also ESMF_AlarmSticky(), ESMF_AlarmNotSticky().
[ringTimeStepCount]
The relative ring duration. If not sticky (see argument below), alarms rings for ringTimeStepCount, then turns itself off. Default is 1: a non-sticky alarm will ring for one clock time step. Mutually exclusive with ringDuration (above); used if ringTimeStepCount > 1. If ringTimeStepCount is 1 (default) and ringDuration is non-zero, ringDuration is used (see above), otherwise ringTimeStepCount is used. See also ESMF_AlarmSticky(), ESMF_AlarmNotSticky().
[refTime]
The reference (i.e. base) time for an interval alarm.
[ringing]
[enabled]
Sets the enabled state. If disabled, an alarm will not function at all. See also ESMF_AlarmEnable(), ESMF_AlarmDisable().
[sticky]
Sets the sticky state. If sticky, once an alarm is ringing, it will remain ringing until turned off manually via a user call to ESMF_AlarmRingerOff(). If not sticky, an alarm will turn itself off after a certain ring duration specified by either ringDuration or ringTimeStepCount (see above). There is an implicit limitation that in order to properly reverse timestep through a ring end time in ESMF_DIRECTION_REVERSE, that time must have already been traversed in the forward direction. This is due to the fact that the Time Manager cannot predict when user code will call ESMF_AlarmRingerOff(). An error message will be logged when this limitation is not satisfied. See also ESMF_AlarmSticky(), ESMF_AlarmNotSticky().
[name]
The new name for this alarm.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 45.6.19 ESMF_AlarmSticky - Set an Alarm's sticky flag

INTERFACE:

       subroutine ESMF_AlarmSticky(alarm, rc)

ARGUMENTS:
       type(ESMF_Alarm), intent(inout)         :: alarm
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,          intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Set an ESMF_Alarm's sticky flag; once alarm is ringing, it remains ringing until ESMF_AlarmRingerOff() is called. There is an implicit limitation that in order to properly reverse timestep through a ring end time in ESMF_DIRECTION_REVERSE, that time must have already been traversed in the forward direction. This is due to the fact that an ESMF_Alarm cannot predict when user code will call ESMF_AlarmRingerOff(). An error message will be logged when this limitation is not satisfied.

The arguments are:

alarm
The object instance to be set sticky.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 45.6.20 ESMF_AlarmValidate - Validate an Alarm's properties

INTERFACE:

       subroutine ESMF_AlarmValidate(alarm, rc)

ARGUMENTS:
       type(ESMF_Alarm),  intent(in)            :: alarm
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,           intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Performs a validation check on an ESMF_Alarm's properties. Must have a valid ringTime, set either directly or indirectly via ringInterval. See ESMF_AlarmCreate().

The arguments are:

alarm
ESMF_Alarm to be validated.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 45.6.21 ESMF_AlarmWasPrevRinging - Check if Alarm was ringing on the previous Clock timestep

INTERFACE:

       function ESMF_AlarmWasPrevRinging(alarm, rc)

RETURN VALUE:
       logical :: ESMF_AlarmWasPrevRinging

ARGUMENTS:
       type(ESMF_Alarm), intent(in)            :: alarm
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,          intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Check if ESMF_Alarm was ringing on the previous clock timestep.

See also method ESMF_ClockGetAlarmList(clock, ESMF_ALARMLIST_PREVRINGING, ...) get a list of all alarms belonging to a ESMF_Clock that were ringing on the previous time step.

The arguments are:

alarm
The object instance to check for previous ringing state.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 45.6.22 ESMF_AlarmWillRingNext - Check if Alarm will ring upon the next Clock timestep

INTERFACE:

       function ESMF_AlarmWillRingNext(alarm, timeStep, rc)

RETURN VALUE:
       logical :: ESMF_AlarmWillRingNext

ARGUMENTS:
       type(ESMF_Alarm),        intent(in)            :: alarm
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
type(ESMF_TimeInterval), intent(in),  optional :: timeStep
integer,                 intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Check if ESMF_Alarm will ring on the next clock timestep, either the current clock timestep or a passed-in timestep.

See also method ESMF_ClockGetAlarmList(clock, ESMF_ALARMLIST_NEXTRINGING, ...) to get a list of all alarms belonging to a ESMF_Clock that will ring on the next time step.

The arguments are:

alarm
The alarm to check for next ringing state.
[timeStep]
Optional timestep to use instead of the clock's.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

# 46 Config Class

## 46.1 Description

ESMF Configuration Management is based on NASA DAO's Inpak 90 package, a Fortran 90 collection of routines/functions for accessing Resource Files in ASCII format.The package is optimized for minimizing formatted I/O, performing all of its string operations in memory using Fortran intrinsic functions.

### 46.1.1 Package history

The ESMF Configuration Management Package was evolved by Leonid Zaslavsky and Arlindo da Silva from Ipack90 package created by Arlindo da Silva at NASA DAO.

Back in the 70's Eli Isaacson wrote IOPACK in Fortran 66. In June of 1987 Arlindo da Silva wrote Inpak77 using Fortran 77 string functions; Inpak 77 is a vastly simplified IOPACK, but has its own goodies not found in IOPACK. Inpak 90 removes some obsolete functionality in Inpak77, and parses the whole resource file in memory for performance.

### 46.1.2 Resource files

A Resource File (RF) is a text file consisting of list of label-value pairs. There is a limit of 250 characters per line and the Resource File can contain a maximum of 200 records. Each label should be followed by some data, the value. An example Resource File follows. It is the file used in the example below.

 # This is an example Resource File.
# It contains a list of <label,value> pairs.
# The colon after the label is required.

# The values after the label can be an list.
# Multiple types are authorized.

my_file_names:         jan87.dat jan88.dat jan89.dat  # all strings
constants:             3.1415   25                    # float and integer
my_favorite_colors:    green blue 022

# Or, the data can be a list of single value pairs.
# It is simplier to retrieve data in this format:

parameter_1:           89
parameter_2:           78.2
input_file_name:       dummy_input.netcdf

# Or, the data can be located in a table using the following
# syntax:

my_table_name::
1000     3000     263.0
925     3000     263.0
850     3000     263.0
700     3000     269.0
500     3000     287.0
400     3000     295.8
300     3000     295.8
::


Note that the colon after the label is required and that the double colon is required to declare tabular data.

Resource files are intended for random access (except between ::'s in a table definition). This means that order in which a particular label-value pair is retrieved is not dependent upon the original order of the pairs. The only exception to this, however, is when the same label appears multiple times within the Resource File.

## 46.2 Use and Examples

This example/test code performs simple Config/Resource File routines. It does not include attaching a Config to a component. The important thing to remember there is that you can have one Config per component.

There are two methodologies for accessing data in a Resource File. This example will demonstrate both.

Note the API section contains a complete description of arguments in the methods/functions demonstrated in this example.

### 46.2.1 Variable declarations

The following are the variable declarations used as arguments in the following code fragments. They represent the locals names for the variables listed in the Resource File (RF). Note they do not need to be the same.

      character(ESMF_MAXPATHLEN) :: fname ! config file name
character(ESMF_MAXPATHLEN) :: fn1, fn2, fn3, input_file ! strings to be read in
integer       :: rc            ! error return code (0 is OK)
integer       :: i_n           ! the first constant in the RF
real          :: param_1       ! the second constant in the RF
real          :: table(7,3)    ! an array to hold the table in the RF

type(ESMF_Config)   :: cf      ! the Config itself


### 46.2.2 Creation of a Config

While there are two methodologies for accessing the data within a Resource File, there is only one way to create the initial Config and load its ASCII text into memory. This is the first step in the process.

Note that subsequent calls to ESMF_ConfigLoadFile will OVERWRITE the current Config NOT append to it. There is no means of appending to a Config.

      cf = ESMF_ConfigCreate(rc=rc)             ! Create the empty Config


      fname = "myResourceFile.rc"                ! Name the Resource File
! into the empty Config


### 46.2.3 How to retrieve a label with a single value

The first method for retrieving information from the Resource File takes advantage of the <label,value> relationship within the file and access the data in a dictionary-like manner. This is the simplest methodology, but it does imply the use of only one value per label in the Resource File.

Remember, that the order in which a particular label/value pair is retrieved is not dependent upon the order which they exist within the Resource File.

    call ESMF_ConfigGetAttribute(cf, radius, label='radius_of_the_earth:', &
default=1.0, rc=rc)


Note that the colon must be included in the label string when using this methodology. It is also important to provide a default value in case the label does not exist in the file

This methodology works for all types. The following is an example of retrieving a string:

    call ESMF_ConfigGetAttribute(cf, input_file, label='input_file_name:', &
default="./default.nc", rc=rc)


The same code fragment can be used to demonstrate what happens when the label is not present. Note that "file_name" does not exist in the Resource File. The result of its absence is the default value provided in the call.

    call ESMF_ConfigGetAttribute(cf, input_file, label='file_name:', &
default="./default.nc", rc=rc)


### 46.2.4 How to retrieve a label with multiple values

When there are multiple, mixed-typed values associated with a label, the values can be retrieved in two steps: 1) Use ESMF_ConfigFindLabel() to find the label in the Config class; 2) use ESMF_ConfigGetAttribute() without the optional 'label' argument to retrieve the values one at a time, reading from left to right in the record.

A second reminder that the order in which a particular label/value pair is retrieved is not dependent upon the order which they exist within the Resource File. The label used in this method allows the user to skip to any point in the file.

      call ESMF_ConfigFindLabel(cf, 'constants:', rc=rc) ! Step a) Find the
! label


Two constants, radius and i_n, can now be retrieved without having to specify their label or use an array. They are also different types.

      call ESMF_ConfigGetAttribute(cf, param_1, rc=rc) ! Step b) read in the
! first constant in
! the sequence
call ESMF_ConfigGetAttribute(cf, i_n, rc=rc)     ! Step c) read in the
! second constant in
! the sequence


This methodology also works with strings.

       call ESMF_ConfigFindLabel(cf, 'my_file_names:', &
rc=rc)                       ! Step a) find the label


       call ESMF_ConfigGetAttribute(cf, fn1, &
rc=rc)                    ! Step b) retrieve the 1st filename
call ESMF_ConfigGetAttribute(cf, fn2, &
rc=rc)                    ! Step c) retrieve the 2nd filename
call ESMF_ConfigGetAttribute(cf, fn3, &
rc=rc)                    ! Step d) retrieve the 3rd filename


### 46.2.5 How to retrieve a table

To access tabular data, the user must use the multi-value method.

      call ESMF_ConfigFindLabel(cf, 'my_table_name::', &
rc=rc)        ! Step a) Set the label location to the
! beginning of the table


Subsequently, call ESMF_ConfigNextLine() is used to move the location to the next row of the table. The example table in the Resource File contains 7 rows and 3 columns (7,3).

      do i = 1, 7
call ESMF_ConfigNextLine(cf, rc=rc) ! Step b) Increment the rows
do j = 1, 3                         ! Step c) Fill in the table
call ESMF_ConfigGetAttribute(cf, table(i,j), rc=rc)
enddo
enddo


### 46.2.6 Destruction of a Config

The work with the configuration file cf is finalized by call to ESMF_ConfigDestroy():

      call ESMF_ConfigDestroy(cf, rc=rc) ! Destroy the Config


## 46.3 Class API

### 46.3.1 ESMF_ConfigAssignment(=) - Config assignment

INTERFACE:

     interface assignment(=)
config1 = config2

ARGUMENTS:
     type(ESMF_Config) :: config1
type(ESMF_Config) :: config2

DESCRIPTION:

Assign config1 as an alias to the same ESMF_Config object in memory as config2. If config2 is invalid, then config1 will be equally invalid after the assignment.

The arguments are:

config1
The ESMF_Config object on the left hand side of the assignment.
config2
The ESMF_Config object on the right hand side of the assignment.

### 46.3.2 ESMF_ConfigOperator(==) - Test if Config objects are equivalent

INTERFACE:

       interface operator(==)
if (config1 == config2) then ... endif
OR
result = (config1 == config2)

RETURN VALUE:
       configical :: result

ARGUMENTS:
       type(ESMF_Config), intent(in) :: config1
type(ESMF_Config), intent(in) :: config2

DESCRIPTION:

Overloads the (==) operator for the ESMF_Config class. Compare two configs for equality; return .true. if equal, .false. otherwise. Comparison is based on whether the objects are distinct, as with two newly created objects, or are simply aliases to the same object as would be the case when assignment was involved.

The arguments are:

config1
The ESMF_Config object on the left hand side of the equality operation.
config2
The ESMF_Config object on the right hand side of the equality operation.

### 46.3.3 ESMF_ConfigOperator(/=) - Test if Config objects are not equivalent

INTERFACE:

       interface operator(/=)
if (config1 /= config2) then ... endif
OR
result = (config1 /= config2)

RETURN VALUE:
       configical :: result

ARGUMENTS:
       type(ESMF_Config), intent(in) :: config1
type(ESMF_Config), intent(in) :: config2

DESCRIPTION:

Overloads the (/=) operator for the ESMF_Config class. Compare two configs for equality; return .true. if not equivalent, .false. otherwise. Comparison is based on whether the Config objects are distinct, as with two newly created objects, or are simply aliases to the same object as would be the case when assignment was involved.

The arguments are:

config1
The ESMF_Config object on the left hand side of the equality operation.
config2
The ESMF_Config object on the right hand side of the equality operation.

### 46.3.4 ESMF_ConfigCreate - Instantiate a Config object

INTERFACE:

       ! Private name; call using ESMF_ConfigCreate()
type(ESMF_Config) function ESMF_ConfigCreateEmpty(rc)

ARGUMENTS:
 -- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,intent(out), optional              :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Instantiates an ESMF_Config object for use in subsequent calls.

The arguments are:

[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 46.3.5 ESMF_ConfigCreate - Instantiate a new Config object from a Config section

INTERFACE:

     ! Private name; call using ESMF_ConfigCreate()
type(ESMF_Config) function ESMF_ConfigCreateFromSection(config, &
openlabel, closelabel, rc)

ARGUMENTS:
       type(ESMF_Config)             :: config
character(len=*),  intent(in) :: openlabel, closelabel
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,intent(out), optional :: rc

DESCRIPTION:

Instantiates an ESMF_Config object from a section of an existing ESMF_Config object delimited by openlabel and closelabel. An error is returned if neither of the input labels is found in input config.

Note that a section is intended as the content of a given ESMF_Config object delimited by two distinct labels. Such content, as well as each of the surrounding labels, are still within the scope of the parent ESMF_Config object. Therefore, including in a section labels used outside that section should be done carefully to prevent parsing conflicts.

The arguments are:

config
The input ESMF_Config object.
openlabel
Label marking the beginning of a section in config.
closelabel
Label marking the end of a section in config.
[rc]
Return code; equals ESMF_SUCCESS if a section is found and a new ESMF_Config object returned.

### 46.3.6 ESMF_ConfigDestroy - Destroy a Config object

INTERFACE:

     subroutine ESMF_ConfigDestroy(config, rc)

ARGUMENTS:
       type(ESMF_Config), intent(inout)          :: config
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,           intent(out),  optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Destroys the config object.

The arguments are:

config
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 46.3.7 ESMF_ConfigFindLabel - Find a label in a Config object

INTERFACE:

     subroutine ESMF_ConfigFindLabel(config, label, isPresent, rc)

ARGUMENTS:
       type(ESMF_Config), intent(inout)           :: config
character(len=*),  intent(in)              :: label
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
logical,           intent(out),  optional  :: isPresent
integer,           intent(out),  optional  :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.
• This interface was modified since ESMF version 5.2.0r. The fact that code using this interface compiles with the current ESMF version does not guarantee that it compiles with previous versions of this interface. If user code compatibility with version 5.2.0r is desired then care must be taken to limit the use of this interface to features that were available in the 5.2.0r release.
Changes made after the 5.2.0r release:
6.1.0
Added the isPresent argument. Allows detection of end-of-line condition to be separate from the rc.

DESCRIPTION:

Finds the label (key) string in the config object starting from the beginning of its content.

Since the search is done by looking for a string, possibly multi-worded, in the whole Config object, it is important to use special conventions to distinguish labels from other words. This is done in the Resource File by using the NASA/DAO convention to finish line labels with a colon (:) and table labels with a double colon (::).

The arguments are:

config
label
Identifying label.
[isPresent]
Set to .true. if the item is found.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors. If the label is not found, and the isPresent argument is not present, an error is returned.

### 46.3.8 ESMF_ConfigFindNextLabel - Find a label in Config object starting from current position

INTERFACE:

     subroutine ESMF_ConfigFindNextLabel(config, label, isPresent, rc)

ARGUMENTS:
       type(ESMF_Config), intent(inout)           :: config
character(len=*),  intent(in)              :: label
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
logical,           intent(out),  optional  :: isPresent
integer,           intent(out),  optional  :: rc

DESCRIPTION:

Finds the label (key) string in the config object, starting from the current position pointer.

This method is equivalent to ESMF_ConfigFindLabel, but the search is performed starting from the current position pointer.

The arguments are:

config
label
Identifying label.
[isPresent]
Set to .true. if the item is found.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors. If the label is not found, and the isPresent argument is not present, an error is returned.

### 46.3.9 ESMF_ConfigGetAttribute - Get an attribute value from Config object

INTERFACE:

        subroutine ESMF_ConfigGetAttribute(config, <value>, &
label, default, rc)

ARGUMENTS:
        type(ESMF_Config), intent(inout)         :: config
<value argument>, see below for supported values
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
character(len=*),  intent(in),  optional :: label
character(len=*),  intent(in),  optional :: default
integer,           intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Gets a value from the config object. When the value is a sequence of characters it will be terminated by the first white space.

Supported values for <value argument> are:

character(len=*), intent(out) :: value
real(ESMF_KIND_R4), intent(out) :: value
real(ESMF_KIND_R8), intent(out) :: value
integer(ESMF_KIND_I4), intent(out) :: value
integer(ESMF_KIND_I8), intent(out) :: value
logical, intent(out) :: value

The arguments are:

config
<value argument>
Returned value.
[label]
Identifing label.
[default]
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 46.3.10 ESMF_ConfigGetAttribute - Get a list of attribute values from Config object

INTERFACE:

        subroutine ESMF_ConfigGetAttribute(config, <value list argument>, &
count, label, default, rc)

ARGUMENTS:
        type(ESMF_Config), intent(inout)         :: config
<value list argument>, see below for values
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,           intent(in)   optional :: count
character(len=*),  intent(in),  optional :: label
character(len=*),  intent(in),  optional :: default
integer,           intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Gets a list of values from the config object.

Supported values for <value list argument> are:

character(len=*), intent(out) :: valueList(:)
real(ESMF_KIND_R4), intent(inout) :: valueList(:)
real(ESMF_KIND_R8), intent(inout) :: valueList(:)
integer(ESMF_KIND_I4), intent(inout) :: valueList(:)
integer(ESMF_KIND_I8), intent(inout) :: valueList(:)
logical, intent(inout) :: valueList(:)

The arguments are:

config
<value list argument>
Returned value.
count
Number of returned values expected.
[label]
Identifing label.
[default]
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 46.3.11 ESMF_ConfigGetChar - Get a character attribute value from Config object

INTERFACE:

       subroutine ESMF_ConfigGetChar(config, value, &
label, default, rc)

ARGUMENTS:
       type(ESMF_Config), intent(inout)         :: config
character,         intent(out)           :: value
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
character(len=*),  intent(in),  optional :: label
character,         intent(in),  optional :: default
integer,           intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Gets a character value from the config object.

The arguments are:

config
value
Returned value.
[label]
Identifying label.
[default]
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 46.3.12 ESMF_ConfigGetDim - Get table sizes from Config object

INTERFACE:

     subroutine ESMF_ConfigGetDim(config, lineCount, columnCount, &
label, rc)

ARGUMENTS:
       type(ESMF_Config), intent(inout)         :: config
integer,           intent(out)           :: lineCount
integer,           intent(out)           :: columnCount
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
character(len=*),  intent(in),  optional :: label
integer,           intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Returns the number of lines in the table in lineCount and the maximum number of words in a table line in columnCount.

After the call, the line pointer is positioned to the end of the table. To reset it to the beginning of the table, use ESMF_ConfigFindLabel.

The arguments are:

config
lineCount
Returned number of lines in the table.
columnCount
Returned maximum number of words in a table line.
[label]
Identifying label (if present), otherwise current line.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 46.3.13 ESMF_ConfigGetLen - Get the length of the line in words from Config object

INTERFACE:

     integer function ESMF_ConfigGetLen(config, label, rc)

ARGUMENTS:
       type(ESMF_Config), intent(inout)          :: config
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
character(len=*),  intent(in),   optional :: label
integer,           intent(out),  optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Gets the length of the line in words by counting words disregarding types. Returns the word count as an integer.

The arguments are:

config
[label]
Identifying label. If not specified, use the current line.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 46.3.14 ESMF_ConfigIsCreated - Check whether a Config object has been created

INTERFACE:

   function ESMF_ConfigIsCreated(config, rc)

RETURN VALUE:
     logical :: ESMF_ConfigIsCreated

ARGUMENTS:
     type(ESMF_Config), intent(in)            :: config
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,             intent(out), optional :: rc

DESCRIPTION:

Return .true. if the config has been created. Otherwise return .false.. If an error occurs, i.e. rc /= ESMF_SUCCESS is returned, the return value of the function will also be .false..

The arguments are:

config
ESMF_Config queried.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

INTERFACE:

     subroutine ESMF_ConfigLoadFile(config, filename, &
delayout, unique, rc)

ARGUMENTS:
       type(ESMF_Config),   intent(inout)         :: config
character(len=*),    intent(in)            :: filename
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
type(ESMF_DELayout), intent(in),  optional :: delayout
logical,             intent(in),  optional :: unique
integer,             intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Resource file with filename is loaded into memory.

The arguments are:

config
filename
Configuration file name.
[delayout]
ESMF_DELayout associated with this config object.
[unique]
If specified as true, uniqueness of labels are checked and error code set if duplicates found.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 46.3.16 ESMF_ConfigNextLine - Find next line in a Config object

INTERFACE:

     subroutine ESMF_ConfigNextLine(config, tableEnd, rc)

ARGUMENTS:
       type(ESMF_Config), intent(inout)          :: config
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
logical,           intent(out),  optional :: tableEnd
integer,           intent(out),  optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Selects the next line (for tables).

The arguments are:

config
[tableEnd]
Returns .true. if end of table mark (::) is encountered.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 46.3.17 ESMF_ConfigPrint - Write content of Config object to unit

INTERFACE:

     subroutine ESMF_ConfigPrint(config, unit, rc)

ARGUMENTS:
       type(ESMF_Config), intent(in)  :: config
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer, optional, intent(in)  :: unit
integer, optional, intent(out) :: rc

DESCRIPTION:

Write content of input ESMF_Config object to unit unit. If unit not provided, writes to standard output.

The arguments are:

config
The input ESMF_Config object.
[unit]
Output unit.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 46.3.18 ESMF_ConfigSetAttribute - Set a value in Config object

INTERFACE:

       subroutine ESMF_ConfigSetAttribute(config, <value argument>, &
label, rc)

ARGUMENTS:
       type(ESMF_Config), intent(inout)           :: config
<value argument>, see below for supported values
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
character(len=*),  intent(in),   optional  :: label
integer,           intent(out),  optional  :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Sets a value in the config object.

Supported values for <value argument> are:

integer(ESMF_KIND_I4), intent(in) :: value

The arguments are:

config
<value argument>
Value to set.
[label]
Identifying attribute label.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 46.3.19 ESMF_ConfigValidate - Validate a Config object

INTERFACE:

     subroutine ESMF_ConfigValidate(config, &
options, rc)

ARGUMENTS:
       type(ESMF_Config), intent(inout)          :: config
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
character (len=*), intent(in),   optional :: options
integer,           intent(out),  optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Checks whether a config object is valid.

The arguments are:

config
ESMF_Config object to be validated.
[options]
If none specified: simply check that the buffer is not full and the pointers are within range. "unusedAttributes" - Report to the default logfile all attributes not retrieved via a call to ESMF_ConfigGetAttribute() or ESMF_ConfigGetChar(). The attribute name (label) will be logged via ESMF_LogErr with the WARNING log message type. For an array-valued attribute, retrieving at least one value via ESMF_ConfigGetAttribute() or ESMF_ConfigGetChar() constitutes being "used."
[rc]
Return code; equals ESMF_SUCCESS if there are no errors. Equals ESMF_RC_ATTR_UNUSED if any unused attributes are found with option "unusedAttributes" above.

# 47 Log Class

## 47.1 Description

The Log class consists of a variety of methods for writing error, warning, and informational messages to files. A default Log is created at ESMF initialization. Other Logs can be created later in the code by the user. Most Log methods take a Log as an optional argument and apply to the default Log when another Log is not specified. A set of standard return codes and associated messages are provided for error handling.

Log provides capabilities to store message entries in a buffer, which is flushed to a file, either when the buffer is full, or when the user calls an ESMF_LogFlush() method. Currently, the default is for the Log to flush after every ten entries. This can easily be changed by using the ESMF_LogSet() method and setting the maxElements property to another value. The ESMF_LogFlush() method is automatically called when the program exits by any means (program completion, halt on error, or when the Log is closed).

The user has the capability to abort the program on conditions such as an error or on a warning by using the ESMF_LogSet() method with the logmsgAbort argument. For example if the logmsgAbort array is set to (ESMF_LOGMSG_ERROR,ESMF_LOGMSG_WARNING), the program will stop on any and all warning or errors. When the logmsgAbort argument is set to ESMF_LOGMSG_ERROR, the program will only abort on errors. Lastly, the user can choose to never abort by using ESMF_LOGMSG_NONE; this is the default.

Log will automatically put the PET number into the Log. Also, the user can either specify ESMF_LOGKIND_SINGLE which writes all the entries to a single Log or ESMF_LOGKIND_MULTI which writes entries to multiple Logs according to the PET number. To distinguish Logs from each other when using ESMF_LOGKIND_MULTI, the PET number (in the format PETx.) will be prepended to the file name where x is the PET number.

Opening multiple log files and writing log messages from all the processors may affect the application performance while running on a large number of processors. For that reason, ESMF_LOGKIND_NONE is provided to switch off the Log capability. All the Log methods have no effect in the ESMF_LOGKIND_NONE mode.

A tracing capability may be enabled by setting the trace flag by using the ESMF_LogSet() method. When tracing is enabled, calls to methods such as ESMF_LogFoundError, ESMF_LogFoundAllocError, and ESMF_LogFoundDeallocError are logged in the default log file. This can result in voluminous output. It is typically used only around areas of code which are being debugged.

Other options that are planned for Log are to adjust the verbosity of output, and to optionally write to stdout instead of file(s).

## 47.2 Constants

### 47.2.1 ESMF_LOGERR

The valid values are:

ESMF_LOGERR_PASSTHRU
A named character constant, with a predefined generic error message, that can be used for the msg argument in any ESMF_Log routine. The message indicated by this named constant is Passing error in return code."

### 47.2.2 ESMF_LOGKIND

DESCRIPTION:
Specifies a single log file, multiple log files (one per PET), or no log files.

The type of this flag is:

type(ESMF_LogKind_Flag)

The valid values are:

ESMF_LOGKIND_SINGLE
Use a single log file, combining messages from all of the PETs. Not supported on some platforms.
ESMF_LOGKIND_MULTI
Use multiple log files -- one per PET.
ESMF_LOGKIND_MULTI_ON_ERROR
Use multiple log files -- one per PET. A log file is only opened when a message of type ESMF_LOGMSG_ERROR is encountered.
ESMF_LOGKIND_NONE
Do not issue messages to a log file.

### 47.2.3 ESMF_LOGMSG

DESCRIPTION:
Specifies a message level

The type of this flag is:

type(ESMF_LogMsg_Flag)

The valid values are:

ESMF_LOGMSG_INFO
Informational messages
ESMF_LOGMSG_WARNING
Warning messages
ESMF_LOGMSG_ERROR
Error messages
ESMF_LOGMSG_TRACE
Trace messages
ESMF_LOGMSG_JSON
JSON format messages

Valid predefined named array constant values are:

ESMF_LOGMSG_ALL
All messages
ESMF_LOGMSG_NONE
No messages
ESMF_LOGMSG_NOTRACE
All messages EXCEPT trace messages

## 47.3 Use and Examples

By default ESMF_Initialize() opens a default Log in ESMF_LOGKIND_MULTI mode. ESMF handles the initialization and finalization of the default Log so the user can immediately start using it. If additional Log objects are desired, they must be explicitly created or opened using ESMF_LogOpen().

ESMF_LogOpen() requires a Log object and filename argument. Additionally, the user can specify single or multi Logs by setting the logkindflag property to ESMF_LOGKIND_SINGLE or ESMF_LOGKIND_MULTI. This is useful as the PET numbers are automatically added to the Log entries. A single Log will put all entries, regardless of PET number, into a single log while a multi Log will create multiple Logs with the PET number prepended to the filename and all entries will be written to their corresponding Log by their PET number.

By default, the Log file is not truncated at the start of a new run; it just gets appended each time. Future functionality may include an option to either truncate or append to the Log file.

In all cases where a Log is opened, a Fortran unit number is assigned to a specific Log. A Log is assigned an unused unit number using the algorithm described in the ESMF_IOUnitGet() method.

The user can then set or get options on how the Log should be used with the ESMF_LogSet() and ESMF_LogGet() methods. These are partially implemented at this time.

Depending on how the options are set, ESMF_LogWrite() either writes user messages directly to a Log file or writes to a buffer that can be flushed when full or by using the ESMF_LogFlush() method. The default is to flush after every ten entries because maxElements is initialized to ten (which means the buffer reaches its full state after every ten writes and then flushes).

A message filtering option may be set with ESMF_LogSet() so that only selected message types are actually written to the log. One key use of this feature is to allow placing informational log write requests into the code for debugging or tracing. Then, when the informational entries are not needed, the messages at that level may be turned off -- leaving only warning and error messages in the logs.

For every ESMF_LogWrite(), a time and date stamp is prepended to the Log entry. The time is given in microsecond precision. The user can call other methods to write to the Log. In every case, all methods eventually make a call implicitly to ESMF_LogWrite() even though the user may never explicitly call it.

When calling ESMF_LogWrite(), the user can supply an optional line, file and method. These arguments can be passed in explicitly or with the help of cpp macros. In the latter case, a define for an ESMF_FILENAME must be placed at the beginning of a file and a define for ESMF_METHOD must be placed at the beginning of each method. The user can then use the ESMF_CONTEXT cpp macro in place of line, file and method to insert the parameters into the method. The user does not have to specify line number as it is a value supplied by cpp.

An example of Log output is given below running with logkindflag property set to ESMF_LOGKIND_MULTI (default) using the default Log:

(Log file PET0.ESMF_LogFile)

20041105 163418.472210 INFO      PET0     Running with ESMF Version 2.2.1


(Log file PET1.ESMF_LogFile)

20041105 163419.186153 ERROR     PET1     ESMF_Field.F90             812
ESMF_FieldGet No Grid or Bad Grid attached to Field


The first entry shows date and time stamp. The time is given in microsecond precision. The next item shown is the type of message (INFO in this case). Next, the PET number is added. Lastly, the content is written.

The second entry shows something slightly different. In this case, we have an ERROR. The method name (ESMF_Field.F90) is automatically provided from the cpp macros as well as the line number (812). Then the content of the message is written.

When done writing messages, the default Log is closed by calling ESMF_LogFinalize() or ESMF_LogClose() for user created Logs. Both methods will release the assigned unit number.

! !PROGRAM: ESMF_LogErrEx - Log Error examples
!
! !DESCRIPTION:
!
! This program shows examples of Log Error writing
!-----------------------------------------------------------------------------


! Macros for cpp usage
! File define
#define ESMF_FILENAME "ESMF_LogErrEx.F90"
! Method define
#define ESMF_METHOD "program ESMF_LogErrEx"
#include "ESMF_LogMacros.inc"

! ESMF Framework module
use ESMF
use ESMF_TestMod
implicit none

! return variables
integer :: rc1, rc2, rc3, rcToTest, allocRcToTest, result
type(ESMF_LOG) :: alog  ! a log object that is not the default log
type(ESMF_LogKind_Flag) :: logkindflag
type(ESMF_Time) :: time
type(ESMF_VM) :: vm
integer, pointer :: intptr(:)


### 47.3.1 Default Log

This example shows how to use the default Log. This example does not use cpp macros but does use multi Logs. A separate Log will be created for each PET.

    ! Initialize ESMF to initialize the default Log
call ESMF_Initialize(vm=vm, defaultlogfilename="LogErrEx.Log", &
logkindflag=ESMF_LOGKIND_MULTI, rc=rc1)


    ! LogWrite
call ESMF_LogWrite("Log Write 2", ESMF_LOGMSG_INFO, rc=rc2)


    ! LogMsgSetError
rcToReturn=rc2)


    ! LogMsgFoundError
call ESMF_TimeSet(time, calkindflag=ESMF_CALKIND_NOCALENDAR)
call ESMF_TimeSyncToRealTime(time, rc=rcToTest)
if (ESMF_LogFoundError(rcToTest, msg="getting wall clock time", &
rcToReturn=rc2)) then
! Error getting time. The previous call will have printed the error
! (This call is expected to provoke an error from the Time Manager.)
endif

! LogMsgFoundAllocError
allocate(intptr(10), stat=allocRcToTest)
if (ESMF_LogFoundAllocError(allocRcToTest, msg="integer array", &
rcToReturn=rc2)) then
! Error during allocation.  The previous call will have logged already
! an error message into the log.
endif
deallocate(intptr)


### 47.3.2 User created Log

This example shows how to use a user created Log. This example uses cpp macros.

    ! Open a Log named "Testlog.txt" associated with alog.
call ESMF_LogOpen(alog, "TestLog.txt", rc=rc1)



%/////////////////////////////////////////////////////////////

\begin{verbatim}
! LogWrite
call ESMF_LogWrite("Log Write 2", ESMF_LOGMSG_INFO, &
line=__LINE__, file=ESMF_FILENAME, &
method=ESMF_METHOD, log=alog, rc=rc2)


    ! LogMsgSetError
line=__LINE__, file=ESMF_FILENAME, &
method=ESMF_METHOD, rcToReturn=rc2, log=alog)


### 47.3.3 Get and Set

This example shows how to use Get and Set routines, on both the default Log and the user created Log from the previous examples.

    ! This is an example showing a query of the default Log.  Please note that
! no Log is passed in the argument list, so the default Log will be used.
call ESMF_LogGet(logkindflag=logkindflag, rc=rc3)


    ! This is an example setting a property of a Log that is not the default.
! It was opened in a previous example, and the handle for it must be
! passed in the argument list.
call ESMF_LogSet(log=alog, logmsgAbort=(/ESMF_LOGMSG_ERROR/), rc=rc2)


    ! Close the user log.
call ESMF_LogClose(alog, rc=rc3)


    ! Finalize ESMF to close the default log
call ESMF_Finalize(rc=rc1)


## 47.4 Restrictions and Future Work

1. Line, file and method are only available when using the C preprocessor Message writing methods are expanded using the ESMF macro ESMF_CONTEXT that adds the predefined symbolic constants __LINE__ and __FILE__ (or the ESMF constant ESMF_FILENAME if defined) and the ESMF constant ESMF_METHOD to the argument list. Using these constants, we can associate a file name, line number and method name with the message. If the CPP preprocessor is not used, this expansion will not be done and hence the ESMF macro ESMF_CONTEXT can not be used, leaving the file name, line number and method out of the Log text.

2. Get and set methods are partially implemented. Currently, the ESMF_LogGet() and ESMF_LogSet() methods are partially implemented.

3. Log only appends entries. All writing to the Log is appended rather than overwriting the Log. Future enhancements include the option to either append to an existing Log or overwrite the existing Log.

4. Avoiding conflicts with the default Log. The private methods ESMF_LogInitialize() and ESMF_LogFinalize() are called during ESMF_Initialize() and ESMF_Finalize() respectively, so they do not need to be called if the default Log is used. If a new Log is required, ESMF_LogOpen() is used with a new Log object passed in so that there are no conflicts with the default Log.

5. ESMF_LOGKIND_SINGLE does not work properly. When the ESMF_LogKind_Flag is set to ESMF_LOGKIND_SINGLE, different system may behave differently. The log messages from some processors may be lost or overwritten by other processors. Users are advised not to use this mode. The MPI-based I/O will be implemented to fix the problem in the future release.

## 47.5 Design and Implementation Notes

1. The Log class was implemented in Fortran and uses the Fortran I/O libraries when the class methods are called from Fortran. The C/C++ Log methods use the Fortran I/O library by calling utility functions that are written in Fortran. These utility functions call the standard Fortran write, open and close functions. At initialization an ESMF_LOG is created. The ESMF_LOG stores information for a specific Log file. When working with more than one Log file, multiple ESMF_LOG's are required (one ESMF_LOG for each Log file). For each Log, a handle is returned through the ESMF_LogInitialize method for the default log or ESMF_LogOpen for a user created log. The user can specify single or multi logs by setting the logkindflag property in the ESMF_LogInitialize or ESMF_Open method to ESMF_LOGKIND_SINGLE or ESMF_LOGKIND_MULTI. Similarly, the user can set the logkindflag property for the default Log with the ESMF_Initialize method call. The logkindflag is useful as the PET numbers are automatically added to the log entries. A single log will put all entries, regardless of PET number, into a single log while a multi log will create multiple logs with the PET number prepended to the filename and all entries will be written to their corresponding log by their PET number.

The properties for a Log are set with the ESMF_LogSet() method and retrieved with the ESMF_LogGet() method.

Additionally, buffering is enabled. Buffering allows ESMF to manage output data streams in a desired way. Writing to the buffer is transparent to the user because all the Log entries are handled automatically by the ESMF_LogWrite() method. All the user has to do is specify the buffer size (the default is ten) by setting the maxElements property. Every time the ESMF_LogWrite() method is called, a LogEntry element is populated with the ESMF_LogWrite() information. When the buffer is full (i.e., when all the LogEntry elements are populated), the buffer will be flushed and all the contents will be written to file. If buffering is not needed, that is maxElements=1 or flushImmediately=ESMF_TRUE, the ESMF_LogWrite() method will immediately write to the Log file(s).

## 47.6 Object Model

The following is a simplified UML diagram showing the structure of the Log class. See Appendix A, A Brief Introduction to UML, for a translation table that lists the symbols in the diagram and their meaning.

## 47.7 Class API

### 47.7.1 ESMF_LogAssignment(=) - Log assignment

INTERFACE:

     interface assignment(=)
log1 = log2

ARGUMENTS:
     type(ESMF_Log) :: log1
type(ESMF_Log) :: log2

DESCRIPTION:

Assign log1 as an alias to the same ESMF_Log object in memory as log2. If log2 is invalid, then log1 will be equally invalid after the assignment.

The arguments are:

log1
The ESMF_Log object on the left hand side of the assignment.
log2
The ESMF_Log object on the right hand side of the assignment.

### 47.7.2 ESMF_LogOperator(==) - Test if Log 1 is equivalent to Log 2

INTERFACE:

       interface operator(==)
if (log1 == log2) then ... endif
OR
result = (log1 == log2)

RETURN VALUE:
       logical :: result

ARGUMENTS:
       type(ESMF_Log), intent(in) :: log1
type(ESMF_Log), intent(in) :: log2

DESCRIPTION:

Overloads the (==) operator for the ESMF_Log class. Compare two logs for equality; return .true. if equal, .false. otherwise. Comparison is based on whether the objects are distinct, as with two newly created logs, or are simply aliases to the same log as would be the case when assignment was involved.

The arguments are:

log1
The ESMF_Log object on the left hand side of the equality operation.
log2
The ESMF_Log object on the right hand side of the equality operation.

### 47.7.3 ESMF_LogOperator(/=) - Test if Log 1 is not equivalent to Log 2

INTERFACE:

       interface operator(/=)
if (log1 /= log2) then ... endif
OR
result = (log1 /= log2)

RETURN VALUE:
       logical :: result

ARGUMENTS:
       type(ESMF_Log), intent(in) :: log1
type(ESMF_Log), intent(in) :: log2

DESCRIPTION:

Overloads the (/=) operator for the ESMF_Log class. Compare two logs for inequality; return .true. if equal, .false. otherwise. Comparison is based on whether the objects are distinct, as with two newly created logs, or are simply aliases to the same log as would be the case when assignment was involved.

The arguments are:

log1
The ESMF_Log object on the left hand side of the non-equality operation.
log2
The ESMF_Log object on the right hand side of the non-equality operation.

### 47.7.4 ESMF_LogClose - Close Log file(s)

INTERFACE:

       subroutine ESMF_LogClose(log, rc)

ARGUMENTS:
       type(ESMF_Log), intent(inout), optional :: log
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,        intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

This routine closes the log file(s) associated with log. If the log is not explicitly closed, it will be closed by ESMF_Finalize.

The arguments are:

[log]
An ESMF_Log object. If not specified, the default log is closed.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 47.7.5 ESMF_LogFlush - Flush the Log file(s)

INTERFACE:

       subroutine ESMF_LogFlush(log, rc)

ARGUMENTS:
       type(ESMF_Log), intent(inout), optional :: log
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,        intent(out),   optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

This subroutine flushes the file buffer associated with log.

The arguments are:

[log]
An optional ESMF_Log object that can be used instead of the default Log.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 47.7.6 ESMF_LogFoundAllocError - Check Fortran allocation status error and write message

INTERFACE:

       function ESMF_LogFoundAllocError(statusToCheck,  &
msg,line,file, &
method,rcToReturn,log)

RETURN VALUE:
       logical                                    :: ESMF_LogFoundAllocError

ARGUMENTS:
       integer,          intent(in)              :: statusToCheck
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
character(len=*), intent(in),    optional :: msg
integer,          intent(in),    optional :: line
character(len=*), intent(in),    optional :: file
character(len=*), intent(in),    optional :: method
integer,          intent(inout), optional :: rcToReturn
type(ESMF_Log),   intent(inout), optional :: log

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

This function returns .true. when statusToCheck indicates an allocation error, otherwise it returns .false.. The status value is typically returned from a Fortran ALLOCATE statement. If an error is indicated, a ESMF memory allocation error message will be written to the ESMF_Log along with a user added msg, line, file and method.

The arguments are:

statusToCheck
Fortran allocation status to check. Fortran specifies that a status of 0 (zero) indicates success.
[msg]
User-provided message string.
[line]
Integer source line number. Expected to be set by using the preprocessor __LINE__ macro.
[file]
User-provided source file name.
[method]
User-provided method string.
[rcToReturn]
If specified, when the allocation status indicates an error, set the rcToReturn value to ESMF_RC_MEM. Otherwise, rcToReturn is not modified.
[log]
An optional ESMF_Log object that can be used instead of the default Log.

### 47.7.7 ESMF_LogFoundDeallocError - Check Fortran deallocation status error and write message

INTERFACE:

       function ESMF_LogFoundDeallocError(statusToCheck,  &
msg,line,file, &
method,rcToReturn,log)

RETURN VALUE:
       logical ::ESMF_LogFoundDeallocError

ARGUMENTS:
       integer,          intent(in)              :: statusToCheck
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
character(len=*), intent(in),    optional :: msg
integer,          intent(in),    optional :: line
character(len=*), intent(in),    optional :: file
character(len=*), intent(in),    optional :: method
integer,          intent(inout), optional :: rcToReturn
type(ESMF_Log),   intent(inout), optional :: log

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

This function returns .true. when statusToCheck indicates a deallocation error, otherwise it returns .false.. The status value is typically returned from a Fortran DEALLOCATE statement. If an error is indicated, a ESMF memory allocation error message will be written to the ESMF_Log along with a user added msg, line, file and method.

The arguments are:

statusToCheck
Fortran deallocation status to check. Fortran specifies that a status of 0 (zero) indicates success.
[msg]
User-provided message string.
[line]
Integer source line number. Expected to be set by using the preprocessor __LINE__ macro.
[file]
User-provided source file name.
[method]
User-provided method string.
[rcToReturn]
If specified, when the deallocation status indicates an error, set the rcToReturn value to ESMF_RC_MEM. Otherwise, rcToReturn is not modified.
[log]
An optional ESMF_Log object that can be used instead of the default Log.

### 47.7.8 ESMF_LogFoundError - Check ESMF return code for error and write message

INTERFACE:

   recursive function ESMF_LogFoundError(rcToCheck,   &
msg, line, file, method, &
rcToReturn, log) result (LogFoundError)

RETURN VALUE:
       logical :: LogFoundError

ARGUMENTS:
       integer,          intent(in),    optional :: rcToCheck
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
character(len=*), intent(in),    optional :: msg
integer,          intent(in),    optional :: line
character(len=*), intent(in),    optional :: file
character(len=*), intent(in),    optional :: method
integer,          intent(inout), optional :: rcToReturn
type(ESMF_Log),   intent(inout), optional :: log

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

This function returns .true. when rcToCheck indicates an return code other than ESMF_SUCCESS, otherwise it returns .false.. If an error is indicated, a ESMF predefined error message will be written to the ESMF_Log along with a user added msg, line, file and method.

The arguments are:

[rcToCheck]
Return code to check. Default is ESMF_SUCCESS.
[msg]
User-provided message string.
[line]
Integer source line number. Expected to be set by using the preprocessor __LINE__ macro.
[file]
User-provided source file name.
[method]
User-provided method string.
[rcToReturn]
If specified, when rcToCheck indicates an error, set the rcToReturn to the value of rcToCheck. Otherwise, rcToReturn is not modified. This is not the return code for this function; it allows the calling code to do an assignment of the error code at the same time it is testing the value.
[log]
An optional ESMF_Log object that can be used instead of the default Log.

### 47.7.9 ESMF_LogFoundNetCDFError - Check NetCDF status code for success or log the associated NetCDF error message.

INTERFACE:

 function ESMF_LogFoundNetCDFError(ncerrToCheck, msg, line, &
file, method, rcToReturn, log)

#if defined ESMF_NETCDF
use netcdf
#elif defined ESMF_PNETCDF
use pnetcdf
#endif

RETURN VALUE:
   logical :: ESMF_LogFoundNetCDFError

ARGUMENTS:
   integer,          intent(in)              :: ncerrToCheck
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
character(len=*), intent(in),    optional :: msg
integer,          intent(in),    optional :: line
character(len=*), intent(in),    optional :: file
character(len=*), intent(in),    optional :: method
integer,          intent(inout), optional :: rcToReturn
type(ESMF_Log),   intent(inout), optional :: log

DESCRIPTION:

This function returns .true. when ncerrToCheck indicates an return code other than 0 (the success code from NetCDF Fortran) or NF_NOERR (the success code for PNetCDF). Otherwise it returns .false.. If an error is indicated, a predefined ESMF error message will be written to the ESMF_Log along with a user added msg, line, file and method. The NetCDF string error representation will also be logged.

The arguments are:

[ncerrToCheck]
NetCDF error code to check.
[msg]
User-provided message string.
[line]
Integer source line number. Expected to be set by using the preprocessor __LINE__ macro.
[file]
User-provided source file name.
[method]
User-provided method string.
[rcToReturn]
If specified, when ncerrToCheck indicates an error, set rcToReturn to ESMF_RC_NETCDF_ERROR. The string representation for the error code will be retrieved from the NetCDF Fortran library and logged alongside any user-provided message string. Otherwise, rcToReturn is not modified. This is not the return code for this function; it allows the calling code to do an assignment of the error code at the same time it is testing the value.
[log]
An optional ESMF_Log object that can be used instead of the default Log.

### 47.7.10 ESMF_LogGet - Return information about a log object

INTERFACE:

       subroutine ESMF_LogGet(log,  &
flush,    &
logmsgAbort, logkindflag, &
maxElements, trace, fileName,  &
highResTimestampFlag, indentCount,  &
noPrefix, rc)

ARGUMENTS:
       type(ESMF_Log),          intent(in),  optional :: log
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
logical,                 intent(out), optional :: flush
type(ESMF_LogMsg_Flag),  pointer,     optional :: logmsgAbort(:)
type(ESMF_LogKind_Flag), intent(out), optional :: logkindflag
integer,                 intent(out), optional :: maxElements
logical,                 intent(out), optional :: trace
character(*),            intent(out), optional :: fileName
logical,                 intent(out), optional :: highResTimestampFlag
integer,                 intent(out), optional :: indentCount
logical,                 intent(out), optional :: noPrefix
integer,                 intent(out), optional :: rc

DESCRIPTION:

This subroutine returns properties about a Log object.

The arguments are:

[log]
An optional ESMF_Log object that can be used instead of the default Log.
[flush]
Flush flag.
[logmsgAbort]
Returns an array containing current message halt settings. If the array is not pre-allocated, ESMF_LogGet will allocate an array of the correct size. If no message types are defined, an array of length zero is returned. It is the callers responsibility to deallocate the array.
[logkindflag]
Defines either single or multilog.
[maxElements]
Maximum number of elements in the Log.
[trace]
Current setting of the Log call tracing flag.
[fileName]
Current file name. When the log has been opened with ESMF_LOGKIND_MULTI, the filename has a PET number prefix.
[highResTimestampFlag]
Current setting of the extended elapsed timestamp flag.
[indentCount]
[noPrefix]
Current setting of the message prefix enable/disable flag.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 47.7.11 ESMF_LogOpen - Open Log file(s)

INTERFACE:

     subroutine ESMF_LogOpen(log, filename,  &
appendflag, logkindflag, noPrefix, rc)

ARGUMENTS:
     type(ESMF_Log),          intent(inout)         :: log
character(len=*),        intent(in)            :: filename
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
logical,                 intent(in),  optional :: appendFlag
type(ESMF_LogKind_Flag), intent(in),  optional :: logkindFlag
logical,                 intent(in),  optional :: noPrefix
integer,                 intent(out), optional :: rc

DESCRIPTION:

This routine opens a file named filename and associates it with the ESMF_Log. When logkindflag is set to ESMF_LOGKIND_MULTI or ESMF_LOGKIND_MULTI_ON_ERROR the file name is prepended with PET number identification. If the incoming log is already open, an error is returned.

The arguments are:

log
An ESMF_Log object.
filename
Name of log file to be opened.
[appendFlag]
If the log file exists, setting to .false. will set the file position to the beginning of the file. Otherwise, new records will be appended to the end of the file. If not specified, defaults to .true..
[logkindFlag]
Set the logkindflag. See section 47.2.2 for a list of valid options. When the ESMF_LOGKIND_MULTI_ON_ERROR is selected, the log opening is deferred until a ESMF_LogWrite with log message of type ESMF_LOGMSG_ERROR is written. If not specified, defaults to ESMF_LOGKIND_MULTI.
[noPrefix]
Set the noPrefix flag. If set to .false., log messages are prefixed with time stamps, message type, and PET number. If set to .true. the messages will be written without prefixes. If not specified, defaults to .false..
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 47.7.12 ESMF_LogOpen - Open Default Log file(s)

INTERFACE:

   ! Private name; call using ESMF_LogOpen ()
subroutine ESMF_LogOpenDefault (filename,  &
appendflag, logkindflag, rc)

ARGUMENTS:
     character(len=*),        intent(in)            :: filename
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
logical,                 intent(in),  optional :: appendflag
type(ESMF_LogKind_Flag), intent(in),  optional :: logkindflag
integer,                 intent(out), optional :: rc

DESCRIPTION:

This routine opens a file named filename and associates it with the default log. When logkindflag is set to ESMF_LOGKIND_MULTI the file name is prepended with PET number identification. If the incoming default log is already open, an error is returned.

The arguments are:

filename
Name of DEFAULT log file to be opened.
[appendflag]
If the log file exists, setting to .false. will set the file position to the beginning of the file. Otherwise, new records will be appended to the end of the file. If not specified, defaults to .true..
[logkindflag]
Set the logkindflag. See section 47.2.2 for a list of valid options. If not specified, defaults to ESMF_LOGKIND_MULTI.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 47.7.13 ESMF_LogSet - Set Log parameters

INTERFACE:

     subroutine ESMF_LogSet(log,  &
flush,  &
logmsgAbort, maxElements, logmsgList,  &
noPrefix, rc)

ARGUMENTS:
       type(ESMF_Log),         intent(inout), optional :: log
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
logical,                intent(in),    optional :: flush
type(ESMF_LogMsg_Flag), intent(in),    optional :: logmsgAbort(:)
integer,                intent(in),    optional :: maxElements
type(ESMF_LogMsg_Flag), intent(in),    optional :: logmsgList(:)
logical,                intent(in),    optional :: trace
logical,                intent(in),    optional :: highResTimestampFlag
integer,                intent(in),    optional :: indentCount
logical,                intent(in),    optional :: noPrefix
integer,                intent(out),   optional :: rc

DESCRIPTION:

This subroutine sets the properties for the Log object.

The arguments are:

[log]
An optional ESMF_Log object. The default is to use the default log that was opened at ESMF_Initialize time.
[flush]
If set to .true., flush log messages immediately, rather than buffering them. Default is to flush after maxElements messages.
[logmsgAbort]
Sets the condition on which ESMF aborts. The array can contain any combination of ESMF_LOGMSG named constants. These named constants are described in section 47.2.3. Default is to always continue processing.
[maxElements]
Maximum number of elements in the Log buffer before flushing occurs. Default is to flush when 10 messages have been accumulated.
[logmsgList]
An array of message types that will be logged. Log write requests not matching the list will be ignored. If an empty array is provided, no messages will be logged. See section 47.2.3 for a list of valid message types. By default, all non-trace messages will be logged.
List of error codes that will not be logged as errors. Default is to log all error codes.
[trace]
If set to .true., calls such as ESMF_LogFoundError(), ESMF_LogFoundAllocError(), and ESMF_LogFoundDeallocError() will be logged in the default log files. This option is intended to be used as a tool for debugging and program flow tracing within the ESMF library. Voluminous output may appear in the log, with a consequent slowdown in performance. Therefore, it is recommended that this option only be enabled before a problematic call to a ESMF method, and disabled afterwards. Default is to not trace these calls.
[highResTimestampFlag]
Sets the extended elapsed timestamp flag. If set to .true., a timestamp from ESMF_VMWtime will be included in each log message. Default is to not add the additional timestamps.
[indentCount]
[noPrefix]
If set to .false., log messages are prefixed with time stamps, message type and PET number. If set to .true. the messages will be written without the prefixes.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 47.7.14 ESMF_LogSetError - Set ESMF return code for error and write msg

INTERFACE:

       subroutine ESMF_LogSetError(rcToCheck,  &
msg, line, file, method, &
rcToReturn, log)

ARGUMENTS:
       integer,          intent(in)              :: rcToCheck
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
character(len=*), intent(in),    optional :: msg
integer,          intent(in),    optional :: line
character(len=*), intent(in),    optional :: file
character(len=*), intent(in),    optional :: method
integer,          intent(out),   optional :: rcToReturn
type(ESMF_Log),   intent(inout), optional :: log

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

This subroutine sets the rcToReturn value to rcToCheck if rcToReturn is present and writes this error code to the ESMF_Log if an error is generated. A predefined error message will added to the ESMF_Log along with a user added msg, line, file and method.

The arguments are:

rcToCheck
rc value for set
[msg]
User-provided message string.
[line]
Integer source line number. Expected to be set by using the preprocessor macro __LINE__ macro.
[file]
User-provided source file name.
[method]
User-provided method string.
[rcToReturn]
If specified, copy the rcToCheck value to rcToreturn. This is not the return code for this function; it allows the calling code to do an assignment of the error code at the same time it is testing the value.
[log]
An optional ESMF_Log object that can be used instead of the default Log.

### 47.7.15 ESMF_LogWrite - Write to Log file(s)

INTERFACE:

       recursive subroutine ESMF_LogWrite(msg, logmsgFlag, &
logmsgList,      & ! DEPRECATED ARGUMENT
line, file, method, log, rc)

ARGUMENTS:
       character(len=*),      intent(in)             :: msg
type(ESMF_LogMsg_Flag),intent(in),optional    :: logmsgFlag
type(ESMF_LogMsg_Flag),intent(in),optional::logmsgList ! DEPRECATED ARG
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,               intent(in),   optional :: line
character(len=*),      intent(in),   optional :: file
character(len=*),      intent(in),   optional :: method
type(ESMF_Log),        intent(inout),optional :: log
integer,               intent(out),  optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.
• This interface was modified since ESMF version 5.2.0r. The fact that code using this interface compiles with the current ESMF version does not guarantee that it compiles with previous versions of this interface. If user code compatibility with version 5.2.0r is desired then care must be taken to limit the use of this interface to features that were available in the 5.2.0r release.
Changes made after the 5.2.0r release:
5.2.0rp1
Added argument logmsgFlag. Started to deprecate argument logmsgList. This corrects inconsistent use of the List suffix on the argument name. In ESMF this suffix indicates one-dimensional array arguments.

DESCRIPTION:

This subroutine writes to the file associated with an ESMF_Log. A message is passed in along with the logmsgFlag, line, file and method. If the write to the ESMF_Log is successful, the function will return a logical true. This function is the base function used by all the other ESMF_Log writing methods.

The arguments are:

msg
User-provided message string.
[logmsgFlag]
The type of message. See Section 47.2.3 for possible values. If not specified, the default is ESMF_LOGMSG_INFO.
[logmsgList]
[line]
Integer source line number. Expected to be set by using the preprocessor macro __LINE__ macro.
[file]
User-provided source file name.
[method]
User-provided method string.
[log]
An optional ESMF_Log object that can be used instead of the default Log.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

# 48 DELayout Class

## 48.1 Description

The DELayout class provides an additional layer of abstraction on top of the Virtual Machine (VM) layer. DELayout does this by introducing DEs (Decomposition Elements) as logical resource units. The DELayout object keeps track of the relationship between its DEs and the resources of the associated VM object.

The relationship between DEs and VM resources (PETs (Persistent Execution Threads) and VASs (Virtual Address Spaces)) contained in a DELayout object is defined during its creation and cannot be changed thereafter. There are, however, a number of hint and specification arguments that can be used to shape the DELayout during its creation.

Contrary to the number of PETs and VASs contained in a VM object, which are fixed by the available resources, the number of DEs contained in a DELayout can be chosen freely to best match the computational problem or other design criteria. Creating a DELayout with less DEs than there are PETs in the associated VM object can be used to share resources between decomposed objects within an ESMF component. Creating a DELayout with more DEs than there are PETs in the associated VM object can be used to evenly partition the computation over the available resources.

The simplest case, however, is where the DELayout contains the same number of DEs as there are PETs in the associated VM context. In this case the DELayout may be used to re-label the hardware and operating system resources held by the VM. For instance, it is possible to order the resources so that specific DEs have best available communication paths. The DELayout will map the DEs to the PETs of the VM according to the resource details provided by the VM instance.

Furthermore, general DE to PET mapping can be used to offer computational resources with finer granularity than the VM does. The DELayout can be queried for computational and communication capacities of DEs and DE pairs, respectively. This information can be used to best utilize the DE resources when partitioning the computational problem. In combination with other ESMF classes, general DE to PET mapping can be used to realize cache blocking, communication hiding and dynamic load balancing.

Finally, the DELayout layer offers primitives that allow a work queue style dynamic load balancing between DEs.

## 48.2 Constants

### 48.2.1 ESMF_PIN

DESCRIPTION:
Specifies which VM resource DEs are pinned to (PETs, VASs, SSIs).

The type of this flag is:

type(ESMF_Pin_Flag)

The valid values are:

ESMF_PIN_DE_TO_PET
Pin DEs to PETs. Only the owning PET has access to a DE.
ESMF_PIN_DE_TO_VAS
Pin DEs to virtual address spaces (VAS). DEs are accessible from all PETs within the same VAS.
ESMF_PIN_DE_TO_SSI
Pin DEs to single system images (SSI) - typically shared memory nodes. DEs are accessible from all PETs within the same SSI. The memory allocation between different DEs is allowed to be non-contiguous.
ESMF_PIN_DE_TO_SSI_CONTIG
Same as ESMF_PIN_DE_TO_SSI, but the shared memory allocation across DEs located on the same SSI must be contigous throughout.

DESCRIPTION:
Reply when a PET offers to service a DE.

The type of this flag is:

The valid values are:

The service offer has been accepted. The PET is expected to service the DE.
The service offer has been denied. The PET is expected to not service the DE.

## 48.3 Use and Examples

The following examples demonstrate how to create, use and destroy DELayout objects.

### 48.3.1 Default DELayout

Without specifying any of the optional parameters the created ESMF_DELayout defaults into having as many DEs as there are PETs in the associated VM object. Consequently the resulting DELayout describes a simple 1-to-1 DE to PET mapping.

  delayout = ESMF_DELayoutCreate(rc=rc)


The default DE to PET mapping is simply:

   DE 0  -> PET 0
DE 1  -> PET 1
...


DELayout objects that are not used any longer should be destroyed.

  call ESMF_DELayoutDestroy(delayout, rc=rc)


The optional vm argument can be provided to DELayoutCreate() to lower the method's overhead by the amount it takes to determine the current VM.

  delayout = ESMF_DELayoutCreate(vm=vm, rc=rc)


By default all PETs of the associated VM will be considered. However, if the optional argument petList is present DEs will only be mapped against the PETs contained in the list. When the following example is executed on four PETs it creates a DELayout with four DEs by default that are mapped to the provided PETs in their given order. It is erroneous to specify PETs that are not part of the VM context on which the DELayout is defined.

  delayout = ESMF_DELayoutCreate(petList=(/(i,i=petCount-1,1,-1)/), rc=rc)


Once the end of the petList has been reached the DE to PET mapping continues from the beginning of the list. For a 4 PET VM the above created DELayout will end up with the following DE to PET mapping:

   DE 0  -> PET 3
DE 1  -> PET 2
DE 2  -> PET 1
DE 2  -> PET 3


### 48.3.2 DELayout with specified number of DEs

The deCount argument can be used to specify the number of DEs. In this example a DELayout is created that contains four times as many DEs as there are PETs in the VM.

  delayout = ESMF_DELayoutCreate(deCount=4*petCount, rc=rc)


Cyclic DE to PET mapping is the default. For 4 PETs this means:

   DE 0, 4,  8, 12  -> PET 0
DE 1, 5,  9, 13  -> PET 1
DE 2, 6, 10, 14  -> PET 2
DE 3, 7, 11, 15  -> PET 3

The default DE to PET mapping can be overridden by providing the deGrouping argument. This argument provides a positive integer group number for each DE in the DELayout. All of the DEs of a group will be mapped against the same PET. The actual group index is arbitrary (but must be positive) and its value is of no consequence.

  delayout = ESMF_DELayoutCreate(deCount=4*petCount, &
deGrouping=(/(i/4,i=0,4*petCount-1)/), rc=rc)


This will achieve blocked DE to PET mapping. For 4 PETs this means:

   DE  0,  1,  2,  3  -> PET 0
DE  4,  5,  6,  7  -> PET 1
DE  8,  9, 10, 11  -> PET 2
DE 12, 13, 14, 15  -> PET 3


### 48.3.3 DELayout with computational and communication weights

The quality of the partitioning expressed by the DE to PET mapping depends on the amount and quality of information provided during DELayout creation. In the following example the compWeights argument is used to specify relative computational weights for all DEs and communication weights for DE pairs are provided by the commWeights argument. The example assumes four DEs.

  allocate(compWeights(4))
allocate(commWeights(4, 4))
! setup compWeights and commWeights according to computational problem
delayout = ESMF_DELayoutCreate(deCount=4, compWeights=compWeights, &
commWeights=commWeights, rc=rc)
deallocate(compWeights, commWeights)


The resulting DE to PET mapping depends on the specifics of the VM object and the provided compWeights and commWeights arrays.

### 48.3.4 DELayout from petMap

Full control over the DE to PET mapping is provided via the petMap argument. This example maps the DEs to PETs in reverse order. In the 4-PET case this will result in the following mapping:

   DE 0 -> PET 3
DE 1 -> PET 2
DE 2 -> PET 1
DE 3 -> PET 0


  delayout = ESMF_DELayoutCreate(petMap=(/(i,i=petCount-1,0,-1)/), rc=rc)


### 48.3.5 DELayout from petMap with multiple DEs per PET

The petMap argument gives full control over DE to PET mapping. The following example run on 4 or more PETs maps DEs to PETs according to the following table:

   DE 0 -> PET 3
DE 1 -> PET 3
DE 2 -> PET 1
DE 3 -> PET 0
DE 4 -> PET 2
DE 5 -> PET 1
DE 6 -> PET 3
DE 7 -> PET 1


  delayout = ESMF_DELayoutCreate(petMap=(/3, 3, 1, 0, 2, 1, 3, 1/), rc=rc)


### 48.3.6 Working with a DELayout - simple 1-to-1 DE-to-PET mapping

The simplest case is a DELayout where there is exactly one DE for every PET. Of course this implies that the number of DEs equals the number of PETs. This special 1-to-1 DE-to-PET mapping is very common and many applications assume it. The following example shows how a DELayout can be queried about its mapping.

First a default DELayout is created where the number of DEs equals the number of PETs, and are associated 1-to-1.

  delayout = ESMF_DELayoutCreate(rc=rc)


Next the DELayout is queried for the oneToOneFlag, and the user code makes a decision based on its value.

  call ESMF_DELayoutGet(delayout, oneToOneFlag=oneToOneFlag, rc=rc)
if (rc /= ESMF_SUCCESS) call ESMF_Finalize(endflag=ESMF_END_ABORT)
if (.not. oneToOneFlag) then
! handle the unexpected case of not dealing with a 1-to-1 mapping
else


1-to-1 mapping is guaranteed in this branch and the following code can work under the simplifying assumption that every PET holds exactly one DE:

    allocate(localDeToDeMap(1))
call ESMF_DELayoutGet(delayout, localDeToDeMap=localDeToDeMap, rc=rc)
if (rc /= ESMF_SUCCESS) finalrc=rc
myDe = localDeToDeMap(1)
deallocate(localDeToDeMap)
if (finalrc /= ESMF_SUCCESS) call ESMF_Finalize(endflag=ESMF_END_ABORT)
endif


### 48.3.7 Working with a DELayout - general DE-to-PET mapping

In general a DELayout may map any number (including zero) of DEs against a single PET. The exact situation can be detected by querying the DELayout for the oneToOneFlag. If this flag comes back as .true. then the DELayout maps exactly one DE against each PET, but if it comes back as .false. the DELayout describes a more general DE-to-PET layout. The following example shows how code can be be written to work for a general DELayout.

First a DELayout is created with two more DEs than there are PETs. The DELayout will consequently map some DEs to the same PET.

  delayout = ESMF_DELayoutCreate(deCount=petCount+2, rc=rc)


The first piece of information needed on each PET is the localDeCount. This number may be different on each PET and indicates how many DEs are mapped against the local PET.

  call ESMF_DELayoutGet(delayout, localDeCount=localDeCount, rc=rc)


The DELayout can further be queried for a list of DEs that are held by the local PET. This information is provided by the localDeToDeMap argument. In ESMF a localDe is an index that enumerates the DEs that are associated with the local PET. In many cases the exact bounds of the localDe index range, e.g. , or does not matter, since it only affects how user code indexes into variables the user allocated, and therefore set the specific bounds. However, there are a few Array and Field level calls that take localDe input arguments. In all those cases where the localDe index variable is passed into an ESMF call as an input argument, it must be defined with a range starting at zero, i.e. .

For consistency with Array and Field, the following code uses a range for the localDe index variable, although it is not strictly necessary here:

  allocate(localDeToDeMap(0:localDeCount-1))
call ESMF_DELayoutGet(delayout, localDeToDeMap=localDeToDeMap, rc=rc)
if (rc /= ESMF_SUCCESS) finalrc=rc
do localDe=0, localDeCount-1
workDe = localDeToDeMap(localDe)
!    print *, "I am PET", localPET, " and I am working on DE ", workDe
enddo
deallocate(localDeToDeMap)
if (finalrc /= ESMF_SUCCESS) call ESMF_Finalize(endflag=ESMF_END_ABORT)


### 48.3.8 Work queue dynamic load balancing

The DELayout API includes two calls that can be used to easily implement work queue dynamic load balancing. The workload is broken up into DEs (more than there are PETs) and processed by the PETs. Load balancing is only possible for ESMF multi-threaded VMs and requires that DEs are pinned to VASs instead of the PETs (default). The following example will run for any VM and DELayout, however, load balancing will only occur under the mentioned conditions.

  delayout = ESMF_DELayoutCreate(deCount=petCount+2, &
pinflag=ESMF_PIN_DE_TO_VAS, rc=rc)


  call ESMF_DELayoutGet(delayout, vasLocalDeCount=localDeCount, rc=rc)
if (rc /= ESMF_SUCCESS) finalrc=rc
allocate(localDeToDeMap(localDeCount))
call ESMF_DELayoutGet(delayout, vasLocalDeToDeMap=localDeToDeMap, rc=rc)
if (rc /= ESMF_SUCCESS) finalrc=rc
do i=1, localDeCount
workDe = localDeToDeMap(i)
print *, "I am PET", localPET, &
" and I am offering service for DE ", workDe
if (rc /= ESMF_SUCCESS) finalrc=rc
! process work associated with workDe
print *, "I am PET", localPET, ", service offer for DE ", workDe, &
" was accepted."
call ESMF_DELayoutServiceComplete(delayout, de=workDe, rc=rc)
if (rc /= ESMF_SUCCESS) finalrc=rc
endif
enddo
deallocate(localDeToDeMap)
if (finalrc /= ESMF_SUCCESS) call ESMF_Finalize(endflag=ESMF_END_ABORT)


## 48.5 Design and Implementation Notes

The DELayout class is a light weight object. It stores the DE to PET and VAS mapping for all DEs within all PET instances and a list of local DEs for each PET instance. The DELayout does not store the computational and communication weights optionally provided as arguments to the create method. These hints are only used during create while they are available in user owned arrays.

## 48.6 Class API

### 48.6.1 ESMF_DELayoutAssignment(=) - DELayout assignment

INTERFACE:

     interface assignment(=)
delayout1 = delayout2

ARGUMENTS:
     type(ESMF_DELayout) :: delayout1
type(ESMF_DELayout) :: delayout2

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Assign delayout1 as an alias to the same ESMF DELayout object in memory as delayout2. If delayout2 is invalid, then delayout1 will be equally invalid after the assignment.

The arguments are:

delayout1
The ESMF_DELayout object on the left hand side of the assignment.
delayout2
The ESMF_DELayout object on the right hand side of the assignment.

### 48.6.2 ESMF_DELayoutOperator(==) - DELayout equality operator

INTERFACE:

   interface operator(==)
if (delayout1 == delayout2) then ... endif
OR
result = (delayout1 == delayout2)

RETURN VALUE:
     logical :: result

ARGUMENTS:
     type(ESMF_DELayout), intent(in) :: delayout1
type(ESMF_DELayout), intent(in) :: delayout2

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Test whether delayout1 and delayout2 are valid aliases to the same ESMF DELayout object in memory. For a more general comparison of two ESMF DELayouts, going beyond the simple alias test, the ESMF_DELayoutMatch() function (not yet implemented) must be used.

The arguments are:

delayout1
The ESMF_DELayout object on the left hand side of the equality operation.
delayout2
The ESMF_DELayout object on the right hand side of the equality operation.

### 48.6.3 ESMF_DELayoutOperator(/=) - DELayout not equal operator

INTERFACE:

   interface operator(/=)
if (delayout1 /= delayout2) then ... endif
OR
result = (delayout1 /= delayout2)

RETURN VALUE:
     logical :: result

ARGUMENTS:
     type(ESMF_DELayout), intent(in) :: delayout1
type(ESMF_DELayout), intent(in) :: delayout2

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Test whether delayout1 and delayout2 are not valid aliases to the same ESMF DELayout object in memory. For a more general comparison of two ESMF DELayouts, going beyond the simple alias test, the ESMF_DELayoutMatch() function (not yet implemented) must be used.

The arguments are:

delayout1
The ESMF_DELayout object on the left hand side of the non-equality operation.
delayout2
The ESMF_DELayout object on the right hand side of the non-equality operation.

### 48.6.4 ESMF_DELayoutCreate - Create DELayout object

INTERFACE:

   ! Private name; call using ESMF_DELayoutCreate()
recursive function ESMF_DELayoutCreateDefault(deCount, &
deGrouping, pinflag, petList, vm, rc)

RETURN VALUE:
     type(ESMF_DELayout) :: ESMF_DELayoutCreateDefault

ARGUMENTS:
 -- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,                      intent(in),  optional :: deCount
integer, target,              intent(in),  optional :: deGrouping(:)
type(ESMF_Pin_Flag),          intent(in),  optional :: pinflag
integer, target,              intent(in),  optional :: petList(:)
type(ESMF_VM),                intent(in),  optional :: vm
integer,                      intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Create an ESMF_DELayout object on the basis of optionally provided restrictions. By default a DELayout with deCount equal to petCount will be created, each DE mapped to a single PET. However, the number of DEs as well grouping of DEs and PETs can be specified via the optional arguments.

The arguments are:

[deCount]
Number of DEs to be provided by the created DELayout. By default the number of DEs equals the number of PETs in the associated VM context. Specifying a deCount smaller than the number of PETs will result in unassociated PETs. This may be used to share VM resources between DELayouts within the same ESMF component. Specifying a deCount greater than the number of PETs will result in multiple DE to PET mapping.
[deGrouping]
This optional argument must be of size deCount. Its content assigns a DE group index to each DE of the DELayout. A group index of -1 indicates that the associated DE isn't member of any particular group. The significance of DE groups is that all the DEs belonging to a certain group will be mapped against the same PET. This does not, however, mean that DEs belonging to different DE groups must be mapped to different PETs.
[pinflag]
This flag specifies which type of resource DEs are pinned to. The default is to pin DEs to PETs. Alternatively it is also possible to pin DEs to VASs. See section 48.2.1 for a list of valid pinning options.
[petList]
List specifying PETs to be used by this DELayout. This can be used to control the PET overlap between DELayouts within the same ESMF component. It is erroneous to specify PETs that are not within the provided VM context. The default is to include all the PETs of the VM.
[vm]
If present, the DELayout object is created on the specified ESMF_VM object. The default is to create on the VM of the current context.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 48.6.5 ESMF_DELayoutCreate - Create DELayout from petMap

INTERFACE:

   ! Private name; call using ESMF_DELayoutCreate()
recursive function ESMF_DELayoutCreateFromPetMap(petMap, &
pinflag, vm, rc)

RETURN VALUE:
     type(ESMF_DELayout) :: ESMF_DELayoutCreateFromPetMap

ARGUMENTS:
     integer,                      intent(in)            :: petMap(:)
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
type(ESMF_Pin_Flag),          intent(in),  optional :: pinflag
type(ESMF_VM),                intent(in),  optional :: vm
integer,                      intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Create an ESMF_DELayout with exactly specified DE to PET mapping.

This ESMF method must be called in unison by all PETs of the VM. Calling this method from a PET not part of the VM or not calling it from a PET that is part of the VM will result in undefined behavior. ESMF does not guard against violation of the unison requirement. The call is not collective, there is no communication between PETs.

The arguments are:

petMap
List specifying the DE-to-PET mapping. The list elements correspond to DE 0, 1, 2, ... and map against the specified PET of the VM context. The size of the petMap argument determines the number of DEs in the created DELayout. It is erroneous to specify a PET identifier that lies outside the VM context.
[pinflag]
This flag specifies which type of resource DEs are pinned to. The default is to pin DEs to PETs. Alternatively it is also possible to pin DEs to VASs. See section 48.2.1 for a list of valid pinning options.
[vm]
If present, the DELayout object is created on the specified ESMF_VM object. The default is to create on the VM of the current context.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 48.6.6 ESMF_DELayoutDestroy - Release resources associated with DELayout object

INTERFACE:

   recursive subroutine ESMF_DELayoutDestroy(delayout, noGarbage, rc)

ARGUMENTS:
     type(ESMF_DELayout),  intent(inout)          :: delayout
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
logical,              intent(in),   optional :: noGarbage
integer,              intent(out),  optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.
• This interface was modified since ESMF version 5.2.0r. The fact that code using this interface compiles with the current ESMF version does not guarantee that it compiles with previous versions of this interface. If user code compatibility with version 5.2.0r is desired then care must be taken to limit the use of this interface to features that were available in the 5.2.0r release.
Changes made after the 5.2.0r release:
7.0.0
Added argument noGarbage. The argument provides a mechanism to override the default garbage collection mechanism when destroying an ESMF object.

DESCRIPTION:

Destroy an ESMF_DELayout object, releasing the resources associated with the object.

By default a small remnant of the object is kept in memory in order to prevent problems with dangling aliases. The default garbage collection mechanism can be overridden with the noGarbage argument.

The arguments are:

delayout
ESMF_DELayout object to be destroyed.
[noGarbage]
If set to .TRUE. the object will be fully destroyed and removed from the ESMF garbage collection system. Note however that under this condition ESMF cannot protect against accessing the destroyed object through dangling aliases - a situation which may lead to hard to debug application crashes.

It is generally recommended to leave the noGarbage argument set to .FALSE. (the default), and to take advantage of the ESMF garbage collection system which will prevent problems with dangling aliases or incorrect sequences of destroy calls. However this level of support requires that a small remnant of the object is kept in memory past the destroy call. This can lead to an unexpected increase in memory consumption over the course of execution in applications that use temporary ESMF objects. For situations where the repeated creation and destruction of temporary objects leads to memory issues, it is recommended to call with noGarbage set to .TRUE., fully removing the entire temporary object from memory.

[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 48.6.7 ESMF_DELayoutGet - Get object-wide DELayout information

INTERFACE:

   recursive subroutine ESMF_DELayoutGet(delayout, vm, deCount,&
petMap, vasMap, oneToOneFlag, pinflag, localDeCount, localDeToDeMap, &
localDeList, &      ! DEPRECATED ARGUMENT
vasLocalDeCount, vasLocalDeToDeMap, &
vasLocalDeList, &   ! DEPRECATED ARGUMENT
rc)

ARGUMENTS:
     type(ESMF_DELayout),      intent(in)            :: delayout
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
type(ESMF_VM),            intent(out), optional :: vm
integer,                  intent(out), optional :: deCount
integer, target,          intent(out), optional :: petMap(:)
integer, target,          intent(out), optional :: vasMap(:)
logical,                  intent(out), optional :: oneToOneFlag
type(ESMF_Pin_Flag),      intent(out), optional :: pinflag
integer,                  intent(out), optional :: localDeCount
integer, target,          intent(out), optional :: localDeToDeMap(:)
integer, target, intent(out), optional :: localDeList(:)  !DEPRECATED ARG
integer,                  intent(out), optional :: vasLocalDeCount
integer, target,          intent(out), optional :: vasLocalDeToDeMap(:)
integer, target, intent(out), optional :: vasLocalDeList(:) !DEPRECATED ARG
integer,                  intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.
• This interface was modified since ESMF version 5.2.0r. The fact that code using this interface compiles with the current ESMF version does not guarantee that it compiles with previous versions of this interface. If user code compatibility with version 5.2.0r is desired then care must be taken to limit the use of this interface to features that were available in the 5.2.0r release.
Changes made after the 5.2.0r release:
5.2.0rp1
Added arguments localDeToDeMap and vasLocalDeToDeMap. Started to deprecate arguments localDeList and vasLocalDeList. The new argument names correctly use the Map suffix and better describe the returned information. This was pointed out by user request.

DESCRIPTION:

The arguments are:

delayout
Queried ESMF_DELayout object.
[vm]
The ESMF_VM object on which delayout is defined.
[deCount]
The total number of DEs in the DELayout.
[petMap]
List of PETs against which the DEs are mapped. The petMap argument must at least be of size deCount.
[vasMap]
List of VASs against which the DEs are mapped. The vasMap argument must at least be of size deCount.
[oneToOneFlag]
A value of .TRUE. indicates that delayout maps each DE to a single PET, and each PET maps to a single DE. All other layouts return a value of .FALSE..
[pinflag]
The type of DE pinning. See section 48.2.1 for a list of valid pinning options.
[localDeCount]
The number of DEs in the DELayout associated with the local PET.
[localDeToDeMap]
Mapping between localDe indices and the (global) DEs associated with the local PET. The localDe index variables are discussed in sections 48.3.7 and 28.2.5. The provided actual argument must be of size localDeCount.
[localDeList]
[vasLocalDeCount]
The number of DEs in the DELayout associated with the local VAS.
[vasLocalDeToDeMap]
Mapping between localDe indices and the (global) DEs associated with the local VAS. The localDe index variables are discussed in sections 48.3.7 and 28.2.5. The provided actual argument must be of size localDeCount.
[vasLocalDeList]
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 48.6.8 ESMF_DELayoutIsCreated - Check whether a DELayout object has been created

INTERFACE:

   function ESMF_DELayoutIsCreated(delayout, rc)

RETURN VALUE:
     logical :: ESMF_DELayoutIsCreated

ARGUMENTS:
     type(ESMF_DELayout), intent(in)            :: delayout
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,             intent(out), optional :: rc

DESCRIPTION:

Return .true. if the delayout has been created. Otherwise return .false.. If an error occurs, i.e. rc /= ESMF_SUCCESS is returned, the return value of the function will also be .false..

The arguments are:

delayout
ESMF_DELayout queried.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 48.6.9 ESMF_DELayoutPrint - Print DELayout information

INTERFACE:

   subroutine ESMF_DELayoutPrint(delayout, rc)

ARGUMENTS:
     type(ESMF_DELayout),  intent(in)            :: delayout
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,              intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Prints internal information about the specified ESMF_DELayout object to stdout.

The arguments are:

delayout
Specified ESMF_DELayout object.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 48.6.10 ESMF_DELayoutServiceComplete - Close service window

INTERFACE:

   recursive subroutine ESMF_DELayoutServiceComplete(delayout, de, rc)

ARGUMENTS:
     type(ESMF_DELayout),  intent(in)            :: delayout
integer,              intent(in)            :: de
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,              intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

The PET who's service offer was accepted for de must use ESMF_DELayoutServiceComplete to close the service window.

The arguments are:

delayout
Specified ESMF_DELayout object.
de
DE for which to close service window.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 48.6.11 ESMF_DELayoutServiceOffer - Offer service for a DE in DELayout

INTERFACE:

   recursive function ESMF_DELayoutServiceOffer(delayout, de, rc)

RETURN VALUE:
     type(ESMF_ServiceReply_Flag) :: ESMF_DELayoutServiceOffer

ARGUMENTS:
     type(ESMF_DELayout),  intent(in)            :: delayout
integer,              intent(in)            :: de
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,              intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Offer service for a DE in the ESMF_DELayout object. This call together with ESMF_DELayoutServiceComplete() provides the synchronization primitives between the PETs of an ESMF multi-threaded VM necessary for dynamic load balancing via a work queue approach.

The calling PET will either receive ESMF_SERVICEREPLY_ACCEPT if the service offer has been accepted by DELayout or ESMF_SERVICEREPLY_DENY if the service offer was denied. The service offer paradigm is different from a simple mutex approach in that the DELayout keeps track of the number of service offers issued for each DE by each PET and accepts only one PET's offer for each offer increment. This requires that all PETs use ESMF_DELayoutServiceOffer() in unison. See section 48.2.2 for the potential return values.

The arguments are:

delayout
Specified ESMF_DELayout object.
de
DE for which service is offered by the calling PET.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 48.6.12 ESMF_DELayoutValidate - Validate DELayout internals

INTERFACE:

   subroutine ESMF_DELayoutValidate(delayout, rc)

ARGUMENTS:
     type(ESMF_DELayout),  intent(in)            :: delayout
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,              intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Validates that the delayout is internally consistent. The method returns an error code if problems are found.

The arguments are:

delayout
Specified ESMF_DELayout object.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

# 49 VM Class

## 49.1 Description

The ESMF VM (Virtual Machine) class is a generic representation of hardware and system software resources. There is exactly one VM object per ESMF Component, providing the execution environment for the Component code. The VM class handles all resource management tasks for the Component class and provides a description of the underlying configuration of the compute resources used by a Component.

In addition to resource description and management, the VM class offers the lowest level of ESMF communication methods. The VM communication calls are very similar to MPI. Data references in VM communication calls must be provided as raw, language-specific, one-dimensional, contiguous data arrays. The similarity between VM and MPI communication calls is striking and there are many equivalent point-to-point and collective communication calls. However, unlike MPI, the VM communication calls support communication between threaded PETs in a completely transparent fashion.

Many ESMF applications do not interact with the VM class directly very much. The resource management aspect is wrapped completely transparent into the ESMF Component concept. Often the only reason that user code queries a Component object for the associated VM object is to inquire about resource information, such as the localPet or the petCount. Further, for most applications the use of higher level communication APIs, such as provided by Array and Field, are much more convenient than using the low level VM communication calls.

The basic elements of a VM are called PETs, which stands for Persistent Execution Threads. These are equivalent to OS threads with a lifetime of at least that of the associated component. All VM functionality is expressed in terms of PETs. In the simplest, and most common case, a PET is equivalent to an MPI process. However, ESMF also supports multi-threading, where multiple PETs run as Pthreads inside the same virtual address space (VAS).

The resource management functions of the VM class become visible when a component, or the driver code, creates sub-components. Section 16.4.7 discusses this aspect from the Superstructure perspective and provides links to the relevant Component examples in the documentation.

There are two parts to resource management, the parent and the child. When the parent component creates a child component, the parent VM object provides the resources on which the child is created with ESMF_GridCompCreate() or ESMF_CplCompCreate(). The optional petList argument to these calls limits the resources that the parent gives to a specific child. The child component, may specify - during its optional ESMF_<Grid/Cpl>CompSetVM() method - how it wants to arrange the inherited resources in its own VM. After this, all standard ESMF methods of the Component, including ESMF_<Grid/Cpl>CompSetServices(), will execute in the child VM. Notice that the ESMF_<Grid/Cpl>CompSetVM() routine, although part of the child Component, must execute before the child VM has been started up. It runs in the parent VM context. The child VM is created and started up just before the user-written set services routine, specified as an argument to ESMF_<Grid/Cpl>CompSetServices(), is entered.

## 49.2 Use and Examples

The concept of the ESMF Virtual Machine (VM) is so fundamental to the framework that every ESMF application uses it. However, for many user applications the VM class is transparently hidden behind the ESMF Component concept and higher data classes (e.g. Array, Field). The interaction between user code and VM is often only indirect. The following examples provide an overview of where the VM class can come into play in user code.

### 49.2.1 Global VM

This complete example program demonstrates the simplest ESMF application, consisting of only a main program without any Components. The global VM, which is automatically created during the ESMF_Initialize() call, is obtained using two different methods. First the global VM will be returned by ESMF_Initialize() if the optional vm argument is specified. The example uses the VM object obtained this way to call the VM print method. Second, the global VM can be obtained anywhere in the user application using the ESMF_VMGetGlobal() call. The identical VM is returned and several VM query methods are called to inquire about the associated resources.

program ESMF_VMDefaultBasicsEx
#include "ESMF.h"

use ESMF
use ESMF_TestMod

implicit none

! local variables
integer:: rc
type(ESMF_VM):: vm
integer:: localPet, petCount, peCount, ssiId, vas


  call ESMF_Initialize(vm=vm, defaultlogfilename="VMDefaultBasicsEx.Log", &
logkindflag=ESMF_LOGKIND_MULTI, rc=rc)
! Providing the optional vm argument to ESMF_Initialize() is one way of
! obtaining the global VM.


  call ESMF_VMPrint(vm, rc=rc)


  call ESMF_VMGetGlobal(vm=vm, rc=rc)
! Calling ESMF_VMGetGlobal() anywhere in the user application is the other
! way to obtain the global VM object.


  call ESMF_VMGet(vm, localPet=localPet, petCount=petCount, peCount=peCount, &
rc=rc)
! The VM object contains information about the associated resources. If the
! user code requires this information it must query the VM object.


  print *, "This PET is localPet: ", localPet
print *, "of a total of ",petCount," PETs in this VM."
print *, "There are ", peCount," PEs referenced by this VM"

call ESMF_VMGet(vm, localPet, peCount=peCount, ssiId=ssiId, vas=vas, rc=rc)


  print *, "This PET is executing in virtual address space (VAS) ", vas
print *, "located on single system image (SSI) ", ssiId
print *, "and is associated with ", peCount, " PEs."


end program


### 49.2.2 Getting the MPI Communicator from an VM object

Sometimes user code requires access to the MPI communicator, e.g. to support legacy code that contains explict MPI communication calls. The correct way of wrapping such code into ESMF is to obtain the MPI intra-communicator out of the VM object. In order not to interfere with ESMF communications it is advisable to duplicate the communicator before using it in user-level MPI calls. In this example the duplicated communicator is used for a user controlled MPI_Barrier().

  integer:: mpic


  integer:: mpic2


  call ESMF_VMGet(vm, mpiCommunicator=mpic, rc=rc)
! The returned MPI communicator spans the same MPI processes that the VM
! is defined on.


  call MPI_Comm_dup(mpic, mpic2, ierr)
! Duplicate the MPI communicator not to interfere with ESMF communications.
! The duplicate MPI communicator can be used in any MPI call in the user
! code. Here the MPI_Barrier() routine is called.
call MPI_Barrier(mpic2, ierr)


### 49.2.3 Nesting ESMF inside a user MPI application

It is possible to nest an ESMF application inside a user application that explicitly calls MPI_Init() and MPI_Finalize(). The ESMF_Initialize() call automatically checks whether MPI has already been initialized, and if so does not call MPI_Init() internally. On the finalize side, ESMF_Finalize() can be instructed to not call MPI_Finalize(), making it the responsibility of the outer code to finalize MPI.

  ! User code initializes MPI.
call MPI_Init(ierr)


  ! ESMF_Initialize() does not call MPI_Init() if it finds MPI initialized.
call ESMF_Initialize(defaultlogfilename="VMUserMpiEx.Log", &
logkindflag=ESMF_LOGKIND_MULTI, rc=rc)


  ! Use ESMF here...


  ! Calling ESMF_Finalize() with endflag=ESMF_END_KEEPMPI instructs ESMF
! to keep MPI active.
call ESMF_Finalize(endflag=ESMF_END_KEEPMPI, rc=rc)


  ! It is the responsibility of the outer user code to finalize MPI.
call MPI_Finalize(ierr)


### 49.2.4 Nesting ESMF inside a user MPI application on a subset of MPI ranks

The previous example demonstrated that it is possible to nest an ESMF application, i.e. ESMF_Initialize()...ESMF_Finalize() inside MPI_Init()...MPI_Finalize(). It is not necessary that all MPI ranks enter the ESMF application. The following example shows how the user code can pass an MPI communicator to ESMF_Initialize(), and enter the ESMF application on a subset of MPI ranks.

  ! User code initializes MPI.
call MPI_Init(ierr)


  ! User code determines the local rank.
call MPI_Comm_rank(MPI_COMM_WORLD, rank, ierr)


  ! User code prepares MPI communicator "esmfComm", that allows rank 0 and 1
! to be grouped together.
if (rank < 2) then
! first communicator split with color=0
call MPI_Comm_split(MPI_COMM_WORLD, 0, 0, esmfComm, ierr)
else
! second communicator split with color=1
call MPI_Comm_split(MPI_COMM_WORLD, 1, 0, esmfComm, ierr)
endif


  if (rank < 2) then
! Only call ESMF_Initialize() on rank 0 and 1, passing the prepared MPI
! communicator that spans these ranks.
call ESMF_Initialize(mpiCommunicator=esmfComm, &
defaultlogfilename="VMUserMpiCommEx.Log", &
logkindflag=ESMF_LOGKIND_MULTI, rc=rc)


    ! Use ESMF here...


    ! Calling ESMF_Finalize() with endflag=ESMF_END_KEEPMPI instructs ESMF
! to keep MPI active.
call ESMF_Finalize(endflag=ESMF_END_KEEPMPI, rc=rc)


  else
! Ranks 2 and above do non-ESMF work...


  endif


  ! Free the MPI communicator before finalizing MPI.
call MPI_Comm_free(esmfComm, ierr)

! It is the responsibility of the outer user code to finalize MPI.
call MPI_Finalize(ierr)


### 49.2.5 Multiple concurrent instances of ESMF under separate MPI communicators

Multiple instances of ESMF can run concurrently under the same user main program on separate MPI communicators. The user program first splits MPI_COMM_WORLD into separate MPI communicators. Each communicator is then used to run a separate ESMF instance by passing it into ESMF_Initialize() on the appropriate MPI ranks.

Care must be taken to set the defaultlogfilename to be unique on each ESMF instances. This prevents concurrent ESMF instances from writing to the same log file. Further, each ESMF instances must call ESMF_Finalize() with the endflag=ESMF_END_KEEPMPI option in order to hand MPI control back to the user program. The outer user program is ultimately responsible for destroying the MPI communicators and to cleanly shut down MPI.

  ! User code initializes MPI.
call MPI_Init(ierr)


  ! User code determines the local rank and overall size of MPI_COMM_WORLD
call MPI_Comm_rank(MPI_COMM_WORLD, rank, ierr)
call MPI_Comm_size(MPI_COMM_WORLD, size, ierr)


  ! User code prepares different MPI communicators.
! Here a single MPI_Comm_split() call is used to split MPI_COMM_WORLD
! into two non-overlapping communicators:
! One communicator for ranks 0 and 1, and the other for ranks 2 and above.
if (rank < 2) then
! first communicator split with color=0
call MPI_Comm_split(MPI_COMM_WORLD, 0, 0, esmfComm, ierr)
else
! second communicator split with color=1
call MPI_Comm_split(MPI_COMM_WORLD, 1, 0, esmfComm, ierr)
endif


  if (rank < 2) then
! Ranks 0 and 1 enter ESMF_Initialize() with the prepared communicator.
! Care is taken to set a unique log file name.
call ESMF_Initialize(mpiCommunicator=esmfComm, &
defaultlogfilename="VMUserMpiCommMultiEx1.Log", &
logkindflag=ESMF_LOGKIND_MULTI, rc=rc)


    ! Use ESMF here...


    ! Finalize ESMF without finalizing MPI. The user application will call
! MPI_Finalize() on all ranks.
call ESMF_Finalize(endflag=ESMF_END_KEEPMPI, rc=rc)


  else
! Ranks 2 and above enter ESMF_Initialize() with the prepared communicator.
! Care is taken to set a unique log file name.
call ESMF_Initialize(mpiCommunicator=esmfComm, &
defaultlogfilename="VMUserMpiCommMultiEx2.Log", &
logkindflag=ESMF_LOGKIND_MULTI, rc=rc)


    ! Use ESMF here...


    ! Finalize ESMF without finalizing MPI. The user application will call
! MPI_Finalize() on all ranks.
call ESMF_Finalize(endflag=ESMF_END_KEEPMPI, rc=rc)


  endif


  ! Free the MPI communicator(s) before finalizing MPI.
call MPI_Comm_free(esmfComm, ierr)

! It is the responsibility of the outer user code to finalize MPI.
call MPI_Finalize(ierr)


### 49.2.6 VM and Components

The following example shows the role that the VM plays in connection with ESMF Components. A single Component is created in the main program. Through the optional petList argument the driver code specifies that only resources associated with PET 0 are given to the gcomp object.

When the Component code is invoked through the standard ESMF Component methods Initialize, Run, or Finalize the Component's VM is automatically entered. Inside of the user-written Component code the Component VM can be obtained by querying the Component object. The VM object will indicate that only a single PET is executing the Component code.

module ESMF_VMComponentEx_gcomp_mod


  recursive subroutine mygcomp_init(gcomp, istate, estate, clock, rc)
type(ESMF_GridComp)   :: gcomp
type(ESMF_State)      :: istate, estate
type(ESMF_Clock)      :: clock
integer, intent(out)  :: rc

! local variables
type(ESMF_VM):: vm

! get this Component's vm
call ESMF_GridCompGet(gcomp, vm=vm)

! the VM object contains information about the execution environment of
! the Component

call ESMF_VMPrint(vm, rc=rc)

rc = 0
end subroutine !--------------------------------------------------------------

recursive subroutine mygcomp_run(gcomp, istate, estate, clock, rc)
type(ESMF_GridComp)   :: gcomp
type(ESMF_State)      :: istate, estate
type(ESMF_Clock)      :: clock
integer, intent(out)  :: rc

! local variables
type(ESMF_VM):: vm

! get this Component's vm
call ESMF_GridCompGet(gcomp, vm=vm)

! the VM object contains information about the execution environment of
! the Component

call ESMF_VMPrint(vm, rc=rc)

rc = 0
end subroutine !--------------------------------------------------------------

recursive subroutine mygcomp_final(gcomp, istate, estate, clock, rc)
type(ESMF_GridComp)   :: gcomp
type(ESMF_State)      :: istate, estate
type(ESMF_Clock)      :: clock
integer, intent(out)  :: rc

! local variables
type(ESMF_VM):: vm

! get this Component's vm
call ESMF_GridCompGet(gcomp, vm=vm)

! the VM object contains information about the execution environment of
! the Component

call ESMF_VMPrint(vm, rc=rc)

rc = 0
end subroutine !--------------------------------------------------------------

end module


program ESMF_VMComponentEx
#include "ESMF.h"
use ESMF
use ESMF_TestMod
use ESMF_VMComponentEx_gcomp_mod
implicit none

! local variables


  gcomp = ESMF_GridCompCreate(petList=(/0/), rc=rc)


  call ESMF_GridCompSetServices(gcomp, userRoutine=mygcomp_register, rc=rc)


  call ESMF_GridCompInitialize(gcomp, rc=rc)


  call ESMF_GridCompRun(gcomp, rc=rc)


  call ESMF_GridCompFinalize(gcomp, rc=rc)


  call ESMF_GridCompDestroy(gcomp, rc=rc)


  call ESMF_Finalize(rc=rc)


end program


### 49.2.7 Communication - Send and Recv

The VM layer provides MPI-like point-to-point communication. Use ESMF_VMSend() and ESMF_VMRecv() to pass data between two PETs. The following code sends data from PET 'src' and receives it on PET 'dst'. Both PETs must be part of the same VM.

  integer, allocatable:: localData(:)


  count = 10
allocate(localData(count))
do i=1, count
localData(i) = localPet*100 + i
enddo


  if (localPet==src) then
call ESMF_VMSend(vm, sendData=localData, count=count, dstPet=dst, rc=rc)
endif


  if (localPet==dst) then
call ESMF_VMRecv(vm, recvData=localData, count=count, srcPet=src, rc=rc)
endif


### 49.2.8 Communication - Scatter and Gather

The VM layer provides MPI-like collective communication. ESMF_VMScatter() scatters data located on root PET across all the PETs of the VM. ESMF_VMGather() provides the opposite operation, gathering data from all the PETs of the VM onto root PET.

  integer, allocatable:: array1(:), array2(:)


  ! allocate data arrays
nsize = 2
nlen = nsize * petCount
allocate(array1(nlen))
allocate(array2(nsize))

! prepare data array1
do i=1, nlen
array1(i) = localPet * 100 + i
enddo


  call ESMF_VMScatter(vm, sendData=array1, recvData=array2, count=nsize, &
rootPet=scatterRoot, rc=rc)


  call ESMF_VMGather(vm, sendData=array2, recvData=array1, count=nsize, &
rootPet=gatherRoot, rc=rc)


### 49.2.9 Communication - AllReduce and AllFullReduce

Use ESMF_VMAllReduce() to reduce data distributed across the PETs of a VM into a result vector, returned on all the PETs. Further, use ESMF_VMAllFullReduce() to reduce the data into a single scalar returned on all PETs.

  integer, allocatable:: array1(:), array2(:)


  ! allocate data arrays
nsize = 2
allocate(array1(nsize))
allocate(array2(nsize))

! prepare data array1
do i=1, nsize
array1(i) = localPet * 100 + i
enddo


  call ESMF_VMAllReduce(vm, sendData=array1, recvData=array2, count=nsize, &
reduceflag=ESMF_REDUCE_SUM, rc=rc)
! Reduce distributed sendData, element by element into recvData and
! return it on all the PETs.


  call ESMF_VMAllFullReduce(vm, sendData=array1, recvData=result, &
count=nsize, reduceflag=ESMF_REDUCE_SUM, rc=rc)
! Fully reduce the distributed sendData into a single scalar and
! return it in recvData on all PETs.


### 49.2.10 Using VM communication methods with data of rank greater than one

In the current implementation of the VM communication methods all the data array arguments are declared as assumed shape dummy arrays of rank one. The assumed shape flavor was chosen in order to minimize the chance of copy in/out problems, associated with the other options for declaring the dummy data arguments. However, currently the interfaces are not overloaded for higher ranks. This restriction requires that users that need to communicate data arrays with rank greater than one, must only pass the first dimension of the data array into the VM communication calls. Specifying the full size of the data arrays (considering all dimensions) ensure that the complete data is transferred in or out of the contiguous array memory.

  integer, allocatable:: sendData(:,:)
integer, allocatable:: recvData(:,:,:,:)


  count1 = 5
count2 = 8
allocate(sendData(count1,count2)) ! 5 x 8 = 40 elements
do j=1, count2
do i=1, count1
sendData(i,j) = localPet*100 + i + (j-1)*count1
enddo
enddo

count1 = 2
count2 = 5
count3 = 1
count4 = 4
allocate(recvData(count1,count2,count3,count4)) ! 2 x 5 x 1 x 4 = 40 elements
do l=1, count4
do k=1, count3
do j=1, count2
do i=1, count1
recvData(i,j,k,l) = 0
enddo
enddo
enddo
enddo


  if (localPet==src) then
call ESMF_VMSend(vm, &
sendData=sendData(:,1), & ! 1st dimension as contiguous array section
count=count1*count2, &    ! total count of elements
dstPet=dst, rc=rc)
endif


  if (localPet==dst) then
call ESMF_VMRecv(vm, &
recvData=recvData(:,1,1,1), & ! 1st dimension as contiguous array section
count=count1*count2*count3*count4, &  ! total count of elements
srcPet=src, rc=rc)
endif


## 49.3 Restrictions and Future Work

1. Only array section syntax that leads to contiguous sub sections is supported. The source and destination arguments in VM communication calls must reference contiguous data arrays. Fortran array sections are not guaranteed to be contiguous in all cases.

2. Non-blocking Reduce() operations not implemented. None of the reduce communication calls have an implementation for the non-blocking feature. This affects:
• ESMF_VMAllFullReduce(),
• ESMF_VMAllReduce(),
• ESMF_VMReduce().

3. Limitations when using mpiuni mode. In mpiuni mode non-blocking communications are limited to one outstanding message per source-destination PET pair. Furthermore, in mpiuni mode the message length must be smaller than the internal ESMF buffer size.

4. Alternative communication paths not accessible. All user accessible VM communication calls are currently implemented using MPI-1.2. VM's implementation of alternative communication techniques, such as shared memory between threaded PETs and POSIX IPC between PETs located on the same single system image, are currently inaccessible to the user. (One exception to this is the mpiuni case for which the VM automatically utilizes a shared memory path.)

5. Data arrays in VM comm calls are assumed shape with rank=1. Currently all dummy arrays in VM comm calls are defined as assumed shape arrays of rank=1. The motivation for this choice is that the use of assumed shape dummy arrays guards against the Fortran copy in/out problem. However it may not be as flexible as desired from the user perspective. Alternatively all dummy arrays could be defined as assumed size arrays, as it is done in most MPI implementations, allowing arrays of various rank to be passed into the comm methods. Arrays of higher rank can be passed into the current interfaces using Fortran array syntax. This approach is explained in section 49.2.10.

## 49.4 Design and Implementation Notes

The VM class provides an additional layer of abstraction on top of the POSIX machine model, making it suitable for HPC applications. There are four key aspects the VM class deals with.

1. Encapsulation of hardware and operating system details within the concept of Persistent Execution Threads (PETs).

2. Resource management in terms of PETs with a guard against over-subscription.

3. Topological description of the underlying configuration of the compute resources in terms of PETs.

4. Transparent communication API for point-to-point and collective PET-based primitives, hiding the many different communication channels and offering best possible performance.

Definition of terms used in the diagram

• PE: A processing element (PE) is an alias for the smallest physical processing unit available on a particular hardware platform. In the language of today's microprocessor architecture technology a PE is identical to a core, however, if future microprocessor designs change the smallest physical processing unit the mapping of the PE to actual hardware will change accordingly. Thus the PE layer separates the hardware specific part of the VM from the hardware-independent part. Each PE is labeled with an id number which identifies it uniquely within all of the VM instances of an ESMF application.

• Core: A Core is the smallest physical processing unit which typically comprises a register set, an integer arithmetic unit, a floating-point unit and various control units. Each Core is labeled with an id number which identifies it uniquely within all of the VM instances of an ESMF application.

• CPU: The central processing unit (CPU) houses single or multiple cores, providing them with the interface to system memory, interconnects and I/O. Typically the CPU provides some level of caching for the instruction and data streams in and out of the Cores. Cores in a multi-core CPU typically share some caches. Each CPU is labeled with an id number which identifies it uniquely within all of the VM instances of an ESMF application.

• SSI: A single system image (SSI) spans all the CPUs controlled by a single running instance of the operating system. SMP and NUMA are typical multi-CPU SSI architectures. Each SSI is labeled with an id number which identifies it uniquely within all of the VM instances of an ESMF application.

• TOE: A thread of execution (TOE) executes an instruction sequence. TOE's come in two flavors: PET and TET.

• PET: A persistent execution thread (PET) executes an instruction sequence on an associated set of data. The PET has a lifetime at least as long as the associated data set. In ESMF the PET is the central concept of abstraction provided by the VM class. The PETs of an VM object are labeled from 0 to N-1 where N is the total number of PETs in the VM object.

• TET: A transient execution thread (TET) executes an instruction sequence on an associated set of data. A TET's lifetime might be shorter than that of the associated data set.

• OS-Instance: The OS-Instance of a TOE describes how a particular TOE is instantiated on the OS level. Using POSIX terminology a TOE will run as a single thread within a single- or multi-threaded process.

• MPI-1, MPI-2: Communication via MPI standards 1 and 2.

• armci: Communication via the aggregate remote memory copy interface.

• SHMEM: Communication via the SHMEM interface.

• OS-IPC: Communication via the operating system's inter process communication interface. Either POSIX IPC or System V IPC.

• InterCon-lib: Communication via the interconnect's library native interface. An example is the Elan library for Quadrics.

The POSIX machine abstraction, while a very powerful concept, needs augmentation when applied to HPC applications. Key elements of the POSIX abstraction are processes, which provide virtually unlimited resources (memory, I/O, sockets, ...) to possibly multiple threads of execution. Similarly POSIX threads create the illusion that there is virtually unlimited processing power available to each POSIX process. While the POSIX abstraction is very suitable for many multi-user/multi-tasking applications that need to share limited physical resources, it does not directly fit the HPC workload where over-subscription of resources is one of the most expensive modes of operation.

ESMF's virtual machine abstraction is based on the POSIX machine model but holds additional information about the available physical processing units in terms of Processing Elements (PEs). A PE is the smallest physical processing unit and encapsulates the hardware details (Cores, CPUs and SSIs).

There is exactly one physical machine layout for each application, and all VM instances have access to this information. The PE is the smallest processing unit which, in today's microprocessor technology, corresponds to a single Core. Cores are arranged in CPUs which in turn are arranged in SSIs. The setup of the physical machine layout is part of the ESMF initialization process.

On top of the PE concept the key abstraction provided by the VM is the PET. All user code is executed by PETs while OS and hardware details are hidden. The VM class contains a number of methods which allow the user to prescribe how the PETs of a desired virtual machine should be instantiated on the OS level and how they should map onto the hardware. This prescription is kept in a private virtual machine plan object which is created at the same time the associated component is being created. Each time component code is entered through one of the component's registered top-level methods (Initialize/Run/Finalize), the virtual machine plan along with a pointer to the respective user function is used to instantiate the user code on the PETs of the associated VM in form of single- or multi-threaded POSIX processes.

The process of starting, entering, exiting and shutting down a VM is very transparent, all spawning and joining of threads is handled by VM methods "behind the scenes". Furthermore, fundamental synchronization and communication primitives are provided on the PET level through a uniform API, hiding details related to the actual instantiation of the participating PETs.

Within a VM object each PE of the physical machine maps to 0 or 1 PETs. Allowing unassigned PEs provides a means to prevent over-subscription between multiple concurrently running virtual machines. Similarly a maximum of one PET per PE prevents over-subscription within a single VM instance. However, over-subscription is possible by subscribing PETs from different virtual machines to the same PE. This type of over-subscription can be desirable for PETs associated with I/O workloads expected to be used infrequently and to block often on I/O requests.

On the OS level each PET of a VM object is represented by a POSIX thread (Pthread) either belonging to a single- or multi-threaded process and maps to at least 1 PE of the physical machine, ensuring its execution. Mapping a single PET to multiple PEs provides resources for user-level multi-threading, in which case the user code inquires how many PEs are associated with its PET and if there are multiple PEs available the user code can spawn an equal number of threads (e.g. OpenMP) without risking over-subscription. Typically these user spawned threads are short-lived and used for fine-grained parallelization in form of TETs. All PEs mapped against a single PET must be part of a unique SSI in order to allow user-level multi-threading!

In addition to discovering the physical machine the ESMF initialization process sets up the default global virtual machine. This VM object, which is the ultimate parent of all VMs created during the course of execution, contains as many PETs as there are PEs in the physical machine. All of its PETs are instantiated in form of single-threaded MPI processes and a 1:1 mapping of PETs to PEs is used for the default global VM.

The VM design and implementation is based on the POSIX process and thread model as well as the MPI-1.2 standard. As a consequence of the latter standard the number of processes is static during the course of execution and is determined at start-up. The VM implementation further requires that the user starts up the ESMF application with as many MPI processes as there are PEs in the available physical machine using the platform dependent mechanism to ensure proper process placement.

All MPI processes participating in a VM are grouped together by means of an MPI_Group object and their context is defined via an MPI_Comm object (MPI intra-communicator). The PET local process id within each virtual machine is equal to the MPI_Comm_rank in the local MPI_Comm context whereas the PET process id is equal to the MPI_Comm_rank in MPI_COMM_WORLD. The PET process id is used within the VM methods to determine the virtual memory space a PET is operating in.

In order to provide a migration path for legacy MPI-applications the VM offers accessor functions to its MPI_Comm object. Once obtained this object may be used in explicit user-code MPI calls within the same context.

## 49.5 Class API

### 49.5.1 ESMF_VMAssignment(=) - VM assignment

INTERFACE:

     interface assignment(=)
vm1 = vm2

ARGUMENTS:
     type(ESMF_VM) :: vm1
type(ESMF_VM) :: vm2

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Assign vm1 as an alias to the same ESMF VM object in memory as vm2. If vm2 is invalid, then vm1 will be equally invalid after the assignment.

The arguments are:

vm1
The ESMF_VM object on the left hand side of the assignment.
vm2
The ESMF_VM object on the right hand side of the assignment.

### 49.5.2 ESMF_VMOperator(==) - VM equality operator

INTERFACE:

   interface operator(==)
if (vm1 == vm2) then ... endif
OR
result = (vm1 == vm2)

RETURN VALUE:
     logical :: result

ARGUMENTS:
     type(ESMF_VM), intent(in) :: vm1
type(ESMF_VM), intent(in) :: vm2

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Test whether vm1 and vm2 are valid aliases to the same ESMF VM object in memory. For a more general comparison of two ESMF VMs, going beyond the simple alias test, the ESMF_VMMatch() function (not yet implemented) must be used.

The arguments are:

vm1
The ESMF_VM object on the left hand side of the equality operation.
vm2
The ESMF_VM object on the right hand side of the equality operation.

### 49.5.3 ESMF_VMOperator(/=) - VM not equal operator

INTERFACE:

   interface operator(/=)
if (vm1 /= vm2) then ... endif
OR
result = (vm1 /= vm2)

RETURN VALUE:
     logical :: result

ARGUMENTS:
     type(ESMF_VM), intent(in) :: vm1
type(ESMF_VM), intent(in) :: vm2

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Test whether vm1 and vm2 are not valid aliases to the same ESMF VM object in memory. For a more general comparison of two ESMF VMs, going beyond the simple alias test, the ESMF_VMMatch() function (not yet implemented) must be used.

The arguments are:

vm1
The ESMF_VM object on the left hand side of the non-equality operation.
vm2
The ESMF_VM object on the right hand side of the non-equality operation.

### 49.5.4 ESMF_VMAllFullReduce - Fully reduce data across VM, result on all PETs

INTERFACE:

    subroutine ESMF_VMAllFullReduce(vm, sendData, recvData, &
count, reduceflag, syncflag, commhandle, rc)

ARGUMENTS:
      type(ESMF_VM),                    intent(in)            :: vm
<type>(ESMF_KIND_<kind>), target, intent(in)            :: sendData(:)
<type>(ESMF_KIND_<kind>),         intent(out)           :: recvData
integer,                          intent(in)            :: count
type(ESMF_Reduce_Flag),           intent(in)            :: reduceflag
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
type(ESMF_Sync_Flag),             intent(in),  optional :: syncflag
type(ESMF_CommHandle),            intent(out), optional :: commhandle
integer,                          intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Collective ESMF_VM communication call that reduces a contiguous data array of <type><kind> across the ESMF_VM object into a single value of the same <type><kind>. The result is returned on all PETs. Different reduction operations can be specified.

This method is overloaded for: ESMF_TYPEKIND_I4, ESMF_TYPEKIND_I8, ESMF_TYPEKIND_R4, ESMF_TYPEKIND_R8.

TODO: The current version of this method does not provide an implementation of the non-blocking feature. When calling this method with syncflag = ESMF_SYNC_NONBLOCKING, error code ESMF_RC_NOT_IMPL will be returned and an error will be logged.

The arguments are:

vm
ESMF_VM object.
sendData
Contiguous data array holding data to be sent. All PETs must specify a valid source array.
recvData
Single data variable to be received. All PETs must specify a valid result variable.
count
Number of elements in sendData. Allowed to be different across the PETs, as long as count > 0.
reduceflag
Reduction operation. See section 52.46 for a list of valid reduce operations.
[syncflag]
Flag indicating whether this call behaves blocking or non-blocking. The default is ESMF_SYNC_BLOCKING. See section 52.56 for a complete list of options.
[commhandle]
If present, a communication handle will be returned in case of a non-blocking request (see argument syncflag). The commhandle can be used in ESMF_VMCommWait() to block the calling PET until the communication call has finished PET-locally. If no commhandle was supplied to a non-blocking call the VM method ESMF_VMCommWaitAll() may be used to block on all currently queued communication calls of the VM context.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 49.5.5 ESMF_VMAllGather - Gather data across VM, result on all PETs

INTERFACE:

    subroutine ESMF_VMAllGather(vm, sendData, recvData, count, &
syncflag, commhandle, rc)

ARGUMENTS:
      type(ESMF_VM),                    intent(in)            :: vm
<type>(ESMF_KIND_<kind>), target, intent(in)            :: sendData(:)
<type>(ESMF_KIND_<kind>), target, intent(out)           :: recvData(:)
integer,                          intent(in)            :: count
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
type(ESMF_Sync_Flag),             intent(in),  optional :: syncflag
type(ESMF_CommHandle),            intent(out), optional :: commhandle
integer,                          intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Collective ESMF_VM communication call that gathers contiguous data from all PETs of an ESMF_VM object into an array on all PETs.

This method is overloaded for: ESMF_TYPEKIND_I4, ESMF_TYPEKIND_I8, ESMF_TYPEKIND_R4, ESMF_TYPEKIND_R8, ESMF_TYPEKIND_LOGICAL.

The arguments are:

vm
ESMF_VM object.
sendData
Contiguous data array holding data to be sent. All PETs must specify a valid source array.
recvData
Contiguous data array for data to be received. All PETs must specify a valid recvData argument.
count
Number of elements to be gathered from each PET. Must be the same on all PETs.
[syncflag]
Flag indicating whether this call behaves blocking or non-blocking. The default is ESMF_SYNC_BLOCKING. See section 52.56 for a complete list of options.
[commhandle]
If present, a communication handle will be returned in case of a non-blocking request (see argument syncflag). The commhandle can be used in ESMF_VMCommWait() to block the calling PET until the communication call has finished PET-locally. If no commhandle was supplied to a non-blocking call the VM method ESMF_VMCommWaitAll() may be used to block on all currently queued communication calls of the VM context.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 49.5.6 ESMF_VMAllGatherV - GatherV data across VM, result on all PETs

INTERFACE:

    subroutine ESMF_VMAllGatherV(vm, sendData, sendCount, &
recvData, recvCounts, recvOffsets, syncflag, commhandle, rc)

ARGUMENTS:
      type(ESMF_VM),                    intent(in)            :: vm
<type>(ESMF_KIND_<kind>), target, intent(in)            :: sendData(:)
integer,                          intent(in)            :: sendCount
<type>(ESMF_KIND_<kind>), target, intent(out)           :: recvData(:)
integer,                          intent(in)            :: recvCounts(:)
integer,                          intent(in)            :: recvOffsets(:)
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
type(ESMF_Sync_Flag),             intent(in),  optional :: syncflag
type(ESMF_CommHandle),            intent(out), optional :: commhandle
integer,                          intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Collective ESMF_VM communication call that gathers contiguous data from all PETs of an ESMF_VM object into an array on all PETs.

This method is overloaded for: ESMF_TYPEKIND_I4, ESMF_TYPEKIND_I8, ESMF_TYPEKIND_R4, ESMF_TYPEKIND_R8.

TODO: The current version of this method does not provide an implementation of the non-blocking feature. When calling this method with syncflag = ESMF_SYNC_NONBLOCKING, error code ESMF_RC_NOT_IMPL will be returned and an error will be logged.

The arguments are:

vm
ESMF_VM object.
sendData
Contiguous data array holding data to be sent. All PETs must specify a valid source array.
sendCount
Number of sendData elements to send from local PET to all other PETs.
recvData
Contiguous data array for data to be received. All PETs must specify a valid recvData argument.
recvCounts
Number of recvData elements to be received from corresponding source PET.
recvOffsets
Offsets in units of elements in recvData marking the start of element sequence to be received from source PET.
[syncflag]
Flag indicating whether this call behaves blocking or non-blocking. The default is ESMF_SYNC_BLOCKING. See section 52.56 for a complete list of options.
[commhandle]
If present, a communication handle will be returned in case of a non-blocking request (see argument syncflag). The commhandle can be used in ESMF_VMCommWait() to block the calling PET until the communication call has finished PET-locally. If no commhandle was supplied to a non-blocking call the VM method ESMF_VMCommWaitAll() may be used to block on all currently queued communication calls of the VM context.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 49.5.7 ESMF_VMAllReduce - Reduce data across VM, result on all PETs

INTERFACE:

    subroutine ESMF_VMAllReduce(vm, sendData, recvData, count, &
reduceflag, syncflag, commhandle, rc)

ARGUMENTS:
      type(ESMF_VM),                    intent(in)            :: vm
<type>(ESMF_KIND_<kind>), target, intent(in)            :: sendData(:)
<type>(ESMF_KIND_<kind>), target, intent(out)           :: recvData(:)
integer,                          intent(in)            :: count
type(ESMF_Reduce_Flag),           intent(in)            :: reduceflag
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
type(ESMF_Sync_Flag),             intent(in),  optional :: syncflag
type(ESMF_CommHandle),            intent(out), optional :: commhandle
integer,                          intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Collective ESMF_VM communication call that reduces a contiguous data array across the ESMF_VM object into a contiguous data array of the same <type><kind>. The result array is returned on all PETs. Different reduction operations can be specified.

This method is overloaded for: ESMF_TYPEKIND_I4, ESMF_TYPEKIND_I8, ESMF_TYPEKIND_R4, ESMF_TYPEKIND_R8.

TODO: The current version of this method does not provide an implementation of the non-blocking feature. When calling this method with syncflag = ESMF_SYNC_NONBLOCKING, error code ESMF_RC_NOT_IMPL will be returned and an error will be logged.

The arguments are:

vm
ESMF_VM object.
sendData
Contiguous data array holding data to be sent. All PETs must specify a valid source array.
recvData
Contiguous data array for data to be received. All PETs must specify a valid recvData argument.
count
Number of elements in sendData and recvData. Must be the same on all PETs.
reduceflag
Reduction operation. See section 52.46 for a list of valid reduce operations.
[syncflag]
Flag indicating whether this call behaves blocking or non-blocking. The default is ESMF_SYNC_BLOCKING. See section 52.56 for a complete list of options.
[commhandle]
If present, a communication handle will be returned in case of a non-blocking request (see argument syncflag). The commhandle can be used in ESMF_VMCommWait() to block the calling PET until the communication call has finished PET-locally. If no commhandle was supplied to a non-blocking call the VM method ESMF_VMCommWaitAll() may be used to block on all currently queued communication calls of the VM context.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 49.5.8 ESMF_VMAllToAll - AllToAll communications across VM

INTERFACE:

    subroutine ESMF_VMAllToAll(vm, sendData, sendCount, &
recvData, recvCount, syncflag, &
commhandle, rc)

ARGUMENTS:
      type(ESMF_VM),                    intent(in)            :: vm
<type>(ESMF_KIND_<kind>), target, intent(in)            :: sendData(:)
integer,                          intent(in)            :: sendCount
<type>(ESMF_KIND_<kind>), target, intent(out)           :: recvData(:)
integer,                          intent(in)            :: recvCount
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
type(ESMF_Sync_Flag),             intent(in),  optional :: syncflag
type(ESMF_CommHandle),            intent(out), optional :: commhandle
integer,                          intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.3.0r. If code using this interface compiles with any version of ESMF starting with 5.3.0r, then it will compile with the current version.

DESCRIPTION:

Collective ESMF_VM communication call that performs a total exchange operation, sending pieces of the contiguous data buffer sendData to all other PETs while receiving data into the contiguous data buffer recvData from all other PETs.

This method is overloaded for: ESMF_TYPEKIND_I4, ESMF_TYPEKIND_I8, ESMF_TYPEKIND_R4, ESMF_TYPEKIND_R8.

TODO: The current version of this method does not provide an implementation of the non-blocking feature. When calling this method with syncflag = ESMF_SYNC_NONBLOCKING, error code ESMF_RC_NOT_IMPL will be returned and an error will be logged.

The arguments are:

vm
ESMF_VM object.
sendData
Contiguous data array holding data to be sent. All PETs must specify a valid source array.
sendCount
Number of sendData elements to send from local PET to each destination PET.
recvData
Contiguous data array for data to be received. All PETs must specify a valid recvData argument.
recvCount
Number of recvData elements to be received by local PET from each source PET.
[syncflag]
Flag indicating whether this call behaves blocking or non-blocking. The default is ESMF_SYNC_BLOCKING. See section 52.56 for a complete list of options.
[commhandle]
If present, a communication handle will be returned in case of a non-blocking request (see argument syncflag). The commhandle can be used in ESMF_VMCommWait() to block the calling PET until the communication call has finished PET-locally. If no commhandle was supplied to a non-blocking call the VM method ESMF_VMCommWaitAll() may be used to block on all currently queued communication calls of the VM context.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 49.5.9 ESMF_VMAllToAllV - AllToAllV communications across VM

INTERFACE:

    subroutine ESMF_VMAllToAllV(vm, sendData, sendCounts, &
sendOffsets, recvData, recvCounts, recvOffsets, syncflag, &
commhandle, rc)

ARGUMENTS:
      type(ESMF_VM),                    intent(in)            :: vm
<type>(ESMF_KIND_<kind>), target, intent(in)            :: sendData(:)
integer,                          intent(in)            :: sendCounts(:)
integer,                          intent(in)            :: sendOffsets(:)
<type>(ESMF_KIND_<kind>), target, intent(out)           :: recvData(:)
integer,                          intent(in)            :: recvCounts(:)
integer,                          intent(in)            :: recvOffsets(:)
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
type(ESMF_Sync_Flag),             intent(in),  optional :: syncflag
type(ESMF_CommHandle),            intent(out), optional :: commhandle
integer,                          intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Collective ESMF_VM communication call that performs a total exchange operation, sending pieces of the contiguous data buffer sendData to all other PETs while receiving data into the contiguous data buffer recvData from all other PETs.

This method is overloaded for: ESMF_TYPEKIND_I4, ESMF_TYPEKIND_I8, ESMF_TYPEKIND_R4, ESMF_TYPEKIND_R8, ESMF_TYPEKIND_LOGICAL.

TODO: The current version of this method does not provide an implementation of the non-blocking feature. When calling this method with syncflag = ESMF_SYNC_NONBLOCKING, error code ESMF_RC_NOT_IMPL will be returned and an error will be logged.

The arguments are:

vm
ESMF_VM object.
sendData
Contiguous data array holding data to be sent. All PETs must specify a valid source array.
sendCounts
Number of sendData elements to send from local PET to destination PET.
sendOffsets
Offsets in units of elements in sendData marking to start of element sequence to be sent from local PET to destination PET.
recvData
Contiguous data array for data to be received. All PETs must specify a valid recvData argument.
recvCounts
Number of recvData elements to be received by local PET from source PET.
recvOffsets
Offsets in units of elements in recvData marking to start of element sequence to be received by local PET from source PET.
[syncflag]
Flag indicating whether this call behaves blocking or non-blocking. The default is ESMF_SYNC_BLOCKING. See section 52.56 for a complete list of options.
[commhandle]
If present, a communication handle will be returned in case of a non-blocking request (see argument syncflag). The commhandle can be used in ESMF_VMCommWait() to block the calling PET until the communication call has finished PET-locally. If no commhandle was supplied to a non-blocking call the VM method ESMF_VMCommWaitAll() may be used to block on all currently queued communication calls of the VM context.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 49.5.10 ESMF_VMBarrier - VM wide barrier

INTERFACE:

   subroutine ESMF_VMBarrier(vm, rc)

ARGUMENTS:
     type(ESMF_VM),  intent(in)            :: vm
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,        intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Collective ESMF_VM communication call that blocks calling PET until all PETs of the VM context have issued the call.

The arguments are:

vm
ESMF_VM object.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

INTERFACE:

    subroutine ESMF_VMBroadcast(vm, bcstData, count, rootPet, &
syncflag, commhandle, rc)

ARGUMENTS:
      type(ESMF_VM),                    intent(in)            :: vm
<type>(ESMF_KIND_<kind>), target, intent(inout)         :: bcstData(:)
integer,                          intent(in)            :: count
integer,                          intent(in)            :: rootPet
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
type(ESMF_Sync_Flag),             intent(in),  optional :: syncflag
type(ESMF_CommHandle),            intent(out), optional :: commhandle
integer,                          intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Collective ESMF_VM communication call that broadcasts a contiguous data array from rootPet to all other PETs of the ESMF_VM object.

This method is overloaded for: ESMF_TYPEKIND_I4, ESMF_TYPEKIND_I8, ESMF_TYPEKIND_R4, ESMF_TYPEKIND_R8, ESMF_TYPEKIND_LOGICAL, ESMF_TYPEKIND_CHARACTER.

The arguments are:

vm
ESMF_VM object.
bcstData
Contiguous data array. On rootPet bcstData holds data that is to be broadcasted to all other PETs. On all other PETs bcstData is used to receive the broadcasted data.
count
Number of elements in /bcstData. Must be the same on all PETs.
rootPet
PET that holds data that is being broadcast.
[syncflag]
Flag indicating whether this call behaves blocking or non-blocking. The default is ESMF_SYNC_BLOCKING. See section 52.56 for a complete list of options.
[commhandle]
If present, a communication handle will be returned in case of a non-blocking request (see argument syncflag). The commhandle can be used in ESMF_VMCommWait() to block the calling PET until the communication call has finished PET-locally. If no commhandle was supplied to a non-blocking call the VM method ESMF_VMCommWaitAll() may be used to block on all currently queued communication calls of the VM context.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 49.5.12 ESMF_VMCommWait - Wait for non-blocking VM communication to complete

INTERFACE:

   subroutine ESMF_VMCommWait(vm, commhandle, rc)

ARGUMENTS:
     type(ESMF_VM),         intent(in)            :: vm
type(ESMF_CommHandle), intent(in)            :: commhandle
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,               intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Wait for non-blocking VM communication specified by the commhandle to complete.

The arguments are:

vm
ESMF_VM object.
commhandle
Handle specifying a previously issued non-blocking communication request.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 49.5.13 ESMF_VMCommWaitAll - Wait for all non-blocking VM comms to complete

INTERFACE:

   subroutine ESMF_VMCommWaitAll(vm, rc)

ARGUMENTS:
     type(ESMF_VM), intent(in)            :: vm
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,       intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Wait for all pending non-blocking VM communication within the specified VM context to complete.

The arguments are:

vm
ESMF_VM object.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 49.5.14 ESMF_VMGather - Gather data from across VM

INTERFACE:

    subroutine ESMF_VMGather(vm, sendData, recvData, count, rootPet, &
syncflag, commhandle, rc)

ARGUMENTS:
      type(ESMF_VM),                    intent(in)            :: vm
<type>(ESMF_KIND_<kind>), target, intent(in)            :: sendData(:)
<type>(ESMF_KIND_<kind>), target, intent(out)           :: recvData(:)
integer,                          intent(in)            :: count
integer,                          intent(in)            :: rootPet
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
type(ESMF_Sync_Flag),             intent(in),  optional :: syncflag
type(ESMF_CommHandle),            intent(out), optional :: commhandle
integer,                          intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Collective ESMF_VM communication call that gathers contiguous data from all PETs of an ESMF_VM object (including rootPet) into an array on rootPet.

This method is overloaded for: ESMF_TYPEKIND_I4, ESMF_TYPEKIND_I8, ESMF_TYPEKIND_R4, ESMF_TYPEKIND_R8, ESMF_TYPEKIND_LOGICAL.

The arguments are:

vm
ESMF_VM object.
sendData
Contiguous data array holding data to be sent. All PETs must specify a valid source array.
recvData
Contiguous data array for data to be received. Only the recvData array specified by the rootPet will be used by this method.
count
Number of elements to be sent from each PET to rootPet. Must be the same on all PETs.
rootPet
PET on which data is gathereds.
[syncflag]
Flag indicating whether this call behaves blocking or non-blocking. The default is ESMF_SYNC_BLOCKING. See section 52.56 for a complete list of options.
[commhandle]
If present, a communication handle will be returned in case of a non-blocking request (see argument syncflag). The commhandle can be used in ESMF_VMCommWait() to block the calling PET until the communication call has finished PET-locally. If no commhandle was supplied to a non-blocking call the VM method ESMF_VMCommWaitAll() may be used to block on all currently queued communication calls of the VM context.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 49.5.15 ESMF_VMGatherV - GatherV data from across VM

INTERFACE:

    subroutine ESMF_VMGatherV(vm, sendData, sendCount, recvData, &
recvCounts, recvOffsets, rootPet, rc)

ARGUMENTS:
      type(ESMF_VM),                    intent(in)            :: vm
<type>(ESMF_KIND_<kind>), target, intent(in)            :: sendData(:)
integer,                          intent(in)            :: sendCount
<type>(ESMF_KIND_<kind>), target, intent(out)           :: recvData(:)
integer,                          intent(in)            :: recvCounts(:)
integer,                          intent(in)            :: recvOffsets(:)
integer,                          intent(in)            :: rootPet
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,                          intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Collective ESMF_VM communication call that gathers contiguous data from all PETs of an ESMF_VM object into an array on rootPet.

This method is overloaded for: ESMF_TYPEKIND_I4, ESMF_TYPEKIND_I8, ESMF_TYPEKIND_R4, ESMF_TYPEKIND_R8.

TODO: The current version of this method does not provide an implementation of the non-blocking feature. When calling this method with syncflag = ESMF_SYNC_NONBLOCKING, error code ESMF_RC_NOT_IMPL will be returned and an error will be logged.

The arguments are:

vm
ESMF_VM object.
sendData
Contiguous data array holding data to be sent. All PETs must specify a valid source array.
sendCount
Number of sendData elements to send from local PET to all other PETs.
recvData
Contiguous data array for data to be received. Only the recvData array specified by the rootPet will be used by this method.
recvCounts
Number of recvData elements to be received from corresponding source PET.
recvOffsets
Offsets in units of elements in recvData marking the start of element sequence to be received from source PET.
rootPet
PET on which data is gathered.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 49.5.16 ESMF_VMGet - Get object-wide information from a VM

INTERFACE:

   ! Private name; call using ESMF_VMGet()
recursive subroutine ESMF_VMGetDefault(vm, localPet, &
petCount, peCount, ssiCount, ssiMinPetCount, ssiMaxPetCount, &
ssiSharedMemoryEnabledFlag, rc)

ARGUMENTS:
     type(ESMF_VM),      intent(in)            :: vm
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,            intent(out), optional :: localPet
integer,            intent(out), optional :: petCount
integer,            intent(out), optional :: peCount
integer,            intent(out), optional :: ssiCount
integer,            intent(out), optional :: ssiMinPetCount
integer,            intent(out), optional :: ssiMaxPetCount
integer,            intent(out), optional :: ssiLocalPetCount
integer,            intent(out), optional :: mpiCommunicator
logical,            intent(out), optional :: openMPEnabledFlag
logical,            intent(out), optional :: ssiSharedMemoryEnabledFlag
integer,            intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.
• This interface was modified since ESMF version 5.2.0r. The fact that code using this interface compiles with the current ESMF version does not guarantee that it compiles with previous versions of this interface. If user code compatibility with version 5.2.0r is desired then care must be taken to limit the use of this interface to features that were available in the 5.2.0r release.
Changes made after the 5.2.0r release:
8.0.0
Added arguments ssiCount, ssiMinPetCount, ssiMaxPetCount, and ssiLocalPetCount to provide access to information about how the VM is mapped across the single system images (SSIs) - typically synonymous to nodes - of the compute environment. This information is useful when constructing custom petLists.
Added argument ssiSharedMemoryEnabledFlag that allows the user to query whether ESMF was compiled with support for shared memory access between PETs on the same SSI.

DESCRIPTION:

Get internal information about the specified ESMF_VM object.

The arguments are:

vm
Queried ESMF_VM object.
[localPet]
Upon return this holds the local id of the PET that issued this call. The valid range of localPet is . A value of is returned on PETs that are not active under the specified vm.
[petCount]
Upon return this holds the number of PETs running under vm.
[peCount]
Upon return this holds the number of PEs referenced by vm.
[ssiCount]
Upon return this holds the number of single system images referenced by vm.
[ssiMinPetCount]
Upon return this holds the smallest number of PETs running in the same single system images under vm.
[ssiMaxPetCount]
Upon return this holds the largest number of PETs running in the same single system images under vm.
[ssiLocalPetCount]
Upon return this holds the number of PETs running in the same single system as localPet.
[mpiCommunicator]
Upon return this holds the MPI intra-communicator used by the specified ESMF_VM object. This communicator may be used for user-level MPI communications. It is recommended that the user duplicates the communicator via MPI_Comm_Dup() in order to prevent any interference with ESMF communications. MPI_COMM_NULL is returned on PETs that are not active under the specified vm.
.TRUE.
ESMF has been compiled with Pthreads.
.FALSE.
ESMF has not been compiled with Pthreads.
[openMPEnabledFlag]
.TRUE.
ESMF has been compiled with OpenMP.
.FALSE.
ESMF has not been compiled with OpenMP.
[ssiSharedMemoryEnabledFlag]
.TRUE.
ESMF has been compiled to support shared memory access between PETs that are on the same single system image (SSI).
.FALSE.
ESMF has not been compiled to support shared memory access between PETs that are on the same single system image (SSI).
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 49.5.17 ESMF_VMGet - Get PET-local VM information

INTERFACE:

   ! Private name; call using ESMF_VMGet()
subroutine ESMF_VMGetPetLocalInfo(vm, pet, peCount, &

ARGUMENTS:
     type(ESMF_VM), intent(in)            :: vm
integer,       intent(in)            :: pet
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,       intent(out), optional :: peCount
integer,       intent(out), optional :: accDeviceCount
integer,       intent(out), optional :: ssiId
integer,       intent(out), optional :: vas
integer,       intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.
• This interface was modified since ESMF version 5.2.0r. The fact that code using this interface compiles with the current ESMF version does not guarantee that it compiles with previous versions of this interface. If user code compatibility with version 5.2.0r is desired then care must be taken to limit the use of this interface to features that were available in the 5.2.0r release.
Changes made after the 5.2.0r release:
7.0.0

DESCRIPTION:

Get internal information about a specific PET within an ESMF_VM object.

The arguments are:

vm
Queried ESMF_VM object.
pet
Queried PET id within the specified ESMF_VM object.
[peCount]
Upon return this holds the number of PEs associated with the specified PET in the ESMF_VM object.
[accDeviceCount]
Upon return this holds the number of accelerated devices accessible from the specified PET in the ESMF_VM object.
[ssiId]
Upon return this holds the id of the single-system image (SSI) the specified PET is running on.
Upon return this holds the number of PETs in the specified PET"s thread group.
Upon return this holds the thread id of the specified PET within the PET"s thread group.
[vas]
Virtual address space in which this PET operates.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 49.5.18 ESMF_VMGetGlobal - Get Global VM

INTERFACE:

   subroutine ESMF_VMGetGlobal(vm, rc)

ARGUMENTS:
     type(ESMF_VM), intent(out)            :: vm
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,       intent(out), optional  :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Get the global ESMF_VM object. This is the VM object that is created during ESMF_Initialize() and is the ultimate parent of all VM objects in an ESMF application. It is identical to the VM object returned by ESMF_Initialize(..., vm=vm, ...).

The ESMF_VMGetGlobal() call provides access to information about the global execution context via the global VM. This call is necessary because ESMF does not created a global ESMF Component during ESMF_Initialize() that could be queried for information about the global execution context of an ESMF application.

Usage of ESMF_VMGetGlobal() from within Component code is strongly discouraged. ESMF Components should only access their own VM objects through Component methods. Global information, if required by the Component user code, should be passed down to the Component from the driver through the Component calling interface.

The arguments are:

vm
Upon return this holds the ESMF_VM object of the global execution context.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 49.5.19 ESMF_VMGetCurrent - Get Current VM

INTERFACE:

   subroutine ESMF_VMGetCurrent(vm, rc)

ARGUMENTS:
     type(ESMF_VM), intent(out)           :: vm
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,       intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Get the ESMF_VM object of the current execution context. Calling ESMF_VMGetCurrent() within an ESMF Component, will return the same VM object as ESMF_GridCompGet(..., vm=vm, ...) or ESMF_CplCompGet(..., vm=vm, ...).

The main purpose of providing ESMF_VMGetCurrent() is to simplify ESMF adoption in legacy code. Specifically, code that uses MPI_COMM_WORLD deep within its calling tree can easily be modified to use the correct MPI communicator of the current ESMF execution context. The advantage is that these modifications are very local, and do not require wide reaching interface changes in the legacy code to pass down the ESMF component object, or the MPI communicator.

The use of ESMF_VMGetCurrent() is strongly discouraged in newly written Component code. Instead, the ESMF Component object should be used as the appropriate container of ESMF context information. This object should be passed between the subroutines of a Component, and be queried for any Component specific information.

Outside of a Component context, i.e. within the driver context, the call to ESMF_VMGetCurrent() is identical to ESMF_VMGetGlobal().

The arguments are:

vm
Upon return this holds the ESMF_VM object of the current execution context.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 49.5.20 ESMF_VMIsCreated - Check whether a VM object has been created

INTERFACE:

   function ESMF_VMIsCreated(vm, rc)

RETURN VALUE:
     logical :: ESMF_VMIsCreated

ARGUMENTS:
     type(ESMF_VM), intent(in)            :: vm
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,       intent(out), optional :: rc

DESCRIPTION:

Return .true. if the vm has been created. Otherwise return .false.. If an error occurs, i.e. rc /= ESMF_SUCCESS is returned, the return value of the function will also be .false..

The arguments are:

vm
ESMF_VM queried.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 49.5.21 ESMF_VMPrint - Print VM information

INTERFACE:

   subroutine ESMF_VMPrint(vm, rc)

ARGUMENTS:
     type(ESMF_VM),  intent(in)            :: vm
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,        intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Print internal information about the specified ESMF_VM to stdout.

The arguments are:

vm
Specified ESMF_VM object.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 49.5.22 ESMF_VMRecv - Receive data from srcPet

INTERFACE:

    subroutine ESMF_VMRecv(vm, recvData, count, srcPet, &
syncflag, commhandle, rc)

ARGUMENTS:
      type(ESMF_VM),                     intent(in)            :: vm
<type>(ESMF_KIND_<kind>), target,  intent(out)           :: recvData(:)
integer,                           intent(in)            :: count
integer,                           intent(in)            :: srcPet
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
type(ESMF_Sync_Flag),              intent(in),  optional :: syncflag
type(ESMF_CommHandle),             intent(out), optional :: commhandle
integer,                           intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Receive contiguous data from srcPet within the same ESMF_VM object.

This method is overloaded for: ESMF_TYPEKIND_I4, ESMF_TYPEKIND_I8, ESMF_TYPEKIND_R4, ESMF_TYPEKIND_R8, ESMF_TYPEKIND_LOGICAL, ESMF_TYPEKIND_CHARACTER.

The arguments are:

vm
ESMF_VM object.
recvData
Contiguous data array for data to be received.
count
Number of elements to be received.
srcPet
Sending PET.
[syncflag]
Flag indicating whether this call behaves blocking or non-blocking. The default is ESMF_SYNC_BLOCKING. See section 52.56 for a complete list of options.
[commhandle]
If present, a communication handle will be returned in case of a non-blocking request (see argument syncflag). The commhandle can be used in ESMF_VMCommWait() to block the calling PET until the communication call has finished PET-locally. If no commhandle was supplied to a non-blocking call the VM method ESMF_VMCommWaitAll() may be used to block on all currently queued communication calls of the VM context.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 49.5.23 ESMF_VMReduce - Reduce data from across VM

INTERFACE:

    subroutine ESMF_VMReduce(vm, sendData, recvData, count, &
reduceflag, rootPet, syncflag, commhandle, rc)

ARGUMENTS:
      type(ESMF_VM),                    intent(in)            :: vm
<type>(ESMF_KIND_<kind>), target, intent(in)            :: sendData(:)
<type>(ESMF_KIND_<kind>), target, intent(out)           :: recvData(:)
integer,                          intent(in)            :: count
type(ESMF_Reduce_Flag),           intent(in)            :: reduceflag
integer,                          intent(in)            :: rootPet
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
type(ESMF_Sync_Flag),             intent(in),  optional :: syncflag
type(ESMF_CommHandle),            intent(out), optional :: commhandle
integer,                          intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Collective ESMF_VM communication call that reduces a contiguous data array across the ESMF_VM object into a contiguous data array of the same <type><kind>. The result array is returned on rootPet. Different reduction operations can be specified.

This method is overloaded for: ESMF_TYPEKIND_I4, ESMF_TYPEKIND_I8, ESMF_TYPEKIND_R4, ESMF_TYPEKIND_R8.

TODO: The current version of this method does not provide an implementation of the non-blocking feature. When calling this method with syncflag = ESMF_SYNC_NONBLOCKING, error code ESMF_RC_NOT_IMPL will be returned and an error will be logged.

The arguments are:

vm
ESMF_VM object.
sendData
Contiguous data array holding data to be sent. All PETs must specify a valid source array.
recvData
Contiguous data array for data to be received. Only the recvData array specified by the rootPet will be used by this method.
count
Number of elements in sendData and recvData. Must be the same on all PETs.
reduceflag
Reduction operation. See section 52.46 for a list of valid reduce operations.
rootPet
PET on which reduced data is returned.
[syncflag]
Flag indicating whether this call behaves blocking or non-blocking. The default is ESMF_SYNC_BLOCKING. See section 52.56 for a complete list of options.
[commhandle]
If present, a communication handle will be returned in case of a non-blocking request (see argument syncflag). The commhandle can be used in ESMF_VMCommWait() to block the calling PET until the communication call has finished PET-locally. If no commhandle was supplied to a non-blocking call the VM method ESMF_VMCommWaitAll() may be used to block on all currently queued communication calls of the VM context.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 49.5.24 ESMF_VMScatter - Scatter data across VM

INTERFACE:

    subroutine ESMF_VMScatter(vm, sendData, recvData, count, &
rootPet, syncflag, commhandle, rc)

ARGUMENTS:
      type(ESMF_VM),                    intent(in)            :: vm
<type>(ESMF_KIND_<kind>), target, intent(in)            :: sendData(:)
<type>(ESMF_KIND_<kind>), target, intent(out)           :: recvData(:)
integer,                          intent(in)            :: count
integer,                          intent(in)            :: rootPet
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
type(ESMF_Sync_Flag),             intent(in),  optional :: syncflag
type(ESMF_CommHandle),            intent(out), optional :: commhandle
integer,                          intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Collective ESMF_VM communication call that scatters contiguous data from the rootPet to all PETs across the ESMF_VM object (including rootPet).

This method is overloaded for: ESMF_TYPEKIND_I4, ESMF_TYPEKIND_I8, ESMF_TYPEKIND_R4, ESMF_TYPEKIND_R8, ESMF_TYPEKIND_LOGICAL.

The arguments are:

vm
ESMF_VM object.
sendData
Contiguous data array holding data to be sent. Only the sendData array specified by the rootPet will be used by this method.
recvData
Contiguous data array for data to be received. All PETs must specify a valid destination array.
count
Number of elements to be sent from rootPet to each of the PETs. Must be the same on all PETs.
rootPet
PET that holds data that is being scattered.
[syncflag]
Flag indicating whether this call behaves blocking or non-blocking. The default is ESMF_SYNC_BLOCKING. See section 52.56 for a complete list of options.
[commhandle]
If present, a communication handle will be returned in case of a non-blocking request (see argument syncflag). The commhandle can be used in ESMF_VMCommWait() to block the calling PET until the communication call has finished PET-locally. If no commhandle was supplied to a non-blocking call the VM method ESMF_VMCommWaitAll() may be used to block on all currently queued communication calls of the VM context.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 49.5.25 ESMF_VMScatterV - ScatterV across VM

INTERFACE:

    subroutine ESMF_VMScatterV(vm, sendData, sendCounts, &
sendOffsets, recvData, recvCount, rootPet, rc)

ARGUMENTS:
      type(ESMF_VM),                    intent(in)            :: vm
<type>(ESMF_KIND_<kind>), target, intent(in)            :: sendData(:)
integer,                          intent(in)            :: sendCounts(:)
integer,                          intent(in)            :: sendOffsets(:)
<type>(ESMF_KIND_<kind>), target, intent(out)           :: recvData(:)
integer,                          intent(in)            :: recvCount
integer,                          intent(in)            :: rootPet
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,                          intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Collective ESMF_VM communication call that scatters contiguous data from the rootPet to all PETs across the ESMF_VM object (including rootPet).

This method is overloaded for: ESMF_TYPEKIND_I4, ESMF_TYPEKIND_I8, ESMF_TYPEKIND_R4, ESMF_TYPEKIND_R8.

The arguments are:

vm
ESMF_VM object.
sendData
Contiguous data array holding data to be sent. Only the sendData array specified by the rootPet will be used by this method.
sendCounts
Number of sendData elements to be sent to corresponding receive PET.
sendOffsets
Offsets in units of elements in sendData marking the start of element sequence to be sent to receive PET.
recvData
Contiguous data array for data to be received. All PETs must specify a valid recvData argument.
recvCount
Number of recvData elements to receive by local PET from rootPet.
rootPet
PET that holds data that is being scattered.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 49.5.26 ESMF_VMSend - Send data to dstPet

INTERFACE:

    subroutine ESMF_VMSend(vm, sendData, count, dstPet, &
syncflag, commhandle, rc)

ARGUMENTS:
      type(ESMF_VM),                    intent(in)            :: vm
<type>(ESMF_KIND_<kind>), target, intent(in)            :: sendData(:)
integer,                          intent(in)            :: count
integer,                          intent(in)            :: dstPet
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
type(ESMF_Sync_Flag),             intent(in),  optional :: syncflag
type(ESMF_CommHandle),            intent(out), optional :: commhandle
integer,                          intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Send contiguous data to dstPet within the same ESMF_VM object.

This method is overloaded for: ESMF_TYPEKIND_I4, ESMF_TYPEKIND_I8, ESMF_TYPEKIND_R4, ESMF_TYPEKIND_R8, ESMF_TYPEKIND_LOGICAL, ESMF_TYPEKIND_CHARACTER.

The arguments are:

vm
ESMF_VM object.
sendData
Contiguous data array holding data to be sent.
count
Number of elements to be sent.
dstPet
Receiving PET.
[syncflag]
Flag indicating whether this call behaves blocking or non-blocking. The default is ESMF_SYNC_BLOCKING. See section 52.56 for a complete list of options.
[commhandle]
If present, a communication handle will be returned in case of a non-blocking request (see argument syncflag). The commhandle can be used in ESMF_VMCommWait() to block the calling PET until the communication call has finished PET-locally. If no commhandle was supplied to a non-blocking call the VM method ESMF_VMCommWaitAll() may be used to block on all currently queued communication calls of the VM context.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 49.5.27 ESMF_VMSendRecv - Send and Recv data to and from PETs

INTERFACE:

    subroutine ESMF_VMSendRecv(vm, sendData, sendCount, dstPet, &
recvData, recvCount, srcPet, syncflag, commhandle, rc)

ARGUMENTS:
      type(ESMF_VM),                    intent(in)            :: vm
<type>(ESMF_KIND_<kind>), target, intent(in)            :: sendData(:)
integer,                          intent(in)            :: sendCount
integer,                          intent(in)            :: dstPet
<type>(ESMF_KIND_<kind>), target, intent(out)           :: recvData(:)
integer,                          intent(in)            :: recvCount
integer,                          intent(in)            :: srcPet
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
type(ESMF_Sync_Flag),             intent(in),  optional :: syncflag
type(ESMF_CommHandle),            intent(out), optional :: commhandle
integer,                          intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Send contiguous data to dstPet within the same ESMF_VM object while receiving contiguous data from srcPet within the same ESMF_VM object. The sendData and recvData arrays must be disjoint!

This method is overloaded for: ESMF_TYPEKIND_I4, ESMF_TYPEKIND_I8, ESMF_TYPEKIND_R4, ESMF_TYPEKIND_R8, ESMF_TYPEKIND_LOGICAL, ESMF_TYPEKIND_CHARACTER.

The arguments are:

vm
ESMF_VM object.
sendData
Contiguous data array holding data to be sent.
sendCount
Number of elements to be sent.
dstPet
PET that holds recvData.
recvData
Contiguous data array for data to be received.
recvCount
Number of elements to be received.
srcPet
PET that holds sendData.
[syncflag]
Flag indicating whether this call behaves blocking or non-blocking. The default is ESMF_SYNC_BLOCKING. See section 52.56 for a complete list of options.
[commhandle]
If present, a communication handle will be returned in case of a non-blocking request (see argument syncflag). The commhandle can be used in ESMF_VMCommWait() to block the calling PET until the communication call has finished PET-locally. If no commhandle was supplied to a non-blocking call the VM method ESMF_VMCommWaitAll() may be used to block on all currently queued communication calls of the VM context.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 49.5.28 ESMF_VMValidate - Validate VM internals

INTERFACE:

   subroutine ESMF_VMValidate(vm, rc)

ARGUMENTS:
     type(ESMF_VM), intent(in)            :: vm
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,       intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Validates that the vm is internally consistent. The method returns an error code if problems are found.

The arguments are:

vm
Specified ESMF_VM object.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 49.5.29 ESMF_VMWtime - Get floating-point number of seconds

INTERFACE:

   subroutine ESMF_VMWtime(time, rc)

ARGUMENTS:
     real(ESMF_KIND_R8), intent(out)           :: time
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,            intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Get floating-point number of seconds of elapsed wall-clock time since the beginning of execution of the application.

The arguments are:

time
Time in seconds.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 49.5.30 ESMF_VMWtimeDelay - Delay execution

INTERFACE:

   recursive subroutine ESMF_VMWtimeDelay(delay, rc)

ARGUMENTS:
     real(ESMF_KIND_R8), intent(in)            :: delay
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,            intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Delay execution for amount of seconds.

The arguments are:

delay
Delay time in seconds.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 49.5.31 ESMF_VMWtimePrec - Timer precision as floating-point number of seconds

INTERFACE:

   subroutine ESMF_VMWtimePrec(prec, rc)

ARGUMENTS:
     real(ESMF_KIND_R8), intent(out)           :: prec
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,            intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Get a run-time estimate of the timer precision as floating-point number of seconds. This is a relatively expensive call since the timer precision is measured several times before the maximum is returned as the estimate. The returned value is PET-specific and may differ across the VM context.

The arguments are:

prec
Timer precision in seconds.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

# 50 Profiling and Tracing

## 50.1 Description

### 50.1.1 Profiling

ESMF's built in profiling capability collects runtime statistics of an executing ESMF application through both automatic and manual code instrumentation. Timing information for all phases of all ESMF components executing in an application can be automatically collected using the ESMF_RUNTIME_PROFILE environment variable (see below for settings). Additionally, arbitrary user-defined code regions can be timed by manually instrumenting code with special API calls. Timing profiles of component phases and user-defined regions can be output in several different formats:

• in text at the end of ESMF Log files
• in separate text file, one per PET (if the ESMF Logs are turned off)
• in a single summary text file that aggregates timings over multiple PETs
• in a binary format for import into Cupid for detailed analysis

The following table lists important environment variables that control aspects of ESMF profiling.

 Environment Variable Description Example Values Default ESMF_RUNTIME_PROFILE Enable/disables all profiling functions ON or OFF OFF ESMF_RUNTIME_PROFILE_PETLIST Limits profiling to an explicit list of PETs 0-9 50 99'' profile all PETs ESMF_RUNTIME_PROFILE_OUTPUT Controls output format of profiles; multiple can be specified in a space separated list TEXT, SUMMARY, BINARY TEXT

### 50.1.2 Tracing

Whereas profiling collects summary information from an application, tracing records a more detailed set of events for later analysis. Trace analysis can be used to understand what happened during a program's execution and is often used for diagnosing problems, debugging, and performance analysis.

ESMF has a built-in tracing capability that records events into special binary log files. Unlike log files written by the ESMF_Log class, which are primarily for human consumption (see Section 47.1), the trace output files are recorded in a compact binary representation and are processed by tools to produce various analyses. ESMF event streams are recorded in the Common Trace Format (CTF). CTF traces include one or more event streams, as well as a metadata file describing the events in the streams.

Several tools are available for reading in the CTF traces output by ESMF. Of the tools listed below, the first one is designed specifically for analyzing ESMF applications and the second two are general purpose tools for working with all CTF traces.

• Cupid is a plugin for the Eclipse Integrated Development Environment that can read and analyze ESMF traces.
• TraceCompass is a general purpose tool for reading, analyzing, and visualizing traces.
• Babeltrace is a command-line tool and library for trace conversion that can read and write CTF traces. Python bindings are available to open CTF traces are iterate through events.

Events that can be captured by the ESMF tracer include the following. Events are recorded with a high-precision timestamp to allow timing analyses.

phase_enter
indicates entry into an initialize, run, or finalize ESMF component routine
phase_exit
indicates exit from an initialize, run, or finalize ESMF component routine
region_enter
indicates entry into a user-defined code region
region_exit
indicates exit from a user-defined code region
mem
records current memory usage information

The following table lists important environment variables that control aspects of ESMF tracing.

 Environment Variable Description Example Values Default ESMF_RUNTIME_TRACE Enable/disables all tracing functions ON or OFF OFF ESMF_RUNTIME_TRACE_CLOCK Sets the type of clock for timestamping events (see Section 50.2.6). REALTIME or MONOTONIC or MONOTONIC_SYNC REALTIME ESMF_RUNTIME_TRACE_PETLIST Limits tracing to an explicit list of PETs 0-9 50 99'' trace all PETs ESMF_RUNTIME_TRACE_COMPONENT Enables/disable tracing of Component phase_enter and phase_exit events ON or OFF ON ESMF_RUNTIME_TRACE_FLUSH Controls frequency of event stream flushing to file DEFAULT or EAGER DEFAULT

## 50.2 Use and Examples

### 50.2.1 Output a Timing Profile to Text

ESMF profiling is disabled by default. To profile an application, set the ESMF_RUNTIME_PROFILE variable to ON prior to executing the application. You do not need to recompile your code to enable profiling.

# csh shell
$setenv ESMF_RUNTIME_PROFILE ON # bash shell$ export ESMF_RUNTIME_PROFILE=ON

# (from now on, only the csh shell version will be shown)


Then execute the application in the usual way. At the end of the run the profile information will be available at the end of each PET log (if ESMF Logs are turned on) or in a set of separate files, one per PET, with names ESMF_Profile.XXX where XXX is the PET number. Below is an example timing profile. Some regions are left out for brevity.

Region                           Count  Total (s)   Self (s)    Mean (s)    Min (s)     Max (s)
[esm] Init 1                   1      4.0878      0.0341      4.0878      4.0878      4.0878
[OCN-TO-ATM] IPDv05p6b       1      2.6007      2.6007      2.6007      2.6007      2.6007
[ATM-TO-OCN] IPDv05p6b       1      1.4333      1.4333      1.4333      1.4333      1.4333
[ATM] IPDv00p2               1      0.0055      0.0055      0.0055      0.0055      0.0055
[OCN] IPDv00p2               1      0.0023      0.0023      0.0023      0.0023      0.0023
[ATM] IPDv00p1               1      0.0011      0.0011      0.0011      0.0011      0.0011
[OCN] IPDv00p1               1      0.0009      0.0009      0.0009      0.0009      0.0009
[ATM-TO-OCN] IPDv05p3        1      0.0008      0.0008      0.0008      0.0008      0.0008
[ATM-TO-OCN] IPDv05p1        1      0.0008      0.0008      0.0008      0.0008      0.0008
[ATM-TO-OCN] IPDv05p2b       1      0.0007      0.0007      0.0007      0.0007      0.0007
[ATM-TO-OCN] IPDv05p4        1      0.0007      0.0007      0.0007      0.0007      0.0007
[ATM-TO-OCN] IPDv05p2a       1      0.0007      0.0007      0.0007      0.0007      0.0007
[ATM-TO-OCN] IPDv05p5        1      0.0007      0.0007      0.0007      0.0007      0.0007
[OCN-TO-ATM] IPDv05p3        1      0.0006      0.0006      0.0006      0.0006      0.0006
[OCN-TO-ATM] IPDv05p4        1      0.0006      0.0006      0.0006      0.0006      0.0006
[OCN-TO-ATM] IPDv05p2b       1      0.0006      0.0006      0.0006      0.0006      0.0006
[OCN-TO-ATM] IPDv05p2a       1      0.0006      0.0006      0.0006      0.0006      0.0006
[OCN-TO-ATM] IPDv05p5        1      0.0006      0.0006      0.0006      0.0006      0.0006
[OCN-TO-ATM] IPDv05p1        1      0.0005      0.0005      0.0005      0.0005      0.0005
[esm] RunPhase1                1      2.7423      0.9432      2.7423      2.7423      2.7423
[OCN-TO-ATM] RunPhase1       864    0.6094      0.6094      0.0007      0.0006      0.0179
[ATM] RunPhase1              864    0.5296      0.2274      0.0006      0.0005      0.0011
ATM:ModelAdvance           864    0.3022      0.3022      0.0003      0.0003      0.0005
[ATM-TO-OCN] RunPhase1       864    0.3345      0.3345      0.0004      0.0002      0.0299
[OCN] RunPhase1              864    0.3256      0.3256      0.0004      0.0003      0.0010
[esm] FinalizePhase1           1      0.0029      0.0020      0.0029      0.0029      0.0029
[OCN-TO-ATM] FinalizePhase1  1      0.0006      0.0006      0.0006      0.0006      0.0006
[ATM-TO-OCN] FinalizePhase1  1      0.0002      0.0002      0.0002      0.0002      0.0002
[OCN] FinalizePhase1         1      0.0001      0.0001      0.0001      0.0001      0.0001
[ATM] FinalizePhase1         1      0.0000      0.0000      0.0000      0.0000      0.0000


A timed region is either an ESMF component phase (e.g., initialize, run, or finalize) or a user-defined region of code surrounded by calls to ESMF_TraceRegionEnter() and ESMF_TraceRegionExit(). (See section 50.2.8 for more information on instrumenting user-defined regions.) Regions are organized hierarchically with sub-regions nested. For example, in the profile above, the [OCN] RunPhase1 is a sub-region of [esm] RunPhase1 and is entirely contained inside that region. Regions with the same name may appear at multiple places in the hierarchy, and so would appear in multiple rows in the table. The statistics in that row apply to that region at that location in the hierarchy. Component names appear in square brackets, e.g., [ATM], [OCN], and [ATM-TO-OCN]. By default, timings are based on elapsed wall clock time and are collected on a per-PET basis. Therefore, regions timings may differ across PETs. Regions are sorted with the most expensive regions appearing at the top. The following describes the meaning of the statistics in each column:

Count
the number of times the region is executed
Total
the aggregate time spent in the region, inclusive of all sub-regions
Self
the aggregate time spend in the region, exclusive of all sub-regions
Mean
the average amount of time for one execution of the region
Min
time of the fastest execution of the region
Max
time of the slowest execution of the region

### 50.2.2 Summarize Timings across Multiple PETs

By default, separate timing profiles are generated for each PET in the application. The per-PET profiles can be aggregated together and output to a single file, ESMF_Profile.summary, by setting the ESMF_RUNTIME_PROFILE_OUTPUT environment variable as follows:

$setenv ESMF_RUNTIME_PROFILE ON # turn on profiling$ setenv ESMF_RUNTIME_PROFILE_OUTPUT SUMMARY  # specify summary output


Note the ESMF_RUNTIME_PROFILE environment variable must also be set to ON since this controls all profiling capabilities. The ESMF_Profile.summary file will contain a tree of timed regions, but aggregated across all PETs. For example:

Region                           PETs   Count    Mean (s)    Min (s)     Min PET Max (s)     Max PET
[esm] Init 1                   4      1        4.0880      4.0878      2       4.0883      1
[OCN-TO-ATM] IPDv05p6b       4      1        2.6007      2.6007      2       2.6007      3
[ATM-TO-OCN] IPDv05p6b       4      1        1.4335      1.4333      0       1.4337      3
[ATM-TO-OCN] IPDv05p4        4      1        0.0037      0.0007      0       0.0060      1
[ATM] IPDv00p2               4      1        0.0034      0.0020      1       0.0055      0
[ATM-TO-OCN] IPDv05p1        4      1        0.0020      0.0007      2       0.0033      3
[OCN] IPDv00p2               4      1        0.0019      0.0015      3       0.0024      2
[ATM-TO-OCN] IPDv05p3        4      1        0.0010      0.0008      0       0.0013      1
[ATM-TO-OCN] IPDv05p2a       4      1        0.0009      0.0007      0       0.0012      3
[ATM] IPDv00p1               4      1        0.0009      0.0007      3       0.0011      0
[ATM-TO-OCN] IPDv05p2b       4      1        0.0008      0.0007      0       0.0010      3
[ATM-TO-OCN] IPDv05p5        4      1        0.0008      0.0007      0       0.0010      3
[ATM-TO-OCN] IPDv05p6a       4      1        0.0008      0.0005      2       0.0012      3
[OCN-TO-ATM] IPDv05p3        4      1        0.0008      0.0006      2       0.0010      3
[OCN-TO-ATM] IPDv05p4        4      1        0.0008      0.0006      0       0.0009      3
[OCN-TO-ATM] IPDv05p2b       4      1        0.0007      0.0006      2       0.0009      3
[OCN] IPDv00p1               4      1        0.0007      0.0005      1       0.0009      2
[OCN-TO-ATM] IPDv05p2a       4      1        0.0007      0.0006      2       0.0009      1
[OCN-TO-ATM] IPDv05p5        4      1        0.0007      0.0006      0       0.0009      3
[OCN-TO-ATM] IPDv05p1        4      1        0.0006      0.0005      0       0.0008      1
[OCN-TO-ATM] IPDv05p6a       4      1        0.0006      0.0004      2       0.0007      1
[esm] RunPhase1                4      1        2.7444      2.7423      0       2.7454      1
[OCN-TO-ATM] RunPhase1       4      864      0.6123      0.6004      2       0.6244      1
[ATM] RunPhase1              4      864      0.5386      0.5296      0       0.5530      1
ATM:ModelAdvance           4      864      0.3038      0.3022      0       0.3065      1
[OCN] RunPhase1              4      864      0.3471      0.3256      0       0.3824      1
[ATM-TO-OCN] RunPhase1       4      864      0.2843      0.1956      1       0.3345      0
[esm] FinalizePhase1           4      1        0.0029      0.0029      1       0.0030      2
[OCN-TO-ATM] FinalizePhase1  4      1        0.0007      0.0006      0       0.0008      3
[ATM-TO-OCN] FinalizePhase1  4      1        0.0002      0.0001      3       0.0002      1
[OCN] FinalizePhase1         4      1        0.0001      0.0001      3       0.0001      0
[ATM] FinalizePhase1         4      1        0.0001      0.0000      0       0.0001      2


The meaning of the statistics in each column in as follows:

PETs
the number of reporting PETs that executed the region
Count
the number of times each reporting PET executed the region or MULTIPLE'' if not all PETs executed the region the same number of times
Mean
the mean across all reporting PETs of the total time spent in the region
Min
the minimum across all reporting PETs of the total time spent in the region
Min PET
the PET that reported the minimum time
Max
the maximum across all reporting PETs of the total time spent in the region
Max PET
the PET that reported the maximum time

Note that setting the ESMF_RUNTIME_PROFILE_PETLIST environment variable (described below) may reduce the number of reporting PETs. Only reporting PETs are included in the summary profile. To output both the per-PET and summary timing profiles, set the ESMF_RUNTIME_PROFILE_OUTPUT environment variable as follows:

$setenv ESMF_RUNTIME_PROFILE_OUTPUT "TEXT SUMMARY"  ### 50.2.3 Limit the Set of Profiled PETs By default, all PETs in an application are profiled. It may be desirable to only profile a subset of PETs to reduce the amount of output. An explicit list of PETs can be specified by setting the ESMF_RUNTIME_PROFILE_PETLIST environment variable. The syntax of this environment variable is to list PET numbers separated by spaces. PET ranges are also supported using the X-Y'' syntax where X < Y. For example: # only profile PETs 0, 20, and 35 through 39$ setenv ESMF_RUNTIME_PROFILE_PETLIST "0 20 35-39"


When used in conjunction with the SUMMARY option above, the summarized profile will only aggregate over the specified set of PETs. The one exception is that PET 0 is always profiled if ESMF_RUNTIME_PROFILE=ON, regardless of the ESMF_RUNTIME_TRACE_PETLIST setting.

### 50.2.4 Include MPI Communication in the Profile

MPI functions can be included in the timing profile to indicate how much time is spent inside communication calls. This can also help to determine load imbalance in the system, since large times spent inside MPI may indicate that communication between PETs is not tightly synchronized. This option includes all MPI calls in the application, whether or not they originate from the ESMF library. Here is a partial example summary profile that contains MPI times:

Region                           PETs   Count    Mean (s)    Min (s)     Min PET Max (s)     Max PET
[esm] RunPhase1                8      1        4.9307      4.6867      0       4.9656      1
[OCN] RunPhase1              8      1824     0.8344      0.8164      0       0.8652      1
[MED] RunPhase1              8      1824     0.8203      0.7900      5       0.8584      1
[ATM] RunPhase1              8      1824     0.6387      0.6212      5       0.6610      1
[ATM-TO-MED] RunPhase1       8      1824     0.5975      0.5317      0       0.6583      5
MPI_Bcast                  8      1824     0.0443      0.0025      4       0.1231      5
MPI_Wait                   8      MULTIPLE 0.0421      0.0032      0       0.0998      2
[MED-TO-OCN] RunPhase1       8      1824     0.4879      0.4497      0       0.5362      4
MPI_Wait                   8      MULTIPLE 0.0234      0.0030      0       0.0821      4
MPI_Bcast                  8      1824     0.0111      0.0024      4       0.0273      5
[OCN-TO-MED] RunPhase1       8      1824     0.4541      0.4075      0       0.4918      4
MPI_Wait                   8      MULTIPLE 0.0339      0.0017      0       0.0824      4
MPI_Bcast                  8      1824     0.0194      0.0026      4       0.0452      6
[MED-TO-ATM] RunPhase1       8      1824     0.4487      0.4005      0       0.4911      5
MPI_Bcast                  8      1824     0.0338      0.0026      4       0.0942      5
MPI_Wait                   8      MULTIPLE 0.0241      0.0022      1       0.0817      2
[esm] Init 1                   8      1        0.6287      0.6287      1       0.6287      4
[ATM-TO-MED] IPDv05p6b       8      1        0.1501      0.1500      1       0.1501      2
MPI_Barrier                8      242      0.0082      0.0006      3       0.0157      7
MPI_Wait                   8      MULTIPLE 0.0034      0.0010      0       0.0053      7
MPI_Allreduce              8      62       0.0030      0.0003      3       0.0063      7
MPI_Alltoall               8      6        0.0015      0.0000      1       0.0022      5
MPI_Allgather              8      21       0.0010      0.0002      1       0.0017      7
MPI_Waitall                8      MULTIPLE 0.0006      0.0001      3       0.0015      7
MPI_Send                   8      MULTIPLE 0.0004      0.0001      7       0.0008      6
MPI_Allgatherv             8      6        0.0001      0.0001      4       0.0001      0
MPI_Scatter                8      5        0.0000      0.0000      0       0.0000      7
MPI_Reduce                 8      5        0.0000      0.0000      1       0.0000      0
MPI_Recv                   8      MULTIPLE 0.0000      0.0000      0       0.0000      3
MPI_Bcast                  8      1        0.0000      0.0000      0       0.0000      7


The procedure for including MPI functions in the timing profile depends on whether the application is dynamically or statically linked. Most applications are dynamically linked, however on some systems (such as Cray), static linking may be used. Note that for either option, ESMF must be built with ESMF_TRACE_BUILD_LIB=ON, which is the default.

In dynamically linked applications, the LD_PRELOAD environment variable must be used when executing the MPI application. This instructs the dynamic linker to interpose certain MPI symbols so they can be captured by the ESMF profiler. To simplify this process, a script is provided at $(ESMF_INSTALL_LIBDIR)/preload.sh that sets the LD_PRELOAD variable. For example, if you typically execute your application as as follows: $ mpirun -np 8 ./myApp


then you should add the preload.sh script in front of the executable when starting the application as follows:

# replace $(ESMF_INSTALL_LIBDIR) with absolute path to the ESMF installation lib directory$ mpirun -np 8 $(ESMF_INSTALL_LIBDIR)/preload.sh ./myApp  An advantage of this approach is that your application does not need to be recompiled. The MPI timing information will be included in the per-PET profiles and/or the summary profile, depending on the setting of ESMF_RUNTIME_PROFILE_OUTPUT. In statically linked applications, the application must be re-linked with specific options provided to the linker. These options instruct the linker to wrap the MPI symbols with the ESMF profiling functions. The linking flags that must be provided are included in the esmf.mk Makefile fragment that is part of the ESMF installation. These link flags should be imported into your application Makefile, and included in the final link command. To do this, first import the esmf.mk file into your application Makefile. The path to this file is typically stored in the ESMFMKFILE environment variable. Then, pass the variables$(ESMF_TRACE_STATICLINKOPTS) and $(ESMF_TRACE_STATICLINKLIBS) to the final linking command. For example: # import esmf.mk include$(ESMFMKFILE)

# other makefile targets here...

# example final link command, with $(ESMF_TRACE_STATICLINKOPTS) and$(ESMF_TRACE_STATICLINKLIBS) added
myApp: myApp.o driver.o model.o
$(ESMF_F90LINKER)$(ESMF_F90LINKOPTS) $(ESMF_F90LINKPATHS)$(ESMF_F90LINKRPATHS) -o $@$^ $(ESMF_F90ESMFLINKLIBS)$(ESMF_TRACE_STATICLINKOPTS) $(ESMF_TRACE_STATICLINKLIBS)  This option will statically wrap all of the MPI functions and include them in the profile output. Execute the application in the normal way with the environment variable ESMF_RUNTIME_PROFILE set to ON. You will see the MPI functions included in the timing profile. ### 50.2.5 Output a Detailed Trace for Analysis ESMF tracing is disabled by default. To enable tracing, set the ESMF_RUNTIME_TRACE environment variable to ON. You do not need to recompile your code to enable tracing. # csh shell$ setenv ESMF_RUNTIME_TRACE ON

# bash shell
$export ESMF_RUNTIME_TRACE=ON  When enabled, the default behavior is to trace all PETs of the ESMF application. Although the ESMF tracer is designed to write events in a compact form, tracing can produce an extremely large number of events depending on the total number of PETs and the length of the run. To reduce output, it is possible to restrict the PETs that produce trace output by setting the ESMF_RUNTIME_TRACE_PETLIST environment variable. For example, this setting: $ setenv ESMF_RUNTIME_TRACE_PETLIST "0 101 192-196"


will instruct the tracer to only trace PETs 0, 101, and 192 through 196 (inclusive). The syntax of this environment variable is to list PET numbers separated by spaces. PET ranges are also supported using the X-Y'' syntax where X < Y. For PET counts greater than 100, it is recommended to set this environment variable. The one exception is that PET 0 is always traced, regardless of the ESMF_RUNTIME_TRACE_PETLIST setting.

ESMF's profiling and tracing options can be used together. A typical use would be to set ESMF_RUNTIME_PROFILE=ON for all PETs to capture summary timings, and set ESMF_RUNTIME_TRACE=ON and ESMF_RUNTIME_TRACE_PETLIST to a subset of of PETs, such as the root PET of each ESMF component. This helps to keep trace sizes small while still providing timing summaries over all PETs.

When tracing is enabled, phase_enter and phase_exit events will automatically be recorded for all initialize, run, and finalize phases of all Components in the application. To trace only user-instrumented regions (via the ESMF_TraceRegionEnter() and ESMF_TraceRegionExit() calls), Component-level tracing can be turned off by setting:

$setenv ESMF_RUNTIME_TRACE_COMPONENT OFF  After running an ESMF application with tracing enabled, a directory called traceout will be created in the run directory and it will contain a metadata file and an event stream file esmf_stream_XXXX for each PET with tracing enabled. Together these files form a valid CTF trace which may be analyzed with any of the tools listed above. Trace events are flushed to file at a regular interval. If the application crashes, some of the most recent events may not be flushed to file. To maximize the number of events appearing in the trace, an option is available to flush events to file more frequently. Because this option may have negative performance implications due to increased file I/O, it is not recommended unless needed. To turn on eager flushing use: $ setenv ESMF_RUNTIME_TRACE_FLUSH EAGER


### 50.2.6 Set the Clock used for Profiling/Tracing

There are three options for the kind of clock to use to timestamp events when profiling/tracing an application. These options are controlled by setting the environment variable ESMF_RUNTIME_TRACE_CLOCK.

REALTIME
The REALTIME clock timestamps events with the current time on the system. This is the default clock if the above environment variable is not set. This setting can be useful when tracing PETs that span multiple physical computing nodes assuming that the system clocks on each node are adequately synchronized. On most HPC systems, system clocks are periodically updated to stay in sync. A disadvantage of this clock is that periodic adjustments mean the clock is not monotonically increasing so some timings may be inaccurate if the system clock jumps forward or backward significantly. Testing has shown that this is not typically an issue on most systems.
MONOTONIC
The MONOTONIC clock is guaranteed to be monotonically increasing and does not suffer from periodic adjustments. The timestamps represent an amount of time since some arbitrary point in the past. There is no guarantee that these timestamps will be synchronized across physical computing nodes, so this option should only be used for tracing a set of PETs running on a single physical machine.
MONOTONIC_SYNC
The MONOTONIC_SYNC clock is similar to the MONOTONIC clock in that it is guaranteed to be monotonically increasing. In addition, at application startup, all PET clocks are synchronized to a common time by determining a PET-local offset to be applied to timestamps. Therefore this option can be used to compare trace streams across physical nodes.

### 50.2.7 Tracing a simple ESMF application

This example illustrates how to trace a simple ESMF application and print the event stream using Babeltrace. The first part of the code is a module representing a trivial ESMF Gridded Component. The second part is a main program that creates and executes the component.

module SimpleComp

use ESMF
implicit none

private
public SetServices

contains

subroutine SetServices(gcomp, rc)
type(ESMF_GridComp)   :: gcomp
integer, intent(out)  :: rc

call ESMF_GridCompSetEntryPoint(gcomp, ESMF_METHOD_INITIALIZE, &
userRoutine=Init, rc=rc)
call ESMF_GridCompSetEntryPoint(gcomp, ESMF_METHOD_RUN, &
userRoutine=Run, rc=rc)
call ESMF_GridCompSetEntryPoint(gcomp, ESMF_METHOD_FINALIZE, &
userRoutine=Finalize, rc=rc)

rc = ESMF_SUCCESS

end subroutine SetServices

subroutine Init(gcomp, istate, estate, clock, rc)
type(ESMF_GridComp):: gcomp
type(ESMF_State):: istate, estate
type(ESMF_Clock):: clock
integer, intent(out):: rc

print *, "Inside Init"

end subroutine Init

subroutine Run(gcomp, istate, estate, clock, rc)
type(ESMF_GridComp):: gcomp
type(ESMF_State):: istate, estate
type(ESMF_Clock):: clock
integer, intent(out):: rc

print *, "Inside Run"

end subroutine Run

subroutine Finalize(gcomp, istate, estate, clock, rc)
type(ESMF_GridComp):: gcomp
type(ESMF_State):: istate, estate
type(ESMF_Clock):: clock
integer, intent(out):: rc

print *, "Inside Finalize"

end subroutine Finalize

end module SimpleComp


program ESMF_TraceEx


      ! Use ESMF framework module
use ESMF
use SimpleComp, only: SetServices


      implicit none

! Local variables
integer :: rc, finalrc, i
type(ESMF_GridComp)     :: gridcomp


      ! initialize ESMF
finalrc = ESMF_SUCCESS
call ESMF_Initialize(vm=vm, defaultlogfilename="TraceEx.Log", &
logkindflag=ESMF_LOGKIND_MULTI, rc=rc)


      ! create the component and then execute
! initialize, run, and finalize routines
gridcomp = ESMF_GridCompCreate(name="test", rc=rc)


      call ESMF_GridCompSetServices(gridcomp, userRoutine=SetServices, rc=rc)


      call ESMF_GridCompInitialize(gridcomp, rc=rc)


      do i=1, 5
call ESMF_GridCompRun(gridcomp, rc=rc)
enddo


      call ESMF_GridCompFinalize(gridcomp, rc=rc)


      call ESMF_GridCompDestroy(gridcomp, rc=rc)


      call ESMF_Finalize(rc=rc)


end program ESMF_TraceEx


Assuming the code above is executed on four PETs with the environment variable ESMF_RUNTIME_TRACE set to ON, then a folder will be created in the run directory called traceout containing a metadata file and four event stream files named esmf_stream_XXXX where XXXX is the PET number. If Babeltrace is available on the system, the list of events can be printed by executing the following from the run directory:

   \$ babeltrace ./traceout

For details about iterating over trace events and performing analyses on CTF traces, see the corresponding documentation in the tools listed in Section 50.1.2.

### 50.2.8 Profiling/Tracing User-defined Code Regions

This example illustrates how to manually instrument code with entry and exit points for user-defined code regions. Note that the API calls ESMF_TraceRegionEnter and ESMF_TraceRegionExit should always appear in pairs, wrapping a particular section of code. The environment variable ESMF_RUNTIME_TRACE or ESMF_RUNTIME_PROFILE must be set to ON to enable these regions. If at least one is not set, the calls to ESMF_TraceRegionEnter and ESMF_TraceRegionExit will simply return immediately. For this reason, it is safe to leave this instrumentation in application code, even when not being profiled.

      ! Use ESMF framework module
use ESMF


      implicit none

! Local variables
integer :: rc, finalrc
integer :: i, j, tmp


      ! initialize ESMF
finalrc = ESMF_SUCCESS
call ESMF_Initialize(vm=vm, defaultlogfilename="TraceUserEx.Log", &
logkindflag=ESMF_LOGKIND_MULTI, rc=rc)


      ! record entrance into "outer_region"
call ESMF_TraceRegionEnter("outer_region", rc=rc)

tmp = 0
do i=1, 10

! record entrance into "inner_region_1"
call ESMF_TraceRegionEnter("inner_region_1", rc=rc)
! arbitrary computation
do j=1,10000
tmp=tmp+j+i
enddo
! record exit from "inner_region_1"
call ESMF_TraceRegionExit("inner_region_1", rc=rc)

tmp = 0

! record entrance into "inner_region_2"
call ESMF_TraceRegionEnter("inner_region_2", rc=rc)
! arbitrary computation
do j=1,5000
tmp=tmp+j+i
enddo
! record exit from "inner_region_2"
call ESMF_TraceRegionExit("inner_region_2", rc=rc)
enddo

! record exit from "outer_region"
call ESMF_TraceRegionExit("outer_region", rc=rc)


      call ESMF_Finalize(rc=rc)


## 50.3 Restrictions and Future Work

1. Limited types of trace events. Currently only a few trace event types are available. The tracer may be extended in the future to record additional types of events.

## 50.4 Class API

### 50.4.1 ESMF_TraceRegionEnter - Trace user-defined region entry event

INTERFACE:

   subroutine ESMF_TraceRegionEnter(name, rc)

ARGUMENTS:
     character(len=*), intent(in) :: name
integer, intent(out), optional  :: rc

DESCRIPTION:

Record an event in the trace for this PET indicating entry into a user-defined region with the given name. This call must be paired with a call to ESMF_TraceRegionExit() with a matching name parameter. User-defined regions may be nested. If tracing is disabled on the calling PET or for the application as a whole, no event will be recorded and the call will return immediately.

The arguments are:

name
A user-defined name for the region of code being entered
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 50.4.2 ESMF_TraceRegionExit - Trace user-defined region exit event

INTERFACE:

   subroutine ESMF_TraceRegionExit(name, rc)

ARGUMENTS:
     character(len=*), intent(in) :: name
integer, intent(out), optional  :: rc

DESCRIPTION:

Record an event in the trace for this PET indicating exit from a user-defined region with the given name. This call must appear after a call to ESMF_TraceRegionEnter() with a matching name parameter. If tracing is disabled on the calling PET or for the application as a whole, no event will be recorded and the call will return immediately.

The arguments are:

name
A user-defined name for the region of code being exited
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

# 51 Fortran I/O and System Utilities

## 51.1 Description

The ESMF Fortran I/O and System utilities provide portable methods to access capabilities which are often implemented in different ways amongst different environments. These utility methods are divided into three groups: command line access, Fortran I/O, and sorting.

Command line arguments may be accessed using three methods: ESMF_UtilGetArg() returns a given command line argument, ESMF_UtilGetArgC() returns a count of the number of command line arguments available. Finally, the ESMF_UtilGetArgIndex() method returns the index of a desired argument value, given its keyword name.

Two I/O methods are implemented: ESMF_IOUnitGet(), to obtain an unopened Fortran unit number within the range of unit numbers that ESMF is allowed to use, and ESMF_IOUnitFlush() to flush the I/O buffer associated with a specific Fortran unit.

Finally, the ESMF_UtilSort() method sorts integer, floating point, and character string data types in either ascending or descending order.

## 51.2 Use and Examples

### 51.2.1 Fortran unit number management

The ESMF_UtilIOUnitGet() method is provided so that applications using ESMF can remain free of unit number conflicts -- both when combined with other third party code, or with ESMF itself. This call is typically used just prior to an OPEN statement:

  call ESMF_UtilIOUnitGet (unit=grid_unit, rc=rc)


By default, unit numbers between 50 and 99 are scanned to find an unopened unit number.

Internally, ESMF also uses ESMF_UtilIOUnitGet() when it needs to open Fortran unit numbers for file I/O. By using the same API for both user and ESMF code, unit number collisions can be avoided.

When integrating ESMF into an application where there are conflicts with other uses of the same unit number range, such as when hard-coded unit number values are used, an alternative unit number range can be specified. The ESMF_Initialize() optional arguments IOUnitLower and IOUnitUpper may be set as needed. Note that IOUnitUpper must be set to a value higher than IOUnitLower, and that both must be non-negative. Otherwise ESMF_Initialize will return a return code of ESMF_FAILURE. ESMF itself does not typically need more than about five units for internal use.

  call ESMF_Initialize (..., IOUnitLower=120, IOUnitUpper=140)


All current Fortran environments have preconnected unit numbers, such as units 5 and 6 for standard input and output, in the single digit range. So it is recommended that the unit number range is chosen to begin at unit 10 or higher to avoid these preconnected units.

### 51.2.2 Flushing output

Fortran run-time libraries generally use buffering techniques to improve I/O performance. However output buffering can be problematic when output is needed, but is trapped'' in the buffer because it is not full. This is a common occurrance when debugging a program, and inserting WRITE statements to track down the bad area of code. If the program crashes before the output buffer has been flushed, the desired debugging output may never be seen -- giving a misleading indication of where the problem occurred. It would be desirable to ensure that the output buffer is flushed at predictable points in the program in order to get the needed results. Likewise, in parallel code, predictable flushing of output buffers is a common requirement, often in conjunction with ESMF_VMBarrier() calls.

The ESMF_UtilIOUnitFlush() API is provided to flush a unit as desired. Here is an example of code which prints debug values, and serializes the output to a terminal in PET order:

  type(ESMF_VM) :: vm

integer :: tty_unit
integer :: me, npets

call ESMF_Initialize (vm=vm, rc=rc)
call ESMF_VMGet (vm, localPet=me, petCount=npes)

call ESMF_UtilIOUnitGet (unit=tty_unit)
open (unit=tty_unit, file='/dev/tty', status='old', action='write')
...
call ESMF_VMBarrier (vm=vm)
do, i=0, npets-1
if (i == me) then
write (tty_unit, *) 'PET: ', i, ', values are: ', a, b, c
call ESMF_UtilIOUnitFlush (unit=tty_unit)
end if
call ESMF_VMBarrier (vm=vm)
end do


## 51.3 Design and Implementation Notes

### 51.3.1 Fortran unit number management

When ESMF needs to open a Fortran I/O unit, it calls ESMF_IOUnitGet() to find an unopened unit number. As delivered, the range of unit numbers that are searched are between ESMF_LOG_FORTRAN_UNIT_NUMBER (normally set to 50), and ESMF_LOG_UPPER (normally set to 99.) Unopened unit numbers are found by using the Fortran INQUIRE statement.

When integrating ESMF into an application where there are conflicts with other uses of the same unit number range, an alternative range can be specified in the ESMF_Initialize() call by setting the IOUnitLower and IOUnitUpper arguments as needed. ESMF_IOUnitGet() will then search the alternate range of unit numbers. Note that IOUnitUpper must be set to a value higher than IOUnitLower, and that both must be non-negative. Otherwise ESMF_Initialize will return a return code of ESMF_FAILURE.

Fortran unit numbers are not standardized in the Fortran 90 Standard. The standard only requires that they be non-negative integers. But other than that, it is up to the compiler writers and application developers to provide and use units which work with the particular implementation. For example, units 5 and 6 are a defacto standard for standard input'' and standard output'' -- even though this is not specified in the actual Fortran standard. The Fortran standard also does not specify which unit numbers can be used, nor does it specify how many can be open simultaneously.

Since all current compilers have preconnected unit numbers, and these are typically found on units lower than 10, it is recommended that applications use unit numbers 10 and higher.

### 51.3.2 Flushing output

When ESMF needs to flush a Fortran unit, the ESMF_IOUnitFlush() API is used to centralize the file flushing capability, because Fortran has not historically had a standard mechanism for flushing output buffers. Most compilers run-time libraries support various library extensions to provide this functionality -- though, being non-standard, the spelling and number of arguments vary between implementations. Fortran 2003 also provides for a FLUSH statement which is built into the language. When possible, ESMF_IOUnitFlush() uses the F2003 FLUSH statement. With older compilers, the appropriate library call is made.

### 51.3.3 Sorting algorithms

The ESMF_UtilSort() algorithms are the same as those in the LAPACK sorting procedures SLASRT() and DLASRT(). Two algorithms are used. For small sorts, arrays with 20 or fewer elements, a simple Insertion sort is used. For larger sorts, a Quicksort algorithm is used.

Compared to the original LAPACK code, a full Fortran 90 style interface is supported for ease of use and enhanced compile time checking. Additional support is also provided for integer and character string data types.

## 51.4 Utility API

### 51.4.1 ESMF_UtilGetArg - Return a command line argument

INTERFACE:

   subroutine ESMF_UtilGetArg(argindex, argvalue, arglength, rc)

ARGUMENTS:
     integer,      intent(in)            :: argindex
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
character(*), intent(out), optional :: argvalue
integer,      intent(out), optional :: arglength
integer,      intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

This method returns a copy of a command line argument specified when the process was started. This argument is the same as an equivalent C++ program would find in the argv array.

Some MPI implementations do not consistently provide command line arguments on PETs other than PET 0. It is therefore recommended that PET 0 call this method and broadcast the results to the other PETs by using the ESMF_VMBroadcast() method.

The arguments are:

argindex
A non-negative index into the command line argument argv array. If argindex is negative or greater than the number of user-specified arguments, ESMF_RC_ARG_VALUE is returned in the rc argument.
[argvalue]
Returns a copy of the desired command line argument. If the provided character string is longer than the command line argument, the string will be blank padded. If the string is too short, truncation will occur and ESMF_RC_ARG_SIZE is returned in the rc argument.
[arglength]
Returns the length of the desired command line argument in characters. The length result does not depend on the length of the value string. It may be used to query the length of the argument.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 51.4.2 ESMF_UtilGetArgC - Return number of command line arguments

INTERFACE:

   subroutine ESMF_UtilGetArgC(count, rc)

ARGUMENTS:
     integer, intent(out)           :: count
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer, intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

This method returns the number of command line arguments specified when the process was started.

The number of arguments returned does not include the name of the command itself - which is typically returned as argument zero.

Some MPI implementations do not consistently provide command line arguments on PETs other than PET 0. It is therefore recommended that PET 0 call this method and broadcast the results to the other PETs by using the ESMF_VMBroadcast() method.

The arguments are:

count
Count of command line arguments.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 51.4.3 ESMF_UtilGetArgIndex - Return the index of a command line argument

INTERFACE:

   subroutine ESMF_UtilGetArgIndex(argvalue, argindex, rc)

ARGUMENTS:
     character(*), intent(in)            :: argvalue
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,      intent(out), optional :: argindex
integer,      intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

This method searches for, and returns the index of a desired command line argument. An example might be to find a specific keyword (e.g., -esmf_path) so that its associated value argument could be obtained by adding 1 to the argindex and calling ESMF_UtilGetArg().

Some MPI implementations do not consistently provide command line arguments on PETs other than PET 0. It is therefore recommended that PET 0 call this method and broadcast the results to the other PETs by using the ESMF_VMBroadcast() method.

The arguments are:

argvalue
A character string which will be searched for in the command line argument list.
[argindex]
If the value string is found, the position will be returned as a non-negative integer. If the string is not found, a negative value will be returned.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 51.4.4 ESMF_UtilIOGetCWD - Get the current directory

INTERFACE:

   subroutine ESMF_UtilIOGetCWD (pathName, rc)

PARAMETERS:
     character(*), intent(out)           :: pathName
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,      intent(out), optional :: rc

DESCRIPTION:

Call the system-dependent routine to get the current directory from the file system.

The arguments are:

pathName
Name of the current working directory.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 51.4.5 ESMF_UtilIOMkDir - Create a directory in the file system

INTERFACE:

    subroutine ESMF_UtilIOMkDir (pathName,  &
mode, relaxedFlag,  &
rc)

PARAMETERS:
      character(*), intent(in)            :: pathName
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,      intent(in),  optional :: mode
logical,      intent(in),  optional :: relaxedFlag
integer,      intent(out), optional :: rc

DESCRIPTION:

Call the system-dependent routine to create a directory in the file system.

The arguments are:

pathName
Name of the directory to be created.
[mode]
File permission mode. Typically an octal constant is used as a value, for example: mode=o'755'. If not specified on POSIX-compliant systems, the default is o'755' - corresponding to owner read/write/execute, group read/execute, and world read/execute. On native Windows, this argument is ignored and default security settings are used.
[relaxedFlag]
When set to .true., if the directory already exists, rc will be set to ESMF_SUCCESS instead of an error. If not specified, the default is .false..
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 51.4.6 ESMF_UtilIORmDir - Remove a directory from the file system

INTERFACE:

    subroutine ESMF_UtilIORmDir (pathName,  &
relaxedFlag, rc)

PARAMETERS:
      character(*), intent(in)            :: pathName
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
logical,      intent(in),  optional :: relaxedFlag
integer,      intent(out), optional :: rc

DESCRIPTION:

Call the system-dependent routine to remove a directory from the file system. Note that the directory must be empty in order to be successfully removed.

The arguments are:

pathName
Name of the directory to be removed.
[relaxedFlag]
If set to .true., and if the specified directory does not exist, the error is ignored and rc will be set to ESMF_SUCCESS. If not specified, the default is .false..
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 51.4.7 ESMF_UtilString2Double - Convert a string to floating point real

INTERFACE:

   function ESMF_UtilString2Double(string, rc)

RETURN VALUE:
     real(ESMF_KIND_R8) :: ESMF_UtilString2Double

ARGUMENTS:
     character(len=*), intent(in)            :: string
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,          intent(out), optional :: rc

DESCRIPTION:

Return the numerical real value represented by the string.

Leading and trailing blanks in string are ignored when directly converting into integers.

This procedure may fail when used in an expression in a write statement with some older, pre-Fortran 2003, compiler environments that do not support re-entrant I/O calls.

The arguments are:

string
The string to be converted
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 51.4.8 ESMF_UtilString2Int - Convert a string to an integer

INTERFACE:

   function ESMF_UtilString2Int(string,  &
specialStringList, specialValueList, rc)

RETURN VALUE:
     integer :: ESMF_UtilString2Int

ARGUMENTS:
     character(len=*), intent(in)            :: string
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
character(len=*), intent(in),  optional :: specialStringList(:)
integer,          intent(in),  optional :: specialValueList(:)
integer,          intent(out), optional :: rc

DESCRIPTION:

Return the numerical integer value represented by the string. If string matches a string in the optional specialStringList, the corresponding special value will be returned instead.

If special strings are to be taken into account, both specialStringList and specialValueList arguments must be present and of same size.

An error is returned, and return value set to 0, if string is not found in specialStringList, and does not convert into an integer value.

Leading and trailing blanks in string are ignored when directly converting into integers.

This procedure may fail when used in an expression in a write statement with some older, pre-Fortran 2003, compiler environments that do not support re-entrant I/O calls.

The arguments are:

string
The string to be converted
[specialStringList]
List of special strings.
[specialValueList]
List of values associated with special strings.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 51.4.9 ESMF_UtilString2Real - Convert a string to floating point real

INTERFACE:

   function ESMF_UtilString2Real(string, rc)

RETURN VALUE:
     real :: ESMF_UtilString2Real

ARGUMENTS:
     character(len=*), intent(in)            :: string
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer,          intent(out), optional :: rc

DESCRIPTION:

Return the numerical real value represented by the string.

Leading and trailing blanks in string are ignored when directly converting into integers.

This procedure may fail when used in an expression in a write statement with some older, pre-Fortran 2003, compiler environments that do not support re-entrant I/O calls.

The arguments are:

string
The string to be converted
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 51.4.10 ESMF_UtilStringInt2String - convert integer to character string

INTERFACE:

     function ESMF_UtilStringInt2String (i, rc)

ARGUMENTS:
       integer, intent(in) :: i
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer, intent(out), optional  :: rc

RETURN VALUE:
       character(int2str_len (i)) :: ESMF_UtilStringInt2String

DESCRIPTION:

Converts given an integer to string representation. The returned string is sized such that it does not contain leading or trailing blanks.

This procedure may fail when used in an expression in a write statement with some older, pre-Fortran 2003, compiler environments that do not support re-entrant I/O calls.

The arguments are:

i
An integer.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 51.4.11 ESMF_UtilStringLowerCase - convert string to lowercase

INTERFACE:

     function ESMF_UtilStringLowerCase(string, rc)

ARGUMENTS:
       character(len=*), intent(in) :: string
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer, intent(out), optional  :: rc

RETURN VALUE:
       character(len (string)) :: ESMF_UtilStringLowerCase

DESCRIPTION:

Converts given string to lowercase.

The arguments are:

string
A character string.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 51.4.12 ESMF_UtilStringUpperCase - convert string to uppercase

INTERFACE:

       function ESMF_UtilStringUpperCase(string, rc)

ARGUMENTS:
       character(len=*), intent(in) :: string
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer, intent(out), optional  :: rc

RETURN VALUE:
       character(len (string)) :: ESMF_UtilStringUpperCase

DESCRIPTION:

Converts given string to uppercase.

The arguments are:

string
A character string.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 51.4.13 ESMF_UtilIOUnitFlush - Flush output on a unit number

INTERFACE:

   subroutine ESMF_UtilIOUnitFlush(unit, rc)

PARAMETERS:
     integer, intent(in)            :: unit
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer, intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Call the system-dependent routine to force output on a specific Fortran unit number.

The arguments are:

unit
A Fortran I/O unit number. If the unit is not connected to a file, no flushing occurs.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 51.4.14 ESMF_UtilIOUnitGet - Scan for a free I/O unit number

INTERFACE:

   subroutine ESMF_UtilIOUnitGet(unit, rc)

ARGUMENTS:
     integer, intent(out)           :: unit
-- The following arguments require argument keyword syntax (e.g. rc=rc). --
integer, intent(out), optional :: rc

STATUS:
• This interface is backward compatible with ESMF versions starting at 5.2.0r. If code using this interface compiles with any version of ESMF starting with 5.2.0r, then it will compile with the current version.

DESCRIPTION:

Scan for, and return, a free Fortran I/O unit number. By default, the range of unit numbers returned is between 50 and 99 (parameters ESMF_LOG_FORTRAN_UNIT_NUMBER and ESMF_LOG_UPPER respectively.) When integrating ESMF into an application where these values conflict with other usages, the range of values may be moved by setting the optional IOUnitLower and IOUnitUpper arguments in the initial ESMF_Initialize() call with values in a safe, alternate, range.

The Fortran unit number which is returned is not reserved in any way. Successive calls without intervening OPEN or CLOSE statements (or other means of connecting to units), might not return a unique unit number. It is recommended that an OPEN statement immediately follow the call to ESMF_IOUnitGet() to activate the unit.

The arguments are:

unit
A Fortran I/O unit number.
[rc]
Return code; equals ESMF_SUCCESS if there are no errors.

### 51.4.15 ESMF_UtilSort - Sort data

INTERFACE:

   subroutine ESMF_UtilSort (list, direction, rc)

ARGUMENTS:
   <list>, see below for supported values
type(ESMF_SortFlag), intent(in) :: direction
integer, intent(out), optional :: rc

DESCRIPTION:

Supported values for <list> are:

integer(ESMF_KIND_I4), intent(inout) :: list(:)
integer(ESMF_KIND_I8), intent(inout) :: list(:)
real(ESMF_KIND_R4), intent(inout) :: list(:)
real(ESMF_KIND_R8), intent(inout) :: list(:)
character(len=*), intent(inout) :: list(:)

Use Quick Sort, reverting to Insertion sort on lists of size <= 20.

This is an ESMFized version of SLASRT from LAPACK version 3.1. Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd. November 2006

The arguments are:

list
Array of data to be sorted. The original data is overwritten by the sorted data.
direction
Direction of sorting. Legal values are ESMF_SORT_ASCENDING and ESMF_SORT_DESCENDING.
[rc]
Return code; equals ESMF_SUCCESS if the sorting is successful.

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