MPI_Type_get_envelope - Returns information about input arguments associated with a data type.

NAME  SYNTAX  C Syntax  Fortran Syntax  Fortran 2008 Syntax  INPUT PARAMETER  OUTPUT PARAMETERS  DESCRIPTION  NOTES  ERRORS  SEE ALSO 

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NAME

MPI_Type_get_envelope − Returns information about input arguments associated with a data type.

SYNTAX

C Syntax

#include <mpi.h>
int MPI_Type_get_envelope(MPI_Datatype datatype, int *num_integers,

int *num_addresses, int *num_datatypes, int *combiner)

Fortran Syntax

USE MPI
! or the older form: INCLUDE ’mpif.h’
MPI_TYPE_GET_ENVELOPE(DATATYPE, NUM_INTEGERS, NUM_ADDRESSES,

			NUM_DATATYPES, COMBINER, IERROR)
		INTEGER		DATATYPE, NUM_INTEGERS, NUM_ADDRESSES
		INTEGER		NUM_DATATYPES, COMBINER, IERROR

Fortran 2008 Syntax

USE mpi_f08
MPI_Type_get_envelope(datatype, num_integers, num_addresses, num_datatypes,

			combiner, ierror)
		TYPE(MPI_Datatype), INTENT(IN) :: datatype
		INTEGER, INTENT(OUT) :: num_integers, num_addresses, num_datatypes,
		combiner
		INTEGER, OPTIONAL, INTENT(OUT) :: ierror

INPUT PARAMETER

datatype

Data type to access (handle).

OUTPUT PARAMETERS

num_integers

Number of input integers used in the call constructing combiner (nonnegative integer).

num_addresses

Number of input addresses used in the call constructing combiner (nonnegative integer).

num_datatypes

Number of input data types used in the call constructing combiner (nonnegative integer).

	combiner		Combiner (state).
	IERROR		Fortran only: Error status (integer).

DESCRIPTION

For the given data type, MPI_Type_get_envelope returns information on the number and type of input arguments used in the call that created the data type. The number-of-arguments values returned can be used to provide sufficiently large arrays in the decoding routine MPI_Type_get_contents. This call and the meaning of the returned values is described below. The combiner reflects the MPI data type constructor call that was used in creating datatype.

NOTES

These are the values that can be returned in combiner and their associated calls:

Values Associated Calls

MPI_COMBINER_NAMED a named predefined data type
MPI_COMBINER_DUP MPI_Type_dup
MPI_COMBINER_CONTIGUOUS MPI_Type_contiguous
MPI_COMBINER_VECTOR MPI_Type_vector
MPI_COMBINER_HVECTOR MPI_Type_hvector
MPI_COMBINER_INDEXED MPI_Type_indexed
MPI_COMBINER_HINDEXED MPI_Type_hindexed
MPI_COMBINER_INDEXED_BLOCK MPI_Type_create_indexed_block
MPI_COMBINER_STRUCT MPI_Type_struct
MPI_COMBINER_SUBARRAY MPI_Type_create_subarray
MPI_COMBINER_DARRAY MPI_Type_create_darray
MPI_COMBINER_F90_REAL MPI_Type_create_f90_real
MPI_COMBINER_F90_COMPLEX MPI_Type_create_f90_complex
MPI_COMBINER_F90_INTEGER MPI_Type_create_f90_integer
MPI_COMBINER_RESIZED MPI_Type_create_resized

If combiner is MPI_COMBINER_NAMED, then datatype is a named predefined data type.

The actual arguments used in the creation call for a data type can be obtained from the call MPI_Type_get_contents.

ERRORS

Almost all MPI routines return an error value; C routines as the value of the function and Fortran routines in the last argument. C++ functions do not return errors. If the default error handler is set to MPI::ERRORS_THROW_EXCEPTIONS, then on error the C++ exception mechanism will be used to throw an MPI::Exception object.

Before the error value is returned, the current MPI error handler is called. By default, this error handler aborts the MPI job, except for I/O function errors. The error handler may be changed with MPI_Comm_set_errhandler; the predefined error handler MPI_ERRORS_RETURN may be used to cause error values to be returned. Note that MPI does not guarantee that an MPI program can continue past an error.

SEE ALSO

MPI_Type_get_contents

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