NAME

MPI_Type_get_extent, MPI_Type_get_extent_x - Returns the lower bound and extent of a data type.

SYNTAX

C Syntax

#include <mpi.h>
int MPI_Type_get_extent(MPI_Datatype datatype, MPI_Aint *lb,
	MPI_Aint *extent)
int MPI_Type_get_extent_x(MPI_Datatype datatype, MPI_Count *lb,
	MPI_Count *extent)

Fortran Syntax (see FORTRAN 77 NOTES)

USE MPI
! or the older form: INCLUDE 'mpif.h'
MPI_TYPE_GET_EXTENT(DATATYPE, LB, EXTENT, IERROR)
	INTEGER	DATATYPE, IERROR
	INTEGER(KIND=MPI_ADDRESS_KIND) LB, EXTENT
MPI_TYPE_GET_EXTENT_X(DATATYPE, LB, EXTENT, IERROR)
	INTEGER	DATATYPE, IERROR
	INTEGER(KIND=MPI_COUNT_KIND) LB, EXTENT

Fortran 2008 Syntax

USE mpi_f08
MPI_Type_get_extent(datatype, lb, extent, ierror)
	TYPE(MPI_Datatype), INTENT(IN) :: datatype
	INTEGER(KIND=MPI_ADDRESS_KIND), INTENT(OUT) :: lb, extent
	INTEGER, OPTIONAL, INTENT(OUT) :: ierror
MPI_Type_get_extent_x(datatype, lb, extent, ierror)
	TYPE(MPI_Datatype), INTENT(IN) :: datatype
	INTEGER(KIND = MPI_COUNT_KIND), INTENT(OUT) :: lb, extent
	INTEGER, OPTIONAL, INTENT(OUT) :: ierror

C++ Syntax

#include <mpi.h>
void MPI::Datatype::Get_extent(MPI::Aint& lb, MPI::Aint& extent)
	const

INPUT PARAMETER

datatype

Data type (handle).

OUTPUT PARAMETERS

lb

Lower bound of data type (integer).

extent

Data type extent (integer).

IERROR

Fortran only: Error status (integer).

DESCRIPTION

MPI_Type_get_extent returns the lower bound and the extent of datatype. For either function, if either the lb or extent parameter cannot express the value to be returned (e.g., if the parameter is too small to hold the output value), it is set to MPI_UNDEFINED.

NOTE

Use of MPI_Type_get_extent is strongly recommended over the old MPI-1 functions MPI_Type_extent and MPI_Type_lb.

FORTRAN 77 NOTES

The MPI standard prescribes portable Fortran syntax for the LB and EXTENT arguments only for Fortran 90. FORTRAN 77 users may use the non-portable syntax

MPI_Type_get_extent:

     INTEGER*MPI_ADDRESS_KIND LB
or


     INTEGER*MPI_ADDRESS_KIND EXTENT

MPI_Type_get_extent_x:

     INTEGER*MPI_COUNT_KIND LB
or


     INTEGER*MPI_COUNT_KIND EXTENT

where MPI_ADDRESS_KIND and MPI_COUNT_KIND are constants defined in mpif.h and give the length of the declared integer in bytes.

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.