MPI_Alloc_mem(3OpenMPI) MPI_Alloc_mem(3OpenMPI)
NAME
MPI_Alloc_mem - Allocates a specified memory segment.
SYNTAX
C Syntax
#include <mpi.h>
int MPI_Alloc_mem(MPI_Aint size, MPI_Info info, void *baseptr)
Fortran Syntax (see FORTRAN NOTES)
INCLUDE 'mpif.h'
MPI_ALLOC_MEM(SIZE, INFO, BASEPTR, IERROR)
INTEGER INFO, IERROR
INTEGER(KIND=MPI_ADDRESS_KIND) SIZE, BASEPTR
C++ Syntax
#include <mpi.h>
void* MPI::Alloc_mem(MPI::Aint size, const MPI::Info& info)
INPUT PARAMETERS
size Size of memory segment in bytes (nonnegative integer).
info Info argument (handle).
OUTPUT PARAMETERS
baseptr Pointer to beginning of memory segment allocated.
IERROR Fortran only: Error status (integer).
DESCRIPTION
MPI_Alloc_mem allocates size bytes of memory. The starting address of this memory is returned in the
variable base.
FORTRAN NOTES
There is no portable FORTRAN 77 syntax for using MPI_Alloc_mem. There is no portable Fortran syntax
for using pointers returned from MPI_Alloc_mem. However, MPI_Alloc_mem can be used with Sun Fortran
compilers.
From FORTRAN 77, you can use the following non-standard declarations for the SIZE and BASEPTR argu-ments: arguments:
ments:
INCLUDE "mpif.h"
INTEGER*MPI_ADDRESS_KIND SIZE, BASEPTR
From either FORTRAN 77 or Fortran 90, you can use "Cray pointers" for the BASEPTR argument. Cray
pointers are described further in the Fortran User's Guide and are supported by many Fortran compil-ers. compilers.
ers. For example,
INCLUDE "mpif.h"
REAL*4 A(100,100)
POINTER (BASEPTR, A)
INTEGER*MPI_ADDRESS_KIND SIZE
SIZE = 4 * 100 * 100
CALL MPI_ALLOC_MEM(SIZE,MPI_INFO_NULL,BASEPTR,IERR)
! use A
CALL MPI_FREE_MEM(A, IERR)
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_Free_mem
Open MPI 1.2 September 2006 MPI_Alloc_mem(3OpenMPI)
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