MPI_Alloc_mem(3OpenMPI)MPI_Alloc_mem(3OpenMPI)NAMEMPI_Alloc_mem - Allocates a specified memory segment.
SYNTAXC 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).
DESCRIPTIONMPI_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 com‐
pilers.
From FORTRAN 77, you can use the following non-standard declarations
for the SIZE and BASEPTR arguments:
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 For‐
tran User's Guide and are supported by many Fortran compilers. 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++ func‐
tions 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)