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)
- 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 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 Fortran
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++ 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