MPI_Buffer_detach(3)

NAME
     MPI_Buffer_detach - Removes an existing buffer

SYNOPSIS
     C:

          #include <mpi.h>

          int MPI_Buffer_detach( bufferptr, size )
          void *bufferptr;
          int  *size;


     C++:

          #include <mpi.h>

          int Detach_buffer(
          void*&            buffer)


     Fortran:

          INCLUDE "mpif.h" (or USE MPI)

          <type> BUFFER_ADDR(*)
          INTEGER size, ierror

          CALL MPI_BUFFER_DETACH(buffer_addr, size, ierror)


STANDARDS
     This release implements the MPI 1.2 standard, as documented by the MPI
     Forum in the spring 1997 release of MPI:  A Message Passing Interface
     Standard.

DESCRIPTION
     The MPI_Buffer_detach routine removes an existing buffer.  This routine
     accepts the following parameters:

     bufferptr Specifies the initial buffer address (choice)

     buffer_addr
               Specifies the initial buffer address (choice)

     size      Specifies the buffer size, in bytes (integer)

     ierror    Specifies the return code value for successful completion,
               which is in MPI_SUCCESS.  MPI_SUCCESS is defined in the mpif.h
               file.
NOTES
     The reason MPI_Buffer_detach returns the address and size of the buffer
     being detached is to allow nested libraries to replace and restore the
     buffer.  For example, consider the following code:

          int size, mysize, idummy;
          void *ptr, *myptr, *dummy;
          MPI_Buffer_detach( &ptr, &size );
          MPI_Buffer_attach( myptr, mysize );

           library code

          MPI_Buffer_detach( &dummy, &idummy );
          MPI_Buffer_attach( ptr, size );


     This is much like the action of the UNIX signal routine and has the same
     strengths (its simplicity) and weaknesses (it works only for nested
     uses).

     The Fortran binding for this routine is different from the C
     implementation.  Because Fortran does not have pointers, it is impossible
     to provide a way to use the output of this routine to exchange buffers.
     In this case, only the size field is set.

     Even though the bufferptr argument is declared as void *, it is really
     the address of a void pointer.  For more details, see the standard.

SEE ALSO
     intro_streams(3), MPI_Bsend(3), MPI_Buffer_attach(3), MPI_Ibsend(3)