MPI_Buffer_attach

--- Attaches a user-defined buffer for sending

Input Parameters

buffer: initial buffer address (choice)

size: buffer size, in bytes (integer)

Notes

The size given should be the sum of the sizes of all outstanding Bsends that you intend to have, plus a few hundred bytes for each Bsend that you do. For the purposes of calculating size, you should use MPI_Pack_size. In other words, in the code
MPI_Buffer_attach( buffer, size );
MPI_Bsend( ..., count=20, datatype=type1, ... );
...
MPI_Bsend( ..., count=40, datatype=type2, ... );
the value of 'size' in the MPI_Buffer_attach call should be greater than the value computed by

MPI_Pack_size( 20, type1, comm, ∧s1 );
MPI_Pack_size( 40, type2, comm, ∧s2 );
size = s1 + s2 + 2 * 100;
where we used an extra 100 bytes for each Bsend's information handle.

Synopsis


#include "mpi.h"
int MPI_Buffer_attach( buffer, size )
void *buffer;
int  size;

Location: bufattach.c