getpartelm.c

mpi并行计算的c++代码 可用vc或gcc编译通过 可以用来搭建并行计算试验环境

/* -*- Mode: C; c-basic-offset:4 ; -*- */
/*
 *
 *  (C) 2003 by Argonne National Laboratory.
 *      See COPYRIGHT in top-level directory.
 */
#include "mpi.h"
#include <stdio.h>
#include "mpitest.h"

static char MTest_descrip[] = "Receive partial datatypes and check that\
MPI_Getelements gives the correct version";

int main( int argc, char *argv[] )
{
    int errs = 0;
    MPI_Datatype outtype, oldtypes[2];
    MPI_Aint     offsets[2];
    int          blklens[2];
    MPI_Comm     comm;
    int          size, rank, src, dest, tag;

    MTest_Init( &argc, &argv );

    comm = MPI_COMM_WORLD;

    MPI_Comm_rank( comm, &rank );
    MPI_Comm_size( comm, &size );
    
    if (size < 2) {
	errs++;
	printf( "This test requires at least 2 processes\n" );
	MPI_Abort( MPI_COMM_WORLD, 1 );
    }
    
    src  = 0;
    dest = 1;

    if (rank == src) {
	int buf[128], position, cnt;
	/* sender */

	/* Create a datatype and send it (multiple of sizeof(int)) */
	/* Create a send struct type */
	oldtypes[0] = MPI_INT;
	oldtypes[1] = MPI_CHAR;
	blklens[0]  = 1;
	blklens[1]  = 4*sizeof(int);
	offsets[0]  = 0;
	offsets[1]  = sizeof(int);
	MPI_Type_struct( 2, blklens, offsets, oldtypes, &outtype );
	MPI_Type_commit( &outtype );

	buf[0] = 4*sizeof(int);
	/* printf( "About to send to %d\n", dest ); */
	MPI_Send( buf, 1, outtype, dest, 0, comm );
	MPI_Type_free( &outtype );

	/* Create a datatype and send it (not a multiple of sizeof(int)) */
	/* Create a send struct type */
	oldtypes[0] = MPI_INT;
	oldtypes[1] = MPI_CHAR;
	blklens[0]  = 1;
	blklens[1]  = 4*sizeof(int)+1;
	offsets[0]  = 0;
	offsets[1]  = sizeof(int);
	MPI_Type_struct( 2, blklens, offsets, oldtypes, &outtype );
	MPI_Type_commit( &outtype );

	buf[0] = 4*sizeof(int) + 1;
	MPI_Send( buf, 1, outtype, dest, 1, comm );
	MPI_Type_free( &outtype );

	/* Pack data and send as packed */
	position = 0;
	cnt = 7;
	MPI_Pack( &cnt, 1, MPI_INT, 
		  buf, 128*sizeof(int), &position, comm );
	MPI_Pack( "message", 7, MPI_CHAR,
		  buf, 128*sizeof(int), &position, comm );
	MPI_Send( buf, position, MPI_PACKED, dest, 2, comm );
    }
    else if (rank == dest) {
	MPI_Status status;
	int        buf[128], i, elms, count;

	/* Receiver */
	/* Create a receive struct type */
	oldtypes[0] = MPI_INT;
	oldtypes[1] = MPI_CHAR;
	blklens[0]  = 1;
	blklens[1]  = 256;
	offsets[0]  = 0;
	offsets[1]  = sizeof(int);
	MPI_Type_struct( 2, blklens, offsets, oldtypes, &outtype );
	MPI_Type_commit( &outtype );

	for (i=0; i<3; i++) {
	    tag = i;
	    /* printf( "about to receive tag %d from %d\n", i, src ); */
	    MPI_Recv( buf, 1, outtype, src, tag, comm, &status );
	    MPI_Get_elements( &status, outtype, &elms );
	    if (elms != buf[0] + 1) {
		errs++;
		printf( "For test %d, Get elements gave %d but should be %d\n",
			i, elms, buf[0] + 1 );
	    }
	    MPI_Get_count( &status, outtype, &count );
	    if (count != MPI_UNDEFINED) {
		errs++;
		printf( "For partial send, Get_count did not return MPI_UNDEFINED\n" );
	    }
	}
	MPI_Type_free( &outtype );
    }

    MTest_Finalize( errs );
    MPI_Finalize();
    return 0;
  
}