spawnmult2.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 "mpitest.h"
#include <stdio.h>
#include <stdlib.h>

/*
 * This tests spawn_mult by using the same executable and no command-line
 * options.  The attribute MPI_APPNUM is used to determine which
 * executable is running.
 */

int main( int argc, char *argv[] )
{
    MPI_Comm parentcomm, intercomm;
    int i, size, rsize, rank;
    int err, errs = 0;
    MPI_Status status;
    int flag;
    static int np[2] = { 1, 1 };
    int *appnum_ptr;

    MTest_Init( &argc, &argv );

    MPI_Comm_get_parent( &parentcomm );
    if (parentcomm == MPI_COMM_NULL) {
	/* Create 2 more processes */
	static char *cmds[2] = { "./spawnmult2", "./spawnmult2" };
	static MPI_Info infos[2] = { MPI_INFO_NULL, MPI_INFO_NULL };
	int errcodes[2];

	MPI_Comm_spawn_multiple( 2, cmds, MPI_ARGVS_NULL, np, infos, 0,
				 MPI_COMM_WORLD, &intercomm, errcodes );

    }
    else {
	intercomm = parentcomm;
    }

    /* We now have a valid intercomm */
    MPI_Comm_remote_size( intercomm, &rsize );
    MPI_Comm_size( intercomm, &size );
    MPI_Comm_rank( intercomm, &rank );

    if (parentcomm == MPI_COMM_NULL) {
	/* This is the master process */
	if (rsize != np[0] + np[1]) { 
	    errs++;
	    printf( "Did not create %d processes (got %d)\n",
		    np[0] + np[1], rsize );
	}
	if (rank == 0) {
	    /* Tell each child process what rank we think they are */
	    for (i=0; i<rsize; i++) {
		MPI_Send( &i, 1, MPI_INT, i, 0, intercomm );
	    }
	    /* We could use intercomm reduce to get the errors from the 
	     * children, but we'll use a simpler loop to make sure that
	     * we get valid data */
	    for (i=0; i<rsize; i++) {
		MPI_Recv( &err, 1, MPI_INT, i, 1, intercomm, 
			  MPI_STATUS_IGNORE );
		errs += err;
	    }
	}
    }
    else {
	/* Child process */
	/* FIXME: This assumes that stdout is handled for the children
	 * (the error count will still be reported to the parent) */
	if (size != 2) {
	    int wsize;
	    errs++;
	    printf( "(Child) Did not create 2 processes (got %d)\n", size);
	    MPI_Comm_size( MPI_COMM_WORLD, &wsize );
	    if (wsize == 2) {
		errs++;
                printf( "(Child) world size is 2 but local intercomm size is not 2\n" );
	    }
	}
           
	MPI_Recv( &i, 1, MPI_INT, 0, 0, intercomm, &status );
	if (i != rank) {
            errs++;
            printf( "Unexpected rank on child %d (%d)\n", rank, i );
	}

	/* Check for correct APPNUM */
	MPI_Comm_get_attr( MPI_COMM_WORLD, MPI_APPNUM, &appnum_ptr, &flag );
	/* My appnum should be my rank in comm world */
	if (flag) {
            if (*appnum_ptr != rank) {
                errs++;
                printf( "appnum is %d but should be %d\n", *appnum_ptr, rank );
	    }
	}
	else {
             errs++;
             printf( "appnum was not set\n" );
	}

	/* Send the errs back to the master process */
        MPI_Ssend( &errs, 1, MPI_INT, 0, 1, intercomm );
    }

    /* It isn't necessary to free the intercomm, but it should not hurt */
    MPI_Comm_free( &intercomm );

    /* Note that the MTest_Finalize get errs only over COMM_WORLD  */
    if (parentcomm == MPI_COMM_NULL) {
	MTest_Finalize( errs );
    }

    MPI_Finalize();
    return 0;
}