bcasttest.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) 2001 by Argonne National Laboratory.
 *      See COPYRIGHT in top-level directory.
 */
#include "mpi.h"
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#define ROOT      0
#define NUM_REPS  5
#define NUM_SIZES 3

int main( int argc, char **argv)
{
    int *buf;
    int i, rank, reps, n;
    int bVerify = 1;
    int sizes[NUM_SIZES] = { 100, 64*1024, 128*1024 };
    int num_errors=0, tot_errors;
    
    MPI_Init(&argc, &argv);
    MPI_Comm_rank(MPI_COMM_WORLD, &rank);

    if (argc > 1)
    {
	if (strcmp(argv[1], "-novalidate") == 0 || strcmp(argv[1], "-noverify") == 0)
	    bVerify = 0;
    }

    buf = (int *) malloc(sizes[NUM_SIZES-1]*sizeof(int));
    memset(buf, 0, sizes[NUM_SIZES-1]*sizeof(int));

    for (n=0; n<NUM_SIZES; n++)
    {
#ifdef DEBUG
	if (rank == ROOT)
	{
	    printf("bcasting %d MPI_INTs %d times\n", sizes[n], NUM_REPS);
	    fflush(stdout);
	}
#endif
	for (reps=0; reps < NUM_REPS; reps++)
	{
	    if (bVerify)
	    {
                if (rank == ROOT)
                {
		    for (i=0; i<sizes[n]; i++)
		    {
			buf[i] = 1000000 * (n * NUM_REPS + reps) + i;
		    }
		}
		else
                {
		    for (i=0; i<sizes[n]; i++)
		    {
                        buf[i] = -1 - (n * NUM_REPS + reps);
		    }
		}
	    }

#	    ifdef DEBUG
	    {
		printf("rank=%d, n=%d, reps=%d\n", rank, n, reps);
	    }
#           endif
	    
	    MPI_Bcast(buf, sizes[n], MPI_INT, ROOT, MPI_COMM_WORLD);

	    if (bVerify)
	    {
	        num_errors = 0;
		for (i=0; i<sizes[n]; i++)
		{
		    if (buf[i] != 1000000 * (n * NUM_REPS + reps) + i)
		    {
		        num_errors++;
			if (num_errors < 10)
			{
			    printf("Error: Rank=%d, n=%d, reps=%d, i=%d, buf[i]=%d expected=%d\n", rank, n, reps, i, buf[i],
				   1000000 * (n * NUM_REPS + reps) +i);
			    fflush(stdout);
			}
		    }
		}
		if (num_errors >= 10)
		{
		    printf("Error: Rank=%d, num_errors = %d\n", rank, num_errors);
		    fflush(stdout);
		}
	    }
	}
    }
    
    /* printf("Node %d done\n", rank); */
    MPI_Reduce( &num_errors, &tot_errors, 1, MPI_INT, MPI_SUM, 0, 
		MPI_COMM_WORLD );
    if (rank == 0 && tot_errors == 0) 
	printf(" No Errors\n");

    fflush(stdout);

    free(buf);

    MPI_Finalize();
    return 0;
}