/* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil ; -*- */

/*

 *  Changes to the original code

 *  (C) 2001 by Argonne National Laboratory.

 *      See COPYRIGHT in top-level directory.

 */

#include "mpi.h"

/*

From: hook@nas.nasa.gov (Edward C. Hook)

 */

#include <stdlib.h>

#include <stdio.h>

#include "mpitest.h"

#include <string.h>

#include <errno.h>

#ifndef EXIT_SUCCESS

#define EXIT_SUCCESS 0

#define EXIT_FAILURE 1

#endif

int main(int argc, char *argv[])

{

    int rank, size;

    int chunk = 128;

    int i;

    int *sb;

    int *rb;

    int status, gstatus;

    MTest_Init(&argc, &argv);

    MPI_Comm_rank(MPI_COMM_WORLD, &rank;;

    MPI_Comm_size(MPI_COMM_WORLD, &size);

    for (i = 1; i < argc; ++i) {

        if (argv[i][0] != '-')

            continue;

        switch (argv[i][1]) {

            case 'm':

                chunk = atoi(argv[++i]);

                break;

            default:

                fprintf(stderr, "Unrecognized argument %s\n", argv[i]);

                MPI_Abort(MPI_COMM_WORLD, EXIT_FAILURE);

        }

    }

    sb = (int *) malloc(size * chunk * sizeof(int));

    if (!sb) {

        perror("can't allocate send buffer");

        MPI_Abort(MPI_COMM_WORLD, EXIT_FAILURE);

    }

    rb = (int *) malloc(size * chunk * sizeof(int));

    if (!rb) {

        perror("can't allocate recv buffer");

        free(sb);

        MPI_Abort(MPI_COMM_WORLD, EXIT_FAILURE);

    }

    for (i = 0; i < size * chunk; ++i) {

        sb[i] = rank + 1;

        rb[i] = 0;

    }

    /* fputs("Before MPI_Alltoall\n",stdout); */

    /* This should really send MPI_CHAR, but since sb and rb were allocated

     * as chunk*size*sizeof(int), the buffers are large enough */

    status = MPI_Alltoall(sb, chunk, MPI_INT, rb, chunk, MPI_INT, MPI_COMM_WORLD);

    /* fputs("Before MPI_Allreduce\n",stdout); */

    MTest_Finalize(status);

    free(sb);

    free(rb);

    return MTestReturnValue(status);

}