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

/*

 *

 *  (C) 2003 by Argonne National Laboratory.

 *      See COPYRIGHT in top-level directory.

 */

#include "mpi.h"

#include "mpitest.h"

#include <stdlib.h>

#include <stdio.h>

/* Gather data from a vector to contiguous. */

int main(int argc, char **argv)

{

    double *vecout, *invec;

    MPI_Comm comm;

    int count, minsize = 2;

    int i, errs = 0;

    int rank, size;

    MTest_Init(&argc, &argv);

    while (MTestGetIntracommGeneral(&comm, minsize, 1)) {

        if (comm == MPI_COMM_NULL)

            continue;

        /* Determine the sender and receiver */

        MPI_Comm_rank(comm, &rank;;

        MPI_Comm_size(comm, &size);

        for (count = 1; count < 9000; count = count * 2) {

            invec = (double *) malloc(count * sizeof(double));

            vecout = (double *) malloc(size * count * sizeof(double));

            for (i = 0; i < count; i++) {

                invec[i] = rank * count + i;

            }

            MPI_Allgather(invec, count, MPI_DOUBLE, vecout, count, MPI_DOUBLE, comm);

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

                if (vecout[i] != i) {

                    errs++;

                    if (errs < 10) {

                        fprintf(stderr, "vecout[%d]=%d\n", i, (int) vecout[i]);

                    }

                }

            }

            free(invec);

            free(vecout);

        }

        MTestFreeComm(&comm);

    }

    /* Do a zero byte gather */

    MPI_Allgather(MPI_IN_PLACE, -1, MPI_DATATYPE_NULL, NULL, 0, MPI_BYTE, MPI_COMM_WORLD);

    MTest_Finalize(errs);

    MPI_Finalize();

    return 0;

}