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

/*

 *  (C) 2001 by Argonne National Laboratory.

 *      See COPYRIGHT in top-level directory.

 */

#include "mpi.h"

#include <stdio.h>

/* stdlib.h Needed for malloc declaration */

#include <stdlib.h>

int main(int argc, char **argv)

{

    int i, n, n_goal = 2048, n_all, rc, n_ranks, *ranks, rank, size, len;

    int group_size;

    MPI_Group *group_array, world_group;

    char msg[MPI_MAX_ERROR_STRING];

    MPI_Init(&argc, &argv);

    MPI_Comm_size(MPI_COMM_WORLD, &size);

    MPI_Comm_rank(MPI_COMM_WORLD, &rank;;

    n = n_goal;

    group_array = (MPI_Group *) malloc(n * sizeof(MPI_Group));

    MPI_Comm_group(MPI_COMM_WORLD, &world_group);

    n_ranks = size;

    ranks = (int *) malloc(size * sizeof(int));

    for (i = 0; i < size; i++)

        ranks[i] = i;

    MPI_Errhandler_set(MPI_COMM_WORLD, MPI_ERRORS_RETURN);

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

        rc = MPI_Group_incl(world_group, n_ranks, ranks, group_array + i);

        if (rc) {

            fprintf(stderr, "Error when creating group number %d\n", i);

            MPI_Error_string(rc, msg, &len;;

            fprintf(stderr, "%s\n", msg);

            n = i + 1;

            break;

        }

        else {

            /* Check that the group was created (and that any errors were

             * caught) */

            rc = MPI_Group_size(group_array[i], &group_size);

            if (group_size != size) {

                fprintf(stderr, "Group number %d not correct (size = %d)\n", i, size);

                n = i + 1;

                break;

            }

        }

    }

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

        rc = MPI_Group_free(group_array + i);

        if (rc) {

            fprintf(stderr, "Error when freeing group number %d\n", i);

            MPI_Error_string(rc, msg, &len;;

            fprintf(stderr, "%s\n", msg);

            break;

        }

    }

    MPI_Errhandler_set(MPI_COMM_WORLD, MPI_ERRORS_ARE_FATAL);

    MPI_Group_free(&world_group);

    MPI_Reduce(&n, &n_all, 1, MPI_INT, MPI_MIN, 0, MPI_COMM_WORLD);

    if (rank == 0) {

        /* printf("Completed test of %d type creations\n", n_all); */

        if (n_all != n_goal) {

            printf("This MPI implementation limits the number of groups that can be created\n\

This is allowed by the standard and is not a bug, but is a limit on the\n\

implementation\n");

        }

        else {

            printf(" No Errors\n");

        }

    }

    free(group_array);

    free(ranks);

    MPI_Finalize();

    return 0;

}