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

/*

 *

 *  (C) 2012 by Argonne National Laboratory.

 *      See COPYRIGHT in top-level directory.

 */

/* regression test for ticket #1574

 *

 * Based on test code from N. Radclif @ Cray. */

#include <stdio.h>

#include <stdlib.h>

#include <mpi.h>

int main(int argc, char **argv)

{

    MPI_Comm c0, c1, ic;

    MPI_Group g0, g1, gworld;

    int a, b, c, d;

    int rank, size, remote_leader, tag;

    int ranks[2];

    int errs = 0;

    tag = 5;

    c0 = c1 = ic = MPI_COMM_NULL;

    g0 = g1 = gworld = MPI_GROUP_NULL;

    MPI_Init(&argc, &argv);

    MPI_Comm_rank(MPI_COMM_WORLD, &rank;;

    MPI_Comm_size(MPI_COMM_WORLD, &size);

    if (size < 33) {

        printf("ERROR: this test requires at least 33 processes\n");

        MPI_Abort(MPI_COMM_WORLD, 1);

        return 1;

    }

    /* group of c0

     * NOTE: a>=32 is essential for exercising the loop bounds bug from tt#1574 */

    a = 32;

    b = 24;

    /* group of c1 */

    c = 25;

    d = 26;

    MPI_Comm_group(MPI_COMM_WORLD, &gworld);

    ranks[0] = a;

    ranks[1] = b;

    MPI_Group_incl(gworld, 2, ranks, &g0;;

    MPI_Comm_create(MPI_COMM_WORLD, g0, &c0;;

    ranks[0] = c;

    ranks[1] = d;

    MPI_Group_incl(gworld, 2, ranks, &g1;;

    MPI_Comm_create(MPI_COMM_WORLD, g1, &c1;;

    if (rank == a || rank == b) {

        remote_leader = c;

        MPI_Intercomm_create(c0, 0, MPI_COMM_WORLD, remote_leader, tag, &ic);

    }

    else if (rank == c || rank == d) {

        remote_leader = a;

        MPI_Intercomm_create(c1, 0, MPI_COMM_WORLD, remote_leader, tag, &ic);

    }

    MPI_Group_free(&g0;;

    MPI_Group_free(&g1;;

    MPI_Group_free(&gworld);

    if (c0 != MPI_COMM_NULL)

        MPI_Comm_free(&c0;;

    if (c1 != MPI_COMM_NULL)

        MPI_Comm_free(&c1;;

    if (ic != MPI_COMM_NULL)

        MPI_Comm_free(&ic);

    MPI_Reduce((rank == 0 ? MPI_IN_PLACE : &errs), &errs, 1, MPI_INT, MPI_SUM, 0, MPI_COMM_WORLD);

    if (rank == 0) {

        if (errs) {

            printf("found %d errors\n", errs);

        }

        else {

            printf(" No errors\n");

        }

    }

    MPI_Finalize();

    return 0;

}