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

/*

 *  (C) 2005 by Argonne National Laboratory.

 *      See COPYRIGHT in top-level directory.

 */

#include <stdio.h>

#include "mpi.h"

/* This is a program to enable testing and demonstration of the debugger

   interface, particularly in terms of showing message queues.  To use

   this, run with a few processes and attach with the debugger when the

   program stops.  You can change the variable "hold" to 0 to allow the

   program to complete. */

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

{

    int wsize, wrank;

    int source, dest, i;

    int buf1[10], buf2[10], buf3[10];

    MPI_Request r[3];

    volatile int hold = 1;

    MPI_Comm dupcomm;

    MPI_Status status;

    MPI_Init(&argc, &argv);

    MPI_Comm_size(MPI_COMM_WORLD, &wsize);

    MPI_Comm_rank(MPI_COMM_WORLD, &wrank);

    /* Set the source and dest in a ring */

    source = (wrank + 1) % wsize;

    dest = (wrank + wsize - 1) % wsize;

    MPI_Comm_dup(MPI_COMM_WORLD, &dupcomm);

    MPI_Comm_set_name(dupcomm, "Dup of comm world");

    for (i = 0; i < 3; i++) {

        MPI_Irecv(MPI_BOTTOM, 0, MPI_INT, source, i + 100, MPI_COMM_WORLD, &r[i]);

    }

    MPI_Send(buf2, 8, MPI_INT, dest, 1, MPI_COMM_WORLD);

    MPI_Send(buf3, 4, MPI_INT, dest, 2, dupcomm);

    while (hold);

    MPI_Recv(buf1, 10, MPI_INT, source, 1, MPI_COMM_WORLD, &status);

    MPI_Recv(buf1, 10, MPI_INT, source, 1, dupcomm, &status);

    for (i = 0; i < 3; i++) {

        MPI_Cancel(&r[i]);

    }

    MPI_Comm_free(&dupcomm);

    MPI_Finalize();

    return 0;

}