/* -*- 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 <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "mpitest.h"

#define IF_VERBOSE(a) if (verbose) { printf a ; fflush(stdout); }

/* This test checks to make sure that two MPI_Comm_connects to two different MPI
 * ports match their corresponding MPI_Comm_accepts.  The root process opens two
 * MPI ports and sends the first port to process 1 and the second to process 2.
 * Then the root process accepts a connection from the second port followed by
 * the first port.  Processes 1 and 2 both connect back to the root but process
 * 2 first sleeps for three seconds to give process 1 time to attempt to connect
 * to the root.  The root should wait until process 2 connects before accepting
 * the connection from process 1.
 */

int main(int argc, char *argv[])
{
    int num_errors = 0, total_num_errors = 0;
    int rank, size;
    char port1[MPI_MAX_PORT_NAME];
    char port2[MPI_MAX_PORT_NAME];
    MPI_Status status;
    MPI_Comm comm1, comm2;
    int verbose = 0;
    int data = 0;

    if (getenv("MPITEST_VERBOSE")) {
        verbose = 1;
    }

    MPI_Init(&argc, &argv);
    MPI_Comm_size(MPI_COMM_WORLD, &size);
    MPI_Comm_rank(MPI_COMM_WORLD, &rank);

    if (size < 3) {
        printf("Three processes needed to run this test.\n");
        MPI_Finalize();
        return 0;
    }

    if (rank == 0) {
        IF_VERBOSE(("0: opening ports.\n"));
        MPI_Open_port(MPI_INFO_NULL, port1);
        MPI_Open_port(MPI_INFO_NULL, port2);

        IF_VERBOSE(("0: opened port1: <%s>\n", port1));
        IF_VERBOSE(("0: opened port2: <%s>\n", port2));
        IF_VERBOSE(("0: sending ports.\n"));
        MPI_Send(port1, MPI_MAX_PORT_NAME, MPI_CHAR, 1, 0, MPI_COMM_WORLD);
        MPI_Send(port2, MPI_MAX_PORT_NAME, MPI_CHAR, 2, 0, MPI_COMM_WORLD);

        IF_VERBOSE(("0: accepting port2.\n"));
        MPI_Comm_accept(port2, MPI_INFO_NULL, 0, MPI_COMM_SELF, &comm2);
        IF_VERBOSE(("0: accepting port1.\n"));
        MPI_Comm_accept(port1, MPI_INFO_NULL, 0, MPI_COMM_SELF, &comm1);

        IF_VERBOSE(("0: closing ports.\n"));
        MPI_Close_port(port1);
        MPI_Close_port(port2);

        IF_VERBOSE(("0: sending 1 to process 1.\n"));
        data = 1;
        MPI_Send(&data, 1, MPI_INT, 0, 0, comm1);

        IF_VERBOSE(("0: sending 2 to process 2.\n"));
        data = 2;
        MPI_Send(&data, 1, MPI_INT, 0, 0, comm2);

        IF_VERBOSE(("0: disconnecting.\n"));
        MPI_Comm_disconnect(&comm1);
        MPI_Comm_disconnect(&comm2);
    }
    else if (rank == 1) {
        IF_VERBOSE(("1: receiving port.\n"));
        MPI_Recv(port1, MPI_MAX_PORT_NAME, MPI_CHAR, 0, 0, MPI_COMM_WORLD, &status);

        IF_VERBOSE(("1: received port1: <%s>\n", port1));
        IF_VERBOSE(("1: connecting.\n"));
        MPI_Comm_connect(port1, MPI_INFO_NULL, 0, MPI_COMM_SELF, &comm1);

        MPI_Recv(&data, 1, MPI_INT, 0, 0, comm1, &status);
        if (data != 1) {
            printf("Received %d from root when expecting 1\n", data);
            fflush(stdout);
            num_errors++;
        }

        IF_VERBOSE(("1: disconnecting.\n"));
        MPI_Comm_disconnect(&comm1);
    }
    else if (rank == 2) {
        IF_VERBOSE(("2: receiving port.\n"));
        MPI_Recv(port2, MPI_MAX_PORT_NAME, MPI_CHAR, 0, 0, MPI_COMM_WORLD, &status);

        IF_VERBOSE(("2: received port2: <%s>\n", port2));
        /* make sure process 1 has time to do the connect before this process
         * attempts to connect */
        MTestSleep(3);
        IF_VERBOSE(("2: connecting.\n"));
        MPI_Comm_connect(port2, MPI_INFO_NULL, 0, MPI_COMM_SELF, &comm2);

        MPI_Recv(&data, 1, MPI_INT, 0, 0, comm2, &status);
        if (data != 2) {
            printf("Received %d from root when expecting 2\n", data);
            fflush(stdout);
            num_errors++;
        }

        IF_VERBOSE(("2: disconnecting.\n"));
        MPI_Comm_disconnect(&comm2);
    }

    MPI_Barrier(MPI_COMM_WORLD);

    MPI_Reduce(&num_errors, &total_num_errors, 1, MPI_INT, MPI_SUM, 0, MPI_COMM_WORLD);
    if (rank == 0) {
        if (total_num_errors) {
            printf(" Found %d errors\n", total_num_errors);
        }
        else {
            printf(" No Errors\n");
        }
        fflush(stdout);
    }
    MPI_Finalize();
    return total_num_errors;
}
