/* -*- 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 <stdio.h>
#include <stdlib.h>
#ifdef HAVE_STRINGS_H
#include <strings.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif

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

/*
static char MTEST_Descrip[] = "A simple test of Comm_connect/accept/disconnect";
*/

int main(int argc, char *argv[])
{
    int errs = 0;
    int rank, size, rsize, i, j, data, num_loops = 100;
    int np = 3;
    MPI_Comm parentcomm, intercomm;
    MPI_Status status;
    char port[MPI_MAX_PORT_NAME] = { 0 };
    int verbose = 0;
    int do_messages = 1;
    char *env;
    int can_spawn;

    env = getenv("MPITEST_VERBOSE");
    if (env) {
        if (*env != '0')
            verbose = 1;
    }

    MTest_Init(&argc, &argv);

    errs += MTestSpawnPossible(&can_spawn);

    if (can_spawn) {
        /* FIXME: Document arguments */
        if (argc > 1) {
            num_loops = atoi(argv[1]);
            if (num_loops < 0)
                num_loops = 0;
            if (num_loops > 100)
                num_loops = 100;
        }
        if (argc > 2) {
            do_messages = atoi(argv[2]);
        }
        MPI_Comm_get_parent(&parentcomm);

        if (parentcomm == MPI_COMM_NULL) {
            MPI_Comm_rank(MPI_COMM_WORLD, &rank);       /* Get rank for verbose msg */
            IF_VERBOSE(("[%d] spawning %d processes\n", rank, np));
            /* Create 3 more processes */
            MPI_Comm_spawn((char *) "./disconnect_reconnect",
                           /*MPI_ARGV_NULL */ &argv[1], np,
                           MPI_INFO_NULL, 0, MPI_COMM_WORLD, &intercomm, MPI_ERRCODES_IGNORE);
        }
        else {
            intercomm = parentcomm;
        }

        /* We now have a valid intercomm */

        MPI_Comm_remote_size(intercomm, &rsize);
        MPI_Comm_size(intercomm, &size);
        MPI_Comm_rank(intercomm, &rank);

        if (parentcomm == MPI_COMM_NULL) {
            IF_VERBOSE(("[%d] parent rank %d alive.\n", rank, rank));
            /* Parent */
            if (rsize != np) {
                errs++;
                printf("Did not create %d processes (got %d)\n", np, rsize);
                fflush(stdout);
            }
            if (rank == 0 && num_loops > 0) {
                MPI_Open_port(MPI_INFO_NULL, port);
                IF_VERBOSE(("[%d] port = %s\n", rank, port));
                MPI_Send(port, MPI_MAX_PORT_NAME, MPI_CHAR, 0, 0, intercomm);
            }
            IF_VERBOSE(("[%d] disconnecting child communicator\n", rank));
            MPI_Comm_disconnect(&intercomm);
            for (i = 0; i < num_loops; i++) {
                IF_VERBOSE(("[%d] accepting connection\n", rank));
                MPI_Comm_accept(port, MPI_INFO_NULL, 0, MPI_COMM_WORLD, &intercomm);
                MPI_Comm_remote_size(intercomm, &rsize);
                if (do_messages && (rank == 0)) {
                    j = 0;
                    for (j = 0; j < rsize; j++) {
                        data = i;
                        IF_VERBOSE(("[%d]sending int to child process %d\n", rank, j));
                        MPI_Send(&data, 1, MPI_INT, j, 100, intercomm);
                        IF_VERBOSE(("[%d] receiving int from child process %d\n", rank, j));
                        data = i - 1;
                        MPI_Recv(&data, 1, MPI_INT, j, 100, intercomm, &status);
                        if (data != i) {
                            errs++;
                        }
                    }
                }
                IF_VERBOSE(("[%d] disconnecting communicator\n", rank));
                MPI_Comm_disconnect(&intercomm);
            }

            /* Errors cannot be sent back to the parent because there is no
             * communicator connected to the children
             * for (i=0; i<rsize; i++)
             * {
             * MPI_Recv(&err, 1, MPI_INT, i, 1, intercomm, MPI_STATUS_IGNORE);
             * errs += err;
             * }
             */
        }
        else {
            IF_VERBOSE(("[%d] child rank %d alive.\n", rank, rank));
            /* Child */
            if (size != np) {
                errs++;
                printf("(Child) Did not create %d processes (got %d)\n", np, size);
                fflush(stdout);
            }

            if (rank == 0 && num_loops > 0) {
                IF_VERBOSE(("[%d] receiving port\n", rank));
                MPI_Recv(port, MPI_MAX_PORT_NAME, MPI_CHAR, 0, 0, intercomm, &status);
            }

            IF_VERBOSE(("[%d] disconnecting communicator\n", rank));
            MPI_Comm_disconnect(&intercomm);
            for (i = 0; i < num_loops; i++) {
                IF_VERBOSE(("[%d] connecting to port (loop %d)\n", rank, i));
                MPI_Comm_connect(port, MPI_INFO_NULL, 0, MPI_COMM_WORLD, &intercomm);
                if (do_messages) {
                    IF_VERBOSE(("[%d] receiving int from parent process 0\n", rank));
                    MPI_Recv(&data, 1, MPI_INT, 0, 100, intercomm, &status);
                    if (data != i) {
                        printf("expected %d but received %d\n", i, data);
                        fflush(stdout);
                        MPI_Abort(MPI_COMM_WORLD, 1);
                    }
                    IF_VERBOSE(("[%d] sending int back to parent process 1\n", rank));
                    MPI_Send(&data, 1, MPI_INT, 0, 100, intercomm);
                }
                IF_VERBOSE(("[%d] disconnecting communicator\n", rank));
                MPI_Comm_disconnect(&intercomm);
            }

            /* Send the errs back to the master process */
            /* Errors cannot be sent back to the parent because there is no
             * communicator connected to the parent */
            /*MPI_Ssend(&errs, 1, MPI_INT, 0, 1, intercomm); */
        }

        /* Note that the MTest_Finalize get errs only over COMM_WORLD */
        /* Note also that both the parent and child will generate "No Errors"
         * if both call MTest_Finalize */
        if (parentcomm == MPI_COMM_NULL) {
            MTest_Finalize(errs);
        }
    }
    else {
        MTest_Finalize(errs);
    }

    IF_VERBOSE(("[%d] calling finalize\n", rank));
    MPI_Finalize();
    return 0;
}