/*
 * Copyright (C) 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); }
#define DATA_VALUE 123
#define DATA_TAG 100
#define SENDER_RANK 1
#define RECEIVER_RANK 2

/*
static char MTEST_Descrip[] = "A simple test of Comm_disconnect";
*/

int main(int argc, char *argv[])
{
    int errs = 0;
    int rank, size, rsize, i, data = -1;
    int np = 3;
    MPI_Comm parentcomm, intercomm;
    MPI_Status status;
    int verbose = 0;
    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) {
        MPI_Comm_get_parent(&parentcomm);

        if (parentcomm == MPI_COMM_NULL) {
            IF_VERBOSE(("spawning %d processes\n", np));
            /* Create 3 more processes */
            MPI_Comm_spawn((char *) "./disconnect3", MPI_ARGV_NULL, 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(("parent rank %d alive.\n", rank));
            /* Parent */
            if (rsize != np) {
                errs++;
                printf("Did not create %d processes (got %d)\n", np, rsize);
                fflush(stdout);
            }
            if (rank == SENDER_RANK) {
                IF_VERBOSE(("sending int\n"));
                i = DATA_VALUE;
                MPI_Send(&i, 1, MPI_INT, RECEIVER_RANK, DATA_TAG, intercomm);
                MPI_Recv(&data, 1, MPI_INT, RECEIVER_RANK, DATA_TAG, intercomm, &status);
                if (data != i) {
                    errs++;
                }
            }
            IF_VERBOSE(("disconnecting child communicator\n"));
            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(("child rank %d alive.\n", rank));
            /* Child */
            if (size != np) {
                errs++;
                printf("(Child) Did not create %d processes (got %d)\n", np, size);
                fflush(stdout);
            }

            if (rank == RECEIVER_RANK) {
                IF_VERBOSE(("receiving int\n"));
                i = -1;
                MPI_Recv(&i, 1, MPI_INT, SENDER_RANK, DATA_TAG, intercomm, &status);
                if (i != DATA_VALUE) {
                    errs++;
                    printf("expected %d but received %d\n", DATA_VALUE, i);
                    fflush(stdout);
                    MPI_Abort(intercomm, 1);
                }
                MPI_Send(&i, 1, MPI_INT, SENDER_RANK, DATA_TAG, intercomm);
            }

            IF_VERBOSE(("disconnecting communicator\n"));
            MPI_Comm_disconnect(&intercomm);

            /* Send the errs back to the parent 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 {
            MPI_Finalize();
        }
    } else {
        MTest_Finalize(errs);
    }

    IF_VERBOSE(("calling finalize\n"));
    return MTestReturnValue(errs);
}
