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

/*

 *

 *  (C) 2012 by Argonne National Laboratory.

 *      See COPYRIGHT in top-level directory.

 */

/* This test attempts to create a large number of communicators, in an effort

 * to exceed the number of communicators that the MPI implementation can

 * provide.  It checks that the implementation detects this error correctly

 * handles it.

 */

/* In this version, we duplicate MPI_COMM_WORLD in a non-blocking

 * fashion until we run out of context IDs. */

#include <stdio.h>

#include <stdlib.h>

#include <mpi.h>

#include "mpitest.h"

#define MAX_NCOMM 100000

#define WAIT_COMM 7

static const int verbose = 0;

int main(int argc, char **argv)

{

    int rank, nproc, mpi_errno;

    int i, j, ncomm, block;

    int errs = 1;

    MPI_Comm *comm_hdls;

    MPI_Request req[WAIT_COMM];

    MTest_Init(&argc, &argv);

    MPI_Comm_rank(MPI_COMM_WORLD, &rank;;

    MPI_Comm_size(MPI_COMM_WORLD, &nproc);

    MPI_Comm_set_errhandler(MPI_COMM_WORLD, MPI_ERRORS_RETURN);

    MPI_Status error_status[WAIT_COMM];

    comm_hdls = malloc(sizeof(MPI_Comm) * MAX_NCOMM);

    ncomm = 0;

    block = 0;

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

        /* Note: the comms we create are all dups of MPI_COMM_WORLD */

        MPI_Comm_idup(MPI_COMM_WORLD, &comm_hdls[i], &req[block++]);

        if (block == WAIT_COMM) {

            mpi_errno = MPI_Waitall(block, req, error_status);

            if (mpi_errno == MPI_SUCCESS) {

                ncomm += block;

            } else {

                if (verbose)

                    printf("%d: Error creating comm %d\n", rank, i);

                for (j = 0; j < block; j++) {

                    if (error_status[j].MPI_ERROR == MPI_SUCCESS) {

                        ncomm += 1;

                    } else if (error_status[j].MPI_ERROR == MPI_ERR_PENDING) {

                        mpi_errno = MPI_Wait(&req[j], MPI_STATUSES_IGNORE);

                        if (mpi_errno == MPI_SUCCESS) {

                            ncomm += 1;

                        } else {

                            if (verbose)

                                printf("%d: Error creating comm %d\n", rank, i);

                        }

                    }

                }

                errs = 0;

                block = 0;

                break;

            }

            block = 0;

        }

    }

    if (block != 0) {

        mpi_errno = MPI_Waitall(block, req, MPI_STATUSES_IGNORE);

        if (mpi_errno == MPI_SUCCESS) {

            ncomm += block;

        } else {

            if (verbose)

                printf("%d: Error creating comm %d\n", rank, i);

            errs = 0;

        }

    }

    for (i = 0; i < ncomm; i++)

        MPI_Comm_free(&comm_hdls[i]);

    free(comm_hdls);

    MTest_Finalize(errs);

    return MTestReturnValue(errs);

}