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

/*

 *

 *  (C) 2013 by Argonne National Laboratory.

 *      See COPYRIGHT in top-level directory.

 */

#include <stdio.h>

#include <stdlib.h>

#include <assert.h>

#include <mpi.h>

#include "mpitest.h"

#include "mcs-mutex.h"

#define NUM_ITER    1000

#define NUM_MUTEXES 1

const int verbose = 0;

double delay_ctr = 0.0;

int main(int argc, char **argv)

{

    int rank, nproc, i;

    double t_mcs_mtx;

    MPI_Comm mtx_comm;

    MCS_Mutex mcs_mtx;

    MPI_Init(&argc, &argv);

    MPI_Comm_rank(MPI_COMM_WORLD, &rank;;

    MPI_Comm_size(MPI_COMM_WORLD, &nproc);

#ifdef USE_WIN_SHARED

    MPI_Comm_split_type(MPI_COMM_WORLD, MPI_COMM_TYPE_SHARED, rank, MPI_INFO_NULL, &mtx_comm);

#else

    mtx_comm = MPI_COMM_WORLD;

#endif

    MCS_Mutex_create(0, mtx_comm, &mcs_mtx);

    MPI_Barrier(MPI_COMM_WORLD);

    t_mcs_mtx = MPI_Wtime();

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

        /* Combining trylock and lock here is helpful for testing because it makes

         * CAS and Fetch-and-op contend for the tail pointer. */

#ifdef USE_CONTIGUOUS_RANK

        if (rank < nproc / 2) {

#else

        if (rank % 2) {

#endif

            int success = 0;

            while (!success) {

                MCS_Mutex_trylock(mcs_mtx, &success);

            }

        }

        else {

            MCS_Mutex_lock(mcs_mtx);

        }

        MCS_Mutex_unlock(mcs_mtx);

    }

    MPI_Barrier(MPI_COMM_WORLD);

    t_mcs_mtx = MPI_Wtime() - t_mcs_mtx;

    MCS_Mutex_free(&mcs_mtx);

    if (rank == 0) {

        if (verbose) {

            printf("Nproc %d, MCS Mtx = %f us\n", nproc, t_mcs_mtx / NUM_ITER * 1.0e6);

        }

    }

    if (mtx_comm != MPI_COMM_WORLD)

        MPI_Comm_free(&mtx_comm);

    MTest_Finalize(0);

    MPI_Finalize();

    return 0;

}