#define BENCHMARK "OSU OpenSHMEM Barrier Latency Test"
/*
 * Copyright (C) 2002-2021 the Network-Based Computing Laboratory
 * (NBCL), The Ohio State University. 
 *
 * Contact: Dr. D. K. Panda (panda@cse.ohio-state.edu)
 *
 * For detailed copyright and licensing information, please refer to the
 * copyright file COPYRIGHT in the top level OMB directory.
 */

#include <shmem.h>
#include <osu_util_pgas.h>

long pSyncBarrier1[_SHMEM_BARRIER_SYNC_SIZE];
long pSyncBarrier2[_SHMEM_BARRIER_SYNC_SIZE];
long pSyncRed1[_SHMEM_REDUCE_SYNC_SIZE];
long pSyncRed2[_SHMEM_REDUCE_SYNC_SIZE];

double pWrk1[_SHMEM_REDUCE_MIN_WRKDATA_SIZE];
double pWrk2[_SHMEM_REDUCE_MIN_WRKDATA_SIZE];

int main(int argc, char *argv[])
{
    int i = 0, rank;
    int skip, numprocs, iterations;
    static double avg_time = 0.0, max_time = 0.0, min_time = 0.0;
    static double latency = 0.0;
    double t_start = 0, t_stop = 0, timer=0;
    int t;
    int po_ret;
    int * size = NULL;

    options.bench = OSHM;

    for ( t = 0; t < _SHMEM_REDUCE_SYNC_SIZE; t += 1) pSyncRed1[t] = _SHMEM_SYNC_VALUE;
    for ( t = 0; t < _SHMEM_REDUCE_SYNC_SIZE; t += 1) pSyncRed2[t] = _SHMEM_SYNC_VALUE;
    for ( t = 0; t < _SHMEM_BARRIER_SYNC_SIZE; t += 1) pSyncBarrier1[t] = _SHMEM_SYNC_VALUE;
    for ( t = 0; t < _SHMEM_BARRIER_SYNC_SIZE; t += 1) pSyncBarrier2[t] = _SHMEM_SYNC_VALUE;

#ifdef OSHM_1_3
    shmem_init();
    rank = shmem_my_pe(); 
    numprocs = shmem_n_pes();
#else
    start_pes(0);
    rank = _my_pe();
    numprocs = _num_pes();
#endif

    po_ret = process_options(argc, argv);

    switch (po_ret) {
        case PO_BAD_USAGE:
            print_usage_pgas(rank, argv[0], size != NULL);
            exit(EXIT_FAILURE);
        case PO_HELP_MESSAGE:
            print_usage_pgas(rank, argv[0], size != NULL);
            exit(EXIT_SUCCESS);
        case PO_VERSION_MESSAGE:
            if (rank == 0) {
                print_version_pgas(HEADER);
            }
            exit(EXIT_SUCCESS);
        case PO_OKAY:
            break;
    }

    if(numprocs < 2) {
        if(rank == 0) {
            fprintf(stderr, "This test requires at least two processes\n");
        }
        return EXIT_FAILURE;
    }

    options.show_size = 0;
    print_header_pgas(HEADER, rank, options.show_full);

    skip = options.skip_large;
    iterations = options.iterations_large;
    timer = 0;

    for(i=0; i < iterations + skip ; i++) {
        t_start = TIME();
        if(i%2)
            shmem_barrier(0, 0, numprocs, pSyncBarrier1);
        else
            shmem_barrier(0, 0, numprocs, pSyncBarrier2);
        t_stop = TIME();

        if(i>=skip){
            timer+=t_stop-t_start;
        } 
    }
            
    shmem_barrier_all();

    latency = (1.0 * timer) / iterations;
    shmem_double_min_to_all(&min_time, &latency, 1, 0, 0, numprocs, pWrk1, pSyncRed1);
    shmem_double_max_to_all(&max_time, &latency, 1, 0, 0, numprocs, pWrk2, pSyncRed2);
    shmem_double_sum_to_all(&avg_time, &latency, 1, 0, 0, numprocs, pWrk1, pSyncRed1);

    avg_time = avg_time/numprocs;
    print_data_pgas(rank, options.show_full, 0, avg_time, min_time, max_time, iterations);

#ifdef OSHM_1_3
    shmem_finalize();
#endif

    return EXIT_SUCCESS;
}

/* vi: set sw=4 sts=4 tw=80: */