source: benchmark/readyQ/churn.cpp @ 1fcbce7

#include "rq_bench.hpp"
#include <libfibre/fibre.h>

unsigned spot_cnt = 2;
FredSemaphore * spots;

struct Churner {
        unsigned long long count = 0;
        unsigned long long blocks = 0;
        bool skip = false;
        __lehmer64_state_t seed;
        bench_sem self;
};

void churner_main( Churner * self ) {
        fibre_park();
        for(;;) {
                unsigned r = __lehmer64( self->seed );
                FredSemaphore & sem = spots[r % spot_cnt];
                if(!self->skip) sem.V();
                self->blocks += sem.P() == SemaphoreWasOpen ? 1 : 0;
                self->skip = false;

                self->count ++;
                if( clock_mode && stop) break;
                if(!clock_mode && self->count >= stop_count) break;
        }

        __atomic_fetch_add(&threads_left, -1, __ATOMIC_SEQ_CST);
}

int main(int argc, char * argv[]) {
        option_t opt[] = {
                BENCH_OPT,
                { 's', "spots", "Number of spots in the system", spot_cnt }
        };
        BENCH_OPT_PARSE("libfibre churn benchmark");

        {
                unsigned long long global_counter = 0;
                unsigned long long global_blocks  = 0;
                uint64_t start, end;
                FibreInit(1, nprocs );
                {
                        spots = new FredSemaphore[spot_cnt]();

                        threads_left = nthreads;
                        Churner * thddata = new Churner[nthreads]();
                        for(unsigned i = 0; i < nthreads; i++ ) {
                                Churner & t = thddata[i];
                                t.skip = i < spot_cnt;
                                t.seed = rand();
                        }
                        Fibre * threads[nthreads];
                        for(unsigned i = 0; i < nthreads; i++) {
                                threads[i] = new Fibre();
                                threads[i]->run(churner_main, &thddata[i]);
                        }
                        printf("Starting\n");

                        bool is_tty = isatty(STDOUT_FILENO);
                        start = timeHiRes();

                        for(unsigned i = 0; i < nthreads; i++ ) {
                                fibre_unpark( threads[i] );
                        }
                        wait<Fibre>(start, is_tty);

                        stop = true;
                        end = timeHiRes();
                        printf("\nDone\n");

                        for(unsigned i = 0; i < spot_cnt; i++) {
                                for(int j = 0; j < 10000; j++) spots[i].V();
                        }

                        for(unsigned i = 0; i < nthreads; i++ ) {
                                fibre_join( threads[i], nullptr );
                                global_counter += thddata[i].count;
                                global_blocks  += thddata[i].blocks;
                        }

                        delete[](spots);
                        delete[](thddata);
                }

                printf("\nDone2\n");

                printf("Duration (ms)        : %'ld\n", to_miliseconds(end - start));
                printf("Number of processors : %'d\n", nprocs);
                printf("Number of threads    : %'d\n", nthreads);
                printf("Number of spots      : %'d\n", spot_cnt);
                printf("Total Operations(ops): %'15llu\n", global_counter);
                printf("Total blocks         : %'15llu\n", global_blocks);
                printf("Ops per second       : %'18.2lf\n", ((double)global_counter) / to_fseconds(end - start));
                printf("ns per ops           : %'18.2lf\n", ((double)(end - start)) / global_counter);
                printf("Ops per threads      : %'15llu\n", global_counter / nthreads);
                printf("Ops per procs        : %'15llu\n", global_counter / nprocs);
                printf("Ops/sec/procs        : %'18.2lf\n", (((double)global_counter) / nprocs) / to_fseconds(end - start));
                printf("ns per ops/procs     : %'18.2lf\n", ((double)(end - start)) / (global_counter / nprocs));
                fflush(stdout);
        }

        return 0;

}