source: mainline/uspace/app/hbench/synch/fibril_mutex.c

/*
 * Copyright (c) 2019 Vojtech Horky
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup hbench
 * @{
 */

#include <fibril_synch.h>
#include <stdatomic.h>
#include "../hbench.h"

/*
 * Simple benchmark for fibril mutexes. There are two fibrils that compete
 * over the same mutex as that is the simplest scenario.
 */

typedef struct {
        fibril_mutex_t mutex;
        uint64_t counter;
        atomic_bool done;
} shared_t;

static errno_t competitor(void *arg)
{
        shared_t *shared = arg;
        fibril_detach(fibril_get_id());

        while (true) {
                fibril_mutex_lock(&shared->mutex);
                uint64_t local = shared->counter;
                fibril_mutex_unlock(&shared->mutex);
                if (local == 0) {
                        break;
                }
        }

        atomic_store(&shared->done, true);

        return EOK;
}

static bool runner(bench_env_t *env, bench_run_t *run, uint64_t size)
{
        shared_t shared;
        fibril_mutex_initialize(&shared.mutex);
        shared.counter = size;
        atomic_store(&shared.done, false);

        fid_t other = fibril_create(competitor, &shared);
        fibril_add_ready(other);

        bench_run_start(run);
        for (uint64_t i = 0; i < size; i++) {
                fibril_mutex_lock(&shared.mutex);
                shared.counter--;
                fibril_mutex_unlock(&shared.mutex);
        }
        bench_run_stop(run);

        while (!atomic_load(&shared.done)) {
                fibril_yield();
        }

        return true;
}

benchmark_t benchmark_fibril_mutex = {
        .name = "fibril_mutex",
        .desc = "Speed of mutex lock/unlock operations",
        .entry = &runner,
        .setup = NULL,
        .teardown = NULL
};

/** @}
 */