/*
 *  sync stress test: producer/consumer
 *  Copyright 2015-2016 Collabora Ltd.
 *
 *  Based on the implementation from the Android Open Source Project,
 *
 *  Copyright 2012 Google, Inc
 *
 *  Permission is hereby granted, free of charge, to any person obtaining a
 *  copy of this software and associated documentation files (the "Software"),
 *  to deal in the Software without restriction, including without limitation
 *  the rights to use, copy, modify, merge, publish, distribute, sublicense,
 *  and/or sell copies of the Software, and to permit persons to whom the
 *  Software is furnished to do so, subject to the following conditions:
 *
 *  The above copyright notice and this permission notice shall be included in
 *  all copies or substantial portions of the Software.
 *
 *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 *  THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
 *  OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 *  ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 *  OTHER DEALINGS IN THE SOFTWARE.
 */

#include <pthread.h>

#include "sync.h"
#include "sw_sync.h"
#include "synctest.h"

/* IMPORTANT NOTE: if you see this test failing on your system, it may be
 * due to a shortage of file descriptors. Please ensure your system has
 * a sensible limit for this test to finish correctly.
 */

/* Returns 1 on error, 0 on success */
static int busy_wait_on_fence(int fence)
{
        int error, active;

        do {
                error = sync_fence_count_with_status(fence, FENCE_STATUS_ERROR);
                ASSERT(error == 0, "Error occurred on fence\n");
                active = sync_fence_count_with_status(fence,
                                                      FENCE_STATUS_ACTIVE);
        } while (active);

        return 0;
}

static struct {
        int iterations;
        int threads;
        int counter;
        int consumer_timeline;
        int *producer_timelines;
        pthread_mutex_t lock;
} test_data_mpsc;

static int mpsc_producer_thread(void *d)
{
        int id = (long)d;
        int fence, valid, i;
        int *producer_timelines = test_data_mpsc.producer_timelines;
        int consumer_timeline = test_data_mpsc.consumer_timeline;
        int iterations = test_data_mpsc.iterations;

        for (i = 0; i < iterations; i++) {
                fence = sw_sync_fence_create(consumer_timeline, "fence", i);
                valid = sw_sync_fence_is_valid(fence);
                ASSERT(valid, "Failure creating fence\n");

                /*
                 * Wait for the consumer to finish. Use alternate
                 * means of waiting on the fence
                 */

                if ((iterations + id) % 8 != 0) {
                        ASSERT(sync_wait(fence, -1) > 0,
                               "Failure waiting on fence\n");
                } else {
                        ASSERT(busy_wait_on_fence(fence) == 0,
                               "Failure waiting on fence\n");
                }

                /*
                 * Every producer increments the counter, the consumer
                 * checks and erases it
                 */
                pthread_mutex_lock(&test_data_mpsc.lock);
                test_data_mpsc.counter++;
                pthread_mutex_unlock(&test_data_mpsc.lock);

                ASSERT(sw_sync_timeline_inc(producer_timelines[id], 1) == 0,
                       "Error advancing producer timeline\n");

                sw_sync_fence_destroy(fence);
        }

        return 0;
}

static int mpcs_consumer_thread(void)
{
        int fence, merged, tmp, valid, it, i;
        int *producer_timelines = test_data_mpsc.producer_timelines;
        int consumer_timeline = test_data_mpsc.consumer_timeline;
        int iterations = test_data_mpsc.iterations;
        int n = test_data_mpsc.threads;

        for (it = 1; it <= iterations; it++) {
                fence = sw_sync_fence_create(producer_timelines[0], "name", it);
                for (i = 1; i < n; i++) {
                        tmp = sw_sync_fence_create(producer_timelines[i],
                                                   "name", it);
                        merged = sync_merge("name", tmp, fence);
                        sw_sync_fence_destroy(tmp);
                        sw_sync_fence_destroy(fence);
                        fence = merged;
                }

                valid = sw_sync_fence_is_valid(fence);
                ASSERT(valid, "Failure merging fences\n");

                /*
                 * Make sure we see an increment from every producer thread.
                 * Vary the means by which we wait.
                 */
                if (iterations % 8 != 0) {
                        ASSERT(sync_wait(fence, -1) > 0,
                               "Producers did not increment as expected\n");
                } else {
                        ASSERT(busy_wait_on_fence(fence) == 0,
                               "Producers did not increment as expected\n");
                }

                ASSERT(test_data_mpsc.counter == n * it,
                       "Counter value mismatch!\n");

                /* Release the producer threads */
                ASSERT(sw_sync_timeline_inc(consumer_timeline, 1) == 0,
                       "Failure releasing producer threads\n");

                sw_sync_fence_destroy(fence);
        }

        return 0;
}

int test_consumer_stress_multi_producer_single_consumer(void)
{
        int iterations = 1 << 12;
        int n = 5;
        long i, ret;
        int producer_timelines[n];
        int consumer_timeline;
        pthread_t threads[n];

        consumer_timeline = sw_sync_timeline_create();
        for (i = 0; i < n; i++)
                producer_timelines[i] = sw_sync_timeline_create();

        test_data_mpsc.producer_timelines = producer_timelines;
        test_data_mpsc.consumer_timeline = consumer_timeline;
        test_data_mpsc.iterations = iterations;
        test_data_mpsc.threads = n;
        test_data_mpsc.counter = 0;
        pthread_mutex_init(&test_data_mpsc.lock, NULL);

        for (i = 0; i < n; i++) {
                pthread_create(&threads[i], NULL, (void * (*)(void *))
                               mpsc_producer_thread, (void *)i);
        }

        /* Consumer thread runs here */
        ret = mpcs_consumer_thread();

        for (i = 0; i < n; i++)
                pthread_join(threads[i], NULL);

        return ret;
}