selftest: sync: stress consumer/producer test

This test is based on the libsync test suite from Android.
This commit includes a stress test that replicates a
consumer/producer pattern.

Signed-off-by: Emilio López <[e-mail]>
Signed-off-by: Shuah Khan <[e-mail]>

tools/testing/selftests/sync/Makefile

···
 TESTS += sync_merge.o
 TESTS += sync_wait.o
 TESTS += sync_stress_parallelism.o
+TESTS += sync_stress_consumer.o
 
 sync_test: $(OBJS) $(TESTS)
 

tools/testing/selftests/sync/sync_stress_consumer.c

···
+/*
+ *  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;
+}

tools/testing/selftests/sync/sync_test.c

···
 	err += RUN_TEST(test_fence_merge_same_fence);
 	err += RUN_TEST(test_fence_multi_timeline_wait);
 	err += RUN_TEST(test_stress_two_threads_shared_timeline);
+	err += RUN_TEST(test_consumer_stress_multi_producer_single_consumer);
 
 	if (err)
 		printf("[FAIL]\tsync errors: %d\n", err);

tools/testing/selftests/sync/synctest.h

···
 /* Stress test - parallelism */
 int test_stress_two_threads_shared_timeline(void);
 
+/* Stress test - consumer */
+int test_consumer_stress_multi_producer_single_consumer(void);
+
 #endif