2 * Copyright 2016 Facebook, Inc.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
17 #include <folly/test/DeterministicSchedule.h>
19 #include <gtest/gtest.h>
21 #include <folly/portability/GFlags.h>
23 using namespace folly::test;
25 TEST(DeterministicSchedule, uniform) {
26 auto p = DeterministicSchedule::uniform(0);
28 for (int i = 0; i < 100000; ++i) {
31 for (int i = 0; i < 10; ++i) {
32 EXPECT_TRUE(buckets[i] > 9000);
36 TEST(DeterministicSchedule, uniformSubset) {
37 auto ps = DeterministicSchedule::uniformSubset(0, 3, 100);
40 for (int i = 0; i < 100000; ++i) {
41 if (i > 0 && (i % 100) == 0) {
42 EXPECT_EQ(seen.size(), 3);
47 EXPECT_TRUE(seen.size() <= 3);
50 for (int i = 0; i < 10; ++i) {
51 EXPECT_TRUE(buckets[i] > 9000);
55 TEST(DeterministicSchedule, buggyAdd) {
56 for (bool bug : {false, true}) {
57 DeterministicSchedule sched(DeterministicSchedule::uniform(0));
59 FOLLY_TEST_DSCHED_VLOG("Test with race condition");
61 FOLLY_TEST_DSCHED_VLOG("Test without race condition");
64 // The use of DeterinisticAtomic is not needed here, but it makes
65 // it easier to understand the sequence of events in logs.
66 DeterministicAtomic<int> test{0};
67 DeterministicAtomic<int> baseline{0};
69 std::vector<std::thread> threads(numThreads);
70 for (int t = 0; t < numThreads; ++t) {
71 threads[t] = DeterministicSchedule::thread([&, t] {
72 baseline.fetch_add(1);
73 // Atomic increment of test protected by mutex m
75 // Some threads use lock() others use try_lock()
83 int newval = test.load() + 1;
85 // Break the atomicity of the increment operation
95 for (auto& t : threads) {
96 DeterministicSchedule::join(t);
99 EXPECT_EQ(test.load(), baseline.load());
101 if (test.load() == baseline.load()) {
102 FOLLY_TEST_DSCHED_VLOG("Didn't catch the bug");
104 FOLLY_TEST_DSCHED_VLOG("Caught the bug");
110 int main(int argc, char** argv) {
111 testing::InitGoogleTest(&argc, argv);
112 gflags::ParseCommandLineFlags(&argc, &argv, true);
113 return RUN_ALL_TESTS();