2 * Copyright 2017 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.
16 #include <folly/Random.h>
17 #include <folly/io/async/EventBase.h>
18 #include <folly/io/async/HHWheelTimer.h>
19 #include <folly/io/async/test/UndelayedDestruction.h>
20 #include <folly/io/async/test/Util.h>
21 #include <folly/portability/GTest.h>
26 using namespace folly;
27 using std::chrono::milliseconds;
29 typedef UndelayedDestruction<HHWheelTimer> StackWheelTimer;
31 class TestTimeout : public HHWheelTimer::Callback {
34 TestTimeout(HHWheelTimer* t, milliseconds timeout) {
35 t->scheduleTimeout(this, timeout);
38 void timeoutExpired() noexcept override {
39 timestamps.emplace_back();
45 void callbackCanceled() noexcept override {
46 canceledTimestamps.emplace_back();
52 std::deque<TimePoint> timestamps;
53 std::deque<TimePoint> canceledTimestamps;
54 std::function<void()> fn;
57 class TestTimeoutDelayed : public TestTimeout {
59 std::chrono::steady_clock::time_point getCurTime() override {
60 return std::chrono::steady_clock::now() - milliseconds(5);
64 struct HHWheelTimerTest : public ::testing::Test {
68 /* Test takes ~2.5 minutes to run */
69 TEST_F(HHWheelTimerTest, Level2) {
70 HHWheelTimer& t = eventBase.timer();
75 ASSERT_EQ(t.count(), 0);
77 t.scheduleTimeout(&t1, milliseconds(605 * 256));
78 t.scheduleTimeout(&t2, milliseconds(300 * 256));
80 ASSERT_EQ(t.count(), 2);
86 ASSERT_EQ(t1.timestamps.size(), 1);
87 ASSERT_EQ(t2.timestamps.size(), 1);
88 ASSERT_EQ(t.count(), 0);
90 // Check that the timeout was delayed by sleep
94 milliseconds(605 * 256),
95 milliseconds(256 * 256));
99 milliseconds(300 * 256),
100 milliseconds(256 * 256));
104 * Test the tick interval parameter
106 TEST_F(HHWheelTimerTest, AtMostEveryN) {
107 // Create a timeout set with a 10ms interval, to fire no more than once
109 milliseconds interval(10);
110 milliseconds atMostEveryN(3);
111 StackWheelTimer t(&eventBase, atMostEveryN);
113 // Create 60 timeouts to be added to ts1 at 1ms intervals.
114 uint32_t numTimeouts = 60;
115 std::vector<TestTimeout> timeouts(numTimeouts);
117 // Create a scheduler timeout to add the timeouts 1ms apart.
119 StackWheelTimer ts1(&eventBase, milliseconds(1));
120 TestTimeout scheduler(&ts1, milliseconds(1));
122 if (index >= numTimeouts) {
125 // Call timeoutExpired() on the timeout so it will record a timestamp.
126 // This is done only so we can record when we scheduled the timeout.
127 // This way if ts1 starts to fall behind a little over time we will still
128 // be comparing the ts1 timeouts to when they were first scheduled (rather
129 // than when we intended to schedule them). The scheduler may fall behind
130 // eventually since we don't really schedule it once every millisecond.
131 // Each time it finishes we schedule it for 1 millisecond in the future.
132 // The amount of time it takes to run, and any delays it encounters
133 // getting scheduled may eventually add up over time.
134 timeouts[index].timeoutExpired();
136 // Schedule the new timeout
137 t.scheduleTimeout(&timeouts[index], interval);
138 // Reschedule ourself
139 ts1.scheduleTimeout(&scheduler, milliseconds(1));
147 // This should take roughly 60 + 10 ms to finish. If it takes more than
148 // 250 ms to finish the system is probably heavily loaded, so skip.
149 if (std::chrono::duration_cast<std::chrono::milliseconds>(
150 end.getTime() - start.getTime())
152 LOG(WARNING) << "scheduling all timeouts takes too long";
156 // We scheduled timeouts 1ms apart, when the HHWheelTimer is only allowed
157 // to wake up at most once every 3ms. It will therefore wake up every 3ms
158 // and fire groups of approximately 3 timeouts at a time.
160 // This is "approximately 3" since it may get slightly behind and fire 4 in
161 // one interval, etc. T_CHECK_TIMEOUT normally allows a few milliseconds of
162 // tolerance. We have to add the same into our checking algorithm here.
163 for (uint32_t idx = 0; idx < numTimeouts; ++idx) {
164 ASSERT_EQ(timeouts[idx].timestamps.size(), 2);
166 TimePoint scheduledTime(timeouts[idx].timestamps[0]);
167 TimePoint firedTime(timeouts[idx].timestamps[1]);
169 // Assert that the timeout fired at roughly the right time.
170 // T_CHECK_TIMEOUT() normally has a tolerance of 5ms. Allow an additional
172 milliseconds tolerance = milliseconds(5) + interval;
173 T_CHECK_TIMEOUT(scheduledTime, firedTime, atMostEveryN, tolerance);
175 // Assert that the difference between the previous timeout and now was
176 // either very small (fired in the same event loop), or larger than
182 TimePoint prev(timeouts[idx - 1].timestamps[1]);
184 auto delta = (firedTime.getTimeStart() - prev.getTimeEnd()) -
185 (firedTime.getTimeWaiting() - prev.getTimeWaiting());
186 if (delta > milliseconds(1)) {
187 T_CHECK_TIMEOUT(prev, firedTime, atMostEveryN);
193 * Test an event loop that is blocking
196 TEST_F(HHWheelTimerTest, SlowLoop) {
197 StackWheelTimer t(&eventBase, milliseconds(1));
202 ASSERT_EQ(t.count(), 0);
204 eventBase.runInLoop([]() {
206 std::this_thread::sleep_for(std::chrono::microseconds(10000));
208 t.scheduleTimeout(&t1, milliseconds(5));
210 ASSERT_EQ(t.count(), 1);
216 ASSERT_EQ(t1.timestamps.size(), 1);
217 ASSERT_EQ(t.count(), 0);
219 // Check that the timeout was delayed by sleep
220 T_CHECK_TIMEOUT(start, t1.timestamps[0], milliseconds(10), milliseconds(1));
221 T_CHECK_TIMEOUT(start, end, milliseconds(10), milliseconds(1));
223 eventBase.runInLoop([]() {
225 std::this_thread::sleep_for(std::chrono::microseconds(10000));
227 t.scheduleTimeout(&t2, milliseconds(5));
229 ASSERT_EQ(t.count(), 1);
235 ASSERT_EQ(t2.timestamps.size(), 1);
236 ASSERT_EQ(t.count(), 0);
238 // Check that the timeout was NOT delayed by sleep
239 T_CHECK_TIMEOUT(start2, t2.timestamps[0], milliseconds(10), milliseconds(1));
240 T_CHECK_TIMEOUT(start2, end2, milliseconds(10), milliseconds(1));
244 * Test upper timer levels. Slow by necessity :/
247 TEST_F(HHWheelTimerTest, Level1) {
248 HHWheelTimer& t = eventBase.timer();
253 ASSERT_EQ(t.count(), 0);
255 t.scheduleTimeout(&t1, milliseconds(605));
256 t.scheduleTimeout(&t2, milliseconds(300));
258 ASSERT_EQ(t.count(), 2);
264 ASSERT_EQ(t1.timestamps.size(), 1);
265 ASSERT_EQ(t2.timestamps.size(), 1);
266 ASSERT_EQ(t.count(), 0);
268 // Check that the timeout was delayed by sleep
270 start, t1.timestamps[0], milliseconds(605), milliseconds(256));
272 start, t2.timestamps[0], milliseconds(300), milliseconds(256));
275 TEST_F(HHWheelTimerTest, Stress) {
276 StackWheelTimer t(&eventBase, milliseconds(1));
278 long timeoutcount = 10000;
279 TestTimeout timeouts[10000];
280 long runtimeouts = 0;
281 for (long i = 0; i < timeoutcount; i++) {
282 long timeout = Random::rand32(1, 10000);
283 if (Random::rand32(3)) {
284 // NOTE: hhwheel timer runs before eventbase runAfterDelay,
285 // so runAfterDelay cancelTimeout() must run at least one timerwheel
286 // before scheduleTimeout, to ensure it runs first.
288 t.scheduleTimeout(&timeouts[i], std::chrono::milliseconds(timeout));
289 eventBase.runAfterDelay(
291 timeouts[i].fn = nullptr;
292 timeouts[i].cancelTimeout();
294 LOG(INFO) << "Ran " << runtimeouts << " timeouts, cancelled";
297 timeouts[i].fn = [&, i, timeout]() {
298 LOG(INFO) << "FAIL:timer " << i << " still fired in " << timeout;
302 t.scheduleTimeout(&timeouts[i], std::chrono::milliseconds(timeout));
303 timeouts[i].fn = [&, i]() {
305 long newtimeout = Random::rand32(1, 10000);
306 t.scheduleTimeout(&timeouts[i], std::chrono::milliseconds(newtimeout));
308 /* sleep override */ usleep(1000);
309 LOG(INFO) << "Ran " << runtimeouts << " timeouts of " << timeoutcount;
310 timeouts[i].fn = [&]() {
312 LOG(INFO) << "Ran " << runtimeouts << " timeouts of " << timeoutcount;
318 LOG(INFO) << "RUNNING TEST";
321 EXPECT_EQ(runtimeouts, timeoutcount);