Let a RepeatingTask stop itself by returning a delay of PlusInfinity.
Bug: none
Change-Id: I5bf87e236019d156ffe85c5b91ce09f5f4042937
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/247160
Reviewed-by: Evan Shrubsole <eshr@webrtc.org>
Reviewed-by: Tomas Gunnarsson <tommi@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#35710}
diff --git a/rtc_base/task_utils/repeating_task.cc b/rtc_base/task_utils/repeating_task.cc
index 1f3eb1d..b9bfdd8 100644
--- a/rtc_base/task_utils/repeating_task.cc
+++ b/rtc_base/task_utils/repeating_task.cc
@@ -38,13 +38,14 @@
return true;
TimeDelta delay = RunClosure();
+ RTC_DCHECK_GE(delay, TimeDelta::Zero());
- // The closure might have stopped this task, in which case we return true to
- // destruct this object.
- if (!alive_flag_->alive())
+ // A delay of +infinity means that the task should not be run again.
+ // Alternatively, the closure might have stopped this task. In either which
+ // case we return true to destruct this object.
+ if (delay.IsPlusInfinity() || !alive_flag_->alive())
return true;
- RTC_DCHECK(delay.IsFinite());
TimeDelta lost_time = clock_->CurrentTime() - next_run_time_;
next_run_time_ += delay;
delay -= lost_time;
diff --git a/rtc_base/task_utils/repeating_task.h b/rtc_base/task_utils/repeating_task.h
index 91a40e0..4c9983c 100644
--- a/rtc_base/task_utils/repeating_task.h
+++ b/rtc_base/task_utils/repeating_task.h
@@ -52,7 +52,10 @@
RTC_GUARDED_BY(task_queue_);
};
-// The template closure pattern is based on rtc::ClosureTask.
+// The template closure pattern is based on rtc::ClosureTask. The provided
+// closure should have a TimeDelta return value, specifing the desired
+// non-negative interval to next repetition, or TimeDelta::PlusInfinity to
+// indicate that the task should be deleted and not called again.
template <class Closure>
class RepeatingTaskImpl final : public RepeatingTaskBase {
public:
diff --git a/rtc_base/task_utils/repeating_task_unittest.cc b/rtc_base/task_utils/repeating_task_unittest.cc
index ac0520a..1d26ee6 100644
--- a/rtc_base/task_utils/repeating_task_unittest.cc
+++ b/rtc_base/task_utils/repeating_task_unittest.cc
@@ -239,34 +239,43 @@
EXPECT_EQ(counter.load(), 1);
}
+TEST(RepeatingTaskTest, TaskCanStopItselfByReturningInfinity) {
+ std::atomic_int counter(0);
+ SimulatedClock clock(Timestamp::Zero());
+ FakeTaskQueue task_queue(&clock);
+ RepeatingTaskHandle handle = RepeatingTaskHandle::Start(&task_queue, [&] {
+ ++counter;
+ return TimeDelta::PlusInfinity();
+ });
+ EXPECT_EQ(task_queue.last_delay(), 0u);
+ // Task cancelled itself so wants to be released.
+ EXPECT_TRUE(task_queue.AdvanceTimeAndRunLastTask());
+ EXPECT_EQ(counter.load(), 1);
+}
+
TEST(RepeatingTaskTest, ZeroReturnValueRepostsTheTask) {
NiceMock<MockClosure> closure;
rtc::Event done;
- RepeatingTaskHandle handle;
EXPECT_CALL(closure, Call())
.WillOnce(Return(TimeDelta::Zero()))
.WillOnce(Invoke([&] {
done.Set();
- handle.Stop();
- return kTimeout;
+ return TimeDelta::PlusInfinity();
}));
TaskQueueForTest task_queue("queue");
- handle =
- RepeatingTaskHandle::Start(task_queue.Get(), MoveOnlyClosure(&closure));
+ RepeatingTaskHandle::Start(task_queue.Get(), MoveOnlyClosure(&closure));
EXPECT_TRUE(done.Wait(kTimeout.ms()));
}
TEST(RepeatingTaskTest, StartPeriodicTask) {
MockFunction<TimeDelta()> closure;
rtc::Event done;
- RepeatingTaskHandle handle;
EXPECT_CALL(closure, Call())
.WillOnce(Return(TimeDelta::Millis(20)))
.WillOnce(Return(TimeDelta::Millis(20)))
.WillOnce(Invoke([&] {
done.Set();
- handle.Stop();
- return kTimeout;
+ return TimeDelta::PlusInfinity();
}));
TaskQueueForTest task_queue("queue");
RepeatingTaskHandle::Start(task_queue.Get(), closure.AsStdFunction());