Fix #7130: Contention scheduling actions in HashedWheelTimerScheduler #7144
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Arkatufus
commented
Apr 9, 2024
Comment on lines
168
to
172
| if (start) | ||
| { | ||
| throw new SchedulerException("cannot enqueue after timer shutdown"); | ||
| var timerDuration = TimeSpan.FromTicks(_tickDuration); | ||
| _timer ??= new PeriodicTimer(timerDuration); | ||
| Task.Run(() => RunAsync(_cts.Token)); // start the clock |
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Do not wait on _workerInitialized if we're the method call that started the timer, because a Wait() can deadlock the scheduler
| private PeriodicTimer? _timer; | ||
| private readonly CancellationTokenSource _cts = new(); | ||
|
|
||
| private void Start() | ||
| { | ||
| if (_workerState == WORKER_STATE_STARTED) | ||
| var start = false; | ||
| lock (_lock) |
Aaronontheweb
approved these changes
Apr 11, 2024
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Fixes #7130
Changes
Notes
Contention (deadlock) happened when
HashedWheelTimerScheduler.Start()was called, causing extraneous timer start time or complete deadlock. Note that number is total milliseconds elapsed for eachTimers.StartSingleTimer()call.