1 // Copyright 2023 The Chromium Authors 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef BASE_TASK_THREAD_POOL_WORKER_THREAD_WAITABLE_EVENT_H_ 6 #define BASE_TASK_THREAD_POOL_WORKER_THREAD_WAITABLE_EVENT_H_ 7 8 #include "base/task/thread_pool/worker_thread.h" 9 10 #include <memory> 11 12 #include "base/base_export.h" 13 #include "base/synchronization/waitable_event.h" 14 #include "base/task/common/checked_lock.h" 15 #include "base/task/thread_pool/tracked_ref.h" 16 17 namespace base { 18 19 namespace internal { 20 21 class BASE_EXPORT WorkerThreadWaitableEvent : public WorkerThread { 22 public: 23 class BASE_EXPORT Delegate : public WorkerThread::Delegate { 24 protected: 25 friend WorkerThreadWaitableEvent; 26 bool TimedWait(TimeDelta timeout) override; 27 // Event to wake up the thread managed by the WorkerThread whose delegate 28 // this is. 29 WaitableEvent wake_up_event_{WaitableEvent::ResetPolicy::AUTOMATIC, 30 WaitableEvent::InitialState::NOT_SIGNALED}; 31 }; 32 33 // Everything is passed to WorkerThread's constructor, except the Delegate. 34 WorkerThreadWaitableEvent(ThreadType thread_type_hint, 35 std::unique_ptr<Delegate> delegate, 36 TrackedRef<TaskTracker> task_tracker, 37 size_t sequence_num, 38 const CheckedLock* predecessor_lock = nullptr); 39 40 WorkerThreadWaitableEvent(const WorkerThread&) = delete; 41 WorkerThreadWaitableEvent& operator=(const WorkerThread&) = delete; 42 43 // Wakes up this WorkerThreadWaitableEvent if it wasn't already awake. After 44 // this is called, this WorkerThreadWaitableEvent will run Tasks from 45 // TaskSources returned by the GetWork() method of its delegate until it 46 // returns nullptr. No-op if Start() wasn't called. DCHECKs if called after 47 // Start() has failed or after Cleanup() has been called. 48 void WakeUp(); 49 50 // WorkerThread: 51 void JoinForTesting() override; 52 void Cleanup() override; 53 Delegate* delegate() override; 54 55 private: 56 const std::unique_ptr<Delegate> delegate_; 57 58 ~WorkerThreadWaitableEvent() override; 59 }; 60 61 } // namespace internal 62 } // namespace base 63 64 #endif // BASE_TASK_THREAD_POOL_WORKER_THREAD_WAITABLE_EVENT_H_ 65