1 // Copyright 2018 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_SEQUENCE_MANAGER_TIME_DOMAIN_H_ 6 #define BASE_TASK_SEQUENCE_MANAGER_TIME_DOMAIN_H_ 7 8 #include "base/base_export.h" 9 #include "base/check.h" 10 #include "base/memory/raw_ptr.h" 11 #include "base/task/common/lazy_now.h" 12 #include "base/task/sequence_manager/tasks.h" 13 #include "base/time/tick_clock.h" 14 #include "base/values.h" 15 #include "third_party/abseil-cpp/absl/types/optional.h" 16 17 namespace base { 18 namespace sequence_manager { 19 20 class SequenceManager; 21 22 namespace internal { 23 class SequenceManagerImpl; 24 } // namespace internal 25 26 // TimeDomain allows subclasses to enable clock overriding 27 // (e.g. auto-advancing virtual time, throttled clock, etc). 28 class BASE_EXPORT TimeDomain : public TickClock { 29 public: 30 TimeDomain(const TimeDomain&) = delete; 31 TimeDomain& operator=(const TimeDomain&) = delete; 32 ~TimeDomain() override = default; 33 34 // Invoked when the thread reaches idle. Gives an opportunity to a virtual 35 // time domain impl to fast-forward time and return true to indicate that 36 // there's more work to run. If RunLoop::QuitWhenIdle has been called then 37 // `quit_when_idle_requested` will be true. 38 virtual bool MaybeFastForwardToWakeUp(absl::optional<WakeUp> next_wake_up, 39 bool quit_when_idle_requested) = 0; 40 41 // Debug info. 42 Value::Dict AsValue() const; 43 44 protected: 45 TimeDomain() = default; 46 47 virtual const char* GetName() const = 0; 48 49 // Tells SequenceManager that internal policy might have changed to 50 // re-evaluate MaybeFastForwardToWakeUp(). 51 void NotifyPolicyChanged(); 52 53 // Called when the TimeDomain is assigned to a SequenceManagerImpl. 54 // `sequence_manager` is expected to be valid for the duration of TimeDomain's 55 // existence. TODO(scheduler-dev): Pass SequenceManager in the constructor. 56 void OnAssignedToSequenceManager( 57 internal::SequenceManagerImpl* sequence_manager); 58 59 private: 60 friend class internal::SequenceManagerImpl; 61 62 raw_ptr<internal::SequenceManagerImpl, DanglingUntriaged> sequence_manager_ = 63 nullptr; 64 }; 65 66 } // namespace sequence_manager 67 } // namespace base 68 69 #endif // BASE_TASK_SEQUENCE_MANAGER_TIME_DOMAIN_H_ 70