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 <optional> 9 10 #include "base/base_export.h" 11 #include "base/check.h" 12 #include "base/memory/raw_ptr.h" 13 #include "base/task/common/lazy_now.h" 14 #include "base/task/sequence_manager/tasks.h" 15 #include "base/time/tick_clock.h" 16 #include "base/values.h" 17 18 namespace base { 19 namespace sequence_manager { 20 21 class SequenceManager; 22 23 namespace internal { 24 class SequenceManagerImpl; 25 } // namespace internal 26 27 // TimeDomain allows subclasses to enable clock overriding 28 // (e.g. auto-advancing virtual time, throttled clock, etc). 29 class BASE_EXPORT TimeDomain : public TickClock { 30 public: 31 TimeDomain(const TimeDomain&) = delete; 32 TimeDomain& operator=(const TimeDomain&) = delete; 33 ~TimeDomain() override = default; 34 35 // Invoked when the thread reaches idle. Gives an opportunity to a virtual 36 // time domain impl to fast-forward time and return true to indicate that 37 // there's more work to run. If RunLoop::QuitWhenIdle has been called then 38 // `quit_when_idle_requested` will be true. 39 virtual bool MaybeFastForwardToWakeUp(std::optional<WakeUp> next_wake_up, 40 bool quit_when_idle_requested) = 0; 41 42 // Debug info. 43 Value::Dict AsValue() const; 44 45 protected: 46 TimeDomain() = default; 47 48 virtual const char* GetName() const = 0; 49 50 // Tells SequenceManager that internal policy might have changed to 51 // re-evaluate MaybeFastForwardToWakeUp(). 52 void NotifyPolicyChanged(); 53 54 // Called when the TimeDomain is assigned to a SequenceManagerImpl. 55 // `sequence_manager` is expected to be valid for the duration of TimeDomain's 56 // existence. TODO(scheduler-dev): Pass SequenceManager in the constructor. 57 void OnAssignedToSequenceManager( 58 internal::SequenceManagerImpl* sequence_manager); 59 60 private: 61 friend class internal::SequenceManagerImpl; 62 63 raw_ptr<internal::SequenceManagerImpl, DanglingUntriaged> sequence_manager_ = 64 nullptr; 65 }; 66 67 } // namespace sequence_manager 68 } // namespace base 69 70 #endif // BASE_TASK_SEQUENCE_MANAGER_TIME_DOMAIN_H_ 71