(reland) Adds TimeDomains to the TaskQueueManager

components/scheduler/base/task_queue_manager.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_RENDERER_SCHEDULER_BASE_TASK_QUEUE_MANAGER_H_
 #define CONTENT_RENDERER_SCHEDULER_BASE_TASK_QUEUE_MANAGER_H_
 
 #include <map>
 
 #include "base/atomic_sequence_num.h"
@@ skipping 12 matching lines @@
 class TickClock;
 
 namespace trace_event {
 class ConvertableToTraceFormat;
 class TracedValue;
 }  // namespace trace_event
 }  // namespace base
 
 namespace scheduler {
 namespace internal {
-class LazyNow;
 class TaskQueueImpl;
 }  // namespace internal
 
+class LazyNow;
+class RealTimeDomain;
+class TimeDomain;
 class TaskQueueManagerDelegate;
 
 // The task queue manager provides N task queues and a selector interface for
 // choosing which task queue to service next. Each task queue consists of two
 // sub queues:
 //
 // 1. Incoming task queue. Tasks that are posted get immediately appended here.
 //    When a task is appended into an empty incoming queue, the task manager
 //    work function (DoWork) is scheduled to run on the main task runner.
 //
 // 2. Work queue. If a work queue is empty when DoWork() is entered, tasks from
 //    the incoming task queue (if any) are moved here. The work queues are
 //    registered with the selector as input to the scheduling decision.
 //
 class SCHEDULER_EXPORT TaskQueueManager
     : public internal::TaskQueueSelector::Observer {
  public:
   // Create a task queue manager where |delegate| identifies the thread
   // on which where the tasks are  eventually run. Category strings must have
   // application lifetime (statics or literals). They may not include " chars.
   TaskQueueManager(scoped_refptr<TaskQueueManagerDelegate> delegate,
                    const char* tracing_category,
                    const char* disabled_by_default_tracing_category,
                    const char* disabled_by_default_verbose_tracing_category);
   ~TaskQueueManager() override;
 
-  // Returns the time of the next pending delayed task in any queue.  Ignores
-  // any delayed tasks whose delay has expired. Returns a null TimeTicks object
-  // if no tasks are pending.  NOTE this is somewhat expensive since every queue
-  // will get locked.
-  base::TimeTicks NextPendingDelayedTaskRunTime();
-
   // Set the number of tasks executed in a single invocation of the task queue
   // manager. Increasing the batch size can reduce the overhead of yielding
   // back to the main message loop -- at the cost of potentially delaying other
   // tasks posted to the main loop. The batch size is 1 by default.
   void SetWorkBatchSize(int work_batch_size);
 
   // These functions can only be called on the same thread that the task queue
   // manager executes its tasks on.
   void AddTaskObserver(base::MessageLoop::TaskObserver* task_observer);
   void RemoveTaskObserver(base::MessageLoop::TaskObserver* task_observer);
@@ skipping 17 matching lines @@
   };
 
   // Called once to set the Observer. This function is called on the main
   // thread. If |observer| is null, then no callbacks will occur.
   // Note |observer| is expected to outlive the SchedulerHelper.
   void SetObserver(Observer* observer);
 
   // Returns the delegate used by the TaskQueueManager.
   const scoped_refptr<TaskQueueManagerDelegate>& delegate() const;
 
+  // Time domains must be registered for the task queues to get updated.
+  void RegisterTimeDomain(const scoped_refptr<TimeDomain>& time_domain);
+  void UnregisterTimeDomain(const scoped_refptr<TimeDomain>& time_domain);
+
+  const scoped_refptr<RealTimeDomain>& real_time_domain() const {
+    return real_time_domain_;
+  }
+
  private:
-  friend class internal::LazyNow;
+  friend class LazyNow;
   friend class internal::TaskQueueImpl;
   friend class TaskQueueManagerTest;
 
   class DeletionSentinel : public base::RefCounted<DeletionSentinel> {
    private:
     friend class base::RefCounted<DeletionSentinel>;
     ~DeletionSentinel() {}
   };
 
   // Unregisters a TaskQueue previously created by |NewTaskQueue()|.
@@ skipping 41 matching lines @@
       internal::TaskQueueImpl* queue,
       internal::TaskQueueImpl::Task* out_previous_task);
 
   bool RunsTasksOnCurrentThread() const;
   bool PostNonNestableDelayedTask(const tracked_objects::Location& from_here,
                                   const base::Closure& task,
                                   base::TimeDelta delay);
 
   int GetNextSequenceNumber();
 
+  bool TryAdvanceTimeDomains();
+
   scoped_refptr<base::trace_event::ConvertableToTraceFormat>
   AsValueWithSelectorResult(bool should_run,
                             internal::TaskQueueImpl* selected_queue) const;
 
-  // Causes DoWork to start calling UpdateWorkQueue for |queue|. Can be called
-  // from any thread.
-  void RegisterAsUpdatableTaskQueue(internal::TaskQueueImpl* queue);
-
-  // Prevents DoWork from calling UpdateWorkQueue for |queue|. Must be called
-  // from the thread the TaskQueueManager was created on.
-  void UnregisterAsUpdatableTaskQueue(internal::TaskQueueImpl* queue);
-
-  // Schedule a call to DoWork at |delayed_run_time| which indirectly calls
-  // TaskQueueImpl::MoveReadyDelayedTasksToIncomingQueue for |queue|.
-  // Can be called from any thread.
-  void ScheduleDelayedWork(internal::TaskQueueImpl* queue,
-                           base::TimeTicks delayed_run_time,
-                           internal::LazyNow* lazy_now);
-
-  // Function calling ScheduleDelayedWork that's suitable for use in base::Bind.
-  void ScheduleDelayedWorkTask(scoped_refptr<internal::TaskQueueImpl> queue,
-                               base::TimeTicks delayed_run_time);
-
-  // Call TaskQueueImpl::MoveReadyDelayedTasksToIncomingQueue for each
-  // registered queue for which the delay has elapsed.
-  void WakeupReadyDelayedQueues(internal::LazyNow* lazy_now);
-
-  void MoveNewlyUpdatableQueuesIntoUpdatableQueueSet();
+  std::set<scoped_refptr<TimeDomain>> time_domains_;
+  scoped_refptr<RealTimeDomain> real_time_domain_;
 
   std::set<scoped_refptr<internal::TaskQueueImpl>> queues_;
 
   // We have to be careful when deleting a queue because some of the code uses
   // raw pointers and doesn't expect the rug to be pulled out from underneath.
   std::set<scoped_refptr<internal::TaskQueueImpl>> queues_to_delete_;
 
-  // This lock guards only |newly_updatable_|.  It's not expected to be heavily
-  // contended.
-  base::Lock newly_updatable_lock_;
-  std::vector<internal::TaskQueueImpl*> newly_updatable_;
-
-  // Set of task queues with avaliable work on the incoming queue.  This should
-  // only be accessed from the main thread.
-  std::set<internal::TaskQueueImpl*> updatable_queue_set_;
-
-  typedef std::multimap<base::TimeTicks, internal::TaskQueueImpl*>
-      DelayedWakeupMultimap;
-
-  DelayedWakeupMultimap delayed_wakeup_multimap_;
 
   base::AtomicSequenceNumber task_sequence_num_;
   base::debug::TaskAnnotator task_annotator_;
 
   base::ThreadChecker main_thread_checker_;
   scoped_refptr<TaskQueueManagerDelegate> delegate_;
   internal::TaskQueueSelector selector_;
 
   base::Closure decrement_pending_and_do_work_closure_;
   base::Closure do_work_closure_;
 
   bool task_was_run_on_quiescence_monitored_queue_;
 
   // The pending_dowork_count_ is only tracked on the main thread since that's
   // where re-entrant problems happen.
   int pending_dowork_count_;
 
   int work_batch_size_;
 
   base::ObserverList<base::MessageLoop::TaskObserver> task_observers_;
 
   const char* tracing_category_;
   const char* disabled_by_default_tracing_category_;
   const char* disabled_by_default_verbose_tracing_category_;
 
   Observer* observer_;  // NOT OWNED
   scoped_refptr<DeletionSentinel> deletion_sentinel_;
+  scoped_refptr<TimeDomain> time_domain_;
   base::WeakPtrFactory<TaskQueueManager> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(TaskQueueManager);
 };
 
 }  // namespace scheduler
 
 #endif  // CONTENT_RENDERER_SCHEDULER_BASE_TASK_QUEUE_MANAGER_H_