Experimental: Remove chromium shared timers

content/renderer/scheduler/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_TASK_QUEUE_MANAGER_H_
 #define CONTENT_RENDERER_SCHEDULER_TASK_QUEUE_MANAGER_H_
 
 #include "base/atomic_sequence_num.h"
 #include "base/debug/task_annotator.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/message_loop/message_loop.h"
 #include "base/pending_task.h"
 #include "base/single_thread_task_runner.h"
 #include "base/synchronization/lock.h"
 #include "base/threading/thread_checker.h"
 #include "content/common/content_export.h"
+#include "content/renderer/scheduler/task_queue_selector.h"
 
 namespace base {
 namespace trace_event {
 class ConvertableToTraceFormat;
 class TracedValue;
 }
 }
 
 namespace cc {
 class TestNowSource;
@@ skipping 10 matching lines @@
 // 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 CONTENT_EXPORT TaskQueueManager {
+class CONTENT_EXPORT TaskQueueManager
+    : public TaskQueueSelector::TaskQueueSelectorObserver {
  public:
   // Keep TaskQueue::PumpPolicyToString in sync with this enum.
   enum class PumpPolicy {
     // Tasks posted to an incoming queue with an AUTO pump policy will be
     // automatically scheduled for execution or transferred to the work queue
     // automatically.
     AUTO,
     // Tasks posted to an incoming queue with an AFTER_WAKEUP pump policy
     // will be scheduled for execution or transferred to the work queue
     // automatically but only after another queue has executed a task.
     AFTER_WAKEUP,
     // Tasks posted to an incoming queue with a MANUAL will not be
     // automatically scheduled for execution or transferred to the work queue.
     // Instead, the selector should call PumpQueue() when necessary to bring
     // in new tasks for execution.
     MANUAL
   };
 
   // Create a task queue manager with |task_queue_count| task queues.
   // |main_task_runner| identifies the thread on which where the tasks are
   // eventually run. |selector| is used to choose which task queue to service.
   // It should outlive this class.
   TaskQueueManager(size_t task_queue_count,
                    scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
                    TaskQueueSelector* selector);
-  ~TaskQueueManager();
+  ~TaskQueueManager() override;
 
   // Returns the task runner which targets the queue selected by |queue_index|.
   scoped_refptr<base::SingleThreadTaskRunner> TaskRunnerForQueue(
       size_t queue_index) const;
 
   // Sets the pump policy for the |queue_index| to |pump_policy|. By
   // default queues are created with AUTO_PUMP_POLICY.
   void SetPumpPolicy(size_t queue_index, PumpPolicy pump_policy);
 
   // Reloads new tasks from the incoming queue for |queue_index| into the work
@@ skipping 21 matching lines @@
   // 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);
 
   void SetTimeSourceForTesting(scoped_refptr<cc::TestNowSource> time_source);
 
+  // TaskQueueSelectorObserver implementation
+  void OnTaskQueueEnabled() override;
+
  private:
   friend class internal::TaskQueue;
 
   // Called by the task queue to register a new pending task and allocate a
   // sequence number for it.
   void DidQueueTask(base::PendingTask* pending_task);
 
   // Post a task to call DoWork() on the main task runner.  Only one pending
   // DoWork is allowed from the main thread, to prevent an explosion of pending
   // DoWorks.
   void MaybePostDoWorkOnMainRunner();
 
   // Use the selector to choose a pending task and run it.
   void DoWork(bool posted_from_main_thread);
 
+  // Delayed Tasks with run_times <= |now| are enqueued onto their work queues.
   // Reloads any empty work queues which have automatic pumping enabled and
   // which are eligible to be auto pumped based on the |previous_task| which was
   // run. Call with an empty |previous_task| if no task was just run. Returns
   // true if any work queue has tasks after doing this.
   // |next_pending_delayed_task| should be the time of the next known delayed
   // task. It is updated if any task is found which should run earlier.
-  bool UpdateWorkQueues(base::TimeTicks* next_pending_delayed_task,
+  bool UpdateWorkQueues(base::TimeTicks now,
                         const base::PendingTask* previous_task);
 
   // Chooses the next work queue to service. Returns true if |out_queue_index|
   // indicates the queue from which the next task should be run, false to
   // avoid running any tasks.
   bool SelectWorkQueueToService(size_t* out_queue_index);
 
   // Runs a single nestable task from the work queue designated by
   // |queue_index|. If |has_previous_task| is true, |previous_task| should
   // contain the previous task in this work batch. Non-nestable task are
@@ skipping 37 matching lines @@
   ObserverList<base::MessageLoop::TaskObserver> task_observers_;
 
   base::WeakPtrFactory<TaskQueueManager> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(TaskQueueManager);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_SCHEDULER_TASK_QUEUE_MANAGER_H_