[scheduler] Implement time-based cpu throttling.

third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl.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 THIRD_PARTY_WEBKIT_SOURCE_PLATFORM_SCHEDULER_RENDERER_RENDERER_SCHEDULER_IMPL_H_
 #define THIRD_PARTY_WEBKIT_SOURCE_PLATFORM_SCHEDULER_RENDERER_RENDERER_SCHEDULER_IMPL_H_
 
 #include "base/atomicops.h"
 #include "base/macros.h"
 #include "base/synchronization/lock.h"
 #include "platform/scheduler/base/pollable_thread_safe_flag.h"
 #include "platform/scheduler/base/queueing_time_estimator.h"
 #include "platform/scheduler/base/thread_load_tracker.h"
 #include "platform/scheduler/child/idle_helper.h"
 #include "platform/scheduler/child/scheduler_helper.h"
 #include "platform/scheduler/renderer/deadline_task_runner.h"
 #include "platform/scheduler/renderer/idle_time_estimator.h"
 #include "platform/scheduler/renderer/render_widget_signals.h"
 #include "platform/scheduler/renderer/task_cost_estimator.h"
-#include "platform/scheduler/renderer/throttling_helper.h"
+#include "platform/scheduler/renderer/task_queue_throttler.h"
 #include "platform/scheduler/renderer/user_model.h"
 #include "platform/scheduler/renderer/web_view_scheduler_impl.h"
 #include "public/platform/scheduler/renderer/renderer_scheduler.h"
 #include "public/platform/scheduler/base/task_time_observer.h"
 
 namespace base {
 namespace trace_event {
 class ConvertableToTraceFormat;
 }
 }
 
 namespace blink {
 namespace scheduler {
 class AutoAdvancingVirtualTimeDomain;
 class RenderWidgetSchedulingState;
 class WebViewSchedulerImpl;
-class ThrottlingHelper;
+class TaskQueueThrottler;
 
 class BLINK_PLATFORM_EXPORT RendererSchedulerImpl
     : public RendererScheduler,
       public IdleHelper::Delegate,
       public SchedulerHelper::Observer,
       public RenderWidgetSignals::Observer,
       public TaskTimeObserver,
       public QueueingTimeEstimator::Client {
  public:
   // Keep RendererScheduler::UseCaseToString in sync with this enum.
@@ skipping 76 matching lines @@
   void SetAllRenderWidgetsHidden(bool hidden) override;
   void SetHasVisibleRenderWidgetWithTouchHandler(
       bool has_visible_render_widget_with_touch_handler) override;
 
   // SchedulerHelper::Observer implementation:
   void OnUnregisterTaskQueue(const scoped_refptr<TaskQueue>& queue) override;
   void OnTriedToExecuteBlockedTask(const TaskQueue& queue,
                                    const base::PendingTask& task) override;
 
   // TaskTimeObserver implementation:
-  void ReportTaskTime(double start_time, double end_time) override;
+  void ReportTaskTime(TaskQueue* task_queue,
+                      double start_time,
+                      double end_time) override;
 
   // QueueingTimeEstimator::Client implementation:
   void OnQueueingTimeForWindowEstimated(base::TimeDelta queueing_time) override;
 
   // Returns a task runner where tasks run at the highest possible priority.
   scoped_refptr<TaskQueue> ControlTaskRunner();
 
   void RegisterTimeDomain(TimeDomain* time_domain);
   void UnregisterTimeDomain(TimeDomain* time_domain);
 
   // Tells the scheduler that all TaskQueues should use virtual time.
   void EnableVirtualTime();
 
   void AddWebViewScheduler(WebViewSchedulerImpl* web_view_scheduler);
   void RemoveWebViewScheduler(WebViewSchedulerImpl* web_view_scheduler);
 
   void AddTaskTimeObserver(TaskTimeObserver* task_time_observer);
   void RemoveTaskTimeObserver(TaskTimeObserver* task_time_observer);
 
+  void CreateTraceEventObjectSnapshot() const;

[alex clarke (OOO till 29th), 2016/09/12 17:45:26]

Please add a comment explaining what this does.

[altimin, 2016/09/14 11:23:15]

Done.

+
   // Test helpers.
   SchedulerHelper* GetSchedulerHelperForTesting();
   TaskCostEstimator* GetLoadingTaskCostEstimatorForTesting();
   TaskCostEstimator* GetTimerTaskCostEstimatorForTesting();
   IdleTimeEstimator* GetIdleTimeEstimatorForTesting();
   base::TimeTicks CurrentIdleTaskDeadlineForTesting() const;
   void RunIdleTasksForTesting(const base::Closure& callback);
   void EndIdlePeriodForTesting(const base::Closure& callback,
                                base::TimeTicks time_remaining);
   bool PolicyNeedsUpdateForTesting();
 
   base::TickClock* tick_clock() const;
 
   RealTimeDomain* real_time_domain() const {
     return helper_.real_time_domain();
   }
 
   AutoAdvancingVirtualTimeDomain* GetVirtualTimeDomain();
 
-  ThrottlingHelper* throttling_helper() { return throttling_helper_.get(); }
+  TaskQueueThrottler* task_queue_throttler() {
+    return task_queue_throttler_.get();
+  }
 
  private:
   friend class RendererSchedulerImplTest;
   friend class RendererSchedulerImplForTest;
   friend class RenderWidgetSchedulingState;
 
   enum class ExpensiveTaskPolicy { RUN, BLOCK, THROTTLE };
 
   enum class TimeDomainType {
     REAL,
@@ skipping 59 matching lines @@
   void OnIdlePeriodStarted() override;
   void OnIdlePeriodEnded() override;
 
   void EndIdlePeriod();
 
   // Returns the serialized scheduler state for tracing.
   std::unique_ptr<base::trace_event::ConvertableToTraceFormat> AsValue(
       base::TimeTicks optional_now) const;
   std::unique_ptr<base::trace_event::ConvertableToTraceFormat> AsValueLocked(
       base::TimeTicks optional_now) const;
+  void CreateTraceEventObjectSnapshotLocked() const;
 
   static bool ShouldPrioritizeInputEvent(const WebInputEvent& web_input_event);
 
   // The amount of time which idle periods can continue being scheduled when the
   // renderer has been hidden, before going to sleep for good.
   static const int kEndIdleWhenHiddenDelayMillis = 10000;
 
   // The amount of time for which loading tasks will be prioritized over
   // other tasks during the initial page load.
   static const int kRailsInitialLoadingPrioritizationMillis = 1000;
@@ skipping 68 matching lines @@
 
   void ApplyTaskQueuePolicy(TaskQueue* task_queue,
                             const TaskQueuePolicy& old_task_queue_policy,
                             const TaskQueuePolicy& new_task_queue_policy) const;
 
   static const char* ExpensiveTaskPolicyToString(
       ExpensiveTaskPolicy expensive_task_policy);
 
   SchedulerHelper helper_;
   IdleHelper idle_helper_;
-  std::unique_ptr<ThrottlingHelper> throttling_helper_;
+  std::unique_ptr<TaskQueueThrottler> task_queue_throttler_;
   RenderWidgetSignals render_widget_scheduler_signals_;
 
   const scoped_refptr<TaskQueue> control_task_runner_;
   const scoped_refptr<TaskQueue> compositor_task_runner_;
   std::set<scoped_refptr<TaskQueue>> loading_task_runners_;
   std::set<scoped_refptr<TaskQueue>> timer_task_runners_;
   std::set<scoped_refptr<TaskQueue>> unthrottled_task_runners_;
   scoped_refptr<TaskQueue> default_loading_task_runner_;
   scoped_refptr<TaskQueue> default_timer_task_runner_;
 
@@ skipping 117 matching lines @@
   PollableThreadSafeFlag policy_may_need_update_;
   base::WeakPtrFactory<RendererSchedulerImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RendererSchedulerImpl);
 };
 
 }  // namespace scheduler
 }  // namespace blink
 
 #endif  // THIRD_PARTY_WEBKIT_SOURCE_PLATFORM_SCHEDULER_RENDERER_RENDERER_SCHEDULER_IMPL_H_