A better idle time estimator

components/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 COMPONENTS_SCHEDULER_RENDERER_RENDERER_SCHEDULER_IMPL_H_
 #define COMPONENTS_SCHEDULER_RENDERER_RENDERER_SCHEDULER_IMPL_H_
 
 #include "base/atomicops.h"
 #include "base/synchronization/lock.h"
 #include "components/scheduler/base/pollable_thread_safe_flag.h"
 #include "components/scheduler/child/idle_helper.h"
 #include "components/scheduler/child/scheduler_helper.h"
 #include "components/scheduler/renderer/deadline_task_runner.h"
+#include "components/scheduler/renderer/idle_time_estimator.h"
 #include "components/scheduler/renderer/renderer_scheduler.h"
 #include "components/scheduler/renderer/task_cost_estimator.h"
 #include "components/scheduler/renderer/user_model.h"
 #include "components/scheduler/scheduler_export.h"
 
 namespace base {
 namespace trace_event {
 class ConvertableToTraceFormat;
 }
 }
@@ skipping 44 matching lines @@
   void ResumeTimerQueue() override;
   void SetTimerQueueSuspensionWhenBackgroundedEnabled(bool enabled) override;
 
   // TaskQueueManager::Observer implementation:
   void OnUnregisterTaskQueue(const scoped_refptr<TaskQueue>& queue) override;
 
   // Test helpers.
   SchedulerHelper* GetSchedulerHelperForTesting();
   TaskCostEstimator* GetLoadingTaskCostEstimatorForTesting();
   TaskCostEstimator* GetTimerTaskCostEstimatorForTesting();
+  IdleTimeEstimator* GetIdleTimeEstimatorForTesting();
   base::TimeTicks CurrentIdleTaskDeadlineForTesting() const;
 
  private:
   friend class RendererSchedulerImplTest;
   friend class RendererSchedulerImplForTest;
 
   struct Policy {
     Policy();
 
     TaskQueue::QueuePriority compositor_queue_priority;
@@ skipping 47 matching lines @@
       const blink::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;
 
+  // The ammount of time in milliseconds we have to respond to user input as

[Sami, 2015/10/09 02:32:19]

typo: amount

[alex clarke (OOO till 29th), 2015/10/15 13:24:01]

Done.

+  // defined by RAILS.
+  static const int kRailsResponseTimeMillis = 50;
+
   // For the purposes of deciding whether or not it's safe to turn timers and
   // loading tasks on only in idle periods, we regard the system as being as
   // being "idle period" starved if there hasn't been an idle period in the last
   // 10 seconds. This was chosen to be long enough to cover most anticipated
   // user gestures.
   static const int kIdlePeriodStarvationThresholdMillis = 10000;
 
   // The amount of time to wait before suspending shared timers after the
   // renderer has been backgrounded. This is used only if background suspension
   // of shared timers is enabled.
@@ skipping 72 matching lines @@
 
   // We have decided to improve thread safety at the cost of some boilerplate
   // (the accessors) for the following data members.
 
   struct MainThreadOnly {
     MainThreadOnly();
     ~MainThreadOnly();
 
     TaskCostEstimator loading_task_cost_estimator;
     TaskCostEstimator timer_task_cost_estimator;
-    cc::RollingTimeDeltaHistory short_idle_period_duration;
+    IdleTimeEstimator idle_time_estimator;
     UseCase current_use_case;
     Policy current_policy;
     base::TimeTicks current_policy_expiration_time;
     base::TimeTicks estimated_next_frame_begin;
-    base::TimeDelta expected_short_idle_period_duration;
+    base::TimeDelta compositor_frame_interval;
+    base::TimeDelta expected_idle_duration;
     int timer_queue_suspend_count;  // TIMER_TASK_QUEUE suspended if non-zero.
     int navigation_task_expected_count;
     bool renderer_hidden;
     bool renderer_backgrounded;
     bool timer_queue_suspension_when_backgrounded_enabled;
     bool timer_queue_suspended_when_backgrounded;
     bool was_shutdown;
     bool loading_tasks_seem_expensive;
     bool timer_tasks_seem_expensive;
     bool touchstart_expected_soon;
@@ skipping 61 matching lines @@
 
   PollableThreadSafeFlag policy_may_need_update_;
   base::WeakPtrFactory<RendererSchedulerImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RendererSchedulerImpl);
 };
 
 }  // namespace scheduler
 
 #endif  // COMPONENTS_SCHEDULER_RENDERER_RENDERER_SCHEDULER_IMPL_H_