[scheduler] Move TimeBudgetPool to a separate file.

third_party/WebKit/Source/platform/scheduler/renderer/task_queue_throttler.h

 // Copyright 2015 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_THROTTLING_HELPER_H_
-#define THIRD_PARTY_WEBKIT_SOURCE_PLATFORM_SCHEDULER_RENDERER_THROTTLING_HELPER_H_
+#ifndef THIRD_PARTY_WEBKIT_SOURCE_PLATFORM_SCHEDULER_RENDERER_TASK_QUEUE_THROTTLER_H_
+#define THIRD_PARTY_WEBKIT_SOURCE_PLATFORM_SCHEDULER_RENDERER_TASK_QUEUE_THROTTLER_H_
 
 #include <set>
 #include <unordered_map>
 
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/optional.h"
 #include "base/threading/thread_checker.h"
 #include "platform/scheduler/base/cancelable_closure_holder.h"
 #include "platform/scheduler/base/time_domain.h"
 #include "public/platform/WebViewScheduler.h"
 
+namespace base {
+namespace trace_event {
+class TracedValue;
+}
+}
+
 namespace blink {
 namespace scheduler {
 
+class BudgetPool;
 class RendererSchedulerImpl;
 class ThrottledTimeDomain;
+class TimeBudgetPool;
 
 // The job of the TaskQueueThrottler is to control when tasks posted on
 // throttled queues get run. The TaskQueueThrottler:
 // - runs throttled tasks once per second,
 // - controls time budget for task queues grouped in TimeBudgetPools.
 //
 // This is done by disabling throttled queues and running
 // a special "heart beat" function |PumpThrottledTasks| which when run
 // temporarily enables throttled queues and inserts a fence to ensure tasks
 // posted from a throttled task run next time the queue is pumped.
 //
 // Of course the TaskQueueThrottler isn't the only sub-system that wants to
 // enable or disable queues. E.g. RendererSchedulerImpl also does this for
 // policy reasons. To prevent the systems from fighting, clients of
 // TaskQueueThrottler must use SetQueueEnabled rather than calling the function
 // directly on the queue.
 //
 // There may be more than one system that wishes to throttle a queue (e.g.
 // renderer suspension vs tab level suspension) so the TaskQueueThrottler keeps
 // a count of the number of systems that wish a queue to be throttled.
 // See IncreaseThrottleRefCount & DecreaseThrottleRefCount.
 //
 // This class is main-thread only.
 class BLINK_PLATFORM_EXPORT TaskQueueThrottler : public TimeDomain::Observer {
  public:
-  // TimeBudgetPool represents a group of task queues which share a limit
-  // on execution time. This limit applies when task queues are already
-  // throttled by TaskQueueThrottler.
-  class BLINK_PLATFORM_EXPORT TimeBudgetPool {
-   public:
-    ~TimeBudgetPool();
-
-    // Throttle task queues from this time budget pool if tasks are running
-    // for more than |cpu_percentage| per cent of wall time.
-    // This function does not affect internal time budget level.
-    void SetTimeBudgetRecoveryRate(base::TimeTicks now, double cpu_percentage);
-
-    // Adds |queue| to given pool. If the pool restriction does not allow
-    // a task to be run immediately and |queue| is throttled, |queue| becomes
-    // disabled.
-    void AddQueue(base::TimeTicks now, TaskQueue* queue);
-
-    // Removes |queue| from given pool. If it is throttled, it does not
-    // become enabled immediately, but a call to |PumpThrottledTasks|
-    // is scheduled.
-    void RemoveQueue(base::TimeTicks now, TaskQueue* queue);
-
-    void RecordTaskRunTime(base::TimeTicks start_time,
-                           base::TimeTicks end_time);
-
-    // Enables this time budget pool. Queues from this pool will be
-    // throttled based on their run time.
-    void EnableThrottling(LazyNow* now);
-
-    // Disables with time budget pool. Queues from this pool will not be
-    // throttled based on their run time. A call to |PumpThrottledTasks|
-    // will be scheduled to enable this queues back again and respect
-    // timer alignment. Internal budget level will not regenerate with time.
-    void DisableThrottling(LazyNow* now);
-
-    bool IsThrottlingEnabled() const;
-
-    // Increase budget level by given value. This function DOES NOT unblock
-    // queues even if they are allowed to run with increased budget level.
-    void GrantAdditionalBudget(base::TimeTicks now,
-                               base::TimeDelta budget_level);
-
-    const char* Name() const;
-
-    // Set callback which will be called every time when this budget pool
-    // is throttled. Throttling duration (time until the queue is allowed
-    // to run again) is passed as a parameter to callback.
-    void SetReportingCallback(
-        base::Callback<void(base::TimeDelta)> reporting_callback);
-
-    // All queues should be removed before calling Close().
-    void Close();
-
-   private:
-    friend class TaskQueueThrottler;
-
-    FRIEND_TEST_ALL_PREFIXES(TaskQueueThrottlerTest, TimeBudgetPool);
-
-    TimeBudgetPool(const char* name,
-                   TaskQueueThrottler* task_queue_throttler,
-                   base::TimeTicks now,
-                   base::Optional<base::TimeDelta> max_budget_level,
-                   base::Optional<base::TimeDelta> max_throttling_duration);
-
-    bool HasEnoughBudgetToRun(base::TimeTicks now);
-    base::TimeTicks GetNextAllowedRunTime();
-
-    // Advances |last_checkpoint_| to |now| if needed and recalculates
-    // budget level.
-    void Advance(base::TimeTicks now);
-
-    // Returns state for tracing.
-    void AsValueInto(base::trace_event::TracedValue* state,
-                     base::TimeTicks now) const;
-
-    // Disable all associated throttled queues.
-    void BlockThrottledQueues(base::TimeTicks now);
-
-    // Increase |current_budget_level_| to satisfy max throttling duration
-    // condition if necessary.
-    // Decrease |current_budget_level_| to satisfy max budget level
-    // condition if necessary.
-    void EnforceBudgetLevelRestrictions();
-
-    const char* name_;  // NOT OWNED
-
-    TaskQueueThrottler* task_queue_throttler_;
-
-    // Max budget level which we can accrue.
-    // Tasks will be allowed to run for this time before being throttled
-    // after a very long period of inactivity.
-    base::Optional<base::TimeDelta> max_budget_level_;
-    // Max throttling duration places a lower limit on time budget level,
-    // ensuring that one long task does not cause extremely long throttling.
-    // Note that this is not the guarantee that every task will run
-    // after desired run time + max throttling duration, but a guarantee
-    // that at least one task will be run every max_throttling_duration.
-    base::Optional<base::TimeDelta> max_throttling_duration_;
-
-    base::TimeDelta current_budget_level_;
-    base::TimeTicks last_checkpoint_;
-    double cpu_percentage_;
-    bool is_enabled_;
-
-    std::unordered_set<TaskQueue*> associated_task_queues_;
-
-    base::Callback<void(base::TimeDelta)> reporting_callback_;
-
-    DISALLOW_COPY_AND_ASSIGN(TimeBudgetPool);
-  };
-
   // TODO(altimin): Do not pass tracing category as const char*,
   // hard-code string instead.
   TaskQueueThrottler(RendererSchedulerImpl* renderer_scheduler,
                      const char* tracing_category);
 
   ~TaskQueueThrottler() override;
 
   // TimeDomain::Observer implementation:
   void OnTimeDomainHasImmediateWork(TaskQueue*) override;
   void OnTimeDomainHasDelayedWork(TaskQueue*) override;
@@ skipping 36 matching lines @@
 
   // Accounts for given task for cpu-based throttling needs.
   void OnTaskRunTimeReported(TaskQueue* task_queue,
                              base::TimeTicks start_time,
                              base::TimeTicks end_time);
 
   void AsValueInto(base::trace_event::TracedValue* state,
                    base::TimeTicks now) const;
 
  private:
+  friend class BudgetPool;

[Sami, 2017/03/08 16:18:01]

I guess these will be removed later?

[altimin, 2017/03/08 16:50:33]

Yep, the comment in the patch description.

+  friend class TimeBudgetPool;
+
   struct Metadata {
     Metadata() : throttling_ref_count(0), time_budget_pool(nullptr) {}
 
     size_t throttling_ref_count;
 
     TimeBudgetPool* time_budget_pool;
   };
   using TaskQueueMap = std::unordered_map<TaskQueue*, Metadata>;
 
   void PumpThrottledTasks();
@@ skipping 26 matching lines @@
   scoped_refptr<TaskQueue> task_runner_;
   RendererSchedulerImpl* renderer_scheduler_;  // NOT OWNED
   base::TickClock* tick_clock_;                // NOT OWNED
   const char* tracing_category_;               // NOT OWNED
   std::unique_ptr<ThrottledTimeDomain> time_domain_;
 
   CancelableClosureHolder pump_throttled_tasks_closure_;
   base::Optional<base::TimeTicks> pending_pump_throttled_tasks_runtime_;
   bool allow_throttling_;
 
-  std::unordered_map<TimeBudgetPool*, std::unique_ptr<TimeBudgetPool>>
+  std::unordered_map<BudgetPool*, std::unique_ptr<BudgetPool>>
       time_budget_pools_;
 
   base::WeakPtrFactory<TaskQueueThrottler> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(TaskQueueThrottler);
 };
 
 }  // namespace scheduler
 }  // namespace blink
 
-#endif  // THIRD_PARTY_WEBKIT_SOURCE_PLATFORM_SCHEDULER_RENDERER_THROTTLING_HELPER_H_
+#endif  // THIRD_PARTY_WEBKIT_SOURCE_PLATFORM_SCHEDULER_RENDERER_TASK_QUEUE_THROTTLER_H_