cc/scheduler/frame_rate_controller.h

   1 // Copyright 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CC_SCHEDULER_FRAME_RATE_CONTROLLER_H_
   6 #define CC_SCHEDULER_FRAME_RATE_CONTROLLER_H_
   7
   8 #include "base/memory/ref_counted.h"
   9 #include "base/memory/scoped_ptr.h"
  10 #include "base/memory/weak_ptr.h"
  11 #include "base/time/time.h"
  12 #include "cc/base/cc_export.h"
  13 #include "cc/output/begin_frame_args.h"
  14
  15 namespace base { class SingleThreadTaskRunner; }
  16
  17 namespace cc {
  18
  19 class TimeSource;
  20 class FrameRateController;
  21
  22 class CC_EXPORT FrameRateControllerClient {
  23  protected:
  24   virtual ~FrameRateControllerClient() {}
  25
  26  public:
  27   // Throttled is true when we have a maximum number of frames pending.
  28   virtual void FrameRateControllerTick(bool throttled,
  29                                        const BeginFrameArgs& args) = 0;
  30 };
  31
  32 class FrameRateControllerTimeSourceAdapter;
  33
  34 // The FrameRateController is used in cases where we self-tick (i.e. BeginFrame
  35 // is not sent by a parent compositor.
  36 class CC_EXPORT FrameRateController {
  37  public:
  38   explicit FrameRateController(scoped_refptr<TimeSource> timer);
  39   // Alternate form of FrameRateController with unthrottled frame-rate.
  40   explicit FrameRateController(base::SingleThreadTaskRunner* task_runner);
  41   virtual ~FrameRateController();
  42
  43   void SetClient(FrameRateControllerClient* client) { client_ = client; }
  44
  45   // Returns a valid BeginFrame on activation to potentially be used
  46   // retroactively.
  47   BeginFrameArgs SetActive(bool active);
  48
  49   bool IsActive() { return active_; }
  50
  51   // Use the following methods to adjust target frame rate.
  52   //
  53   // Multiple frames can be in-progress, but for every DidSwapBuffers, a
  54   // DidFinishFrame should be posted.
  55   //
  56   // If the rendering pipeline crashes, call DidAbortAllPendingFrames.
  57   void DidSwapBuffers();
  58   void DidSwapBuffersComplete();
  59   void DidAbortAllPendingFrames();
  60   void SetMaxSwapsPending(int max_swaps_pending);  // 0 for unlimited.
  61   int MaxSwapsPending() const { return max_swaps_pending_; }
  62   int NumSwapsPendingForTesting() const { return num_frames_pending_; }
  63
  64   void SetTimebaseAndInterval(base::TimeTicks timebase,
  65                               base::TimeDelta interval);
  66   void SetDeadlineAdjustment(base::TimeDelta delta);
  67
  68  protected:
  69   friend class FrameRateControllerTimeSourceAdapter;
  70   void OnTimerTick();
  71
  72   void PostManualTick();
  73   void ManualTick();
  74
  75     // This returns null for unthrottled frame-rate.
  76   base::TimeTicks NextTickTime();
  77   // This returns now for unthrottled frame-rate.
  78   base::TimeTicks LastTickTime();
  79
  80   FrameRateControllerClient* client_;
  81   int num_frames_pending_;
  82   int max_swaps_pending_;
  83   base::TimeDelta interval_;
  84   base::TimeDelta deadline_adjustment_;
  85   scoped_refptr<TimeSource> time_source_;
  86   scoped_ptr<FrameRateControllerTimeSourceAdapter> time_source_client_adapter_;
  87   bool active_;
  88
  89   // Members for unthrottled frame-rate.
  90   bool is_time_source_throttling_;
  91   base::WeakPtrFactory<FrameRateController> weak_factory_;
  92   base::SingleThreadTaskRunner* task_runner_;
  93
  94  private:
  95   DISALLOW_COPY_AND_ASSIGN(FrameRateController);
  96 };
  97
  98 }  // namespace cc
  99
 100 #endif  // CC_SCHEDULER_FRAME_RATE_CONTROLLER_H_