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.h"
  12 #include "cc/base/cc_export.h"
  13
  14 namespace cc {
  15
  16 class Thread;
  17 class TimeSource;
  18
  19 class CC_EXPORT FrameRateControllerClient {
  20  public:
  21   // Throttled is true when we have a maximum number of frames pending.
  22   virtual void BeginFrame(bool throttled) = 0;
  23
  24  protected:
  25   virtual ~FrameRateControllerClient() {}
  26 };
  27
  28 class FrameRateControllerTimeSourceAdapter;
  29
  30 class CC_EXPORT FrameRateController {
  31  public:
  32   enum {
  33     DEFAULT_MAX_FRAMES_PENDING = 2
  34   };
  35
  36   explicit FrameRateController(scoped_refptr<TimeSource> timer);
  37   // Alternate form of FrameRateController with unthrottled frame-rate.
  38   explicit FrameRateController(Thread* thread);
  39   virtual ~FrameRateController();
  40
  41   void SetClient(FrameRateControllerClient* client) { client_ = client; }
  42
  43   void SetActive(bool active);
  44
  45   // Use the following methods to adjust target frame rate.
  46   //
  47   // Multiple frames can be in-progress, but for every DidSwapBuffers, a
  48   // DidFinishFrame should be posted.
  49   //
  50   // If the rendering pipeline crashes, call DidAbortAllPendingFrames.
  51   void DidSwapBuffers();
  52   void DidSwapBuffersComplete();
  53   void DidAbortAllPendingFrames();
  54   void SetMaxFramesPending(int max_frames_pending);  // 0 for unlimited.
  55   int MaxFramesPending() const { return max_frames_pending_; }
  56   int NumFramesPendingForTesting() const { return num_frames_pending_; }
  57
  58   // This returns null for unthrottled frame-rate.
  59   base::TimeTicks NextTickTime();
  60
  61   // This returns now for unthrottled frame-rate.
  62   base::TimeTicks LastTickTime();
  63
  64   void SetTimebaseAndInterval(base::TimeTicks timebase,
  65                               base::TimeDelta interval);
  66   void SetSwapBuffersCompleteSupported(bool supported);
  67
  68  protected:
  69   friend class FrameRateControllerTimeSourceAdapter;
  70   void OnTimerTick();
  71
  72   void PostManualTick();
  73   void ManualTick();
  74
  75   FrameRateControllerClient* client_;
  76   int num_frames_pending_;
  77   int max_frames_pending_;
  78   scoped_refptr<TimeSource> time_source_;
  79   scoped_ptr<FrameRateControllerTimeSourceAdapter> time_source_client_adapter_;
  80   bool active_;
  81   bool swap_buffers_complete_supported_;
  82
  83   // Members for unthrottled frame-rate.
  84   bool is_time_source_throttling_;
  85   base::WeakPtrFactory<FrameRateController> weak_factory_;
  86   Thread* thread_;
  87
  88   DISALLOW_COPY_AND_ASSIGN(FrameRateController);
  89 };
  90
  91 }  // namespace cc
  92
  93 #endif  // CC_SCHEDULER_FRAME_RATE_CONTROLLER_H_