cc/frame_rate_controller.cc

   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 #include "cc/frame_rate_controller.h"
   6
   7 #include "base/debug/trace_event.h"
   8 #include "base/logging.h"
   9 #include "cc/delay_based_time_source.h"
  10 #include "cc/time_source.h"
  11 #include "cc/thread.h"
  12
  13 namespace {
  14
  15 // This will be the maximum number of pending frames unless
  16 // FrameRateController::setMaxFramesPending is called.
  17 const int defaultMaxFramesPending = 2;
  18
  19 }  // namespace
  20
  21 namespace cc {
  22
  23 class FrameRateControllerTimeSourceAdapter : public TimeSourceClient {
  24 public:
  25     static scoped_ptr<FrameRateControllerTimeSourceAdapter> create(FrameRateController* frameRateController) {
  26         return make_scoped_ptr(new FrameRateControllerTimeSourceAdapter(frameRateController));
  27     }
  28     virtual ~FrameRateControllerTimeSourceAdapter() {}
  29
  30     virtual void onTimerTick() OVERRIDE {
  31       m_frameRateController->onTimerTick();
  32     }
  33
  34 private:
  35     explicit FrameRateControllerTimeSourceAdapter(FrameRateController* frameRateController)
  36         : m_frameRateController(frameRateController) {}
  37
  38     FrameRateController* m_frameRateController;
  39 };
  40
  41 FrameRateController::FrameRateController(scoped_refptr<TimeSource> timer)
  42     : m_client(0)
  43     , m_numFramesPending(0)
  44     , m_maxFramesPending(defaultMaxFramesPending)
  45     , m_timeSource(timer)
  46     , m_active(false)
  47     , m_swapBuffersCompleteSupported(true)
  48     , m_isTimeSourceThrottling(true)
  49     , m_thread(0)
  50     , m_weakFactory(ALLOW_THIS_IN_INITIALIZER_LIST(this))
  51 {
  52     m_timeSourceClientAdapter = FrameRateControllerTimeSourceAdapter::create(this);
  53     m_timeSource->setClient(m_timeSourceClientAdapter.get());
  54 }
  55
  56 FrameRateController::FrameRateController(Thread* thread)
  57     : m_client(0)
  58     , m_numFramesPending(0)
  59     , m_maxFramesPending(defaultMaxFramesPending)
  60     , m_active(false)
  61     , m_swapBuffersCompleteSupported(true)
  62     , m_isTimeSourceThrottling(false)
  63     , m_thread(thread)
  64     , m_weakFactory(ALLOW_THIS_IN_INITIALIZER_LIST(this))
  65 {
  66 }
  67
  68 FrameRateController::~FrameRateController()
  69 {
  70     if (m_isTimeSourceThrottling)
  71         m_timeSource->setActive(false);
  72 }
  73
  74 void FrameRateController::setActive(bool active)
  75 {
  76     if (m_active == active)
  77         return;
  78     TRACE_EVENT1("cc", "FrameRateController::setActive", "active", active);
  79     m_active = active;
  80
  81     if (m_isTimeSourceThrottling)
  82         m_timeSource->setActive(active);
  83     else {
  84         if (active)
  85             postManualTick();
  86         else
  87             m_weakFactory.InvalidateWeakPtrs();
  88     }
  89 }
  90
  91 void FrameRateController::setMaxFramesPending(int maxFramesPending)
  92 {
  93     DCHECK(maxFramesPending > 0);
  94     m_maxFramesPending = maxFramesPending;
  95 }
  96
  97 void FrameRateController::setTimebaseAndInterval(base::TimeTicks timebase, base::TimeDelta interval)
  98 {
  99     if (m_isTimeSourceThrottling)
 100         m_timeSource->setTimebaseAndInterval(timebase, interval);
 101 }
 102
 103 void FrameRateController::setSwapBuffersCompleteSupported(bool supported)
 104 {
 105     m_swapBuffersCompleteSupported = supported;
 106 }
 107
 108 void FrameRateController::onTimerTick()
 109 {
 110     DCHECK(m_active);
 111
 112     // Check if we have too many frames in flight.
 113     bool throttled = m_numFramesPending >= m_maxFramesPending;
 114     TRACE_COUNTER_ID1("cc", "ThrottledVSyncInterval", m_thread, throttled);
 115
 116     if (m_client)
 117         m_client->vsyncTick(throttled);
 118
 119     if (m_swapBuffersCompleteSupported && !m_isTimeSourceThrottling && m_numFramesPending < m_maxFramesPending)
 120         postManualTick();
 121 }
 122
 123 void FrameRateController::postManualTick()
 124 {
 125     if (m_active)
 126         m_thread->postTask(base::Bind(&FrameRateController::manualTick, m_weakFactory.GetWeakPtr()));
 127 }
 128
 129 void FrameRateController::manualTick()
 130 {
 131     onTimerTick();
 132 }
 133
 134 void FrameRateController::didBeginFrame()
 135 {
 136     if (m_swapBuffersCompleteSupported)
 137         m_numFramesPending++;
 138     else if (!m_isTimeSourceThrottling)
 139         postManualTick();
 140 }
 141
 142 void FrameRateController::didFinishFrame()
 143 {
 144     DCHECK(m_swapBuffersCompleteSupported);
 145
 146     m_numFramesPending--;
 147     if (!m_isTimeSourceThrottling)
 148         postManualTick();
 149 }
 150
 151 void FrameRateController::didAbortAllPendingFrames()
 152 {
 153     m_numFramesPending = 0;
 154 }
 155
 156 base::TimeTicks FrameRateController::nextTickTime()
 157 {
 158     if (m_isTimeSourceThrottling)
 159         return m_timeSource->nextTickTime();
 160
 161     return base::TimeTicks();
 162 }
 163
 164 }  // namespace cc