cc/scheduler/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/scheduler/frame_rate_controller.h"
   6
   7 #include "base/bind.h"
   8 #include "base/debug/trace_event.h"
   9 #include "base/location.h"
  10 #include "base/logging.h"
  11 #include "base/single_thread_task_runner.h"
  12 #include "cc/scheduler/delay_based_time_source.h"
  13 #include "cc/scheduler/time_source.h"
  14 #include "ui/gfx/frame_time.h"
  15
  16 namespace cc {
  17
  18 class FrameRateControllerTimeSourceAdapter : public TimeSourceClient {
  19  public:
  20   static scoped_ptr<FrameRateControllerTimeSourceAdapter> Create(
  21       FrameRateController* frame_rate_controller) {
  22     return make_scoped_ptr(
  23         new FrameRateControllerTimeSourceAdapter(frame_rate_controller));
  24   }
  25   virtual ~FrameRateControllerTimeSourceAdapter() {}
  26
  27   virtual void OnTimerTick() OVERRIDE {
  28     frame_rate_controller_->OnTimerTick();
  29   }
  30
  31  private:
  32   explicit FrameRateControllerTimeSourceAdapter(
  33       FrameRateController* frame_rate_controller)
  34       : frame_rate_controller_(frame_rate_controller) {}
  35
  36   FrameRateController* frame_rate_controller_;
  37 };
  38
  39 FrameRateController::FrameRateController(scoped_refptr<TimeSource> timer)
  40     : client_(NULL),
  41       num_frames_pending_(0),
  42       max_swaps_pending_(0),
  43       interval_(BeginFrameArgs::DefaultInterval()),
  44       time_source_(timer),
  45       active_(false),
  46       is_time_source_throttling_(true),
  47       task_runner_(NULL),
  48       weak_factory_(this) {
  49   time_source_client_adapter_ =
  50       FrameRateControllerTimeSourceAdapter::Create(this);
  51   time_source_->SetClient(time_source_client_adapter_.get());
  52 }
  53
  54 FrameRateController::FrameRateController(
  55     base::SingleThreadTaskRunner* task_runner)
  56     : client_(NULL),
  57       num_frames_pending_(0),
  58       max_swaps_pending_(0),
  59       interval_(BeginFrameArgs::DefaultInterval()),
  60       active_(false),
  61       is_time_source_throttling_(false),
  62       task_runner_(task_runner),
  63       weak_factory_(this) {}
  64
  65 FrameRateController::~FrameRateController() {
  66   if (is_time_source_throttling_)
  67     time_source_->SetActive(false);
  68 }
  69
  70 BeginFrameArgs FrameRateController::SetActive(bool active) {
  71   if (active_ == active)
  72     return BeginFrameArgs();
  73   TRACE_EVENT1("cc", "FrameRateController::SetActive", "active", active);
  74   active_ = active;
  75
  76   if (is_time_source_throttling_) {
  77     base::TimeTicks missed_tick_time = time_source_->SetActive(active);
  78     if (!missed_tick_time.is_null()) {
  79       base::TimeTicks deadline = NextTickTime();
  80       return  BeginFrameArgs::Create(
  81           missed_tick_time, deadline + deadline_adjustment_, interval_);
  82     }
  83   } else {
  84     if (active)
  85       PostManualTick();
  86     else
  87       weak_factory_.InvalidateWeakPtrs();
  88   }
  89
  90   return BeginFrameArgs();
  91 }
  92
  93 void FrameRateController::SetMaxSwapsPending(int max_swaps_pending) {
  94   DCHECK_GE(max_swaps_pending, 0);
  95   max_swaps_pending_ = max_swaps_pending;
  96 }
  97
  98 void FrameRateController::SetTimebaseAndInterval(base::TimeTicks timebase,
  99                                                  base::TimeDelta interval) {
 100   interval_ = interval;
 101   if (is_time_source_throttling_)
 102     time_source_->SetTimebaseAndInterval(timebase, interval);
 103 }
 104
 105 void FrameRateController::SetDeadlineAdjustment(base::TimeDelta delta) {
 106   deadline_adjustment_ = delta;
 107 }
 108
 109 void FrameRateController::OnTimerTick() {
 110   TRACE_EVENT0("cc", "FrameRateController::OnTimerTick");
 111   DCHECK(active_);
 112
 113   // Check if we have too many frames in flight.
 114   bool throttled =
 115       max_swaps_pending_ && num_frames_pending_ >= max_swaps_pending_;
 116   TRACE_COUNTER_ID1("cc", "ThrottledCompositor", task_runner_, throttled);
 117
 118   if (client_) {
 119     // TODO(brianderson): Use an adaptive parent compositor deadline.
 120     base::TimeTicks frame_time = LastTickTime();
 121     base::TimeTicks deadline = NextTickTime();
 122     BeginFrameArgs args = BeginFrameArgs::Create(
 123         frame_time, deadline + deadline_adjustment_, interval_);
 124     client_->FrameRateControllerTick(throttled, args);
 125   }
 126
 127   if (!is_time_source_throttling_ && !throttled)
 128     PostManualTick();
 129 }
 130
 131 void FrameRateController::PostManualTick() {
 132   if (active_) {
 133     task_runner_->PostTask(FROM_HERE,
 134                            base::Bind(&FrameRateController::ManualTick,
 135                                       weak_factory_.GetWeakPtr()));
 136   }
 137 }
 138
 139 void FrameRateController::ManualTick() {
 140   OnTimerTick();
 141 }
 142
 143 void FrameRateController::DidSwapBuffers() {
 144   num_frames_pending_++;
 145 }
 146
 147 void FrameRateController::DidSwapBuffersComplete() {
 148   DCHECK_GT(num_frames_pending_, 0);
 149   num_frames_pending_--;
 150   if (!is_time_source_throttling_)
 151     PostManualTick();
 152 }
 153
 154 void FrameRateController::DidAbortAllPendingFrames() {
 155   num_frames_pending_ = 0;
 156 }
 157
 158 base::TimeTicks FrameRateController::NextTickTime() {
 159   if (is_time_source_throttling_)
 160     return time_source_->NextTickTime();
 161
 162   return base::TimeTicks();
 163 }
 164
 165 base::TimeTicks FrameRateController::LastTickTime() {
 166   if (is_time_source_throttling_)
 167     return time_source_->LastTickTime();
 168
 169   return gfx::FrameTime::Now();
 170 }
 171
 172 }  // namespace cc