src/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       manual_tick_pending_(false),
  48       task_runner_(NULL),
  49       weak_factory_(this) {
  50   time_source_client_adapter_ =
  51       FrameRateControllerTimeSourceAdapter::Create(this);
  52   time_source_->SetClient(time_source_client_adapter_.get());
  53 }
  54
  55 FrameRateController::FrameRateController(
  56     base::SingleThreadTaskRunner* task_runner)
  57     : client_(NULL),
  58       num_frames_pending_(0),
  59       max_swaps_pending_(0),
  60       interval_(BeginFrameArgs::DefaultInterval()),
  61       active_(false),
  62       is_time_source_throttling_(false),
  63       manual_tick_pending_(false),
  64       task_runner_(task_runner),
  65       weak_factory_(this) {}
  66
  67 FrameRateController::~FrameRateController() {
  68   if (is_time_source_throttling_)
  69     time_source_->SetActive(false);
  70 }
  71
  72 BeginFrameArgs FrameRateController::SetActive(bool active) {
  73   if (active_ == active)
  74     return BeginFrameArgs();
  75   TRACE_EVENT1("cc", "FrameRateController::SetActive", "active", active);
  76   active_ = active;
  77
  78   if (is_time_source_throttling_) {
  79     base::TimeTicks missed_tick_time = time_source_->SetActive(active);
  80     if (!missed_tick_time.is_null()) {
  81       base::TimeTicks deadline = NextTickTime();
  82       return  BeginFrameArgs::Create(
  83           missed_tick_time, deadline + deadline_adjustment_, interval_);
  84     }
  85   } else {
  86     if (active) {
  87       PostManualTick();
  88     } else {
  89       weak_factory_.InvalidateWeakPtrs();
  90       manual_tick_pending_ = false;
  91     }
  92   }
  93
  94   return BeginFrameArgs();
  95 }
  96
  97 void FrameRateController::SetMaxSwapsPending(int max_swaps_pending) {
  98   DCHECK_GE(max_swaps_pending, 0);
  99   max_swaps_pending_ = max_swaps_pending;
 100 }
 101
 102 void FrameRateController::SetTimebaseAndInterval(base::TimeTicks timebase,
 103                                                  base::TimeDelta interval) {
 104   interval_ = interval;
 105   if (is_time_source_throttling_)
 106     time_source_->SetTimebaseAndInterval(timebase, interval);
 107 }
 108
 109 void FrameRateController::SetDeadlineAdjustment(base::TimeDelta delta) {
 110   deadline_adjustment_ = delta;
 111 }
 112
 113 void FrameRateController::OnTimerTick() {
 114   TRACE_EVENT0("cc", "FrameRateController::OnTimerTick");
 115   DCHECK(active_);
 116
 117   // Check if we have too many frames in flight.
 118   bool throttled =
 119       max_swaps_pending_ && num_frames_pending_ >= max_swaps_pending_;
 120   TRACE_COUNTER_ID1("cc", "ThrottledCompositor", task_runner_, throttled);
 121
 122   if (client_) {
 123     // TODO(brianderson): Use an adaptive parent compositor deadline.
 124     base::TimeTicks frame_time = LastTickTime();
 125     base::TimeTicks deadline = NextTickTime();
 126     BeginFrameArgs args = BeginFrameArgs::Create(
 127         frame_time, deadline + deadline_adjustment_, interval_);
 128     client_->FrameRateControllerTick(throttled, args);
 129   }
 130
 131   if (!is_time_source_throttling_ && !throttled)
 132     PostManualTick();
 133 }
 134
 135 void FrameRateController::PostManualTick() {
 136   if (active_ && !manual_tick_pending_) {
 137     manual_tick_pending_ = true;
 138     task_runner_->PostTask(FROM_HERE,
 139                            base::Bind(&FrameRateController::ManualTick,
 140                                       weak_factory_.GetWeakPtr()));
 141   }
 142 }
 143
 144 void FrameRateController::ManualTick() {
 145   manual_tick_pending_ = false;
 146   OnTimerTick();
 147 }
 148
 149 void FrameRateController::DidSwapBuffers() {
 150   num_frames_pending_++;
 151 }
 152
 153 void FrameRateController::DidSwapBuffersComplete() {
 154   DCHECK_GT(num_frames_pending_, 0);
 155   num_frames_pending_--;
 156   if (!is_time_source_throttling_)
 157     PostManualTick();
 158 }
 159
 160 void FrameRateController::DidAbortAllPendingFrames() {
 161   num_frames_pending_ = 0;
 162 }
 163
 164 base::TimeTicks FrameRateController::NextTickTime() {
 165   if (is_time_source_throttling_)
 166     return time_source_->NextTickTime();
 167
 168   return base::TimeTicks();
 169 }
 170
 171 base::TimeTicks FrameRateController::LastTickTime() {
 172   if (is_time_source_throttling_)
 173     return time_source_->LastTickTime();
 174
 175   return gfx::FrameTime::Now();
 176 }
 177
 178 }  // namespace cc