Hoist begin frame sources out of scheduler

cc/scheduler/scheduler.cc

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/scheduler/scheduler.h"
 
 #include <algorithm>
 
 #include "base/auto_reset.h"
 #include "base/logging.h"
@@ skipping 13 matching lines @@
 // for message latency and kernel scheduling variability.
 const base::TimeDelta kDeadlineFudgeFactor =
     base::TimeDelta::FromMicroseconds(1000);
 }
 
 scoped_ptr<Scheduler> Scheduler::Create(
     SchedulerClient* client,
     const SchedulerSettings& settings,
     int layer_tree_host_id,
     base::SingleThreadTaskRunner* task_runner,
-    BeginFrameSource* external_frame_source,
+    BeginFrameSource* begin_frame_source,
     scoped_ptr<CompositorTimingHistory> compositor_timing_history) {
-  scoped_ptr<SyntheticBeginFrameSource> synthetic_frame_source;
-  if (!settings.use_external_begin_frame_source) {
-    synthetic_frame_source = SyntheticBeginFrameSource::Create(
-        task_runner, BeginFrameArgs::DefaultInterval());
-  }
-  scoped_ptr<BackToBackBeginFrameSource> unthrottled_frame_source =
-      BackToBackBeginFrameSource::Create(task_runner);
-  return make_scoped_ptr(new Scheduler(
-      client, settings, layer_tree_host_id, task_runner, external_frame_source,
-      std::move(synthetic_frame_source), std::move(unthrottled_frame_source),
-      std::move(compositor_timing_history)));
+  return make_scoped_ptr(new Scheduler(client, settings, layer_tree_host_id,
+                                       task_runner, begin_frame_source,
+                                       std::move(compositor_timing_history)));
 }
 
 Scheduler::Scheduler(
     SchedulerClient* client,
     const SchedulerSettings& settings,
     int layer_tree_host_id,
     base::SingleThreadTaskRunner* task_runner,
-    BeginFrameSource* external_frame_source,
-    scoped_ptr<SyntheticBeginFrameSource> synthetic_frame_source,
-    scoped_ptr<BackToBackBeginFrameSource> unthrottled_frame_source,
+    BeginFrameSource* begin_frame_source,
     scoped_ptr<CompositorTimingHistory> compositor_timing_history)
     : settings_(settings),
       client_(client),
       layer_tree_host_id_(layer_tree_host_id),
       task_runner_(task_runner),
-      external_frame_source_(external_frame_source),
-      synthetic_frame_source_(std::move(synthetic_frame_source)),
-      unthrottled_frame_source_(std::move(unthrottled_frame_source)),
-      frame_source_(BeginFrameSourceMultiplexer::Create()),
-      observing_frame_source_(false),
+      begin_frame_source_(begin_frame_source),
+      observing_begin_frame_source_(false),
       compositor_timing_history_(std::move(compositor_timing_history)),
       begin_impl_frame_deadline_mode_(
           SchedulerStateMachine::BEGIN_IMPL_FRAME_DEADLINE_MODE_NONE),
       begin_impl_frame_tracker_(BEGINFRAMETRACKER_FROM_HERE),
       state_machine_(settings),
       inside_process_scheduled_actions_(false),
       inside_action_(SchedulerStateMachine::ACTION_NONE),
       weak_factory_(this) {
   TRACE_EVENT1("cc", "Scheduler::Scheduler", "settings", settings_.AsValue());
   DCHECK(client_);
   DCHECK(!state_machine_.BeginFrameNeeded());
-  DCHECK(!settings_.use_external_begin_frame_source || external_frame_source_);
-  DCHECK(settings_.use_external_begin_frame_source || synthetic_frame_source_);
-  DCHECK(unthrottled_frame_source_);
 
   begin_retro_frame_closure_ =
       base::Bind(&Scheduler::BeginRetroFrame, weak_factory_.GetWeakPtr());
   begin_impl_frame_deadline_closure_ = base::Bind(
       &Scheduler::OnBeginImplFrameDeadline, weak_factory_.GetWeakPtr());
 
-  frame_source_->AddSource(primary_frame_source());
-  primary_frame_source()->SetClientReady();
-
-  frame_source_->AddSource(unthrottled_frame_source_.get());
-  unthrottled_frame_source_->SetClientReady();
-
-  if (settings_.throttle_frame_production) {
-    frame_source_->SetActiveSource(primary_frame_source());
-  } else {
-    frame_source_->SetActiveSource(unthrottled_frame_source_.get());
-  }
+  begin_frame_source_->SetClientReady();
   ProcessScheduledActions();
 }
 
 Scheduler::~Scheduler() {
-  if (observing_frame_source_)
-    frame_source_->RemoveObserver(this);
-  frame_source_->SetActiveSource(nullptr);
+  if (observing_begin_frame_source_)
+    begin_frame_source_->RemoveObserver(this);
 }
 
 base::TimeTicks Scheduler::Now() const {
   base::TimeTicks now = base::TimeTicks::Now();
   TRACE_EVENT1(TRACE_DISABLED_BY_DEFAULT("cc.debug.scheduler.now"),
                "Scheduler::Now",
                "now",
                now);
   return now;
 }
 
-void Scheduler::CommitVSyncParameters(base::TimeTicks timebase,
-                                      base::TimeDelta interval) {
-  if (authoritative_vsync_interval_ != base::TimeDelta()) {
-    interval = authoritative_vsync_interval_;
-  } else if (interval == base::TimeDelta()) {
-    // TODO(brianderson): We should not be receiving 0 intervals.
-    interval = BeginFrameArgs::DefaultInterval();
-  }
-
-  last_vsync_timebase_ = timebase;
-
-  if (synthetic_frame_source_)
-    synthetic_frame_source_->OnUpdateVSyncParameters(timebase, interval);
-}
-
 void Scheduler::SetEstimatedParentDrawTime(base::TimeDelta draw_time) {
   DCHECK_GE(draw_time.ToInternalValue(), 0);
   estimated_parent_draw_time_ = draw_time;
 }
 
 void Scheduler::SetVisible(bool visible) {
   state_machine_.SetVisible(visible);
   UpdateCompositorTimingHistoryRecordingEnabled();
   ProcessScheduledActions();
 }
@@ skipping 93 matching lines @@
   TRACE_EVENT0("cc", "Scheduler::DidLoseOutputSurface");
   begin_retro_frame_args_.clear();
   begin_retro_frame_task_.Cancel();
   state_machine_.DidLoseOutputSurface();
   UpdateCompositorTimingHistoryRecordingEnabled();
   ProcessScheduledActions();
 }
 
 void Scheduler::DidCreateAndInitializeOutputSurface() {
   TRACE_EVENT0("cc", "Scheduler::DidCreateAndInitializeOutputSurface");
-  DCHECK(!observing_frame_source_);
+  DCHECK(!observing_begin_frame_source_);
   DCHECK(begin_impl_frame_deadline_task_.IsCancelled());
   state_machine_.DidCreateAndInitializeOutputSurface();
   compositor_timing_history_->DidCreateAndInitializeOutputSurface();
   UpdateCompositorTimingHistoryRecordingEnabled();
   ProcessScheduledActions();
 }
 
 void Scheduler::NotifyBeginMainFrameStarted(
     base::TimeTicks main_thread_start_time) {
   TRACE_EVENT0("cc", "Scheduler::NotifyBeginMainFrameStarted");
@@ skipping 10 matching lines @@
 
   // Tying this to SendBeginMainFrameNotExpectedSoon will have some
   // false negatives, but we want to avoid running long idle tasks when
   // we are actually active.
   client_->SendBeginMainFrameNotExpectedSoon();
 }
 
 void Scheduler::SetupNextBeginFrameIfNeeded() {
   // Never call SetNeedsBeginFrames if the frame source already has the right
   // value.
-  if (observing_frame_source_ != state_machine_.BeginFrameNeeded()) {
+  if (observing_begin_frame_source_ != state_machine_.BeginFrameNeeded()) {
     if (state_machine_.BeginFrameNeeded()) {
       // Call AddObserver as soon as possible.
-      observing_frame_source_ = true;
-      frame_source_->AddObserver(this);
+      observing_begin_frame_source_ = true;
+      begin_frame_source_->AddObserver(this);
       devtools_instrumentation::NeedsBeginFrameChanged(layer_tree_host_id_,
                                                        true);
     } else if (state_machine_.begin_impl_frame_state() ==
                SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_IDLE) {
       // Call RemoveObserver in between frames only.
-      observing_frame_source_ = false;
-      frame_source_->RemoveObserver(this);
+      observing_begin_frame_source_ = false;
+      begin_frame_source_->RemoveObserver(this);
       BeginImplFrameNotExpectedSoon();
       devtools_instrumentation::NeedsBeginFrameChanged(layer_tree_host_id_,
                                                        false);
     }
   }
 
   PostBeginRetroFrameIfNeeded();
 }
 
 void Scheduler::OnBeginFrameSourcePausedChanged(bool paused) {
@@ skipping 36 matching lines @@
   // actually make rendering for this call, handle it like a "retro frame".
   // TODO(brainderson): Add a test for this functionality ASAP!
   if (adjusted_args.type == BeginFrameArgs::MISSED) {
     begin_retro_frame_args_.push_back(adjusted_args);
     PostBeginRetroFrameIfNeeded();
     return true;
   }
 
   bool should_defer_begin_frame =
       !begin_retro_frame_args_.empty() ||
-      !begin_retro_frame_task_.IsCancelled() || !observing_frame_source_ ||
+      !begin_retro_frame_task_.IsCancelled() ||
+      !observing_begin_frame_source_ ||
       (state_machine_.begin_impl_frame_state() !=
        SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_IDLE);
 
   if (should_defer_begin_frame) {
     begin_retro_frame_args_.push_back(adjusted_args);
     TRACE_EVENT_INSTANT0(
         "cc", "Scheduler::BeginFrame deferred", TRACE_EVENT_SCOPE_THREAD);
     // Queuing the frame counts as "using it", so we need to return true.
   } else {
     BeginImplFrameWithDeadline(adjusted_args);
   }
   return true;
 }
 
 void Scheduler::SetChildrenNeedBeginFrames(bool children_need_begin_frames) {
   state_machine_.SetChildrenNeedBeginFrames(children_need_begin_frames);
   ProcessScheduledActions();
 }
 
-void Scheduler::SetAuthoritativeVSyncInterval(const base::TimeDelta& interval) {
-  authoritative_vsync_interval_ = interval;
-  if (synthetic_frame_source_) {
-    synthetic_frame_source_->OnUpdateVSyncParameters(last_vsync_timebase_,
-                                                     interval);
-  }
-}
-
 void Scheduler::SetVideoNeedsBeginFrames(bool video_needs_begin_frames) {
   state_machine_.SetVideoNeedsBeginFrames(video_needs_begin_frames);
   ProcessScheduledActions();
 }
 
 void Scheduler::OnDrawForOutputSurface(bool resourceless_software_draw) {
   DCHECK(settings_.using_synchronous_renderer_compositor);
   DCHECK_EQ(state_machine_.begin_impl_frame_state(),
             SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_IDLE);
   DCHECK(!BeginImplFrameDeadlinePending());
@@ skipping 31 matching lines @@
   while (!begin_retro_frame_args_.empty()) {
     const BeginFrameArgs& args = begin_retro_frame_args_.front();
     base::TimeTicks expiration_time = args.deadline;
     if (now <= expiration_time)
       break;
     TRACE_EVENT_INSTANT2(
         "cc", "Scheduler::BeginRetroFrame discarding", TRACE_EVENT_SCOPE_THREAD,
         "expiration_time - now", (expiration_time - now).InMillisecondsF(),
         "BeginFrameArgs", begin_retro_frame_args_.front().AsValue());
     begin_retro_frame_args_.pop_front();
-    frame_source_->DidFinishFrame(begin_retro_frame_args_.size());
+    begin_frame_source_->DidFinishFrame(begin_retro_frame_args_.size());
   }
 
   if (begin_retro_frame_args_.empty()) {
     TRACE_EVENT_INSTANT0("cc",
                          "Scheduler::BeginRetroFrames all expired",
                          TRACE_EVENT_SCOPE_THREAD);
   } else {
     BeginFrameArgs front = begin_retro_frame_args_.front();
     begin_retro_frame_args_.pop_front();
     BeginImplFrameWithDeadline(front);
   }
 }
 
 // There could be a race between the posted BeginRetroFrame and a new
 // BeginFrame arriving via the normal mechanism. Scheduler::BeginFrame
 // will check if there is a pending BeginRetroFrame to ensure we handle
 // BeginFrames in FIFO order.
 void Scheduler::PostBeginRetroFrameIfNeeded() {
   TRACE_EVENT1(TRACE_DISABLED_BY_DEFAULT("cc.debug.scheduler"),
                "Scheduler::PostBeginRetroFrameIfNeeded",
                "state",
                AsValue());
-  if (!observing_frame_source_)
+  if (!observing_begin_frame_source_)
     return;
 
   if (begin_retro_frame_args_.empty() || !begin_retro_frame_task_.IsCancelled())
     return;
 
   // begin_retro_frame_args_ should always be empty for the
   // synchronous compositor.
   DCHECK(!settings_.using_synchronous_renderer_compositor);
 
   if (state_machine_.begin_impl_frame_state() !=
@@ skipping 49 matching lines @@
                                                  bmf_to_activate_estimate);
 
   if (ShouldRecoverMainLatency(adjusted_args, can_activate_before_deadline)) {
     TRACE_EVENT_INSTANT0("cc", "SkipBeginMainFrameToReduceLatency",
                          TRACE_EVENT_SCOPE_THREAD);
     state_machine_.SetSkipNextBeginMainFrameToReduceLatency();
   } else if (ShouldRecoverImplLatency(adjusted_args,
                                       can_activate_before_deadline)) {
     TRACE_EVENT_INSTANT0("cc", "SkipBeginImplFrameToReduceLatency",
                          TRACE_EVENT_SCOPE_THREAD);
-    frame_source_->DidFinishFrame(begin_retro_frame_args_.size());
+    begin_frame_source_->DidFinishFrame(begin_retro_frame_args_.size());
     return;
   }
 
   BeginImplFrame(adjusted_args);
 
   // The deadline will be scheduled in ProcessScheduledActions.
   state_machine_.OnBeginImplFrameDeadlinePending();
   ProcessScheduledActions();
 }
 
@@ skipping 11 matching lines @@
   compositor_timing_history_->WillFinishImplFrame(
       state_machine_.needs_redraw());
   FinishImplFrame();
 }
 
 void Scheduler::FinishImplFrame() {
   state_machine_.OnBeginImplFrameIdle();
   ProcessScheduledActions();
 
   client_->DidFinishImplFrame();
-  frame_source_->DidFinishFrame(begin_retro_frame_args_.size());
+  begin_frame_source_->DidFinishFrame(begin_retro_frame_args_.size());
   begin_impl_frame_tracker_.Finish();
 }
 
 // BeginImplFrame starts a compositor frame that will wait up until a deadline
 // for a BeginMainFrame+activation to complete before it times out and draws
 // any asynchronous animation and scroll/pinch updates.
 void Scheduler::BeginImplFrame(const BeginFrameArgs& args) {
   DCHECK_EQ(state_machine_.begin_impl_frame_state(),
             SchedulerStateMachine::BEGIN_IMPL_FRAME_STATE_IDLE);
   DCHECK(!BeginImplFrameDeadlinePending());
@@ skipping 230 matching lines @@
   state->BeginDictionary("state_machine");
   state_machine_.AsValueInto(state);
   state->EndDictionary();
 
   // Only trace frame sources when explicitly enabled - http://crbug.com/420607
   bool frame_tracing_enabled = false;
   TRACE_EVENT_CATEGORY_GROUP_ENABLED(
       TRACE_DISABLED_BY_DEFAULT("cc.debug.scheduler.frames"),
       &frame_tracing_enabled);
   if (frame_tracing_enabled) {
-    state->BeginDictionary("frame_source_");
-    frame_source_->AsValueInto(state);
+    state->BeginDictionary("begin_frame_source_");
+    begin_frame_source_->AsValueInto(state);
     state->EndDictionary();
   }
 
   state->BeginDictionary("scheduler_state");
-  state->SetBoolean("external_frame_source_", !!external_frame_source_);
   state->SetBoolean("throttle_frame_production_",
                     settings_.throttle_frame_production);
-  state->SetDouble("authoritative_vsync_interval_ms",
-                   authoritative_vsync_interval_.InMillisecondsF());
-  state->SetDouble(
-      "last_vsync_timebase_ms",
-      (last_vsync_timebase_ - base::TimeTicks()).InMillisecondsF());
   state->SetDouble("estimated_parent_draw_time_ms",
                    estimated_parent_draw_time_.InMillisecondsF());
-  state->SetBoolean("observing_frame_source", observing_frame_source_);
+  state->SetBoolean("observing_frame_source", observing_begin_frame_source_);

[Sami, 2016/03/09 14:36:23]

nit: please update the string to match the new name too.

   state->SetInteger("begin_retro_frame_args",
                     static_cast<int>(begin_retro_frame_args_.size()));
   state->SetBoolean("begin_retro_frame_task",
                     !begin_retro_frame_task_.IsCancelled());
   state->SetBoolean("begin_impl_frame_deadline_task",
                     !begin_impl_frame_deadline_task_.IsCancelled());
   state->SetString("inside_action",
                    SchedulerStateMachine::ActionToString(inside_action_));
 
   state->BeginDictionary("begin_impl_frame_args");
@@ skipping 81 matching lines @@
 }
 
 bool Scheduler::IsBeginMainFrameSentOrStarted() const {
   return (state_machine_.begin_main_frame_state() ==
               SchedulerStateMachine::BEGIN_MAIN_FRAME_STATE_SENT ||
           state_machine_.begin_main_frame_state() ==
               SchedulerStateMachine::BEGIN_MAIN_FRAME_STATE_STARTED);
 }
 
 }  // namespace cc