cc: Control defer_commits logic by Scheduler

cc/scheduler/scheduler_state_machine.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_state_machine.h"
 
 #include "base/debug/trace_event.h"
 #include "base/format_macros.h"
 #include "base/logging.h"
 #include "base/strings/stringprintf.h"
@@ skipping 28 matching lines @@
       visible_(false),
       can_start_(false),
       can_draw_(false),
       has_pending_tree_(false),
       pending_tree_is_ready_for_activation_(false),
       active_tree_needs_first_draw_(false),
       did_create_and_initialize_first_output_surface_(false),
       smoothness_takes_priority_(false),
       skip_next_begin_main_frame_to_reduce_latency_(false),
       skip_begin_main_frame_to_reduce_latency_(false),
-      continuous_painting_(false) {
+      continuous_painting_(false),
+      defer_commits_(false) {
 }
 
 const char* SchedulerStateMachine::OutputSurfaceStateToString(
     OutputSurfaceState state) {
   switch (state) {
     case OUTPUT_SURFACE_ACTIVE:
       return "OUTPUT_SURFACE_ACTIVE";
     case OUTPUT_SURFACE_LOST:
       return "OUTPUT_SURFACE_LOST";
     case OUTPUT_SURFACE_CREATING:
@@ skipping 169 matching lines @@
                           did_create_and_initialize_first_output_surface_);
   minor_state->SetBoolean("smoothness_takes_priority",
                           smoothness_takes_priority_);
   minor_state->SetBoolean("main_thread_is_in_high_latency_mode",
                           MainThreadIsInHighLatencyMode());
   minor_state->SetBoolean("skip_begin_main_frame_to_reduce_latency",
                           skip_begin_main_frame_to_reduce_latency_);
   minor_state->SetBoolean("skip_next_begin_main_frame_to_reduce_latency",
                           skip_next_begin_main_frame_to_reduce_latency_);
   minor_state->SetBoolean("continuous_painting", continuous_painting_);
+  minor_state->SetBoolean("defer_commits", defer_commits_);
   state->Set("minor_state", minor_state.release());
 
   return state.PassAs<base::Value>();
 }
 
 void SchedulerStateMachine::AdvanceCurrentFrameNumber() {
   current_frame_number_++;
 
   // "Drain" the ManageTiles funnel.
   if (manage_tiles_funnel_ > 0)
@@ skipping 182 matching lines @@
   // because of smoothness_takes_priority.
   if (smoothness_takes_priority_ &&
       (has_pending_tree_ || active_tree_needs_first_draw_)) {
     return false;
   }
 
   // We do not need commits if we are not visible.
   if (!visible_)
     return false;
 
+  // We do not need commits if commits are deferred.
+  if (defer_commits_)
+    return false;
+
   // We want to start the first commit after we get a new output surface ASAP.
   if (output_surface_state_ == OUTPUT_SURFACE_WAITING_FOR_FIRST_COMMIT)
     return true;
 
   // We should not send BeginMainFrame while we are in
   // BEGIN_IMPL_FRAME_STATE_IDLE since we might have new
   // user input arriving soon.
   // TODO(brianderson): Allow sending BeginMainFrame while idle when the main
   // thread isn't consuming user input.
   if (begin_impl_frame_state_ == BEGIN_IMPL_FRAME_STATE_IDLE &&
@@ skipping 276 matching lines @@
 // Note: If SupportsProactiveBeginFrame is false, the scheduler should poll
 // for changes in it's draw state so it can request a BeginFrame when it's
 // actually ready.
 bool SchedulerStateMachine::SupportsProactiveBeginFrame() const {
   // It is undesirable to proactively request BeginFrames if we are
   // using a synchronous compositor because we *must* draw for every
   // BeginFrame, which could cause duplicate draws.
   return !settings_.using_synchronous_renderer_compositor;
 }
 
+void SchedulerStateMachine::SetDeferCommits(bool defer_commits) {
+  defer_commits_ = defer_commits;
+}
+
 // These are the cases where we definitely (or almost definitely) have a
 // new frame to animate and/or draw and can draw.
 bool SchedulerStateMachine::BeginFrameNeededToAnimateOrDraw() const {
   // The output surface is the provider of BeginImplFrames, so we are not going
   // to get them even if we ask for them.
   if (!HasInitializedOutputSurface())
     return false;
 
   // If we can't draw, don't tick until we are notified that we can draw again.
   if (!can_draw_)
     return false;
 
+  if (defer_commits_)

[brianderson, 2014/06/17 15:57:01]

Comment?

[simonhong, 2014/06/18 21:52:05]

Done.

+    return false;
+
   // The forced draw respects our normal draw scheduling, so we need to
   // request a BeginImplFrame for it.
   if (forced_redraw_state_ == FORCED_REDRAW_STATE_WAITING_FOR_DRAW)
     return true;
 
   // There's no need to produce frames if we are not visible.
   if (!visible_)
     return false;
 
   // We need to draw a more complete frame than we did the last BeginImplFrame,
@@ skipping 15 matching lines @@
 bool SchedulerStateMachine::ProactiveBeginFrameWanted() const {
   // The output surface is the provider of BeginImplFrames,
   // so we are not going to get them even if we ask for them.
   if (!HasInitializedOutputSurface())
     return false;
 
   // Do not be proactive when invisible.
   if (!visible_)
     return false;
 
+  if (defer_commits_)

[brianderson, 2014/06/17 15:57:01]

Comment?

[simonhong, 2014/06/18 21:52:05]

Done.

+    return false;
+
   // We should proactively request a BeginImplFrame if a commit is pending
   // because we will want to draw if the commit completes quickly.
   if (needs_commit_ || commit_state_ != COMMIT_STATE_IDLE)
     return true;
 
   // If the pending tree activates quickly, we'll want a BeginImplFrame soon
   // to draw the new active tree.
   if (has_pending_tree_)
     return true;
 
@@ skipping 276 matching lines @@
     case OUTPUT_SURFACE_ACTIVE:
     case OUTPUT_SURFACE_WAITING_FOR_FIRST_COMMIT:
     case OUTPUT_SURFACE_WAITING_FOR_FIRST_ACTIVATION:
       return true;
   }
   NOTREACHED();
   return false;
 }
 
 }  // namespace cc