cc: Post the missed BeginFrame to a new stack

cc/surfaces/display_scheduler.cc

 // Copyright 2015 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/surfaces/display_scheduler.h"
 
 #include <vector>
 
+#include "base/auto_reset.h"
 #include "base/stl_util.h"
 #include "base/trace_event/trace_event.h"
 #include "cc/output/output_surface.h"
 
 namespace cc {
 
 DisplayScheduler::DisplayScheduler(BeginFrameSource* begin_frame_source,
                                    base::SingleThreadTaskRunner* task_runner,
                                    int max_pending_swaps)
     : begin_frame_source_(begin_frame_source),
       task_runner_(task_runner),
+      inside_surface_damaged_(false),
       output_surface_lost_(false),
       root_surface_resources_locked_(true),
       inside_begin_frame_deadline_interval_(false),
       needs_draw_(false),
       expecting_root_surface_damage_because_of_resize_(false),
       all_active_child_surfaces_ready_to_draw_(false),
       pending_swaps_(0),
       max_pending_swaps_(max_pending_swaps),
       observing_begin_frame_source_(false),
       root_surface_damaged_(false),
@@ skipping 45 matching lines @@
   SurfaceDamaged(root_surface_id);
 }
 
 // Indicates that there was damage to one of the surfaces.
 // Has some logic to wait for multiple active surfaces before
 // triggering the deadline.
 void DisplayScheduler::SurfaceDamaged(const SurfaceId& surface_id) {
   TRACE_EVENT1("cc", "DisplayScheduler::SurfaceDamaged", "surface_id",
                surface_id.ToString());
 
+  // We may cause a new BeginFrame to be run inside this method, but to help
+  // avoid being reentrant to the caller of SurfaceDamaged, track when this is
+  // happening with |inside_surface_damaged_|.
+  base::AutoReset<bool>(&inside_surface_damaged_, true);
+
   needs_draw_ = true;
 
   if (surface_id == root_surface_id_) {
     root_surface_damaged_ = true;
     expecting_root_surface_damage_because_of_resize_ = false;
   } else {
     child_surface_ids_damaged_.insert(surface_id);
 
     // TODO(mithro): Use hints from SetNeedsBeginFrames and SwapAborts.
     all_active_child_surfaces_ready_to_draw_ = base::STLIncludes(
@@ skipping 36 matching lines @@
 
   expect_damage_from_root_surface_ = root_surface_damaged_;
   root_surface_damaged_ = false;
 }
 
 bool DisplayScheduler::OnBeginFrameDerivedImpl(const BeginFrameArgs& args) {
   base::TimeTicks now = base::TimeTicks::Now();
   TRACE_EVENT2("cc", "DisplayScheduler::BeginFrame", "args", args.AsValue(),
                "now", now);
 
+  if (inside_surface_damaged_) {
+    // Repost this so that we don't run a missed BeginFrame on the same
+    // callstack. Otherwise we end up running unexpected scheduler actions
+    // immediately while inside some other action (such as submitting a
+    // CompositorFrame for a SurfaceFactory).
+    DCHECK_EQ(args.type, BeginFrameArgs::MISSED);
+    DCHECK(missed_begin_frame_task_.IsCancelled());
+    missed_begin_frame_task_.Reset(base::Bind(
+        base::IgnoreResult(&DisplayScheduler::OnBeginFrameDerivedImpl),
+        // The CancelableCallback will not run after it is destroyed, which
+        // happens when |this| is destroyed.
+        base::Unretained(this), args));
+    task_runner_->PostTask(FROM_HERE, missed_begin_frame_task_.callback());
+    return true;
+  }
+
   // If we get another BeginFrame before the previous deadline,
   // synchronously trigger the previous deadline before progressing.
   if (inside_begin_frame_deadline_interval_) {
     OnBeginFrameDeadline();
   }
 
   // Schedule the deadline.
   current_begin_frame_args_ = args;
   current_begin_frame_args_.deadline -=
       BeginFrameArgs::DefaultEstimatedParentDrawTime();
   inside_begin_frame_deadline_interval_ = true;
   ScheduleBeginFrameDeadline();
 
+  // If we get another BeginFrame before a posted missed frame, just drop the
+  // missed frame. Also if this was the missed frame, drop the Callback inside
+  // it. Do this last because this might be the missed frame and we don't want
+  // to destroy |args| prematurely.
+  missed_begin_frame_task_.Cancel();
+
   return true;
 }
 
 void DisplayScheduler::OnBeginFrameSourcePausedChanged(bool paused) {
   // BeginFrameSources used with DisplayScheduler do not make use of this
   // feature.
   if (paused)
     NOTIMPLEMENTED();
 }
 
@@ skipping 112 matching lines @@
     // We are going idle, so reset expectations.
     child_surface_ids_to_expect_damage_from_.clear();
     child_surface_ids_damaged_prev_.clear();
     child_surface_ids_damaged_.clear();
     all_active_child_surfaces_ready_to_draw_ = true;
     expect_damage_from_root_surface_ = false;
 
     if (observing_begin_frame_source_) {
       observing_begin_frame_source_ = false;
       begin_frame_source_->RemoveObserver(this);
+      // A missed BeginFrame may be queued, so drop that too if we're going to
+      // stop listening.
+      missed_begin_frame_task_.Cancel();
     }
   }
 }
 
 void DisplayScheduler::OnBeginFrameDeadline() {
   TRACE_EVENT0("cc", "DisplayScheduler::OnBeginFrameDeadline");
 
   AttemptDrawAndSwap();
   begin_frame_source_->DidFinishFrame(this, 0);
 }
 
 void DisplayScheduler::DidSwapBuffers() {
   pending_swaps_++;
   TRACE_EVENT_ASYNC_BEGIN1("cc", "DisplayScheduler:pending_swaps", this,
                            "pending_frames", pending_swaps_);
 }
 
 void DisplayScheduler::DidSwapBuffersComplete() {
   pending_swaps_--;
   TRACE_EVENT_ASYNC_END1("cc", "DisplayScheduler:pending_swaps", this,
                          "pending_frames", pending_swaps_);
   ScheduleBeginFrameDeadline();
 }
 
 }  // namespace cc