Add SwapPromise support to LayerTreeHost and LayerTreeImpl

cc/trees/thread_proxy.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/trees/thread_proxy.h"
 
 #include <string>
 
 #include "base/auto_reset.h"
 #include "base/bind.h"
 #include "base/debug/trace_event.h"
 #include "base/metrics/histogram.h"
+#include "cc/base/swap_promise.h"
 #include "cc/debug/benchmark_instrumentation.h"
 #include "cc/input/input_handler.h"
 #include "cc/output/context_provider.h"
 #include "cc/output/output_surface.h"
 #include "cc/quads/draw_quad.h"
 #include "cc/resources/prioritized_resource_manager.h"
 #include "cc/scheduler/delay_based_time_source.h"
 #include "cc/scheduler/frame_rate_controller.h"
 #include "cc/scheduler/scheduler.h"
 #include "cc/trees/blocking_task_runner.h"
 #include "cc/trees/layer_tree_host.h"
 #include "cc/trees/layer_tree_impl.h"
 #include "ui/gfx/frame_time.h"
 
+namespace {
+
 // Measured in seconds.
 const double kSmoothnessTakesPriorityExpirationDelay = 0.25;
 
 const size_t kDurationHistorySize = 60;
 const double kCommitAndActivationDurationEstimationPercentile = 50.0;
 const double kDrawDurationEstimationPercentile = 100.0;
 const int kDrawDurationEstimatePaddingInMicroseconds = 0;
 
+class SwapPromiseChecker {
+ public:
+  explicit SwapPromiseChecker(cc::LayerTreeHost* layer_tree_host)
+        : layer_tree_host_(layer_tree_host) {}
+
+  ~SwapPromiseChecker() {
+    if (layer_tree_host_->HasQueuedSwapPromise())

[danakj, 2013/11/13 23:23:35]

Do you even need this? You could just always call Break and it just does nothing
if its empty?

[Yufeng Shen (Slow to review), 2013/11/14 22:09:55]

Done.

+      layer_tree_host_->BreakSwapPromise(cc::SwapPromise::COMMIT_FAILS);
+  }
+
+ private:
+  cc::LayerTreeHost* layer_tree_host_;
+};
+
+}  // namespace
+
 namespace cc {
 
 struct ThreadProxy::ReadbackRequest {
   CompletionEvent completion;
   bool success;
   void* pixels;
   gfx::Rect rect;
 };
 
 struct ThreadProxy::CommitPendingRequest {
@@ skipping 678 matching lines @@
   if (!layer_tree_host_)
     return;
 
   if (defer_commits_) {
     pending_deferred_commit_ = begin_main_frame_state.Pass();
     layer_tree_host_->DidDeferCommit();
     TRACE_EVENT0("cc", "EarlyOut_DeferCommits");
     return;
   }
 
+  // If the commit finishes, LTH will transfer its swap promises to LTI.

[danakj, 2013/11/13 23:22:09]

Spell out LayerTreeHost and LayerTreeImpl

[Yufeng Shen (Slow to review), 2013/11/14 22:09:55]

Done.

+  // The dtor of SwapPromiseChecker will check LTH's swap promises, and

[danakj, 2013/11/13 23:22:09]

destructor

check the LayerTreeHost's swap promises

[Yufeng Shen (Slow to review), 2013/11/14 22:09:55]

Done.

+  // break those swap promises if the commit ever aborts.
+  SwapPromiseChecker swap_promise_checker(layer_tree_host_);
+
   // Do not notify the impl thread of commit requests that occur during
   // the apply/animate/layout part of the BeginMainFrameAndCommit process since
   // those commit requests will get painted immediately. Once we have done
   // the paint, commit_requested_ will be set to false to allow new commit
   // requests to be scheduled.
   commit_requested_ = true;
   commit_request_sent_to_impl_thread_ = true;
 
   // On the other hand, the AnimationRequested flag needs to be cleared
   // here so that any animation requests generated by the apply or animate
@@ skipping 359 matching lines @@
       layer_tree_host_impl_->Readback(readback_request_on_impl_thread_->pixels,
                                       readback_request_on_impl_thread_->rect);
       result.did_readback = true;
     }
     readback_request_on_impl_thread_->success = result.did_readback;
     readback_request_on_impl_thread_->completion.Signal();
     readback_request_on_impl_thread_ = NULL;
   } else if (draw_frame) {
     DCHECK(swap_requested);
     result.did_swap = layer_tree_host_impl_->SwapBuffers(frame);
+    if (result.did_swap)
+      layer_tree_host_impl_->active_tree()->FinishSwapPromise();
+    else
+      layer_tree_host_impl_->active_tree()->BreakSwapPromise(
+          SwapPromise::SWAP_FAILS);
 
     // We don't know if we have incomplete tiles if we didn't actually swap.
     if (result.did_swap) {
       DCHECK(!frame.has_no_damage);
       SetSwapUsedIncompleteTileOnImplThread(frame.contains_incomplete_tile);
     }
   }
 
   // Tell the main thread that the the newly-commited frame was drawn.
   if (next_frame_is_newly_committed_frame_on_impl_thread_) {
@@ skipping 468 matching lines @@
   commit_to_activate_duration_history_.InsertSample(
       base::TimeTicks::HighResNow() - commit_complete_time_);
 }
 
 void ThreadProxy::DidManageTiles() {
   DCHECK(IsImplThread());
   scheduler_on_impl_thread_->DidManageTiles();
 }
 
 }  // namespace cc