cc: Send shared variables between main and impl side using the channel

cc/trees/thread_proxy.h

 // 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.
 
 #ifndef CC_TREES_THREAD_PROXY_H_
 #define CC_TREES_THREAD_PROXY_H_
 
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
@@ skipping 44 matching lines @@
   // with the following stages. For efficiency we can early out at any stage if
   // we decide that no further processing is necessary.
   enum CommitPipelineStage {
     NO_PIPELINE_STAGE,
     ANIMATE_PIPELINE_STAGE,
     UPDATE_LAYERS_PIPELINE_STAGE,
     COMMIT_PIPELINE_STAGE,
   };
 
   struct MainThreadOnly {
-    MainThreadOnly(ThreadProxy* proxy, int layer_tree_host_id);
+    MainThreadOnly(ThreadProxy* proxy, LayerTreeHost* layer_tree_host);
     ~MainThreadOnly();
 
     const int layer_tree_host_id;
 
+    LayerTreeHost* layer_tree_host;
+
     // The furthest pipeline stage which has been requested for the next
     // commit.
     CommitPipelineStage max_requested_pipeline_stage;
     // The commit pipeline stage that is currently being processed.
     CommitPipelineStage current_pipeline_stage;
     // The commit pipeline stage at which processing for the current commit
     // will stop. Only valid while we are executing the pipeline (i.e.,
     // |current_pipeline_stage| is set to a pipeline stage).
     CommitPipelineStage final_pipeline_stage;
 
+    bool commit_waits_for_activation;
+
     bool started;
     bool prepare_tiles_pending;
     bool defer_commits;
 
     RendererCapabilities renderer_capabilities_main_thread_copy;
 
     // TODO(khushalsagar): Make this scoped_ptr<ChannelMain> when ProxyMain
     // and ProxyImpl are split.
     ChannelMain* channel_main;
 
     base::WeakPtrFactory<ThreadProxy> weak_factory;
   };
 
-  // Accessed on the main thread, or when main thread is blocked.
-  struct MainThreadOrBlockedMainThread {
-    explicit MainThreadOrBlockedMainThread(LayerTreeHost* host);
-    ~MainThreadOrBlockedMainThread();
-
+  // Accessed on the impl thread when the main thread is blocked for a commit.
+  struct BlockedMainCommitOnly {
+    BlockedMainCommitOnly();
+    ~BlockedMainCommitOnly();
     LayerTreeHost* layer_tree_host;
-    bool commit_waits_for_activation;
-    bool main_thread_inside_commit;
   };
 
   struct CompositorThreadOnly {
     CompositorThreadOnly(
         ThreadProxy* proxy,
         int layer_tree_host_id,
         RenderingStatsInstrumentation* rendering_stats_instrumentation,
         scoped_ptr<BeginFrameSource> external_begin_frame_source);
     ~CompositorThreadOnly();
 
     const int layer_tree_host_id;
 
     scoped_ptr<Scheduler> scheduler;
 
-    // Set when the main thread is waiting on a
-    // ScheduledActionSendBeginMainFrame to be issued.
-    CompletionEvent* begin_main_frame_sent_completion_event;
+    // Set when the main thread is waiting on a pending tree activation.
+    bool next_commit_waits_for_activation;
 
-    // Set when the main thread is waiting on a commit to complete.
+    // Set when the main thread is waiting on a commit to complete or on a
+    // pending tree activation.
     CompletionEvent* commit_completion_event;
 
-    // Set when the main thread is waiting on a pending tree activation.
-    CompletionEvent* completion_event_for_commit_held_on_tree_activation;
-
     // Set when the next draw should post DidCommitAndDrawFrame to the main
     // thread.
     bool next_frame_is_newly_committed_frame;
 
     bool inside_draw;
 
     bool input_throttled_until_commit;
 
     // Whether a commit has been completed since the last time animations were
     // ticked. If this happens, we need to animate again.
@@ skipping 10 matching lines @@
     BeginFrameArgs last_processed_begin_main_frame_args;
 
     scoped_ptr<LayerTreeHostImpl> layer_tree_host_impl;
 
     ChannelImpl* channel_impl;
 
     base::WeakPtrFactory<ThreadProxy> weak_factory;
   };
 
   const MainThreadOnly& main() const;
-  const MainThreadOrBlockedMainThread& blocked_main() const;
   const CompositorThreadOnly& impl() const;
 
   // Proxy implementation
   void FinishAllRendering() override;
   bool IsStarted() const override;
   bool CommitToActiveTree() const override;
   void SetOutputSurface(OutputSurface* output_surface) override;
   void SetVisible(bool visible) override;
   void SetThrottleFrameProduction(bool throttle) override;
   const RendererCapabilities& GetRendererCapabilities() const override;
@@ skipping 106 matching lines @@
   void FinishAllRenderingOnImpl(CompletionEvent* completion) override;
   void SetVisibleOnImpl(CompletionEvent* completion, bool visible) override;
   void ReleaseOutputSurfaceOnImpl(CompletionEvent* completion) override;
   void FinishGLOnImpl(CompletionEvent* completion) override;
   void MainFrameWillHappenOnImplForTesting(
       CompletionEvent* completion,
       bool* main_frame_will_happen) override;
   void SetNeedsCommitOnImpl() override;
   void SetNeedsRedrawOnImpl(const gfx::Rect& damage_rect) override;
   void BeginMainFrameAbortedOnImpl(CommitEarlyOutReason reason) override;
-  void StartCommitOnImpl(CompletionEvent* completion) override;
+  void StartCommitOnImpl(CompletionEvent* completion,
+                         LayerTreeHost* layer_tree_host,
+                         bool hold_commit_for_activation) override;
+  void InitializeImplOnImpl(CompletionEvent* completion,
+                            LayerTreeHost* layer_tree_host) override;
+  void LayerTreeHostClosedOnImpl(CompletionEvent* completion) override;
 
  protected:
   ThreadProxy(
       LayerTreeHost* layer_tree_host,
       scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
       scoped_refptr<base::SingleThreadTaskRunner> impl_task_runner,
       scoped_ptr<BeginFrameSource> external_begin_frame_source);
 
  private:
   // Called on main thread.
 
   // Returns |true| if the request was actually sent, |false| if one was
   // already outstanding.
   bool SendCommitRequestToImplThreadIfNeeded(
       CommitPipelineStage required_stage);
 
   // Called on impl thread.
   struct SchedulerStateRequest;
 
-  void InitializeImplOnImplThread(CompletionEvent* completion);
-  void LayerTreeHostClosedOnImplThread(CompletionEvent* completion);
   DrawResult DrawSwapInternal(bool forced_draw);
 
   LayerTreeHost* layer_tree_host();
   const LayerTreeHost* layer_tree_host() const;
 
   // Use accessors instead of this variable directly.
   MainThreadOnly main_thread_only_vars_unsafe_;
   MainThreadOnly& main();
 
   // Use accessors instead of this variable directly.
-  MainThreadOrBlockedMainThread main_thread_or_blocked_vars_unsafe_;
-  MainThreadOrBlockedMainThread& blocked_main();
+  BlockedMainCommitOnly main_thread_blocked_commit_vars_unsafe_;
+  BlockedMainCommitOnly& blocked_main_commit();
 
   // Use accessors instead of this variable directly.
   CompositorThreadOnly compositor_thread_vars_unsafe_;
   CompositorThreadOnly& impl();
 
   // TODO(khushalsagar): Remove this. Temporary variable to hold the channel.
   scoped_ptr<ThreadedChannel> threaded_channel_;
 
   base::WeakPtr<ThreadProxy> main_thread_weak_ptr_;
   base::WeakPtr<ThreadProxy> impl_thread_weak_ptr_;
 
   DISALLOW_COPY_AND_ASSIGN(ThreadProxy);
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_THREAD_PROXY_H_