gpu: Thread-safe command buffer state lookup.

gpu/ipc/client/command_buffer_proxy_impl.h

Index: gpu/ipc/client/command_buffer_proxy_impl.h
diff --git a/gpu/ipc/client/command_buffer_proxy_impl.h b/gpu/ipc/client/command_buffer_proxy_impl.h
index 89300514ca5aec9da9fb5178c788aba04928ad1c..00f844a8d2c74a7cabcdc6c7058c328390a32415 100644
--- a/gpu/ipc/client/command_buffer_proxy_impl.h
+++ b/gpu/ipc/client/command_buffer_proxy_impl.h
@@ -96,11 +96,10 @@ class GPU_EXPORT CommandBufferProxyImpl
 
   // CommandBuffer implementation:
   State GetLastState() override;
-  int32_t GetLastToken() override;
   void Flush(int32_t put_offset) override;
   void OrderingBarrier(int32_t put_offset) override;
-  void WaitForTokenInRange(int32_t start, int32_t end) override;
-  void WaitForGetOffsetInRange(int32_t start, int32_t end) override;
+  State WaitForTokenInRange(int32_t start, int32_t end) override;
+  State WaitForGetOffsetInRange(int32_t start, int32_t end) override;
   void SetGetBuffer(int32_t shm_id) override;
   scoped_refptr<gpu::Buffer> CreateTransferBuffer(size_t size,
                                                   int32_t* id) override;
@@ -128,6 +127,7 @@ class GPU_EXPORT CommandBufferProxyImpl
   bool IsFenceSyncRelease(uint64_t release) override;
   bool IsFenceSyncFlushed(uint64_t release) override;
   bool IsFenceSyncFlushReceived(uint64_t release) override;
+  bool IsFenceSyncReleased(uint64_t release) override;
   void SignalSyncToken(const gpu::SyncToken& sync_token,
                        const base::Closure& callback) override;
   bool CanWaitUnverifiedSyncToken(const gpu::SyncToken* sync_token) override;
@@ -157,12 +157,6 @@ class GPU_EXPORT CommandBufferProxyImpl
   void SetUpdateVSyncParametersCallback(
       const UpdateVSyncParametersCallback& callback);
 
-  // TODO(apatrick): this is a temporary optimization while skia is calling
-  // ContentGLContext::MakeCurrent prior to every GL call. It saves returning 6
-  // ints redundantly when only the error is needed for the
-  // CommandBufferProxyImpl implementation.
-  gpu::error::Error GetLastError() override;
-
   int32_t route_id() const { return route_id_; }
 
   const scoped_refptr<GpuChannelHost>& channel() const { return channel_; }
@@ -211,6 +205,9 @@ class GPU_EXPORT CommandBufferProxyImpl
   // Try to read an updated copy of the state from shared memory, and calls
   // OnGpuStateError() if the new state has an error.
   void TryUpdateState();
+  // Like above but calls the error handler and disconnects channel by posting
+  // a task.
+  void TryUpdateStateThreadSafe();
   // Like the above but does not call the error event handler if the new state
   // has an error.
   void TryUpdateStateDontReportError();
@@ -240,6 +237,16 @@ class GPU_EXPORT CommandBufferProxyImpl
   // The shared memory area used to update state.
   gpu::CommandBufferSharedState* shared_state() const;
 
+  // The shared memory area used to update state.
+  std::unique_ptr<base::SharedMemory> shared_state_shm_;
+
+  // The last cached state received from the service.
+  State last_state_;
+
+  // Lock to access shared state e.g. sync token release count across multiple
+  // threads. This allows tracking command buffer progress from another thread.
+  base::Lock last_state_lock_;
+
   // There should be a lock_ if this is going to be used across multiple
   // threads, or we guarantee it is used by a single thread by using a thread
   // checker if no lock_ is set.
@@ -252,12 +259,6 @@ class GPU_EXPORT CommandBufferProxyImpl
   // Unowned list of DeletionObservers.
   base::ObserverList<DeletionObserver> deletion_observers_;
 
-  // The last cached state received from the service.
-  State last_state_;
-
-  // The shared memory area used to update state.
-  std::unique_ptr<base::SharedMemory> shared_state_shm_;
-
   scoped_refptr<GpuChannelHost> channel_;
   const gpu::CommandBufferId command_buffer_id_;
   const int32_t route_id_;