Implement GpuArcVideoService for arc video accelerator

content/common/gpu/media/gpu_arc_video_service.h

+// 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.
+
+#ifndef CONTENT_COMMON_GPU_MEDIA_GPU_ARC_VIDEO_SERVICE_H_
+#define CONTENT_COMMON_GPU_MEDIA_GPU_ARC_VIDEO_SERVICE_H_
+
+#include <map>
+
+#include "base/memory/ref_counted.h"
+#include "base/threading/non_thread_safe.h"
+#include "base/threading/thread.h"
+#include "media/video/arc_video_accelerator.h"
+
+namespace base {
+class SingleThreadTaskRunner;
+class WaitableEvent;
+}
+
+namespace IPC {
+class Sender;
+}
+
+namespace content {
+
+// GpuArcVideoService manages life-cycle and IPC message translation for
+// ArcVideoAccelerator.
+//
+// For each creation requests from GpuChannelManager, GpuArcVideoService will
+// create a new IPC channel. All messages to ArcVideoAccelerator are handled on
+// |arc_video_accelerator_thread_|.
+class GpuArcVideoService : public base::NonThreadSafe {
+ public:
+  class AcceleratorStub;
+
+  // |gpu_channel_manager| is used to send reply message for CreateChannel.
+  // |shutdown_event| should signal an event when this process shutdown in
+  // order to notify our new IPC channel to terminate.
+  GpuArcVideoService(
+      IPC::Sender* gpu_channel_manager,
+      base::WaitableEvent* shutdown_event,
+      const scoped_refptr<base::SingleThreadTaskRunner>& io_task_runner);
+
+  // Upon deletion, all ArcVideoAccelerator will be deleted and the associated
+  // IPC channels are closed.
+  ~GpuArcVideoService();
+
+  void Initialize();
+
+  // Creates a new accelerator stub. The creation result, as an IPC message,
+  // will be send
+  // back via |gpu_channel_manager_|.
+  void CreateChannel();

[Owen Lin, 2015/12/15 03:04:06]

I mean if we have a callback for this function. It is easy to understand (and
more flexible) How the channel is returned. You can send the message inside the
callback.

typedef Callback<void(Handle)> CreateChannelCallback;

void CreateChannel(const CreateChannelCallback& callback);

[kcwu, 2015/12/16 14:05:33]

Done.

+
+  // Removes the reference of |stub| (and trigger deletion) from this class.
+  void RemoveClientOnArcThread(AcceleratorStub* stub);
+
+ private:
+  void CreateClientOnArcThread();
+  void RemoveAllClientsOnArcThread(base::WaitableEvent* done);
+
+  // |gpu_channel_manager_| outlives this class. So a raw pointer is safe.
+  IPC::Sender* gpu_channel_manager_;
+
+  // Shutdown event of GPU process.
+  base::WaitableEvent* shutdown_event_;
+
+  // GPU io thread task runner.
+  scoped_refptr<base::SingleThreadTaskRunner> io_task_runner_;
+
+  // GPU main thread task runner.
+  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
+
+  // Arc accelerator thread.
+  base::Thread arc_video_accelerator_thread_;
+
+  // Arc accelerator task runner.
+  scoped_refptr<base::SingleThreadTaskRunner> arc_task_runner_;
+
+  // Bookkeeping all accelerator stubs. Only accessed on arc thread.
+  std::map<AcceleratorStub*, scoped_ptr<AcceleratorStub>> accelerator_stubs_;
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(GpuArcVideoService);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_COMMON_GPU_MEDIA_GPU_ARC_VIDEO_SERVICE_H_