Switch stream creation and closing in Chrome audio rendering from IPC to Mojo

content/renderer/media/audio_output_client.h

+// Copyright 2016 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_RENDERER_MEDIA_AUDIO_OUTPUT_CLIENT_H_
+#define CONTENT_RENDERER_MEDIA_AUDIO_OUTPUT_CLIENT_H_
+
+#include <map>
+
+#include "base/files/file.h"
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/shared_memory_handle.h"
+#include "base/message_loop/message_loop.h"
+#include "base/sync_socket.h"
+#include "base/threading/thread_checker.h"
+#include "content/common/content_export.h"
+#include "media/mojo/interfaces/audio_output.mojom.h"
+#include "mojo/edk/embedder/embedder.h"
+#include "mojo/public/c/system/buffer.h"
+#include "mojo/public/cpp/bindings/binding.h"
+#include "mojo/public/cpp/bindings/binding.h"
+#include "mojo/public/cpp/bindings/interface_request.h"
+#include "mojo/public/cpp/system/handle.h"
+
+namespace base {
+class SingleThreadTaskRunner;
+}
+
+namespace media {
+class AudioParameters;
+}
+
+namespace content {
+
+class AudioMessageFilter;
+class ServiceRegistry;
+
+class CONTENT_EXPORT AudioOutputClient
+    : public base::RefCounted<AudioOutputClient> {
+ public:
+  using AudioOutputStreamPtrMap =
+      std::map<int, media::mojom::AudioOutputStreamPtr>;
+
+  // Creates a Mojo Audio Output Client. It's going to be created by
+  // RenderThreadImpl::init() and be bound to RenderThread. This means that all
+  // future Mojo service calls and all Mojo callbacks are going to be
+  // performed on the RenderThread.
+  explicit AudioOutputClient(
+      ServiceRegistry* service_registry,
+      const scoped_refptr<base::SingleThreadTaskRunner> thread_task_runner =
+          base::MessageLoop::current()->task_runner());
+
+  // Creates stream by calling the AudioOutput.CreateStream Mojo interface
+  // function using the Mojo service. This function could be called on any
+  // thread and is going to call itself in the RenderThread if it's not
+  // already running there.
+  void CreateStream(int stream_id,
+                    const media::AudioParameters& params,
+                    const media::mojom::AudioOutput::CreateStreamCallback&
+                        create_stream_callback);
+
+  // Callback for AudioOutput.CreateStream which contains information about
+  // the new created stream. Called on RenderThread. This function is going to
+  // notify the |audio_message_filter_| of the stream creation by calling
+  // StreamCreated. StreamCreated could only be ran on |io_task_runner_| and
+  // this is why CreateStreamOnIOThread is going to be used to do that.
+  void CreateStreamCallback(int stream_id,

[Henrik Grunell, 2016/05/20 13:35:41]

Maybe call this StreamCreated()?

+                            media::mojom::AudioOutputStreamPtr stream,
+                            mojo::ScopedSharedBufferHandle shared_buffer,
+                            mojo::ScopedHandle socket_descriptor);
+
+  // Closes stream by calling the AudioOutputStream.Close Mojo interface
+  // function using the Mojo service. This function could be called on any
+  // thread and is going to call itself in the RenderThread if it's not
+  // already running there.
+  void CloseStream(int stream_id);
+
+ private:
+  friend class base::RefCounted<AudioOutputClient>;
+  friend class AudioOutputClientTest;
+  FRIEND_TEST_ALL_PREFIXES(AudioOutputClientTest, CreateStream);
+  FRIEND_TEST_ALL_PREFIXES(AudioOutputClientTest,
+                           CloseAuthorizedNotCreatedStream);
+  FRIEND_TEST_ALL_PREFIXES(AudioOutputClientTest, CloseCreatedStream);
+
+  ~AudioOutputClient();
+
+  // Notifies the |audio_message_filter_| of the stream creation. Can only be
+  // called on |io_task_runner_|.

[Henrik Grunell, 2016/05/20 13:35:41]

Explain why this is needed. (Why is it needed? Can't everything be done here for
create stream?)

+  void CreateStreamOnIOThread(
+      AudioOutputClient::AudioOutputStreamPtrMap::iterator stream,
+      base::SharedMemoryHandle handle,
+      base::SyncSocket::TransitDescriptor socket_descriptor,
+      uint32_t length);
+
+  // Called when there is an error with AudioOutputStream Mojo interface in
+  // the renderer. This function is going to call ReportErrorOnIOThread in the
+  // RenderThread.
+  void OnStreamError(int stream_id);
+
+  // Notifies the |audio_message_filter_| of a stream error. Can only be called
+  // on |io_task_runner_|.
+  void ReportErrorOnIOThread(int stream_id);
+
+  const scoped_refptr<base::SingleThreadTaskRunner> thread_task_runner_;
+  media::mojom::AudioOutputPtr service_;
+  AudioOutputStreamPtrMap streams_;
+
+  DISALLOW_COPY_AND_ASSIGN(AudioOutputClient);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_RENDERER_MEDIA_AUDIO_OUTPUT_CLIENT_H_