Introduce ChannelMojo

ipc/mojo/ipc_channel_mojo.h

Index: ipc/mojo/ipc_channel_mojo.h
diff --git a/ipc/mojo/ipc_channel_mojo.h b/ipc/mojo/ipc_channel_mojo.h
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+// Copyright 2014 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 IPC_IPC_CHANNEL_MOJO_H_
+#define IPC_IPC_CHANNEL_MOJO_H_
+
+#include <vector>
+
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/scoped_vector.h"
+#include "base/memory/weak_ptr.h"
+#include "ipc/ipc_channel.h"
+#include "ipc/ipc_channel_factory.h"
+#include "ipc/ipc_export.h"
+#include "ipc/mojo/ipc_message_pipe_reader.h"
+#include "mojo/public/cpp/system/core.h"
+
+namespace mojo {
+namespace embedder {
+struct ChannelInfo;
+}
+}
+
+namespace IPC {
+
+// Mojo-based IPC::Channel implementation over a platform handle.
+//
+// ChannelMojo builds Mojo MessagePipe using underlying pipe given by
+// "bootstrap" IPC::Channel which creates and owns platform pipe like
+// named socket. The bootstrap Channel is used only for establishing
+// the underlying connection. ChannelMojo takes its handle over once
+// the it is made and puts MessagePipe on it.
+//
+// ChannelMojo has a couple of MessagePipes:
+//
+// * The first MessagePipe, which is built on top of bootstrap handle,
+//   is the "control" pipe. It is used to communicate out-of-band
+//   control messages that aren't visible from IPC::Listener.
+//
+// * The second MessagePipe, which is created by the server channel
+//   and sent to client Channel over the control pipe, is used
+//   to send IPC::Messages as an IPC::Sender.
+//
+// TODO(morrita): Extract handle creation part of IPC::Channel into
+//                separate class to clarify what ChannelMojo relies
+//                on.
+// TODO(morrita): Add APIs to create extra MessagePipes to let
+//                Mojo-based objects talk over this Channel.
+//
+class IPC_MOJO_EXPORT ChannelMojo : public Channel {
+ public:
+  // Create ChannelMojo on top of given |bootstrap| channel.
+  static scoped_ptr<ChannelMojo> Create(
+      scoped_ptr<Channel> bootstrap, Mode mode, Listener* listener,
+      scoped_refptr<base::TaskRunner> io_thread_task_runner);
+
+  // Create ChannelMojo. A bootstrap channel is created as well.
+  static scoped_ptr<ChannelMojo> Create(
+      const ChannelHandle &channel_handle, Mode mode, Listener* listener,
+      scoped_refptr<base::TaskRunner> io_thread_task_runner);
+
+  // Create a factory object for ChannelMojo.
+  // The factory is used to create Mojo-based ChannelProxy family.
+  static scoped_ptr<ChannelFactory> CreateFactory(
+      const ChannelHandle &channel_handle, Mode mode,
+      scoped_refptr<base::TaskRunner> io_thread_task_runner);
+
+  virtual ~ChannelMojo();
+
+  // Channel implementation
+  virtual bool Connect() OVERRIDE;
+  virtual void Close() OVERRIDE;
+  virtual bool Send(Message* message) OVERRIDE;
+  virtual base::ProcessId GetPeerPID() const OVERRIDE;
+  virtual base::ProcessId GetSelfPID() const OVERRIDE;
+  virtual ChannelHandle TakePipeHandle() OVERRIDE;
+
+#if defined(OS_POSIX) && !defined(OS_NACL)
+  virtual int GetClientFileDescriptor() const OVERRIDE;
+  virtual int TakeClientFileDescriptor() OVERRIDE;
+#endif  // defined(OS_POSIX) && !defined(OS_NACL)
+
+  // Called from MessagePipeReader implementations
+  void OnMessageReceived(Message& message);
+  void OnConnected(mojo::ScopedMessagePipeHandle pipe);
+  void OnPipeClosed(internal::MessagePipeReader* reader);
+  void OnPipeError(internal::MessagePipeReader* reader);
+  void set_peer_pid(base::ProcessId pid) { peer_pid_ = pid; }
+
+ private:
+  struct ChannelInfoDeleter {
+    void operator()(mojo::embedder::ChannelInfo* ptr) const;
+  };
+
+  // ChannelMojo needs to kill its MessagePipeReader in delayed manner
+  // because the channel wants to kill these readers during the
+  // notifications invoked by them.
+  typedef internal::MessagePipeReader::DelayedDeleter ReaderDeleter;
+
+  class ControlReader;
+  class ServerControlReader;
+  class ClientControlReader;
+  class MessageReader;
+
+  ChannelMojo(scoped_ptr<Channel> bootstrap, Mode mode, Listener* listener,
+              scoped_refptr<base::TaskRunner> io_thread_task_runner);
+
+  void InitOnIOThread(mojo::ScopedMessagePipeHandle control_pipe);
+  scoped_ptr<ControlReader> CreateControlReader(
+      mojo::ScopedMessagePipeHandle pipe);
+  void DidCreateChannel(mojo::embedder::ChannelInfo*);
+
+  base::WeakPtrFactory<ChannelMojo> weak_factory_;
+  scoped_ptr<Channel> bootstrap_;
+  Mode mode_;
+  Listener* listener_;
+  base::ProcessId peer_pid_;
+  scoped_ptr<mojo::embedder::ChannelInfo,
+             ChannelInfoDeleter> channel_info_;
+
+  scoped_ptr<ControlReader, ReaderDeleter> control_reader_;
+  scoped_ptr<MessageReader, ReaderDeleter> message_reader_;
+  ScopedVector<Message> pending_messages_;
+
+  DISALLOW_COPY_AND_ASSIGN(ChannelMojo);
+};
+
+}  // namespace IPC
+
+#endif  // IPC_IPC_CHANNEL_MOJO_H_