ChannelMojo: Handle when ChannelMojo outlives ChannelMojoHost

ipc/mojo/ipc_channel_mojo.h

 // 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"
@@ skipping 14 matching lines @@
 
 namespace IPC {
 
 namespace internal {
 class ControlReader;
 class ServerControlReader;
 class ClientControlReader;
 class MessageReader;
 }
 
-class ChannelMojoHost;
-
 // 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 MojoBootstrap::Delegate {
  public:
+  class Delegate {
+   public:
+    virtual ~Delegate() {}
+    virtual base::WeakPtr<Delegate> ToWeakPtr() = 0;
+    virtual scoped_refptr<base::TaskRunner> GetIOTaskRunner() = 0;
+    virtual void OnChannelCreated(base::WeakPtr<ChannelMojo> channel) = 0;
+  };
+
   // Create ChannelMojo. A bootstrap channel is created as well.
-  // |host| must not be null.
-  static scoped_ptr<ChannelMojo> Create(ChannelMojoHost* host,
+  // |host| must not be null for server channels.
+  static scoped_ptr<ChannelMojo> Create(Delegate* delegate,
                                         const ChannelHandle& channel_handle,
                                         Mode mode,
                                         Listener* listener);
 
   // Create a factory object for ChannelMojo.
   // The factory is used to create Mojo-based ChannelProxy family.
   // |host| must not be null.
   static scoped_ptr<ChannelFactory> CreateServerFactory(
-      ChannelMojoHost* host,
+      Delegate* delegate,
       const ChannelHandle& channel_handle);
 
   static scoped_ptr<ChannelFactory> CreateClientFactory(
       const ChannelHandle& channel_handle);
 
   virtual ~ChannelMojo();
 
   // ChannelMojoHost tells the client handle using this API.
   void OnClientLaunched(base::ProcessHandle handle);
 
@@ skipping 25 matching lines @@
   virtual void OnBootstrapError() OVERRIDE;
 
   // 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; }
 
  protected:
-  ChannelMojo(ChannelMojoHost* host,
+  ChannelMojo(Delegate* delegate,
               const ChannelHandle& channel_handle,
               Mode mode,
               Listener* listener);
 
  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;
 
+  void InitDelegate(ChannelMojo::Delegate* delegate);
   void InitControlReader(mojo::embedder::ScopedPlatformHandle handle);
 
   scoped_ptr<MojoBootstrap> bootstrap_;
-  ChannelMojoHost* const host_;
+  base::WeakPtr<Delegate> delegate_;
   Mode mode_;
   Listener* listener_;
   base::ProcessId peer_pid_;
   scoped_ptr<mojo::embedder::ChannelInfo,
              ChannelInfoDeleter> channel_info_;
 
   scoped_ptr<internal::ControlReader, ReaderDeleter> control_reader_;
   scoped_ptr<internal::MessageReader, ReaderDeleter> message_reader_;
   ScopedVector<Message> pending_messages_;
 
   base::WeakPtrFactory<ChannelMojo> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ChannelMojo);
 };
 
 }  // namespace IPC
 
 #endif  // IPC_IPC_CHANNEL_MOJO_H_