ipc/mojo/ipc_channel_mojo.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef IPC_IPC_CHANNEL_MOJO_H_
   6 #define IPC_IPC_CHANNEL_MOJO_H_
   7
   8 #include <vector>
   9
  10 #include "base/memory/scoped_ptr.h"
  11 #include "base/memory/scoped_vector.h"
  12 #include "base/memory/weak_ptr.h"
  13 #include "base/synchronization/lock.h"
  14 #include "ipc/ipc_channel.h"
  15 #include "ipc/ipc_channel_factory.h"
  16 #include "ipc/ipc_export.h"
  17 #include "ipc/mojo/ipc_message_pipe_reader.h"
  18 #include "ipc/mojo/ipc_mojo_bootstrap.h"
  19 #include "ipc/mojo/scoped_ipc_support.h"
  20 #include "third_party/mojo/src/mojo/edk/embedder/channel_info_forward.h"
  21 #include "third_party/mojo/src/mojo/public/cpp/system/core.h"
  22
  23 namespace IPC {
  24
  25 // Mojo-based IPC::Channel implementation over a platform handle.
  26 //
  27 // ChannelMojo builds Mojo MessagePipe using underlying pipe given by
  28 // "bootstrap" IPC::Channel which creates and owns platform pipe like
  29 // named socket. The bootstrap Channel is used only for establishing
  30 // the underlying connection. ChannelMojo takes its handle over once
  31 // the it is made and puts MessagePipe on it.
  32 //
  33 // ChannelMojo has a couple of MessagePipes:
  34 //
  35 // * The first MessagePipe, which is built on top of bootstrap handle,
  36 //   is the "control" pipe. It is used to communicate out-of-band
  37 //   control messages that aren't visible from IPC::Listener.
  38 //
  39 // * The second MessagePipe, which is created by the server channel
  40 //   and sent to client Channel over the control pipe, is used
  41 //   to send IPC::Messages as an IPC::Sender.
  42 //
  43 // TODO(morrita): Extract handle creation part of IPC::Channel into
  44 //                separate class to clarify what ChannelMojo relies
  45 //                on.
  46 // TODO(morrita): Add APIs to create extra MessagePipes to let
  47 //                Mojo-based objects talk over this Channel.
  48 //
  49 class IPC_MOJO_EXPORT ChannelMojo
  50     : public Channel,
  51       public MojoBootstrap::Delegate,
  52       public NON_EXPORTED_BASE(internal::MessagePipeReader::Delegate) {
  53  public:
  54   class Delegate {
  55    public:
  56     virtual ~Delegate() {}
  57     virtual base::WeakPtr<Delegate> ToWeakPtr() = 0;
  58     virtual void OnChannelCreated(base::WeakPtr<ChannelMojo> channel) = 0;
  59   };
  60
  61   // True if ChannelMojo should be used regardless of the flag.
  62   static bool ShouldBeUsed();
  63
  64   // Create ChannelMojo. A bootstrap channel is created as well.
  65   // |host| must not be null for server channels.
  66   static scoped_ptr<ChannelMojo> Create(
  67       Delegate* delegate,
  68       scoped_refptr<base::TaskRunner> io_runner,
  69       const ChannelHandle& channel_handle,
  70       Mode mode,
  71       Listener* listener);
  72
  73   // Create a factory object for ChannelMojo.
  74   // The factory is used to create Mojo-based ChannelProxy family.
  75   // |host| must not be null.
  76   static scoped_ptr<ChannelFactory> CreateServerFactory(
  77       Delegate* delegate,
  78       scoped_refptr<base::TaskRunner> io_runner,
  79       const ChannelHandle& channel_handle);
  80
  81   static scoped_ptr<ChannelFactory> CreateClientFactory(
  82       Delegate* delegate,
  83       scoped_refptr<base::TaskRunner> io_runner,
  84       const ChannelHandle& channel_handle);
  85
  86   ~ChannelMojo() override;
  87
  88   // ChannelMojoHost tells the client handle using this API.
  89   void OnClientLaunched(base::ProcessHandle handle);
  90
  91   // Channel implementation
  92   bool Connect() override;
  93   void Close() override;
  94   bool Send(Message* message) override;
  95   bool IsSendThreadSafe() const override;
  96   base::ProcessId GetPeerPID() const override;
  97   base::ProcessId GetSelfPID() const override;
  98
  99 #if defined(OS_POSIX) && !defined(OS_NACL)
 100   int GetClientFileDescriptor() const override;
 101   base::ScopedFD TakeClientFileDescriptor() override;
 102 #endif  // defined(OS_POSIX) && !defined(OS_NACL)
 103
 104   // These access protected API of IPC::Message, which has ChannelMojo
 105   // as a friend class.
 106   static MojoResult WriteToMessageAttachmentSet(
 107       const std::vector<MojoHandle>& handle_buffer,
 108       Message* message);
 109   static MojoResult ReadFromMessageAttachmentSet(
 110       Message* message,
 111       std::vector<MojoHandle>* handles);
 112
 113   // MojoBootstrapDelegate implementation
 114   void OnBootstrapError() override;
 115
 116   // MessagePipeReader::Delegate
 117   void OnMessageReceived(Message& message) override;
 118   void OnPipeClosed(internal::MessagePipeReader* reader) override;
 119   void OnPipeError(internal::MessagePipeReader* reader) override;
 120
 121  protected:
 122   ChannelMojo(Delegate* delegate,
 123               scoped_refptr<base::TaskRunner> io_runner,
 124               const ChannelHandle& channel_handle,
 125               Mode mode,
 126               Listener* listener);
 127
 128   mojo::ScopedMessagePipeHandle CreateMessagingPipe(
 129       mojo::embedder::ScopedPlatformHandle handle);
 130   void InitMessageReader(mojo::ScopedMessagePipeHandle pipe, int32_t peer_pid);
 131
 132   Listener* listener() const { return listener_; }
 133   void set_peer_pid(base::ProcessId pid) { peer_pid_ = pid; }
 134
 135  private:
 136   struct ChannelInfoDeleter {
 137     void operator()(mojo::embedder::ChannelInfo* ptr) const;
 138   };
 139
 140   // ChannelMojo needs to kill its MessagePipeReader in delayed manner
 141   // because the channel wants to kill these readers during the
 142   // notifications invoked by them.
 143   typedef internal::MessagePipeReader::DelayedDeleter ReaderDeleter;
 144
 145   void InitOnIOThread(ChannelMojo::Delegate* delegate);
 146
 147   scoped_ptr<MojoBootstrap> bootstrap_;
 148   base::WeakPtr<Delegate> delegate_;
 149   Mode mode_;
 150   Listener* listener_;
 151   base::ProcessId peer_pid_;
 152   scoped_refptr<base::TaskRunner> io_runner_;
 153   scoped_ptr<mojo::embedder::ChannelInfo,
 154              ChannelInfoDeleter> channel_info_;
 155
 156   // Guards |message_reader_| and |pending_messages_|
 157   //
 158   // * The contents of |pending_messages_| can be modified from any thread.
 159   // * |message_reader_| is modified only from the IO thread,
 160   //   but they can be referenced from other threads.
 161   base::Lock lock_;
 162   scoped_ptr<internal::MessagePipeReader, ReaderDeleter> message_reader_;
 163   ScopedVector<Message> pending_messages_;
 164
 165   scoped_ptr<ScopedIPCSupport> ipc_support_;
 166
 167   base::WeakPtrFactory<ChannelMojo> weak_factory_;
 168
 169   DISALLOW_COPY_AND_ASSIGN(ChannelMojo);
 170 };
 171
 172 }  // namespace IPC
 173
 174 #endif  // IPC_IPC_CHANNEL_MOJO_H_