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   using CreateMessagingPipeCallback =
  55       base::Callback<void(mojo::ScopedMessagePipeHandle)>;
  56   using CreateMessagingPipeOnIOThreadCallback =
  57       base::Callback<void(mojo::ScopedMessagePipeHandle,
  58                           mojo::embedder::ChannelInfo*)>;
  59
  60   class Delegate {
  61    public:
  62     virtual ~Delegate() {}
  63     virtual base::WeakPtr<Delegate> ToWeakPtr() = 0;
  64     virtual void OnChannelCreated(base::WeakPtr<ChannelMojo> channel) = 0;
  65   };
  66
  67   // True if ChannelMojo should be used regardless of the flag.
  68   static bool ShouldBeUsed();
  69
  70   // Create ChannelMojo. A bootstrap channel is created as well.
  71   // |host| must not be null for server channels.
  72   static scoped_ptr<ChannelMojo> Create(
  73       Delegate* delegate,
  74       scoped_refptr<base::TaskRunner> io_runner,
  75       const ChannelHandle& channel_handle,
  76       Mode mode,
  77       Listener* listener);
  78
  79   // Create a factory object for ChannelMojo.
  80   // The factory is used to create Mojo-based ChannelProxy family.
  81   // |host| must not be null.
  82   static scoped_ptr<ChannelFactory> CreateServerFactory(
  83       Delegate* delegate,
  84       scoped_refptr<base::TaskRunner> io_runner,
  85       const ChannelHandle& channel_handle);
  86
  87   static scoped_ptr<ChannelFactory> CreateClientFactory(
  88       Delegate* delegate,
  89       scoped_refptr<base::TaskRunner> io_runner,
  90       const ChannelHandle& channel_handle);
  91
  92   ~ChannelMojo() override;
  93
  94   // ChannelMojoHost tells the client handle using this API.
  95   void OnClientLaunched(base::ProcessHandle handle);
  96
  97   // Channel implementation
  98   bool Connect() override;
  99   void Close() override;
 100   bool Send(Message* message) override;
 101   bool IsSendThreadSafe() const override;
 102   base::ProcessId GetPeerPID() const override;
 103   base::ProcessId GetSelfPID() const override;
 104
 105 #if defined(OS_POSIX) && !defined(OS_NACL)
 106   int GetClientFileDescriptor() const override;
 107   base::ScopedFD TakeClientFileDescriptor() override;
 108 #endif  // defined(OS_POSIX) && !defined(OS_NACL)
 109
 110   // These access protected API of IPC::Message, which has ChannelMojo
 111   // as a friend class.
 112   static MojoResult WriteToMessageAttachmentSet(
 113       const std::vector<MojoHandle>& handle_buffer,
 114       Message* message);
 115   static MojoResult ReadFromMessageAttachmentSet(
 116       Message* message,
 117       std::vector<MojoHandle>* handles);
 118
 119   // MojoBootstrapDelegate implementation
 120   void OnBootstrapError() override;
 121
 122   // MessagePipeReader::Delegate
 123   void OnMessageReceived(Message& message) override;
 124   void OnPipeClosed(internal::MessagePipeReader* reader) override;
 125   void OnPipeError(internal::MessagePipeReader* reader) override;
 126
 127  protected:
 128   ChannelMojo(Delegate* delegate,
 129               scoped_refptr<base::TaskRunner> io_runner,
 130               const ChannelHandle& channel_handle,
 131               Mode mode,
 132               Listener* listener);
 133
 134   void CreateMessagingPipe(mojo::embedder::ScopedPlatformHandle handle,
 135                            const CreateMessagingPipeCallback& callback);
 136   void InitMessageReader(mojo::ScopedMessagePipeHandle pipe, int32_t peer_pid);
 137
 138   Listener* listener() const { return listener_; }
 139   void set_peer_pid(base::ProcessId pid) { peer_pid_ = pid; }
 140
 141  private:
 142   struct ChannelInfoDeleter {
 143     explicit ChannelInfoDeleter(scoped_refptr<base::TaskRunner> io_runner);
 144     ~ChannelInfoDeleter();
 145
 146     void operator()(mojo::embedder::ChannelInfo* ptr) const;
 147
 148     scoped_refptr<base::TaskRunner> io_runner;
 149   };
 150
 151   // ChannelMojo needs to kill its MessagePipeReader in delayed manner
 152   // because the channel wants to kill these readers during the
 153   // notifications invoked by them.
 154   typedef internal::MessagePipeReader::DelayedDeleter ReaderDeleter;
 155
 156   void InitOnIOThread(ChannelMojo::Delegate* delegate);
 157
 158   static void CreateMessagingPipeOnIOThread(
 159       mojo::embedder::ScopedPlatformHandle handle,
 160       scoped_refptr<base::TaskRunner> callback_runner,
 161       const CreateMessagingPipeOnIOThreadCallback& callback);
 162   void OnMessagingPipeCreated(const CreateMessagingPipeCallback& callback,
 163                               mojo::ScopedMessagePipeHandle handle,
 164                               mojo::embedder::ChannelInfo* channel_info);
 165
 166   scoped_ptr<MojoBootstrap> bootstrap_;
 167   base::WeakPtr<Delegate> delegate_;
 168   Mode mode_;
 169   Listener* listener_;
 170   base::ProcessId peer_pid_;
 171   scoped_refptr<base::TaskRunner> io_runner_;
 172   scoped_ptr<mojo::embedder::ChannelInfo,
 173              ChannelInfoDeleter> channel_info_;
 174
 175   // Guards |message_reader_| and |pending_messages_|
 176   //
 177   // * The contents of |pending_messages_| can be modified from any thread.
 178   // * |message_reader_| is modified only from the IO thread,
 179   //   but they can be referenced from other threads.
 180   base::Lock lock_;
 181   scoped_ptr<internal::MessagePipeReader, ReaderDeleter> message_reader_;
 182   ScopedVector<Message> pending_messages_;
 183
 184   scoped_ptr<ScopedIPCSupport> ipc_support_;
 185
 186   base::WeakPtrFactory<ChannelMojo> weak_factory_;
 187
 188   DISALLOW_COPY_AND_ASSIGN(ChannelMojo);
 189 };
 190
 191 }  // namespace IPC
 192
 193 #endif  // IPC_IPC_CHANNEL_MOJO_H_