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   // True if ChannelMojo should be used regardless of the flag.
  61   static bool ShouldBeUsed();
  62
  63   // Create ChannelMojo. A bootstrap channel is created as well.
  64   // |broker| must outlive the newly created channel.
  65   static scoped_ptr<ChannelMojo> Create(
  66       scoped_refptr<base::TaskRunner> io_runner,
  67       const ChannelHandle& channel_handle,
  68       Mode mode,
  69       Listener* listener,
  70       AttachmentBroker* broker);
  71
  72   // Create a factory object for ChannelMojo.
  73   // The factory is used to create Mojo-based ChannelProxy family.
  74   // |host| must not be null.
  75   // TODO(erikchen): Remove default parameter for |broker|. It exists only to
  76   // make the upcoming refactor decomposable into smaller CLs.
  77   // http://crbug.com/493414.
  78   // |broker| must outlive the factory and all channels it creates.
  79   static scoped_ptr<ChannelFactory> CreateServerFactory(
  80       scoped_refptr<base::TaskRunner> io_runner,
  81       const ChannelHandle& channel_handle,
  82       AttachmentBroker* broker = nullptr);
  83
  84   // TODO(erikchen): Remove default parameter for |broker|. It exists only to
  85   // make the upcoming refactor decomposable into smaller CLs.
  86   // http://crbug.com/493414.
  87   // |broker| must outlive the factory and all channels it creates.
  88   static scoped_ptr<ChannelFactory> CreateClientFactory(
  89       scoped_refptr<base::TaskRunner> io_runner,
  90       const ChannelHandle& channel_handle,
  91       AttachmentBroker* broker = nullptr);
  92
  93   ~ChannelMojo() override;
  94
  95   // Channel implementation
  96   bool Connect() override;
  97   void Close() override;
  98   bool Send(Message* message) override;
  99   bool IsSendThreadSafe() const override;
 100   base::ProcessId GetPeerPID() const override;
 101   base::ProcessId GetSelfPID() const override;
 102
 103 #if defined(OS_POSIX) && !defined(OS_NACL)
 104   int GetClientFileDescriptor() const override;
 105   base::ScopedFD TakeClientFileDescriptor() override;
 106 #endif  // defined(OS_POSIX) && !defined(OS_NACL)
 107
 108   // These access protected API of IPC::Message, which has ChannelMojo
 109   // as a friend class.
 110   static MojoResult WriteToMessageAttachmentSet(
 111       const std::vector<MojoHandle>& handle_buffer,
 112       Message* message);
 113   static MojoResult ReadFromMessageAttachmentSet(
 114       Message* message,
 115       std::vector<MojoHandle>* handles);
 116
 117   // MojoBootstrapDelegate implementation
 118   void OnBootstrapError() override;
 119
 120   // MessagePipeReader::Delegate
 121   void OnMessageReceived(Message& message) override;
 122   void OnPipeClosed(internal::MessagePipeReader* reader) override;
 123   void OnPipeError(internal::MessagePipeReader* reader) override;
 124
 125  protected:
 126   ChannelMojo(scoped_refptr<base::TaskRunner> io_runner,
 127               const ChannelHandle& channel_handle,
 128               Mode mode,
 129               Listener* listener,
 130               AttachmentBroker* broker);
 131
 132   void CreateMessagingPipe(mojo::embedder::ScopedPlatformHandle handle,
 133                            const CreateMessagingPipeCallback& callback);
 134   void InitMessageReader(mojo::ScopedMessagePipeHandle pipe, int32_t peer_pid);
 135
 136   Listener* listener() const { return listener_; }
 137   void set_peer_pid(base::ProcessId pid) { peer_pid_ = pid; }
 138
 139  private:
 140   struct ChannelInfoDeleter {
 141     explicit ChannelInfoDeleter(scoped_refptr<base::TaskRunner> io_runner);
 142     ~ChannelInfoDeleter();
 143
 144     void operator()(mojo::embedder::ChannelInfo* ptr) const;
 145
 146     scoped_refptr<base::TaskRunner> io_runner;
 147   };
 148
 149   // ChannelMojo needs to kill its MessagePipeReader in delayed manner
 150   // because the channel wants to kill these readers during the
 151   // notifications invoked by them.
 152   typedef internal::MessagePipeReader::DelayedDeleter ReaderDeleter;
 153
 154   void InitOnIOThread();
 155
 156   static void CreateMessagingPipeOnIOThread(
 157       mojo::embedder::ScopedPlatformHandle handle,
 158       scoped_refptr<base::TaskRunner> callback_runner,
 159       const CreateMessagingPipeOnIOThreadCallback& callback);
 160   void OnMessagingPipeCreated(const CreateMessagingPipeCallback& callback,
 161                               mojo::ScopedMessagePipeHandle handle,
 162                               mojo::embedder::ChannelInfo* channel_info);
 163
 164   scoped_ptr<MojoBootstrap> bootstrap_;
 165   Listener* listener_;
 166   base::ProcessId peer_pid_;
 167   scoped_refptr<base::TaskRunner> io_runner_;
 168   scoped_ptr<mojo::embedder::ChannelInfo,
 169              ChannelInfoDeleter> channel_info_;
 170
 171   // Guards |message_reader_|, |waiting_connect_| and |pending_messages_|
 172   //
 173   // * The contents of |pending_messages_| can be modified from any thread.
 174   // * |message_reader_| is modified only from the IO thread,
 175   //   but they can be referenced from other threads.
 176   base::Lock lock_;
 177   scoped_ptr<internal::MessagePipeReader, ReaderDeleter> message_reader_;
 178   ScopedVector<Message> pending_messages_;
 179   bool waiting_connect_;
 180
 181   scoped_ptr<ScopedIPCSupport> ipc_support_;
 182
 183   base::WeakPtrFactory<ChannelMojo> weak_factory_;
 184
 185   DISALLOW_COPY_AND_ASSIGN(ChannelMojo);
 186 };
 187
 188 }  // namespace IPC
 189
 190 #endif  // IPC_IPC_CHANNEL_MOJO_H_