ipc/ipc_sync_message_filter.h

   1 // Copyright (c) 2011 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_SYNC_MESSAGE_FILTER_H_
   6 #define IPC_IPC_SYNC_MESSAGE_FILTER_H_
   7 #pragma once
   8
   9 #include "base/basictypes.h"
  10 #include "base/memory/ref_counted.h"
  11 #include "base/synchronization/lock.h"
  12 #include "ipc/ipc_channel_proxy.h"
  13 #include "ipc/ipc_sync_message.h"
  14 #include <set>
  15
  16 namespace base {
  17 class WaitableEvent;
  18 }
  19
  20 class MessageLoop;
  21
  22 namespace IPC {
  23
  24 class MessageReplyDeserializer;
  25
  26 // This MessageFilter allows sending synchronous IPC messages from a thread
  27 // other than the listener thread associated with the SyncChannel.  It does not
  28 // support fancy features that SyncChannel does, such as handling recursion or
  29 // receiving messages while waiting for a response.  Note that this object can
  30 // be used to send simultaneous synchronous messages from different threads.
  31 class SyncMessageFilter : public ChannelProxy::MessageFilter,
  32                           public Message::Sender {
  33  public:
  34   explicit SyncMessageFilter(base::WaitableEvent* shutdown_event);
  35   virtual ~SyncMessageFilter();
  36
  37   // Message::Sender implementation.
  38   virtual bool Send(Message* message);
  39
  40   // ChannelProxy::MessageFilter implementation.
  41   virtual void OnFilterAdded(Channel* channel);
  42   virtual void OnChannelError();
  43   virtual void OnChannelClosing();
  44   virtual bool OnMessageReceived(const Message& message);
  45
  46  private:
  47   void SendOnIOThread(Message* message);
  48   // Signal all the pending sends as done, used in an error condition.
  49   void SignalAllEvents();
  50
  51   // The channel to which this filter was added.
  52   Channel* channel_;
  53
  54   MessageLoop* listener_loop_;  // The process's main thread.
  55   MessageLoop* io_loop_;  // The message loop where the Channel lives.
  56
  57   typedef std::set<PendingSyncMsg*> PendingSyncMessages;
  58   PendingSyncMessages pending_sync_messages_;
  59
  60   // Locks data members above.
  61   base::Lock lock_;
  62
  63   base::WaitableEvent* shutdown_event_;
  64
  65   DISALLOW_COPY_AND_ASSIGN(SyncMessageFilter);
  66 };
  67
  68 }  // namespace IPC
  69
  70 #endif  // IPC_IPC_SYNC_MESSAGE_FILTER_H_