1// Copyright (c) 2012 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 8#include <set> 9 10#include "base/basictypes.h" 11#include "base/memory/ref_counted.h" 12#include "base/synchronization/lock.h" 13#include "ipc/ipc_sender.h" 14#include "ipc/ipc_sync_message.h" 15#include "ipc/message_filter.h" 16 17namespace base { 18class MessageLoopProxy; 19class WaitableEvent; 20} 21 22namespace IPC { 23 24// This MessageFilter allows sending synchronous IPC messages from a thread 25// other than the listener thread associated with the SyncChannel. It does not 26// support fancy features that SyncChannel does, such as handling recursion or 27// receiving messages while waiting for a response. Note that this object can 28// be used to send simultaneous synchronous messages from different threads. 29class IPC_EXPORT SyncMessageFilter : public MessageFilter, public Sender { 30 public: 31 explicit SyncMessageFilter(base::WaitableEvent* shutdown_event); 32 33 // MessageSender implementation. 34 virtual bool Send(Message* message) OVERRIDE; 35 36 // MessageFilter implementation. 37 virtual void OnFilterAdded(Sender* sender) OVERRIDE; 38 virtual void OnChannelError() OVERRIDE; 39 virtual void OnChannelClosing() OVERRIDE; 40 virtual bool OnMessageReceived(const Message& message) OVERRIDE; 41 42 protected: 43 virtual ~SyncMessageFilter(); 44 45 private: 46 void SendOnIOThread(Message* message); 47 // Signal all the pending sends as done, used in an error condition. 48 void SignalAllEvents(); 49 50 // The channel to which this filter was added. 51 Sender* sender_; 52 53 // The process's main thread. 54 scoped_refptr<base::MessageLoopProxy> listener_loop_; 55 56 // The message loop where the Channel lives. 57 scoped_refptr<base::MessageLoopProxy> io_loop_; 58 59 typedef std::set<PendingSyncMsg*> PendingSyncMessages; 60 PendingSyncMessages pending_sync_messages_; 61 62 // Locks data members above. 63 base::Lock lock_; 64 65 base::WaitableEvent* shutdown_event_; 66 67 DISALLOW_COPY_AND_ASSIGN(SyncMessageFilter); 68}; 69 70} // namespace IPC 71 72#endif // IPC_IPC_SYNC_MESSAGE_FILTER_H_ 73