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_channel_proxy.h" 14 #include "ipc/ipc_sync_message.h" 15 16 namespace base { 17 class MessageLoopProxy; 18 class WaitableEvent; 19 } 20 21 namespace IPC { 22 23 // This MessageFilter allows sending synchronous IPC messages from a thread 24 // other than the listener thread associated with the SyncChannel. It does not 25 // support fancy features that SyncChannel does, such as handling recursion or 26 // receiving messages while waiting for a response. Note that this object can 27 // be used to send simultaneous synchronous messages from different threads. 28 class IPC_EXPORT SyncMessageFilter : public ChannelProxy::MessageFilter, 29 public Sender { 30 public: 31 explicit SyncMessageFilter(base::WaitableEvent* shutdown_event); 32 33 // MessageSender implementation. 34 virtual bool Send(Message* message) OVERRIDE; 35 36 // ChannelProxy::MessageFilter implementation. 37 virtual void OnFilterAdded(Channel* channel) 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 Channel* channel_; 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