1 /* 2 * Copyright (C) 2009 Google Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions are 6 * met: 7 * 8 * * Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * * Redistributions in binary form must reproduce the above 11 * copyright notice, this list of conditions and the following disclaimer 12 * in the documentation and/or other materials provided with the 13 * distribution. 14 * * Neither the name of Google Inc. nor the names of its 15 * contributors may be used to endorse or promote products derived from 16 * this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 #ifndef MessagePortChannel_h 32 #define MessagePortChannel_h 33 34 #include "PlatformString.h" 35 36 #include <wtf/OwnPtr.h> 37 #include <wtf/PassOwnPtr.h> 38 #include <wtf/PassRefPtr.h> 39 #include <wtf/RefCounted.h> 40 #include <wtf/RefPtr.h> 41 42 namespace WebCore { 43 44 class MessagePort; 45 class PlatformMessagePortChannel; 46 class ScriptExecutionContext; 47 class String; 48 49 // MessagePortChannel is a platform-independent interface to the remote side of a message channel. 50 // It acts as a wrapper around the platform-dependent PlatformMessagePortChannel implementation which ensures that the platform-dependent close() method is invoked before destruction. 51 class MessagePortChannel : public Noncopyable { 52 public: 53 static void createChannel(PassRefPtr<MessagePort>, PassRefPtr<MessagePort>); 54 55 // Creates a new wrapper for the passed channel. 56 static PassOwnPtr<MessagePortChannel> create(PassRefPtr<PlatformMessagePortChannel>); 57 58 // Entangles the channel with a port (called when a port has been cloned, after the clone has been marshalled to its new owning thread and is ready to receive messages). 59 // Returns false if the entanglement failed because the port was closed. 60 bool entangleIfOpen(MessagePort*); 61 62 // Disentangles the channel from a given port so it no longer forwards messages to the port. Called when the port is being cloned and no new owning thread has yet been established. 63 void disentangle(); 64 65 // Closes the port (ensures that no further messages can be added to either queue). 66 void close(); 67 68 // Used by MessagePort.postMessage() to prevent callers from passing a port's own entangled port. 69 bool isConnectedTo(MessagePort*); 70 71 // Returns true if the proxy currently contains messages for this port. 72 bool hasPendingActivity(); 73 74 class EventData { 75 public: 76 static PassOwnPtr<EventData> create(const String&, PassOwnPtr<MessagePortChannel>); 77 message()78 const String& message() { return m_message; } channel()79 PassOwnPtr<MessagePortChannel> channel() { return m_channel.release(); } 80 81 private: 82 EventData(const String& message, PassOwnPtr<MessagePortChannel>); 83 String m_message; 84 OwnPtr<MessagePortChannel> m_channel; 85 }; 86 87 // Sends a message and optional cloned port to the remote port. 88 void postMessageToRemote(PassOwnPtr<EventData>); 89 90 // Extracts a message from the message queue for this port. 91 bool tryGetMessageFromRemote(OwnPtr<EventData>&); 92 93 // Returns the entangled port if run by the same thread (see MessagePort::locallyEntangledPort() for more details). 94 MessagePort* locallyEntangledPort(const ScriptExecutionContext*); 95 96 ~MessagePortChannel(); 97 channel()98 PlatformMessagePortChannel* channel() const { return m_channel.get(); } 99 100 private: 101 MessagePortChannel(PassRefPtr<PlatformMessagePortChannel>); 102 RefPtr<PlatformMessagePortChannel> m_channel; 103 }; 104 105 } // namespace WebCore 106 107 #endif // MessagePortChannel_h 108