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 "SerializedScriptValue.h" 37 38 #include <wtf/OwnPtr.h> 39 #include <wtf/Forward.h> 40 #include <wtf/PassOwnPtr.h> 41 #include <wtf/PassRefPtr.h> 42 #include <wtf/RefCounted.h> 43 #include <wtf/RefPtr.h> 44 45 namespace WebCore { 46 47 class MessagePort; 48 class MessagePortChannel; 49 class PlatformMessagePortChannel; 50 class ScriptExecutionContext; 51 class SerializedScriptValue; 52 53 // The overwhelmingly common case is sending a single port, so handle that efficiently with an inline buffer of size 1. 54 typedef Vector<OwnPtr<MessagePortChannel>, 1> MessagePortChannelArray; 55 56 // MessagePortChannel is a platform-independent interface to the remote side of a message channel. 57 // It acts as a wrapper around the platform-dependent PlatformMessagePortChannel implementation which ensures that the platform-dependent close() method is invoked before destruction. 58 class MessagePortChannel { 59 WTF_MAKE_NONCOPYABLE(MessagePortChannel); WTF_MAKE_FAST_ALLOCATED; 60 public: 61 static void createChannel(PassRefPtr<MessagePort>, PassRefPtr<MessagePort>); 62 63 // Creates a new wrapper for the passed channel. 64 static PassOwnPtr<MessagePortChannel> create(PassRefPtr<PlatformMessagePortChannel>); 65 66 // Entangles the channel with a port (called when a port has been cloned, after the clone has been marshaled to its new owning thread and is ready to receive messages). 67 // Returns false if the entanglement failed because the port was closed. 68 bool entangleIfOpen(MessagePort*); 69 70 // 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. 71 void disentangle(); 72 73 // Closes the port (ensures that no further messages can be added to either queue). 74 void close(); 75 76 // Used by MessagePort.postMessage() to prevent callers from passing a port's own entangled port. 77 bool isConnectedTo(MessagePort*); 78 79 // Returns true if the proxy currently contains messages for this port. 80 bool hasPendingActivity(); 81 82 class EventData { 83 WTF_MAKE_NONCOPYABLE(EventData); WTF_MAKE_FAST_ALLOCATED; 84 public: 85 static PassOwnPtr<EventData> create(PassRefPtr<SerializedScriptValue>, PassOwnPtr<MessagePortChannelArray>); 86 message()87 SerializedScriptValue* message() { return m_message.get(); } channels()88 PassOwnPtr<MessagePortChannelArray> channels() { return m_channels.release(); } 89 90 private: 91 EventData(PassRefPtr<SerializedScriptValue> message, PassOwnPtr<MessagePortChannelArray>); 92 RefPtr<SerializedScriptValue> m_message; 93 OwnPtr<MessagePortChannelArray> m_channels; 94 }; 95 96 // Sends a message and optional cloned port to the remote port. 97 void postMessageToRemote(PassOwnPtr<EventData>); 98 99 // Extracts a message from the message queue for this port. 100 bool tryGetMessageFromRemote(OwnPtr<EventData>&); 101 102 // Returns the entangled port if run by the same thread (see MessagePort::locallyEntangledPort() for more details). 103 MessagePort* locallyEntangledPort(const ScriptExecutionContext*); 104 105 ~MessagePortChannel(); 106 channel()107 PlatformMessagePortChannel* channel() const { return m_channel.get(); } 108 109 private: 110 MessagePortChannel(PassRefPtr<PlatformMessagePortChannel>); 111 RefPtr<PlatformMessagePortChannel> m_channel; 112 }; 113 114 } // namespace WebCore 115 116 #endif // MessagePortChannel_h 117