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 "SerializedScriptValue.h" 35#include <memory> 36#include <wtf/Forward.h> 37#include <wtf/PassRefPtr.h> 38#include <wtf/RefCounted.h> 39#include <wtf/RefPtr.h> 40#include <wtf/text/WTFString.h> 41 42namespace WebCore { 43 44 class MessagePort; 45 class MessagePortChannel; 46 class PlatformMessagePortChannel; 47 class ScriptExecutionContext; 48 class SerializedScriptValue; 49 50 // The overwhelmingly common case is sending a single port, so handle that efficiently with an inline buffer of size 1. 51 typedef Vector<std::unique_ptr<MessagePortChannel>, 1> MessagePortChannelArray; 52 53 // MessagePortChannel is a platform-independent interface to the remote side of a message channel. 54 // It acts as a wrapper around the platform-dependent PlatformMessagePortChannel implementation which ensures that the platform-dependent close() method is invoked before destruction. 55 class MessagePortChannel { 56 WTF_MAKE_NONCOPYABLE(MessagePortChannel); WTF_MAKE_FAST_ALLOCATED; 57 public: 58 explicit MessagePortChannel(PassRefPtr<PlatformMessagePortChannel>); 59 static void createChannel(PassRefPtr<MessagePort>, PassRefPtr<MessagePort>); 60 61 // 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). 62 // Returns false if the entanglement failed because the port was closed. 63 bool entangleIfOpen(MessagePort*); 64 65 // 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. 66 void disentangle(); 67 68 // Closes the port (ensures that no further messages can be added to either queue). 69 void close(); 70 71 // Used by MessagePort.postMessage() to prevent callers from passing a port's own entangled port. 72 bool isConnectedTo(MessagePort*); 73 74 // Returns true if the proxy currently contains messages for this port. 75 bool hasPendingActivity(); 76 77 // Sends a message and optional cloned port to the remote port. 78 void postMessageToRemote(PassRefPtr<SerializedScriptValue>, std::unique_ptr<MessagePortChannelArray>); 79 80 // Extracts a message from the message queue for this port. 81 bool tryGetMessageFromRemote(RefPtr<SerializedScriptValue>&, std::unique_ptr<MessagePortChannelArray>&); 82 83 // Returns the entangled port if run by the same thread (see MessagePort::locallyEntangledPort() for more details). 84 MessagePort* locallyEntangledPort(const ScriptExecutionContext*); 85 86 ~MessagePortChannel(); 87 88 private: 89 RefPtr<PlatformMessagePortChannel> m_channel; 90 }; 91 92} // namespace WebCore 93 94#endif // MessagePortChannel_h 95