1 /*
2 * Copyright (C) 2008 Apple 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
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 *
25 */
26
27 #include "config.h"
28 #include "core/dom/MessagePort.h"
29
30 #include "bindings/v8/ExceptionState.h"
31 #include "bindings/v8/ExceptionStatePlaceholder.h"
32 #include "bindings/v8/SerializedScriptValue.h"
33 #include "core/dom/Document.h"
34 #include "core/dom/ExceptionCode.h"
35 #include "core/dom/ExecutionContext.h"
36 #include "core/events/MessageEvent.h"
37 #include "core/events/ThreadLocalEventNames.h"
38 #include "core/frame/DOMWindow.h"
39 #include "core/workers/WorkerGlobalScope.h"
40 #include "public/platform/WebString.h"
41 #include "wtf/Functional.h"
42 #include "wtf/text/AtomicString.h"
43
44 namespace WebCore {
45
create(ExecutionContext & executionContext)46 PassRefPtr<MessagePort> MessagePort::create(ExecutionContext& executionContext)
47 {
48 RefPtr<MessagePort> port = adoptRef(new MessagePort(executionContext));
49 port->suspendIfNeeded();
50 return port.release();
51 }
52
MessagePort(ExecutionContext & executionContext)53 MessagePort::MessagePort(ExecutionContext& executionContext)
54 : ActiveDOMObject(&executionContext)
55 , m_started(false)
56 , m_closed(false)
57 , m_weakFactory(this)
58 {
59 ScriptWrappable::init(this);
60 }
61
~MessagePort()62 MessagePort::~MessagePort()
63 {
64 close();
65 }
66
postMessage(PassRefPtr<SerializedScriptValue> message,const MessagePortArray * ports,ExceptionState & exceptionState)67 void MessagePort::postMessage(PassRefPtr<SerializedScriptValue> message, const MessagePortArray* ports, ExceptionState& exceptionState)
68 {
69 if (!isEntangled())
70 return;
71 ASSERT(executionContext());
72 ASSERT(m_entangledChannel);
73
74 OwnPtr<MessagePortChannelArray> channels;
75 // Make sure we aren't connected to any of the passed-in ports.
76 if (ports) {
77 for (unsigned int i = 0; i < ports->size(); ++i) {
78 MessagePort* dataPort = (*ports)[i].get();
79 if (dataPort == this) {
80 exceptionState.throwDOMException(DataCloneError, "Item #" + String::number(i) + " in the array of ports contains the source port.");
81 return;
82 }
83 }
84 channels = MessagePort::disentanglePorts(ports, exceptionState);
85 if (exceptionState.hadException())
86 return;
87 }
88
89 blink::WebString messageString = message->toWireString();
90 blink::WebMessagePortChannelArray* webChannels = 0;
91 if (channels && channels->size()) {
92 webChannels = new blink::WebMessagePortChannelArray(channels->size());
93 for (size_t i = 0; i < channels->size(); ++i)
94 (*webChannels)[i] = (*channels)[i].leakPtr();
95 }
96 m_entangledChannel->postMessage(messageString, webChannels);
97 }
98
disentangle()99 PassOwnPtr<blink::WebMessagePortChannel> MessagePort::disentangle()
100 {
101 ASSERT(m_entangledChannel);
102 m_entangledChannel->setClient(0);
103 return m_entangledChannel.release();
104 }
105
106 // Invoked to notify us that there are messages available for this port.
107 // This code may be called from another thread, and so should not call any non-threadsafe APIs (i.e. should not call into the entangled channel or access mutable variables).
messageAvailable()108 void MessagePort::messageAvailable()
109 {
110 ASSERT(executionContext());
111 executionContext()->postTask(bind(&MessagePort::dispatchMessages, m_weakFactory.createWeakPtr()));
112 }
113
start()114 void MessagePort::start()
115 {
116 // Do nothing if we've been cloned or closed.
117 if (!isEntangled())
118 return;
119
120 ASSERT(executionContext());
121 if (m_started)
122 return;
123
124 m_started = true;
125 messageAvailable();
126 }
127
close()128 void MessagePort::close()
129 {
130 if (isEntangled())
131 m_entangledChannel->setClient(0);
132 m_closed = true;
133 }
134
entangle(PassOwnPtr<blink::WebMessagePortChannel> remote)135 void MessagePort::entangle(PassOwnPtr<blink::WebMessagePortChannel> remote)
136 {
137 // Only invoked to set our initial entanglement.
138 ASSERT(!m_entangledChannel);
139 ASSERT(executionContext());
140
141 m_entangledChannel = remote;
142 m_entangledChannel->setClient(this);
143 }
144
interfaceName() const145 const AtomicString& MessagePort::interfaceName() const
146 {
147 return EventTargetNames::MessagePort;
148 }
149
tryGetMessageFrom(blink::WebMessagePortChannel & webChannel,RefPtr<SerializedScriptValue> & message,OwnPtr<MessagePortChannelArray> & channels)150 static bool tryGetMessageFrom(blink::WebMessagePortChannel& webChannel, RefPtr<SerializedScriptValue>& message, OwnPtr<MessagePortChannelArray>& channels)
151 {
152 blink::WebString messageString;
153 blink::WebMessagePortChannelArray webChannels;
154 if (!webChannel.tryGetMessage(&messageString, webChannels))
155 return false;
156
157 if (webChannels.size()) {
158 channels = adoptPtr(new MessagePortChannelArray(webChannels.size()));
159 for (size_t i = 0; i < webChannels.size(); ++i)
160 (*channels)[i] = adoptPtr(webChannels[i]);
161 }
162 message = SerializedScriptValue::createFromWire(messageString);
163 return true;
164 }
165
dispatchMessages()166 void MessagePort::dispatchMessages()
167 {
168 // Messages for contexts that are not fully active get dispatched too, but JSAbstractEventListener::handleEvent() doesn't call handlers for these.
169 // The HTML5 spec specifies that any messages sent to a document that is not fully active should be dropped, so this behavior is OK.
170 if (!started())
171 return;
172
173 RefPtr<SerializedScriptValue> message;
174 OwnPtr<MessagePortChannelArray> channels;
175 while (m_entangledChannel && tryGetMessageFrom(*m_entangledChannel, message, channels)) {
176 // close() in Worker onmessage handler should prevent next message from dispatching.
177 if (executionContext()->isWorkerGlobalScope() && toWorkerGlobalScope(executionContext())->isClosing())
178 return;
179
180 OwnPtr<MessagePortArray> ports = MessagePort::entanglePorts(*executionContext(), channels.release());
181 RefPtr<Event> evt = MessageEvent::create(ports.release(), message.release());
182
183 dispatchEvent(evt.release(), ASSERT_NO_EXCEPTION);
184 }
185 }
186
hasPendingActivity() const187 bool MessagePort::hasPendingActivity() const
188 {
189 // The spec says that entangled message ports should always be treated as if they have a strong reference.
190 // We'll also stipulate that the queue needs to be open (if the app drops its reference to the port before start()-ing it, then it's not really entangled as it's unreachable).
191 return m_started && isEntangled();
192 }
193
disentanglePorts(const MessagePortArray * ports,ExceptionState & exceptionState)194 PassOwnPtr<MessagePortChannelArray> MessagePort::disentanglePorts(const MessagePortArray* ports, ExceptionState& exceptionState)
195 {
196 if (!ports || !ports->size())
197 return nullptr;
198
199 // HashSet used to efficiently check for duplicates in the passed-in array.
200 HashSet<MessagePort*> portSet;
201
202 // Walk the incoming array - if there are any duplicate ports, or null ports or cloned ports, throw an error (per section 8.3.3 of the HTML5 spec).
203 for (unsigned i = 0; i < ports->size(); ++i) {
204 MessagePort* port = (*ports)[i].get();
205 if (!port || port->isNeutered() || portSet.contains(port)) {
206 String type;
207 if (!port)
208 type = "null";
209 else if (port->isNeutered())
210 type = "already neutered";
211 else
212 type = "a duplicate";
213 exceptionState.throwDOMException(DataCloneError, "Item #" + String::number(i) + " in the array of ports is " + type + ".");
214 return nullptr;
215 }
216 portSet.add(port);
217 }
218
219 // Passed-in ports passed validity checks, so we can disentangle them.
220 OwnPtr<MessagePortChannelArray> portArray = adoptPtr(new MessagePortChannelArray(ports->size()));
221 for (unsigned i = 0; i < ports->size(); ++i)
222 (*portArray)[i] = (*ports)[i]->disentangle();
223 return portArray.release();
224 }
225
entanglePorts(ExecutionContext & context,PassOwnPtr<MessagePortChannelArray> channels)226 PassOwnPtr<MessagePortArray> MessagePort::entanglePorts(ExecutionContext& context, PassOwnPtr<MessagePortChannelArray> channels)
227 {
228 if (!channels || !channels->size())
229 return nullptr;
230
231 OwnPtr<MessagePortArray> portArray = adoptPtr(new MessagePortArray(channels->size()));
232 for (unsigned int i = 0; i < channels->size(); ++i) {
233 RefPtr<MessagePort> port = MessagePort::create(context);
234 port->entangle((*channels)[i].release());
235 (*portArray)[i] = port.release();
236 }
237 return portArray.release();
238 }
239
240 } // namespace WebCore
241