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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 
32 #include "config.h"
33 
34 #if ENABLE(WORKERS)
35 
36 #include "WorkerContextExecutionProxy.h"
37 
38 #include "DOMCoreException.h"
39 #include "DedicatedWorkerContext.h"
40 #include "Event.h"
41 #include "EventSource.h"
42 #include "Notification.h"
43 #include "NotificationCenter.h"
44 #include "EventException.h"
45 #include "MessagePort.h"
46 #include "RangeException.h"
47 #include "SharedWorker.h"
48 #include "SharedWorkerContext.h"
49 #include "V8Binding.h"
50 #include "V8DOMMap.h"
51 #include "V8Index.h"
52 #include "V8Proxy.h"
53 #include "V8WorkerContext.h"
54 #include "V8WorkerContextEventListener.h"
55 #if ENABLE(WEB_SOCKETS)
56 #include "WebSocket.h"
57 #endif
58 #include "Worker.h"
59 #include "WorkerContext.h"
60 #include "WorkerLocation.h"
61 #include "WorkerNavigator.h"
62 #include "WorkerScriptController.h"
63 #include "XMLHttpRequest.h"
64 #include "XMLHttpRequestException.h"
65 
66 namespace WebCore {
67 
reportFatalErrorInV8(const char * location,const char * message)68 static void reportFatalErrorInV8(const char* location, const char* message)
69 {
70     // FIXME: We temporarily deal with V8 internal error situations such as out-of-memory by crashing the worker.
71     CRASH();
72 }
73 
WorkerContextExecutionProxy(WorkerContext * workerContext)74 WorkerContextExecutionProxy::WorkerContextExecutionProxy(WorkerContext* workerContext)
75     : m_workerContext(workerContext)
76     , m_recursion(0)
77 {
78     initV8IfNeeded();
79 }
80 
~WorkerContextExecutionProxy()81 WorkerContextExecutionProxy::~WorkerContextExecutionProxy()
82 {
83     dispose();
84 }
85 
dispose()86 void WorkerContextExecutionProxy::dispose()
87 {
88     // Detach all events from their JS wrappers.
89     for (size_t eventIndex = 0; eventIndex < m_events.size(); ++eventIndex) {
90         Event* event = m_events[eventIndex];
91         if (forgetV8EventObject(event))
92           event->deref();
93     }
94     m_events.clear();
95 
96     // Dispose the context.
97     if (!m_context.IsEmpty()) {
98         m_context.Dispose();
99         m_context.Clear();
100     }
101 }
102 
retrieve()103 WorkerContextExecutionProxy* WorkerContextExecutionProxy::retrieve()
104 {
105     // Happens on frame destruction, check otherwise GetCurrent() will crash.
106     if (!v8::Context::InContext())
107         return 0;
108     v8::Handle<v8::Context> context = v8::Context::GetCurrent();
109     v8::Handle<v8::Object> global = context->Global();
110     global = V8DOMWrapper::lookupDOMWrapper(V8WorkerContext::GetTemplate(), global);
111     // Return 0 if the current executing context is not the worker context.
112     if (global.IsEmpty())
113         return 0;
114     WorkerContext* workerContext = V8WorkerContext::toNative(global);
115     return workerContext->script()->proxy();
116 }
117 
initV8IfNeeded()118 void WorkerContextExecutionProxy::initV8IfNeeded()
119 {
120     static bool v8Initialized = false;
121 
122     if (v8Initialized)
123         return;
124 
125     // Tell V8 not to call the default OOM handler, binding code will handle it.
126     v8::V8::IgnoreOutOfMemoryException();
127     v8::V8::SetFatalErrorHandler(reportFatalErrorInV8);
128 
129     v8::ResourceConstraints resource_constraints;
130     uint32_t here;
131     resource_constraints.set_stack_limit(&here - kWorkerMaxStackSize / sizeof(uint32_t*));
132     v8::SetResourceConstraints(&resource_constraints);
133 
134     v8Initialized = true;
135 }
136 
initContextIfNeeded()137 void WorkerContextExecutionProxy::initContextIfNeeded()
138 {
139     // Bail out if the context has already been initialized.
140     if (!m_context.IsEmpty())
141         return;
142 
143     // Create a new environment
144     v8::Persistent<v8::ObjectTemplate> globalTemplate;
145     m_context = v8::Context::New(0, globalTemplate);
146 
147     // Starting from now, use local context only.
148     v8::Local<v8::Context> context = v8::Local<v8::Context>::New(m_context);
149     v8::Context::Scope scope(context);
150 
151     // Allocate strings used during initialization.
152     v8::Handle<v8::String> implicitProtoString = v8::String::New("__proto__");
153 
154     // Create a new JS object and use it as the prototype for the shadow global object.
155     V8ClassIndex::V8WrapperType contextType = V8ClassIndex::DEDICATEDWORKERCONTEXT;
156 #if ENABLE(SHARED_WORKERS)
157     if (!m_workerContext->isDedicatedWorkerContext())
158         contextType = V8ClassIndex::SHAREDWORKERCONTEXT;
159 #endif
160     v8::Handle<v8::Function> workerContextConstructor = V8DOMWrapper::getConstructorForContext(contextType, context);
161     v8::Local<v8::Object> jsWorkerContext = SafeAllocation::newInstance(workerContextConstructor);
162     // Bail out if allocation failed.
163     if (jsWorkerContext.IsEmpty()) {
164         dispose();
165         return;
166     }
167 
168     // Wrap the object.
169     V8DOMWrapper::setDOMWrapper(jsWorkerContext, V8ClassIndex::ToInt(contextType), m_workerContext);
170 
171     V8DOMWrapper::setJSWrapperForDOMObject(m_workerContext, v8::Persistent<v8::Object>::New(jsWorkerContext));
172     m_workerContext->ref();
173 
174     // Insert the object instance as the prototype of the shadow object.
175     v8::Handle<v8::Object> globalObject = m_context->Global();
176     globalObject->Set(implicitProtoString, jsWorkerContext);
177 }
178 
forgetV8EventObject(Event * event)179 bool WorkerContextExecutionProxy::forgetV8EventObject(Event* event)
180 {
181     if (getDOMObjectMap().contains(event)) {
182         getDOMObjectMap().forget(event);
183         return true;
184     }
185     return false;
186 }
187 
evaluate(const String & script,const String & fileName,int baseLine,WorkerContextExecutionState * state)188 ScriptValue WorkerContextExecutionProxy::evaluate(const String& script, const String& fileName, int baseLine, WorkerContextExecutionState* state)
189 {
190     v8::HandleScope hs;
191 
192     initContextIfNeeded();
193     v8::Context::Scope scope(m_context);
194 
195     v8::TryCatch exceptionCatcher;
196 
197     v8::Local<v8::String> scriptString = v8ExternalString(script);
198     v8::Handle<v8::Script> compiledScript = V8Proxy::compileScript(scriptString, fileName, baseLine);
199     v8::Local<v8::Value> result = runScript(compiledScript);
200 
201     if (exceptionCatcher.HasCaught()) {
202         v8::Local<v8::Message> message = exceptionCatcher.Message();
203         state->hadException = true;
204         state->exception = ScriptValue(exceptionCatcher.Exception());
205         state->errorMessage = toWebCoreString(message->Get());
206         state->lineNumber = message->GetLineNumber();
207         state->sourceURL = toWebCoreString(message->GetScriptResourceName());
208         exceptionCatcher.Reset();
209     } else
210         state->hadException = false;
211 
212     if (result.IsEmpty() || result->IsUndefined())
213         return ScriptValue();
214 
215     return ScriptValue(result);
216 }
217 
runScript(v8::Handle<v8::Script> script)218 v8::Local<v8::Value> WorkerContextExecutionProxy::runScript(v8::Handle<v8::Script> script)
219 {
220     if (script.IsEmpty())
221         return v8::Local<v8::Value>();
222 
223     // Compute the source string and prevent against infinite recursion.
224     if (m_recursion >= kMaxRecursionDepth) {
225         v8::Local<v8::String> code = v8ExternalString("throw RangeError('Recursion too deep')");
226         script = V8Proxy::compileScript(code, "", 0);
227     }
228 
229     if (V8Proxy::handleOutOfMemory())
230         ASSERT(script.IsEmpty());
231 
232     if (script.IsEmpty())
233         return v8::Local<v8::Value>();
234 
235     // Run the script and keep track of the current recursion depth.
236     v8::Local<v8::Value> result;
237     {
238         m_recursion++;
239         result = script->Run();
240         m_recursion--;
241     }
242 
243     // Handle V8 internal error situation (Out-of-memory).
244     if (result.IsEmpty())
245         return v8::Local<v8::Value>();
246 
247     return result;
248 }
249 
findOrCreateEventListener(v8::Local<v8::Value> object,bool isInline,bool findOnly)250 PassRefPtr<V8EventListener> WorkerContextExecutionProxy::findOrCreateEventListener(v8::Local<v8::Value> object, bool isInline, bool findOnly)
251 {
252     return findOnly ? V8EventListenerList::findWrapper(object, isInline) : V8EventListenerList::findOrCreateWrapper<V8WorkerContextEventListener>(object, isInline);
253 }
254 
trackEvent(Event * event)255 void WorkerContextExecutionProxy::trackEvent(Event* event)
256 {
257     m_events.append(event);
258 }
259 
260 } // namespace WebCore
261 
262 #endif // ENABLE(WORKERS)
263