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
29 #if ENABLE(WORKERS)
30
31 #include "WorkerScriptController.h"
32
33 #include "JSDOMBinding.h"
34 #include "JSWorkerContext.h"
35 #include "ScriptSourceCode.h"
36 #include "ScriptValue.h"
37 #include "WorkerContext.h"
38 #include "WorkerMessagingProxy.h"
39 #include "WorkerThread.h"
40 #include <interpreter/Interpreter.h>
41 #include <runtime/Completion.h>
42 #include <runtime/Completion.h>
43 #include <runtime/JSLock.h>
44
45 using namespace JSC;
46
47 namespace WebCore {
48
WorkerScriptController(WorkerContext * workerContext)49 WorkerScriptController::WorkerScriptController(WorkerContext* workerContext)
50 : m_globalData(JSGlobalData::create())
51 , m_workerContext(workerContext)
52 , m_executionForbidden(false)
53 {
54 }
55
~WorkerScriptController()56 WorkerScriptController::~WorkerScriptController()
57 {
58 m_workerContextWrapper = 0; // Unprotect the global object.
59
60 ASSERT(!m_globalData->heap.protectedObjectCount());
61 ASSERT(!m_globalData->heap.isBusy());
62 m_globalData->heap.destroy();
63 }
64
initScript()65 void WorkerScriptController::initScript()
66 {
67 ASSERT(!m_workerContextWrapper);
68
69 JSLock lock(false);
70
71 RefPtr<Structure> prototypeStructure = JSWorkerContextPrototype::createStructure(jsNull());
72 RefPtr<Structure> structure = JSWorkerContext::createStructure(new (m_globalData.get()) JSWorkerContextPrototype(prototypeStructure.release()));
73 m_workerContextWrapper = new (m_globalData.get()) JSWorkerContext(structure.release(), m_workerContext);
74 }
75
evaluate(const ScriptSourceCode & sourceCode)76 ScriptValue WorkerScriptController::evaluate(const ScriptSourceCode& sourceCode)
77 {
78 {
79 MutexLocker lock(m_sharedDataMutex);
80 if (m_executionForbidden)
81 return noValue();
82 }
83
84 initScriptIfNeeded();
85 JSLock lock(false);
86
87 ExecState* exec = m_workerContextWrapper->globalExec();
88 m_workerContextWrapper->startTimeoutCheck();
89 Completion comp = JSC::evaluate(exec, exec->dynamicGlobalObject()->globalScopeChain(), sourceCode.jsSourceCode(), m_workerContextWrapper);
90 m_workerContextWrapper->stopTimeoutCheck();
91
92 m_workerContext->thread()->messagingProxy()->reportWorkerThreadActivity(m_workerContext->hasPendingActivity());
93
94 if (comp.complType() == Normal || comp.complType() == ReturnValue)
95 return comp.value();
96
97 if (comp.complType() == Throw)
98 reportException(exec, comp.value());
99 return noValue();
100 }
101
forbidExecution()102 void WorkerScriptController::forbidExecution()
103 {
104 // This function is called from another thread.
105 // Mutex protection for m_executionForbidden is needed to guarantee that the value is synchronized between processors, because
106 // if it were not, the worker could re-enter JSC::evaluate(), but with timeout already reset.
107 // It is not critical for Interpreter::m_timeoutTime to be synchronized, we just rely on it reaching the worker thread's processor sooner or later.
108 MutexLocker lock(m_sharedDataMutex);
109 m_executionForbidden = true;
110 m_globalData->interpreter->setTimeoutTime(1); // 1 ms is the smallest timeout that can be set.
111 }
112
113 } // namespace WebCore
114
115 #endif // ENABLE(WORKERS)
116