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      1 /*
      2  * Copyright (C) 2008, 2010 Apple Inc. All Rights Reserved.
      3  * Copyright (C) 2009 Google Inc. All Rights Reserved.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  * 1. Redistributions of source code must retain the above copyright
      9  *    notice, this list of conditions and the following disclaimer.
     10  * 2. Redistributions in binary form must reproduce the above copyright
     11  *    notice, this list of conditions and the following disclaimer in the
     12  *    documentation and/or other materials provided with the distribution.
     13  *
     14  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
     15  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     17  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
     18  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     19  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     20  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     21  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
     22  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     24  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     25  *
     26  */
     27 
     28 #include "config.h"
     29 #include "core/workers/Worker.h"
     30 
     31 #include "bindings/v8/ExceptionState.h"
     32 #include "core/dom/Document.h"
     33 #include "core/dom/EventListener.h"
     34 #include "core/dom/EventNames.h"
     35 #include "core/dom/MessageEvent.h"
     36 #include "core/inspector/InspectorInstrumentation.h"
     37 #include "core/loader/FrameLoader.h"
     38 #include "core/loader/cache/ResourceFetcher.h"
     39 #include "core/page/DOMWindow.h"
     40 #include "core/page/Frame.h"
     41 #include "core/page/UseCounter.h"
     42 #include "core/workers/WorkerGlobalScopeProxy.h"
     43 #include "core/workers/WorkerScriptLoader.h"
     44 #include "core/workers/WorkerThread.h"
     45 #include "wtf/MainThread.h"
     46 
     47 namespace WebCore {
     48 
     49 inline Worker::Worker(ScriptExecutionContext* context)
     50     : AbstractWorker(context)
     51     , m_contextProxy(WorkerGlobalScopeProxy::create(this))
     52 {
     53     ScriptWrappable::init(this);
     54 }
     55 
     56 PassRefPtr<Worker> Worker::create(ScriptExecutionContext* context, const String& url, ExceptionState& es)
     57 {
     58     ASSERT(isMainThread());
     59     UseCounter::count(toDocument(context)->domWindow(), UseCounter::WorkerStart);
     60 
     61     RefPtr<Worker> worker = adoptRef(new Worker(context));
     62 
     63     worker->suspendIfNeeded();
     64 
     65     KURL scriptURL = worker->resolveURL(url, es);
     66     if (scriptURL.isEmpty())
     67         return 0;
     68 
     69     // The worker context does not exist while loading, so we must ensure that the worker object is not collected, nor are its event listeners.
     70     worker->setPendingActivity(worker.get());
     71 
     72     worker->m_scriptLoader = WorkerScriptLoader::create();
     73     worker->m_scriptLoader->loadAsynchronously(context, scriptURL, DenyCrossOriginRequests, worker.get());
     74 
     75     return worker.release();
     76 }
     77 
     78 Worker::~Worker()
     79 {
     80     ASSERT(isMainThread());
     81     ASSERT(scriptExecutionContext()); // The context is protected by worker context proxy, so it cannot be destroyed while a Worker exists.
     82     m_contextProxy->workerObjectDestroyed();
     83 }
     84 
     85 const AtomicString& Worker::interfaceName() const
     86 {
     87     return eventNames().interfaceForWorker;
     88 }
     89 
     90 void Worker::postMessage(PassRefPtr<SerializedScriptValue> message, const MessagePortArray* ports, ExceptionState& es)
     91 {
     92     // Disentangle the port in preparation for sending it to the remote context.
     93     OwnPtr<MessagePortChannelArray> channels = MessagePort::disentanglePorts(ports, es);
     94     if (es.hadException())
     95         return;
     96     m_contextProxy->postMessageToWorkerGlobalScope(message, channels.release());
     97 }
     98 
     99 void Worker::terminate()
    100 {
    101     m_contextProxy->terminateWorkerGlobalScope();
    102 }
    103 
    104 bool Worker::canSuspend() const
    105 {
    106     // FIXME: It is not currently possible to suspend a worker, so pages with workers can not go into page cache.
    107     return false;
    108 }
    109 
    110 void Worker::stop()
    111 {
    112     terminate();
    113 }
    114 
    115 bool Worker::hasPendingActivity() const
    116 {
    117     return m_contextProxy->hasPendingActivity() || ActiveDOMObject::hasPendingActivity();
    118 }
    119 
    120 void Worker::didReceiveResponse(unsigned long identifier, const ResourceResponse&)
    121 {
    122     InspectorInstrumentation::didReceiveScriptResponse(scriptExecutionContext(), identifier);
    123 }
    124 
    125 void Worker::notifyFinished()
    126 {
    127     if (m_scriptLoader->failed())
    128         dispatchEvent(Event::create(eventNames().errorEvent, false, true));
    129     else {
    130         WorkerThreadStartMode startMode = DontPauseWorkerGlobalScopeOnStart;
    131         if (InspectorInstrumentation::shouldPauseDedicatedWorkerOnStart(scriptExecutionContext()))
    132             startMode = PauseWorkerGlobalScopeOnStart;
    133         m_contextProxy->startWorkerGlobalScope(m_scriptLoader->url(), scriptExecutionContext()->userAgent(m_scriptLoader->url()), m_scriptLoader->script(), startMode);
    134         InspectorInstrumentation::scriptImported(scriptExecutionContext(), m_scriptLoader->identifier(), m_scriptLoader->script());
    135     }
    136     m_scriptLoader = nullptr;
    137 
    138     unsetPendingActivity(this);
    139 }
    140 
    141 } // namespace WebCore
    142