Source/WebCore/workers/Worker.cpp

/*
 * Copyright (C) 2008, 2010 Apple Inc. All Rights Reserved.
 * Copyright (C) 2009 Google Inc. All Rights Reserved.
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 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
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 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
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#include "config.h"

#include "Worker.h"

#include "DOMWindow.h"
#include "CachedResourceLoader.h"
#include "ContentSecurityPolicy.h"
#include "Document.h"
#include "EventListener.h"
#include "EventNames.h"
#include "ExceptionCode.h"
#include "Frame.h"
#include "FrameLoader.h"
#include "InspectorInstrumentation.h"
#include "MessageEvent.h"
#include "NetworkStateNotifier.h"
#include "SecurityOrigin.h"
#include "TextEncoding.h"
#include "WorkerGlobalScopeProxy.h"
#include "WorkerScriptLoader.h"
#include "WorkerThread.h"
#include <wtf/HashSet.h>
#include <wtf/MainThread.h>

namespace WebCore {

static HashSet<Worker*>* allWorkers;

void networkStateChanged(bool isOnLine)
{
    for (auto& worker : *allWorkers)
        worker->notifyNetworkStateChange(isOnLine);
}

inline Worker::Worker(ScriptExecutionContext& context)
    : ActiveDOMObject(&context)
    , m_contextProxy(WorkerGlobalScopeProxy::create(this))
{
    if (!allWorkers) {
        allWorkers = new HashSet<Worker*>;
        networkStateNotifier().addNetworkStateChangeListener(networkStateChanged);
    }

    HashSet<Worker*>::AddResult addResult = allWorkers->add(this);
    ASSERT_UNUSED(addResult, addResult.isNewEntry);
}

RefPtr<Worker> Worker::create(ScriptExecutionContext& context, const String& url, ExceptionCode& ec)
{
    ASSERT(isMainThread());

    // We don't currently support nested workers, so workers can only be created from documents.
    ASSERT_WITH_SECURITY_IMPLICATION(context.isDocument());

    Ref<Worker> worker = adoptRef(*new Worker(context));

    worker->suspendIfNeeded();

    bool shouldBypassMainWorldContentSecurityPolicy = context.shouldBypassMainWorldContentSecurityPolicy();
    URL scriptURL = worker->resolveURL(url, shouldBypassMainWorldContentSecurityPolicy, ec);
    if (scriptURL.isEmpty())
        return nullptr;

    worker->m_shouldBypassMainWorldContentSecurityPolicy = shouldBypassMainWorldContentSecurityPolicy;

    // The worker context does not exist while loading, so we must ensure that the worker object is not collected, nor are its event listeners.
    worker->setPendingActivity(worker.ptr());

    worker->m_scriptLoader = WorkerScriptLoader::create();
    auto contentSecurityPolicyEnforcement = shouldBypassMainWorldContentSecurityPolicy ? ContentSecurityPolicyEnforcement::DoNotEnforce : ContentSecurityPolicyEnforcement::EnforceChildSrcDirective;
    worker->m_scriptLoader->loadAsynchronously(&context, scriptURL, FetchOptions::Mode::SameOrigin, contentSecurityPolicyEnforcement, worker.ptr());
    return WTFMove(worker);
}

Worker::~Worker()
{
    ASSERT(isMainThread());
    ASSERT(scriptExecutionContext()); // The context is protected by worker context proxy, so it cannot be destroyed while a Worker exists.
    allWorkers->remove(this);
    m_contextProxy->workerObjectDestroyed();
}

void Worker::postMessage(RefPtr<SerializedScriptValue>&& message, const MessagePortArray* ports, ExceptionCode& ec)
{
    // Disentangle the port in preparation for sending it to the remote context.
    auto channels = MessagePort::disentanglePorts(ports, ec);
    if (ec)
        return;
    m_contextProxy->postMessageToWorkerGlobalScope(WTFMove(message), WTFMove(channels));
}

void Worker::terminate()
{
    m_contextProxy->terminateWorkerGlobalScope();
}

bool Worker::canSuspendForDocumentSuspension() const
{
    // FIXME: It is not currently possible to suspend a worker, so pages with workers can not go into page cache.
    return false;
}

const char* Worker::activeDOMObjectName() const
{
    return "Worker";
}

void Worker::stop()
{
    terminate();
}

bool Worker::hasPendingActivity() const
{
    return m_contextProxy->hasPendingActivity() || ActiveDOMObject::hasPendingActivity();
}

void Worker::notifyNetworkStateChange(bool isOnLine)
{
    m_contextProxy->notifyNetworkStateChange(isOnLine);
}

void Worker::didReceiveResponse(unsigned long identifier, const ResourceResponse& response)
{
    const URL& responseURL = response.url();
    if (!responseURL.protocolIsBlob() && !responseURL.protocolIs("file") && !SecurityOrigin::create(responseURL)->isUnique())
        m_contentSecurityPolicyResponseHeaders = ContentSecurityPolicyResponseHeaders(response);
    InspectorInstrumentation::didReceiveScriptResponse(scriptExecutionContext(), identifier);
}

void Worker::notifyFinished()
{
    if (m_scriptLoader->failed())
        dispatchEvent(Event::create(eventNames().errorEvent, false, true));
    else {
        const ContentSecurityPolicyResponseHeaders& contentSecurityPolicyResponseHeaders = m_contentSecurityPolicyResponseHeaders ? m_contentSecurityPolicyResponseHeaders.value() : scriptExecutionContext()->contentSecurityPolicy()->responseHeaders();
        m_contextProxy->startWorkerGlobalScope(m_scriptLoader->url(), scriptExecutionContext()->userAgent(m_scriptLoader->url()), m_scriptLoader->script(), contentSecurityPolicyResponseHeaders, m_shouldBypassMainWorldContentSecurityPolicy, DontPauseWorkerGlobalScopeOnStart);
        InspectorInstrumentation::scriptImported(scriptExecutionContext(), m_scriptLoader->identifier(), m_scriptLoader->script());
    }
    m_scriptLoader = nullptr;

    unsetPendingActivity(this);
}

} // namespace WebCore