Source/WebCore/dom/ScriptRunner.h

/*
 * Copyright (C) 2010 Google, Inc. All rights reserved.
 * Copyright (C) 2011-2017 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
 */

#pragma once

#include "PendingScriptClient.h"
#include <WebCore/Timer.h>
#include <wtf/CheckedRef.h>
#include <wtf/Deque.h>
#include <wtf/HashSet.h>
#include <wtf/TZoneMalloc.h>
#include <wtf/Vector.h>
#include <wtf/WeakRef.h>

namespace WebCore {

class Document;
class ScriptElement;
class LoadableScript;
class WeakPtrImplWithEventTargetData;

class ScriptRunner final : public PendingScriptClient, public CanMakeCheckedPtr<ScriptRunner> {
    WTF_MAKE_TZONE_ALLOCATED(ScriptRunner);
    WTF_MAKE_NONCOPYABLE(ScriptRunner);
    WTF_OVERRIDE_DELETE_FOR_CHECKED_PTR(ScriptRunner);
public:
    explicit ScriptRunner(Document&);
    ~ScriptRunner();

    void ref() const;
    void deref() const;

    // CheckedPtr interface
    uint32_t checkedPtrCount() const final { return CanMakeCheckedPtr::checkedPtrCount(); }
    uint32_t checkedPtrCountWithoutThreadCheck() const final { return CanMakeCheckedPtr::checkedPtrCountWithoutThreadCheck(); }
    void incrementCheckedPtrCount() const final { CanMakeCheckedPtr::incrementCheckedPtrCount(); }
    void decrementCheckedPtrCount() const final { CanMakeCheckedPtr::decrementCheckedPtrCount(); }
    void setDidBeginCheckedPtrDeletion() final { CanMakeCheckedPtr::setDidBeginCheckedPtrDeletion(); }

    enum ExecutionType { ASYNC_EXECUTION, IN_ORDER_EXECUTION };
    void queueScriptForExecution(ScriptElement&, LoadableScript&, ExecutionType);
    bool hasPendingScripts() const { return !m_scriptsToExecuteSoon.isEmpty() || !m_scriptsToExecuteInOrder.isEmpty() || !m_pendingAsyncScripts.isEmpty(); }
    void suspend();
    void resume();
    void notifyScriptReady(ScriptElement*, ExecutionType);

    void didBeginYieldingParser() { suspend(); }
    void didEndYieldingParser() { resume(); }

    void documentFinishedParsing();

    void clearPendingScripts();

private:
    void timerFired();

    void notifyFinished(PendingScript&) override;

    WeakRef<Document, WeakPtrImplWithEventTargetData> m_document;
    Deque<Ref<PendingScript>> m_scriptsToExecuteInOrder;
    Vector<Ref<PendingScript>> m_scriptsToExecuteSoon; // https://html.spec.whatwg.org/#set-of-scripts-that-will-execute-as-soon-as-possible
    HashSet<Ref<PendingScript>> m_pendingAsyncScripts;
    Timer m_timer;
};

}