/*
 * Copyright (C) 2013-2024 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. AND ITS CONTRIBUTORS ``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 ITS CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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 * THE POSSIBILITY OF SUCH DAMAGE.
 */

#pragma once

#include <JavaScriptCore/Heap.h>
#include <wtf/Noncopyable.h>

namespace JSC {

class HeapIterationScope {
    WTF_MAKE_NONCOPYABLE(HeapIterationScope);
public:
    HeapIterationScope(Heap&);
    ~HeapIterationScope();

private:
    JSC::Heap& m_heap;
};

inline HeapIterationScope::HeapIterationScope(JSC::Heap& heap)
    : m_heap(heap)
{
    // FIXME: It would be nice to assert we're holding the API lock when iterating the heap so we know no other thread is mutating the heap
    // but adding `ASSERT_WITH_MESSAGE(heap.vm().currentThreadIsHoldingAPILock(), "Trying to iterate the JS heap without the API lock");`
    // causes spurious crashes since the only thing technically needed is just heap.hasAccess() but that doesn't verify this thread is
    // the one with access only that *some* thread has access.
    m_heap.willStartIterating();
}

inline HeapIterationScope::~HeapIterationScope()
{
    m_heap.didFinishIterating();
}

} // namespace JSC
