Source/JavaScriptCore/runtime/JSMicrotaskDispatcher.h

/*
 * Copyright (C) 2026 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
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 * 1. Redistributions of source code must retain the above copyright
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 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
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 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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#pragma once

#include <JavaScriptCore/JSCell.h>
#include <JavaScriptCore/MicrotaskQueue.h>
#include <JavaScriptCore/VM.h>
#include <JavaScriptCore/WriteBarrier.h>

namespace JSC {

class JSMicrotaskDispatcher final : public JSCell {
public:
    using Base = JSCell;

    static constexpr unsigned StructureFlags = Base::StructureFlags | StructureIsImmortal;
    static constexpr DestructionMode needsDestruction = NeedsDestruction;

    DECLARE_EXPORT_INFO;

    template<typename CellType, SubspaceAccess mode>
    static GCClient::IsoSubspace* subspaceFor(VM& vm)
    {
        return vm.jsMicrotaskDispatcherSpace<mode>();
    }

    static Structure* createStructure(VM&, JSGlobalObject*, JSValue);

    static JSMicrotaskDispatcher* create(VM&, Structure*, Ref<MicrotaskDispatcher>&&, JSGlobalObject* = nullptr);
    JS_EXPORT_PRIVATE static JSMicrotaskDispatcher* create(VM&, Ref<MicrotaskDispatcher>&&, JSGlobalObject* = nullptr);

    MicrotaskDispatcher* dispatcher() const { return m_dispatcher.ptr(); }

    JSGlobalObject* globalObject() const { return m_globalObject.get(); }

    MicrotaskDispatcher::Type cachedType() const { return m_type; }

    DECLARE_VISIT_CHILDREN;
    static void destroy(JSCell*);

private:
    JSMicrotaskDispatcher(VM&, Structure*, Ref<MicrotaskDispatcher>&&, JSGlobalObject*);

    const Ref<MicrotaskDispatcher> m_dispatcher;
    WriteBarrier<JSGlobalObject> m_globalObject;
    MicrotaskDispatcher::Type m_type;
};

} // namespace JSC