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 * 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.
 * 3.  Neither the name of Apple Inc. ("Apple") nor the names of
 *     its contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE 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
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 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#pragma once

#include "JSDOMBinding.h"
#include "ScriptExecutionContext.h"
#include <JavaScriptCore/JSObject.h>
#include <JavaScriptCore/Weak.h>
#include <JavaScriptCore/WeakInlines.h>
#include <wtf/TZoneMalloc.h>
#include <wtf/Threading.h>

namespace WebCore {

template<typename ImplementationClass> struct JSDOMCallbackConverterTraits;

// We have to clean up this data on the context thread because unprotecting a
// JSObject on the wrong thread without synchronization would corrupt the heap
// (and synchronization would be slow).

class JSCallbackData {
    WTF_MAKE_TZONE_ALLOCATED_EXPORT(JSCallbackData, WEBCORE_EXPORT);
public:
    enum class CallbackType { Function, Object, FunctionOrObject };

    JSCallbackData(JSC::JSObject* callback, JSDOMGlobalObject* globalObject, void* owner)
        : m_globalObject(globalObject)
        , m_callback(callback, &m_weakOwner, owner)
    {
    }

    ~JSCallbackData()
    {
#if !PLATFORM(IOS_FAMILY)
        ASSERT(m_thread.ptr() == &Thread::currentSingleton());
#endif
    }

    JSDOMGlobalObject* globalObject() { return m_globalObject.get(); }
    JSC::JSObject* callback() { return m_callback.get(); }

    template<typename Visitor> void visitJSFunction(Visitor&);

    WEBCORE_EXPORT static JSC::JSValue invokeCallback(JSDOMGlobalObject&, JSC::JSObject* callback, JSC::JSValue thisValue, JSC::MarkedArgumentBuffer&, CallbackType, JSC::PropertyName functionName, NakedPtr<JSC::Exception>& returnedException);

    JSC::JSValue invokeCallback(JSC::JSValue thisValue, JSC::MarkedArgumentBuffer& args, CallbackType callbackType, JSC::PropertyName functionName, NakedPtr<JSC::Exception>& returnedException)
    {
        auto* globalObject = this->globalObject();
        if (!globalObject)
            return { };

        return JSCallbackData::invokeCallback(*globalObject, callback(), thisValue, args, callbackType, functionName, returnedException);
    }

private:
    JSC::Weak<JSDOMGlobalObject> m_globalObject;

    class WeakOwner : public JSC::WeakHandleOwner {
        bool isReachableFromOpaqueRoots(JSC::Handle<JSC::Unknown>, void* owner, JSC::AbstractSlotVisitor& visitor, ASCIILiteral* reason) override
    {
            if (reason) [[unlikely]]
                *reason = "Callback owner is an opaque root"_s;
            return visitor.containsOpaqueRoot(owner);
    }
    };
    WeakOwner m_weakOwner;
    JSC::Weak<JSC::JSObject> m_callback;

#if ASSERT_ENABLED
    const Ref<Thread> m_thread { Thread::currentSingleton() };
#endif
};

class DeleteCallbackDataTask : public ScriptExecutionContext::Task {
public:
    template <typename CallbackDataType>
    explicit DeleteCallbackDataTask(CallbackDataType* data)
        : ScriptExecutionContext::Task(ScriptExecutionContext::Task::CleanupTask, [data = std::unique_ptr<CallbackDataType>(data)] (ScriptExecutionContext&) {
        })
    {
    }
};

} // namespace WebCore
