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/*
* Copyright (C) 2012 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
* 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 "JSCJSValue.h"
namespace JSC {
class WeakHandleOwner;
class WeakImpl {
public:
enum State {
Live = 0x0,
Dead = 0x1,
Finalized = 0x2,
Deallocated = 0x3
};
enum {
StateMask = 0x3
};
WeakImpl();
WeakImpl(JSValue, WeakHandleOwner*, void* context);
State state();
void setState(State);
const JSValue& jsValue();
static ptrdiff_t offsetOfJSValue() { return OBJECT_OFFSETOF(WeakImpl, m_jsValue); }
WeakHandleOwner* weakHandleOwner();
static ptrdiff_t offsetOfWeakHandleOwner() { return OBJECT_OFFSETOF(WeakImpl, m_weakHandleOwner); }
void* context();
static WeakImpl* asWeakImpl(JSValue*);
private:
const JSValue m_jsValue;
WeakHandleOwner* m_weakHandleOwner;
void* m_context;
};
inline WeakImpl::WeakImpl()
: m_weakHandleOwner(0)
, m_context(0)
{
setState(Deallocated);
}
inline WeakImpl::WeakImpl(JSValue jsValue, WeakHandleOwner* weakHandleOwner, void* context)
: m_jsValue(jsValue)
, m_weakHandleOwner(weakHandleOwner)
, m_context(context)
{
ASSERT(state() == Live);
ASSERT(m_jsValue && m_jsValue.isCell());
}
inline WeakImpl::State WeakImpl::state()
{
return static_cast<State>(reinterpret_cast<uintptr_t>(m_weakHandleOwner) & StateMask);
}
inline void WeakImpl::setState(WeakImpl::State state)
{
ASSERT(state >= this->state());
m_weakHandleOwner = reinterpret_cast<WeakHandleOwner*>((reinterpret_cast<uintptr_t>(m_weakHandleOwner) & ~StateMask) | state);
}
inline const JSValue& WeakImpl::jsValue()
{
return m_jsValue;
}
inline WeakHandleOwner* WeakImpl::weakHandleOwner()
{
return reinterpret_cast<WeakHandleOwner*>((reinterpret_cast<uintptr_t>(m_weakHandleOwner) & ~StateMask));
}
inline void* WeakImpl::context()
{
return m_context;
}
inline WeakImpl* WeakImpl::asWeakImpl(JSValue* slot)
{
return reinterpret_cast_ptr<WeakImpl*>(reinterpret_cast_ptr<char*>(slot) + OBJECT_OFFSETOF(WeakImpl, m_jsValue));
}
} // namespace JSC
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