1/* 2 * Copyright (C) 2012 Apple Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' 14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, 15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS 17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF 23 * THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26#ifndef WeakImpl_h 27#define WeakImpl_h 28 29#include "JSCJSValue.h" 30 31namespace JSC { 32 33class WeakHandleOwner; 34 35class WeakImpl { 36public: 37 enum State { 38 Live = 0x0, 39 Dead = 0x1, 40 Finalized = 0x2, 41 Deallocated = 0x3 42 }; 43 44 enum { 45 StateMask = 0x3 46 }; 47 48 WeakImpl(); 49 WeakImpl(JSValue, WeakHandleOwner*, void* context); 50 51 State state(); 52 void setState(State); 53 54 const JSValue& jsValue(); 55 WeakHandleOwner* weakHandleOwner(); 56 void* context(); 57 58 static WeakImpl* asWeakImpl(JSValue*); 59 60private: 61 const JSValue m_jsValue; 62 WeakHandleOwner* m_weakHandleOwner; 63 void* m_context; 64}; 65 66inline WeakImpl::WeakImpl() 67 : m_weakHandleOwner(0) 68 , m_context(0) 69{ 70 setState(Deallocated); 71} 72 73inline WeakImpl::WeakImpl(JSValue jsValue, WeakHandleOwner* weakHandleOwner, void* context) 74 : m_jsValue(jsValue) 75 , m_weakHandleOwner(weakHandleOwner) 76 , m_context(context) 77{ 78 ASSERT(state() == Live); 79 ASSERT(m_jsValue && m_jsValue.isCell()); 80} 81 82inline WeakImpl::State WeakImpl::state() 83{ 84 return static_cast<State>(reinterpret_cast<uintptr_t>(m_weakHandleOwner) & StateMask); 85} 86 87inline void WeakImpl::setState(WeakImpl::State state) 88{ 89 ASSERT(state >= this->state()); 90 m_weakHandleOwner = reinterpret_cast<WeakHandleOwner*>((reinterpret_cast<uintptr_t>(m_weakHandleOwner) & ~StateMask) | state); 91} 92 93inline const JSValue& WeakImpl::jsValue() 94{ 95 return m_jsValue; 96} 97 98inline WeakHandleOwner* WeakImpl::weakHandleOwner() 99{ 100 return reinterpret_cast<WeakHandleOwner*>((reinterpret_cast<uintptr_t>(m_weakHandleOwner) & ~StateMask)); 101} 102 103inline void* WeakImpl::context() 104{ 105 return m_context; 106} 107 108inline WeakImpl* WeakImpl::asWeakImpl(JSValue* slot) 109{ 110 return reinterpret_cast_ptr<WeakImpl*>(reinterpret_cast_ptr<char*>(slot) + OBJECT_OFFSETOF(WeakImpl, m_jsValue)); 111} 112 113} // namespace JSC 114 115#endif // WeakImpl_h 116