1/* 2 * Copyright (C) 2013 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 WeakObjCPtr_h 27#define WeakObjCPtr_h 28 29#include <objc/runtime.h> 30#include <type_traits> 31#include <wtf/RetainPtr.h> 32 33#if __has_include(<objc/objc-internal.h>) 34#include <objc/objc-internal.h> 35#else 36extern "C" { 37id objc_loadWeakRetained(id*); 38id objc_initWeak(id*, id); 39void objc_destroyWeak(id*); 40} 41#endif 42 43namespace WebKit { 44 45template<typename T> class WeakObjCPtr { 46public: 47 typedef typename std::remove_pointer<T>::type ValueType; 48 49 WeakObjCPtr() 50 : m_weakReference(nullptr) 51 { 52 } 53 54 WeakObjCPtr(ValueType *ptr) 55 { 56 objc_initWeak(&m_weakReference, ptr); 57 } 58 59 ~WeakObjCPtr() 60 { 61 objc_destroyWeak(&m_weakReference); 62 } 63 64 WeakObjCPtr& operator=(ValueType *ptr) 65 { 66 objc_storeWeak(&m_weakReference, ptr); 67 68 return *this; 69 } 70 71 RetainPtr<ValueType> get() const 72 { 73 return adoptNS(objc_loadWeakRetained(const_cast<id*>(&m_weakReference))); 74 } 75 76 ValueType *getAutoreleased() const 77 { 78 return static_cast<ValueType *>(objc_loadWeak(const_cast<id*>(&m_weakReference))); 79 } 80 81private: 82 id m_weakReference; 83}; 84 85} // namespace WebKit 86 87#endif // WeakObjCPtr_h 88