1/* 2 * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2013 Apple Inc. All rights reserved. 3 * 4 * This library is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU Library General Public 6 * License as published by the Free Software Foundation; either 7 * version 2 of the License, or (at your option) any later version. 8 * 9 * This library is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 * Library General Public License for more details. 13 * 14 * You should have received a copy of the GNU Library General Public License 15 * along with this library; see the file COPYING.LIB. If not, write to 16 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, 17 * Boston, MA 02110-1301, USA. 18 * 19 */ 20 21// RefPtr and PassRefPtr are documented at http://webkit.org/coding/RefPtr.html 22 23#ifndef WTF_RefPtr_h 24#define WTF_RefPtr_h 25 26#include "FastMalloc.h" 27#include "PassRefPtr.h" 28#include <algorithm> 29#include <utility> 30 31namespace WTF { 32 33 enum HashTableDeletedValueType { HashTableDeletedValue }; 34 35 template<typename T> class RefPtr { 36 WTF_MAKE_FAST_ALLOCATED; 37 public: 38 ALWAYS_INLINE RefPtr() : m_ptr(nullptr) { } 39 ALWAYS_INLINE RefPtr(T* ptr) : m_ptr(ptr) { refIfNotNull(ptr); } 40 ALWAYS_INLINE RefPtr(const RefPtr& o) : m_ptr(o.m_ptr) { refIfNotNull(m_ptr); } 41 template<typename U> RefPtr(const RefPtr<U>& o) : m_ptr(o.get()) { refIfNotNull(m_ptr); } 42 43 ALWAYS_INLINE RefPtr(RefPtr&& o) : m_ptr(o.release().leakRef()) { } 44 template<typename U> RefPtr(RefPtr<U>&& o) : m_ptr(o.release().leakRef()) { } 45 46 // See comments in PassRefPtr.h for an explanation of why this takes a const reference. 47 template<typename U> RefPtr(const PassRefPtr<U>&); 48 49 template<typename U> RefPtr(PassRef<U>&&); 50 51 // Hash table deleted values, which are only constructed and never copied or destroyed. 52 RefPtr(HashTableDeletedValueType) : m_ptr(hashTableDeletedValue()) { } 53 bool isHashTableDeletedValue() const { return m_ptr == hashTableDeletedValue(); } 54 55 ALWAYS_INLINE ~RefPtr() { derefIfNotNull(m_ptr); } 56 57 T* get() const { return m_ptr; } 58 59 void clear(); 60 PassRefPtr<T> release() { PassRefPtr<T> tmp = adoptRef(m_ptr); m_ptr = nullptr; return tmp; } 61 PassRef<T> releaseNonNull() { ASSERT(m_ptr); PassRef<T> tmp = adoptRef(*m_ptr); m_ptr = nullptr; return tmp; } 62 63 T& operator*() const { return *m_ptr; } 64 ALWAYS_INLINE T* operator->() const { return m_ptr; } 65 66 bool operator!() const { return !m_ptr; } 67 68 // This conversion operator allows implicit conversion to bool but not to other integer types. 69 typedef T* (RefPtr::*UnspecifiedBoolType); 70 operator UnspecifiedBoolType() const { return m_ptr ? &RefPtr::m_ptr : nullptr; } 71 72 RefPtr& operator=(const RefPtr&); 73 RefPtr& operator=(T*); 74 RefPtr& operator=(const PassRefPtr<T>&); 75 template<typename U> RefPtr& operator=(const RefPtr<U>&); 76 template<typename U> RefPtr& operator=(const PassRefPtr<U>&); 77 RefPtr& operator=(RefPtr&&); 78 template<typename U> RefPtr& operator=(RefPtr<U>&&); 79 template<typename U> RefPtr& operator=(PassRef<U>); 80 81 void swap(RefPtr&); 82 83 static T* hashTableDeletedValue() { return reinterpret_cast<T*>(-1); } 84 85 private: 86 T* m_ptr; 87 }; 88 89 template<typename T> template<typename U> inline RefPtr<T>::RefPtr(const PassRefPtr<U>& o) 90 : m_ptr(o.leakRef()) 91 { 92 } 93 94 template<typename T> template<typename U> inline RefPtr<T>::RefPtr(PassRef<U>&& reference) 95 : m_ptr(&reference.leakRef()) 96 { 97 } 98 99 template<typename T> inline void RefPtr<T>::clear() 100 { 101 T* ptr = m_ptr; 102 m_ptr = nullptr; 103 derefIfNotNull(ptr); 104 } 105 106 template<typename T> inline RefPtr<T>& RefPtr<T>::operator=(const RefPtr& o) 107 { 108 RefPtr ptr = o; 109 swap(ptr); 110 return *this; 111 } 112 113 template<typename T> template<typename U> inline RefPtr<T>& RefPtr<T>::operator=(const RefPtr<U>& o) 114 { 115 RefPtr ptr = o; 116 swap(ptr); 117 return *this; 118 } 119 120 template<typename T> inline RefPtr<T>& RefPtr<T>::operator=(T* optr) 121 { 122 RefPtr ptr = optr; 123 swap(ptr); 124 return *this; 125 } 126 127 template<typename T> inline RefPtr<T>& RefPtr<T>::operator=(const PassRefPtr<T>& o) 128 { 129 RefPtr ptr = o; 130 swap(ptr); 131 return *this; 132 } 133 134 template<typename T> template<typename U> inline RefPtr<T>& RefPtr<T>::operator=(const PassRefPtr<U>& o) 135 { 136 RefPtr ptr = o; 137 swap(ptr); 138 return *this; 139 } 140 141 template<typename T> inline RefPtr<T>& RefPtr<T>::operator=(RefPtr&& o) 142 { 143 RefPtr ptr = WTF::move(o); 144 swap(ptr); 145 return *this; 146 } 147 148 template<typename T> template<typename U> inline RefPtr<T>& RefPtr<T>::operator=(RefPtr<U>&& o) 149 { 150 RefPtr ptr = WTF::move(o); 151 swap(ptr); 152 return *this; 153 } 154 155 template<typename T> template<typename U> inline RefPtr<T>& RefPtr<T>::operator=(PassRef<U> reference) 156 { 157 RefPtr ptr = WTF::move(reference); 158 swap(ptr); 159 return *this; 160 } 161 162 template<class T> inline void RefPtr<T>::swap(RefPtr& o) 163 { 164 std::swap(m_ptr, o.m_ptr); 165 } 166 167 template<class T> inline void swap(RefPtr<T>& a, RefPtr<T>& b) 168 { 169 a.swap(b); 170 } 171 172 template<typename T, typename U> inline bool operator==(const RefPtr<T>& a, const RefPtr<U>& b) 173 { 174 return a.get() == b.get(); 175 } 176 177 template<typename T, typename U> inline bool operator==(const RefPtr<T>& a, U* b) 178 { 179 return a.get() == b; 180 } 181 182 template<typename T, typename U> inline bool operator==(T* a, const RefPtr<U>& b) 183 { 184 return a == b.get(); 185 } 186 187 template<typename T, typename U> inline bool operator!=(const RefPtr<T>& a, const RefPtr<U>& b) 188 { 189 return a.get() != b.get(); 190 } 191 192 template<typename T, typename U> inline bool operator!=(const RefPtr<T>& a, U* b) 193 { 194 return a.get() != b; 195 } 196 197 template<typename T, typename U> inline bool operator!=(T* a, const RefPtr<U>& b) 198 { 199 return a != b.get(); 200 } 201 202 template<typename T, typename U> inline RefPtr<T> static_pointer_cast(const RefPtr<U>& p) 203 { 204 return RefPtr<T>(static_cast<T*>(p.get())); 205 } 206 207 template<typename T> inline T* getPtr(const RefPtr<T>& p) 208 { 209 return p.get(); 210 } 211 212} // namespace WTF 213 214using WTF::RefPtr; 215using WTF::static_pointer_cast; 216 217#endif // WTF_RefPtr_h 218