1 // Safe sequence implementation -*- C++ -*- 2 3 // Copyright (C) 2003, 2004, 2005, 2006, 2009, 2010 4 // Free Software Foundation, Inc. 5 // 6 // This file is part of the GNU ISO C++ Library. This library is free 7 // software; you can redistribute it and/or modify it under the 8 // terms of the GNU General Public License as published by the 9 // Free Software Foundation; either version 3, or (at your option) 10 // any later version. 11 12 // This library is distributed in the hope that it will be useful, 13 // but WITHOUT ANY WARRANTY; without even the implied warranty of 14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 // GNU General Public License for more details. 16 17 // Under Section 7 of GPL version 3, you are granted additional 18 // permissions described in the GCC Runtime Library Exception, version 19 // 3.1, as published by the Free Software Foundation. 20 21 // You should have received a copy of the GNU General Public License and 22 // a copy of the GCC Runtime Library Exception along with this program; 23 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 24 // <http://www.gnu.org/licenses/>. 25 26 /** @file debug/safe_sequence.h 27 * This file is a GNU debug extension to the Standard C++ Library. 28 */ 29 30 #ifndef _GLIBCXX_DEBUG_SAFE_SEQUENCE_H 31 #define _GLIBCXX_DEBUG_SAFE_SEQUENCE_H 1 32 33 #include <debug/debug.h> 34 #include <debug/macros.h> 35 #include <debug/functions.h> 36 #include <debug/safe_base.h> 37 38 namespace __gnu_debug 39 { 40 template<typename _Iterator, typename _Sequence> 41 class _Safe_iterator; 42 43 /** A simple function object that returns true if the passed-in 44 * value is not equal to the stored value. It saves typing over 45 * using both bind1st and not_equal. 46 */ 47 template<typename _Type> 48 class _Not_equal_to 49 { 50 _Type __value; 51 52 public: 53 explicit _Not_equal_to(const _Type& __v) : __value(__v) { } 54 55 bool 56 operator()(const _Type& __x) const 57 { return __value != __x; } 58 }; 59 60 /** A function object that returns true when the given random access 61 iterator is at least @c n steps away from the given iterator. */ 62 template<typename _Iterator> 63 class _After_nth_from 64 { 65 typedef typename std::iterator_traits<_Iterator>::difference_type 66 difference_type; 67 68 _Iterator _M_base; 69 difference_type _M_n; 70 71 public: 72 _After_nth_from(const difference_type& __n, const _Iterator& __base) 73 : _M_base(__base), _M_n(__n) { } 74 75 bool 76 operator()(const _Iterator& __x) const 77 { return __x - _M_base >= _M_n; } 78 }; 79 80 /** 81 * @brief Base class for constructing a @a safe sequence type that 82 * tracks iterators that reference it. 83 * 84 * The class template %_Safe_sequence simplifies the construction of 85 * @a safe sequences that track the iterators that reference the 86 * sequence, so that the iterators are notified of changes in the 87 * sequence that may affect their operation, e.g., if the container 88 * invalidates its iterators or is destructed. This class template 89 * may only be used by deriving from it and passing the name of the 90 * derived class as its template parameter via the curiously 91 * recurring template pattern. The derived class must have @c 92 * iterator and @const_iterator types that are instantiations of 93 * class template _Safe_iterator for this sequence. Iterators will 94 * then be tracked automatically. 95 */ 96 template<typename _Sequence> 97 class _Safe_sequence : public _Safe_sequence_base 98 { 99 public: 100 /** Invalidates all iterators @c x that reference this sequence, 101 are not singular, and for which @c pred(x) returns @c 102 true. The user of this routine should be careful not to make 103 copies of the iterators passed to @p pred, as the copies may 104 interfere with the invalidation. */ 105 template<typename _Predicate> 106 void 107 _M_invalidate_if(_Predicate __pred); 108 109 /** Transfers all iterators that reference this memory location 110 to this sequence from whatever sequence they are attached 111 to. */ 112 template<typename _Iterator> 113 void 114 _M_transfer_iter(const _Safe_iterator<_Iterator, _Sequence>& __x); 115 }; 116 117 template<typename _Sequence> 118 template<typename _Predicate> 119 void 120 _Safe_sequence<_Sequence>:: 121 _M_invalidate_if(_Predicate __pred) 122 { 123 typedef typename _Sequence::iterator iterator; 124 typedef typename _Sequence::const_iterator const_iterator; 125 126 __gnu_cxx::__scoped_lock sentry(this->_M_get_mutex()); 127 for (_Safe_iterator_base* __iter = _M_iterators; __iter;) 128 { 129 iterator* __victim = static_cast<iterator*>(__iter); 130 __iter = __iter->_M_next; 131 if (!__victim->_M_singular()) 132 { 133 if (__pred(__victim->base())) 134 __victim->_M_invalidate_single(); 135 } 136 } 137 138 for (_Safe_iterator_base* __iter2 = _M_const_iterators; __iter2;) 139 { 140 const_iterator* __victim = static_cast<const_iterator*>(__iter2); 141 __iter2 = __iter2->_M_next; 142 if (!__victim->_M_singular()) 143 { 144 if (__pred(__victim->base())) 145 __victim->_M_invalidate_single(); 146 } 147 } 148 } 149 150 template<typename _Sequence> 151 template<typename _Iterator> 152 void 153 _Safe_sequence<_Sequence>:: 154 _M_transfer_iter(const _Safe_iterator<_Iterator, _Sequence>& __x) 155 { 156 _Safe_sequence_base* __from = __x._M_sequence; 157 if (!__from) 158 return; 159 160 typedef typename _Sequence::iterator iterator; 161 typedef typename _Sequence::const_iterator const_iterator; 162 163 __gnu_cxx::__scoped_lock sentry(this->_M_get_mutex()); 164 for (_Safe_iterator_base* __iter = __from->_M_iterators; __iter;) 165 { 166 iterator* __victim = static_cast<iterator*>(__iter); 167 __iter = __iter->_M_next; 168 if (!__victim->_M_singular() && __victim->base() == __x.base()) 169 __victim->_M_attach_single(static_cast<_Sequence*>(this)); 170 } 171 172 for (_Safe_iterator_base* __iter2 = __from->_M_const_iterators; 173 __iter2;) 174 { 175 const_iterator* __victim = static_cast<const_iterator*>(__iter2); 176 __iter2 = __iter2->_M_next; 177 if (!__victim->_M_singular() && __victim->base() == __x.base()) 178 __victim->_M_attach_single(static_cast<_Sequence*>(this)); 179 } 180 } 181 } // namespace __gnu_debug 182 183 #endif 184