1 // Safe sequence implementation -*- C++ -*- 2 3 // Copyright (C) 2003, 2004, 2005, 2006 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 2, 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 // You should have received a copy of the GNU General Public License along 18 // with this library; see the file COPYING. If not, write to the Free 19 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 20 // USA. 21 22 // As a special exception, you may use this file as part of a free software 23 // library without restriction. Specifically, if other files instantiate 24 // templates or use macros or inline functions from this file, or you compile 25 // this file and link it with other files to produce an executable, this 26 // file does not by itself cause the resulting executable to be covered by 27 // the GNU General Public License. This exception does not however 28 // invalidate any other reasons why the executable file might be covered by 29 // the GNU General Public License. 30 31 /** @file debug/safe_sequence.h 32 * This file is a GNU debug extension to the Standard C++ Library. 33 */ 34 35 #ifndef _GLIBCXX_DEBUG_SAFE_SEQUENCE_H 36 #define _GLIBCXX_DEBUG_SAFE_SEQUENCE_H 1 37 38 #include <debug/debug.h> 39 #include <debug/macros.h> 40 #include <debug/functions.h> 41 #include <debug/safe_base.h> 42 43 namespace __gnu_debug 44 { 45 template<typename _Iterator, typename _Sequence> 46 class _Safe_iterator; 47 48 /** A simple function object that returns true if the passed-in 49 * value is not equal to the stored value. It saves typing over 50 * using both bind1st and not_equal. 51 */ 52 template<typename _Type> 53 class _Not_equal_to 54 { 55 _Type __value; 56 57 public: 58 explicit _Not_equal_to(const _Type& __v) : __value(__v) { } 59 60 bool 61 operator()(const _Type& __x) const 62 { return __value != __x; } 63 }; 64 65 /** A function object that returns true when the given random access 66 iterator is at least @c n steps away from the given iterator. */ 67 template<typename _Iterator> 68 class _After_nth_from 69 { 70 typedef typename std::iterator_traits<_Iterator>::difference_type 71 difference_type; 72 73 _Iterator _M_base; 74 difference_type _M_n; 75 76 public: 77 _After_nth_from(const difference_type& __n, const _Iterator& __base) 78 : _M_base(__base), _M_n(__n) { } 79 80 bool 81 operator()(const _Iterator& __x) const 82 { return __x - _M_base >= _M_n; } 83 }; 84 85 /** 86 * @brief Base class for constructing a "safe" sequence type that 87 * tracks iterators that reference it. 88 * 89 * The class template %_Safe_sequence simplifies the construction of 90 * "safe" sequences that track the iterators that reference the 91 * sequence, so that the iterators are notified of changes in the 92 * sequence that may affect their operation, e.g., if the container 93 * invalidates its iterators or is destructed. This class template 94 * may only be used by deriving from it and passing the name of the 95 * derived class as its template parameter via the curiously 96 * recurring template pattern. The derived class must have @c 97 * iterator and @const_iterator types that are instantiations of 98 * class template _Safe_iterator for this sequence. Iterators will 99 * then be tracked automatically. 100 */ 101 template<typename _Sequence> 102 class _Safe_sequence : public _Safe_sequence_base 103 { 104 public: 105 /** Invalidates all iterators @c x that reference this sequence, 106 are not singular, and for which @c pred(x) returns @c 107 true. The user of this routine should be careful not to make 108 copies of the iterators passed to @p pred, as the copies may 109 interfere with the invalidation. */ 110 template<typename _Predicate> 111 void 112 _M_invalidate_if(_Predicate __pred); 113 114 /** Transfers all iterators that reference this memory location 115 to this sequence from whatever sequence they are attached 116 to. */ 117 template<typename _Iterator> 118 void 119 _M_transfer_iter(const _Safe_iterator<_Iterator, _Sequence>& __x); 120 }; 121 122 template<typename _Sequence> 123 template<typename _Predicate> 124 void 125 _Safe_sequence<_Sequence>:: 126 _M_invalidate_if(_Predicate __pred) 127 { 128 typedef typename _Sequence::iterator iterator; 129 typedef typename _Sequence::const_iterator const_iterator; 130 131 __gnu_cxx::__scoped_lock sentry(this->_M_get_mutex()); 132 for (_Safe_iterator_base* __iter = _M_iterators; __iter;) 133 { 134 iterator* __victim = static_cast<iterator*>(__iter); 135 __iter = __iter->_M_next; 136 if (!__victim->_M_singular()) 137 { 138 if (__pred(__victim->base())) 139 __victim->_M_invalidate_single(); 140 } 141 } 142 143 for (_Safe_iterator_base* __iter2 = _M_const_iterators; __iter2;) 144 { 145 const_iterator* __victim = static_cast<const_iterator*>(__iter2); 146 __iter2 = __iter2->_M_next; 147 if (!__victim->_M_singular()) 148 { 149 if (__pred(__victim->base())) 150 __victim->_M_invalidate_single(); 151 } 152 } 153 } 154 155 template<typename _Sequence> 156 template<typename _Iterator> 157 void 158 _Safe_sequence<_Sequence>:: 159 _M_transfer_iter(const _Safe_iterator<_Iterator, _Sequence>& __x) 160 { 161 _Safe_sequence_base* __from = __x._M_sequence; 162 if (!__from) 163 return; 164 165 typedef typename _Sequence::iterator iterator; 166 typedef typename _Sequence::const_iterator const_iterator; 167 168 __gnu_cxx::__scoped_lock sentry(this->_M_get_mutex()); 169 for (_Safe_iterator_base* __iter = __from->_M_iterators; __iter;) 170 { 171 iterator* __victim = static_cast<iterator*>(__iter); 172 __iter = __iter->_M_next; 173 if (!__victim->_M_singular() && __victim->base() == __x.base()) 174 __victim->_M_attach_single(static_cast<_Sequence*>(this)); 175 } 176 177 for (_Safe_iterator_base* __iter2 = __from->_M_const_iterators; 178 __iter2;) 179 { 180 const_iterator* __victim = static_cast<const_iterator*>(__iter2); 181 __iter2 = __iter2->_M_next; 182 if (!__victim->_M_singular() && __victim->base() == __x.base()) 183 __victim->_M_attach_single(static_cast<_Sequence*>(this)); 184 } 185 } 186 } // namespace __gnu_debug 187 188 #endif 189