1 // Safe sequence implementation  -*- C++ -*-
2 
3 // Copyright (C) 2010-2022 Free Software Foundation, Inc.
4 //
5 // This file is part of the GNU ISO C++ Library.  This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 3, or (at your option)
9 // any later version.
10 
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 // GNU General Public License for more details.
15 
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
19 
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
23 // <http://www.gnu.org/licenses/>.
24 
25 /** @file debug/safe_sequence.tcc
26  *  This file is a GNU debug extension to the Standard C++ Library.
27  */
28 
29 #ifndef _GLIBCXX_DEBUG_SAFE_SEQUENCE_TCC
30 #define _GLIBCXX_DEBUG_SAFE_SEQUENCE_TCC 1
31 
32 namespace __gnu_debug
33 {
34   template<typename _Sequence>
35     template<typename _Predicate>
36       void
37       _Safe_sequence<_Sequence>::
_M_invalidate_if(_Predicate __pred)38       _M_invalidate_if(_Predicate __pred)
39       {
40           typedef typename _Sequence::iterator iterator;
41           typedef typename _Sequence::const_iterator const_iterator;
42 
43           __gnu_cxx::__scoped_lock sentry(this->_M_get_mutex());
44           for (_Safe_iterator_base* __iter = _M_iterators; __iter;)
45             {
46               iterator* __victim = static_cast<iterator*>(__iter);
47               __iter = __iter->_M_next;
48               if (!__victim->_M_singular() && __pred(__victim->base()))
49                 {
50                     __victim->_M_invalidate();
51                 }
52             }
53 
54           for (_Safe_iterator_base* __iter2 = _M_const_iterators; __iter2;)
55             {
56               const_iterator* __victim = static_cast<const_iterator*>(__iter2);
57               __iter2 = __iter2->_M_next;
58               if (!__victim->_M_singular() && __pred(__victim->base()))
59                 {
60                     __victim->_M_invalidate();
61                 }
62             }
63       }
64 
65   template<typename _Sequence>
66     template<typename _Predicate>
67       void
68       _Safe_sequence<_Sequence>::
_M_transfer_from_if(_Safe_sequence & __from,_Predicate __pred)69       _M_transfer_from_if(_Safe_sequence& __from, _Predicate __pred)
70       {
71           if (this == std::__addressof(__from))
72             return;
73 
74           typedef typename _Sequence::iterator iterator;
75           typedef typename _Sequence::const_iterator const_iterator;
76 
77           _Safe_iterator_base* __transfered_iterators = 0;
78           _Safe_iterator_base* __transfered_const_iterators = 0;
79           _Safe_iterator_base* __last_iterator = 0;
80           _Safe_iterator_base* __last_const_iterator = 0;
81           {
82             // We lock __from first and detach iterator(s) to transfer
83             __gnu_cxx::__scoped_lock sentry(__from._M_get_mutex());
84 
85             for (_Safe_iterator_base* __iter = __from._M_iterators; __iter;)
86               {
87                 _Safe_iterator_base* __victim_base = __iter;
88                 iterator* __victim = static_cast<iterator*>(__victim_base);
89                 __iter = __iter->_M_next;
90                 if (!__victim->_M_singular() && __pred(__victim->base()))
91                     {
92                       __victim->_M_detach_single();
93                       if (__transfered_iterators)
94                         {
95                           __victim_base->_M_next = __transfered_iterators;
96                           __transfered_iterators->_M_prior = __victim_base;
97                         }
98                       else
99                         __last_iterator = __victim_base;
100                       __victim_base->_M_sequence = this;
101                       __victim_base->_M_version = this->_M_version;
102                       __transfered_iterators = __victim_base;
103                     }
104               }
105 
106             for (_Safe_iterator_base* __iter2 = __from._M_const_iterators;
107                      __iter2;)
108               {
109                 _Safe_iterator_base* __victim_base = __iter2;
110                 const_iterator* __victim =
111                     static_cast<const_iterator*>(__victim_base);
112                 __iter2 = __iter2->_M_next;
113                 if (!__victim->_M_singular() && __pred(__victim->base()))
114                     {
115                       __victim->_M_detach_single();
116                       if (__transfered_const_iterators)
117                         {
118                           __victim_base->_M_next = __transfered_const_iterators;
119                           __transfered_const_iterators->_M_prior = __victim_base;
120                         }
121                       else
122                         __last_const_iterator = __victim;
123                       __victim_base->_M_sequence = this;
124                       __victim_base->_M_version = this->_M_version;
125                       __transfered_const_iterators = __victim_base;
126                     }
127               }
128           }
129 
130           // Now we can lock *this and add the transfered iterators if any
131           if (__last_iterator || __last_const_iterator)
132             {
133               __gnu_cxx::__scoped_lock sentry(this->_M_get_mutex());
134               if (__last_iterator)
135                 {
136                     if (this->_M_iterators)
137                       {
138                         this->_M_iterators->_M_prior = __last_iterator;
139                         __last_iterator->_M_next = this->_M_iterators;
140                       }
141                     this->_M_iterators = __transfered_iterators;
142                 }
143               if (__last_const_iterator)
144                 {
145                     if (this->_M_const_iterators)
146                       {
147                         this->_M_const_iterators->_M_prior = __last_const_iterator;
148                         __last_const_iterator->_M_next = this->_M_const_iterators;
149                       }
150                     this->_M_const_iterators = __transfered_const_iterators;
151                 }
152             }
153       }
154 } // namespace __gnu_debug
155 
156 #endif
157