libstdc++-v3/include/debug/safe_sequence.h

   1 // Safe sequence implementation  -*- C++ -*-
   2
   3 // Copyright (C) 2003, 2004, 2005, 2006, 2009
   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 "safe" sequence type that
  82    * tracks iterators that reference it.
  83    *
  84    * The class template %_Safe_sequence simplifies the construction of
  85    * "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