# safe_sequence.h

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    00001 // Safe sequence implementation  -*- C++ -*-
    00002
    00003 // Copyright (C) 2003, 2004, 2005, 2006, 2009
    00004 // Free Software Foundation, Inc.
    00005 //
    00006 // This file is part of the GNU ISO C++ Library.  This library is free
    00007 // software; you can redistribute it and/or modify it under the
    00008 // terms of the GNU General Public License as published by the
    00009 // Free Software Foundation; either version 3, or (at your option)
    00010 // any later version.
    00011
    00012 // This library is distributed in the hope that it will be useful,
    00013 // but WITHOUT ANY WARRANTY; without even the implied warranty of
    00014 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    00015 // GNU General Public License for more details.
    00016
    00017 // Under Section 7 of GPL version 3, you are granted additional
    00018 // permissions described in the GCC Runtime Library Exception, version
    00019 // 3.1, as published by the Free Software Foundation.
    00020
    00021 // You should have received a copy of the GNU General Public License and
    00022 // a copy of the GCC Runtime Library Exception along with this program;
    00023 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
    00024 // <http://www.gnu.org/licenses/>.
    00025
    00026 /** @file debug/safe_sequence.h
    00027  *  This file is a GNU debug extension to the Standard C++ Library.
    00028  */
    00029
    00030 #ifndef _GLIBCXX_DEBUG_SAFE_SEQUENCE_H
    00031 #define _GLIBCXX_DEBUG_SAFE_SEQUENCE_H 1
    00032
    00033 #include <debug/debug.h>
    00034 #include <debug/macros.h>
    00035 #include <debug/functions.h>
    00036 #include <debug/safe_base.h>
    00037
    00038 namespace __gnu_debug
    00039 {
    00040   template<typename _Iterator, typename _Sequence>
    00041     class _Safe_iterator;
    00042
    00043   /** A simple function object that returns true if the passed-in
    00044    *  value is not equal to the stored value. It saves typing over
    00045    *  using both bind1st and not_equal.
    00046    */
    00047   template<typename _Type>
    00048     class _Not_equal_to
    00049     {
    00050       _Type __value;
    00051
    00052     public:
    00053       explicit _Not_equal_to(const _Type& __v) : __value(__v) { }
    00054
    00055       bool
    00056       operator()(const _Type& __x) const
    00057       { return __value != __x; }
    00058     };
    00059
    00060   /** A function object that returns true when the given random access
    00061       iterator is at least @c n steps away from the given iterator. */
    00062   template<typename _Iterator>
    00063     class _After_nth_from
    00064     {
    00065       typedef typename std::iterator_traits<_Iterator>::difference_type
    00066       difference_type;
    00067
    00068       _Iterator _M_base;
    00069       difference_type _M_n;
    00070
    00071     public:
    00072       _After_nth_from(const difference_type& __n, const _Iterator& __base)
    00073       : _M_base(__base), _M_n(__n) { }
    00074
    00075       bool
    00076       operator()(const _Iterator& __x) const
    00077       { return __x - _M_base >= _M_n; }
    00078     };
    00079
    00080   /**
    00081    * @brief Base class for constructing a "safe" sequence type that
    00082    * tracks iterators that reference it.
    00083    *
    00084    * The class template %_Safe_sequence simplifies the construction of
    00085    * "safe" sequences that track the iterators that reference the
    00086    * sequence, so that the iterators are notified of changes in the
    00087    * sequence that may affect their operation, e.g., if the container
    00088    * invalidates its iterators or is destructed. This class template
    00089    * may only be used by deriving from it and passing the name of the
    00090    * derived class as its template parameter via the curiously
    00091    * recurring template pattern. The derived class must have @c
    00092    * iterator and @const_iterator types that are instantiations of
    00093    * class template _Safe_iterator for this sequence. Iterators will
    00094    * then be tracked automatically.
    00095    */
    00096   template<typename _Sequence>
    00097     class _Safe_sequence : public _Safe_sequence_base
    00098     {
    00099     public:
    00100       /** Invalidates all iterators @c x that reference this sequence,
    00101       are not singular, and for which @c pred(x) returns @c
    00102       true. The user of this routine should be careful not to make
    00103       copies of the iterators passed to @p pred, as the copies may
    00104       interfere with the invalidation. */
    00105       template<typename _Predicate>
    00106         void
    00107         _M_invalidate_if(_Predicate __pred);
    00108
    00109       /** Transfers all iterators that reference this memory location
    00110       to this sequence from whatever sequence they are attached
    00111       to. */
    00112       template<typename _Iterator>
    00113         void
    00114         _M_transfer_iter(const _Safe_iterator<_Iterator, _Sequence>& __x);
    00115     };
    00116
    00117   template<typename _Sequence>
    00118     template<typename _Predicate>
    00119       void
    00120       _Safe_sequence<_Sequence>::
    00121       _M_invalidate_if(_Predicate __pred)
    00122       {
    00123         typedef typename _Sequence::iterator iterator;
    00124         typedef typename _Sequence::const_iterator const_iterator;
    00125
    00126     __gnu_cxx::__scoped_lock sentry(this->_M_get_mutex());
    00127         for (_Safe_iterator_base* __iter = _M_iterators; __iter;)
    00128       {
    00129         iterator* __victim = static_cast<iterator*>(__iter);
    00130         __iter = __iter->_M_next;
    00131         if (!__victim->_M_singular())
    00132           {
    00133         if (__pred(__victim->base()))
    00134           __victim->_M_invalidate_single();
    00135           }
    00136       }
    00137
    00138         for (_Safe_iterator_base* __iter2 = _M_const_iterators; __iter2;)
    00139       {
    00140         const_iterator* __victim = static_cast<const_iterator*>(__iter2);
    00141         __iter2 = __iter2->_M_next;
    00142         if (!__victim->_M_singular())
    00143           {
    00144         if (__pred(__victim->base()))
    00145           __victim->_M_invalidate_single();
    00146           }
    00147       }
    00148       }
    00149
    00150   template<typename _Sequence>
    00151     template<typename _Iterator>
    00152       void
    00153       _Safe_sequence<_Sequence>::
    00154       _M_transfer_iter(const _Safe_iterator<_Iterator, _Sequence>& __x)
    00155       {
    00156     _Safe_sequence_base* __from = __x._M_sequence;
    00157     if (!__from)
    00158       return;
    00159
    00160         typedef typename _Sequence::iterator iterator;
    00161         typedef typename _Sequence::const_iterator const_iterator;
    00162
    00163     __gnu_cxx::__scoped_lock sentry(this->_M_get_mutex());
    00164         for (_Safe_iterator_base* __iter = __from->_M_iterators; __iter;)
    00165       {
    00166         iterator* __victim = static_cast<iterator*>(__iter);
    00167         __iter = __iter->_M_next;
    00168         if (!__victim->_M_singular() && __victim->base() == __x.base())
    00169           __victim->_M_attach_single(static_cast<_Sequence*>(this));
    00170       }
    00171
    00172         for (_Safe_iterator_base* __iter2 = __from->_M_const_iterators;
    00173          __iter2;)
    00174       {
    00175         const_iterator* __victim = static_cast<const_iterator*>(__iter2);
    00176         __iter2 = __iter2->_M_next;
    00177         if (!__victim->_M_singular() && __victim->base() == __x.base())
    00178           __victim->_M_attach_single(static_cast<_Sequence*>(this));
    00179       }
    00180       }
    00181 } // namespace __gnu_debug
    00182
    00183 #endif