libstdc++
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00001 // Safe container/iterator base implementation -*- C++ -*- 00002 00003 // Copyright (C) 2011 Free Software Foundation, Inc. 00004 // 00005 // This file is part of the GNU ISO C++ Library. This library is free 00006 // software; you can redistribute it and/or modify it under the 00007 // terms of the GNU General Public License as published by the 00008 // Free Software Foundation; either version 3, or (at your option) 00009 // any later version. 00010 00011 // This library is distributed in the hope that it will be useful, 00012 // but WITHOUT ANY WARRANTY; without even the implied warranty of 00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00014 // GNU General Public License for more details. 00015 00016 // Under Section 7 of GPL version 3, you are granted additional 00017 // permissions described in the GCC Runtime Library Exception, version 00018 // 3.1, as published by the Free Software Foundation. 00019 00020 // You should have received a copy of the GNU General Public License and 00021 // a copy of the GCC Runtime Library Exception along with this program; 00022 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 00023 // <http://www.gnu.org/licenses/>. 00024 00025 /** @file debug/safe_unordered_base.h 00026 * This file is a GNU debug extension to the Standard C++ Library. 00027 */ 00028 00029 #ifndef _GLIBCXX_DEBUG_SAFE_UNORDERED_BASE_H 00030 #define _GLIBCXX_DEBUG_SAFE_UNORDERED_BASE_H 1 00031 00032 #include <debug/safe_base.h> 00033 00034 namespace __gnu_debug 00035 { 00036 class _Safe_unordered_container_base; 00037 00038 /** \brief Basic functionality for a @a safe iterator. 00039 * 00040 * The %_Safe_local_iterator_base base class implements the functionality 00041 * of a safe local iterator that is not specific to a particular iterator 00042 * type. It contains a pointer back to the container it references 00043 * along with iterator version information and pointers to form a 00044 * doubly-linked list of local iterators referenced by the container. 00045 * 00046 * This class must not perform any operations that can throw an 00047 * exception, or the exception guarantees of derived iterators will 00048 * be broken. 00049 */ 00050 class _Safe_local_iterator_base : public _Safe_iterator_base 00051 { 00052 protected: 00053 /** Initializes the iterator and makes it singular. */ 00054 _Safe_local_iterator_base() 00055 { } 00056 00057 /** Initialize the iterator to reference the container pointed to 00058 * by @p __seq. @p __constant is true when we are initializing a 00059 * constant local iterator, and false if it is a mutable local iterator. 00060 * Note that @p __seq may be NULL, in which case the iterator will be 00061 * singular. Otherwise, the iterator will reference @p __seq and 00062 * be nonsingular. 00063 */ 00064 _Safe_local_iterator_base(const _Safe_sequence_base* __seq, bool __constant) 00065 { this->_M_attach(const_cast<_Safe_sequence_base*>(__seq), __constant); } 00066 00067 /** Initializes the iterator to reference the same container that 00068 @p __x does. @p __constant is true if this is a constant 00069 iterator, and false if it is mutable. */ 00070 _Safe_local_iterator_base(const _Safe_local_iterator_base& __x, 00071 bool __constant) 00072 { this->_M_attach(__x._M_sequence, __constant); } 00073 00074 _Safe_local_iterator_base& 00075 operator=(const _Safe_local_iterator_base&); 00076 00077 explicit 00078 _Safe_local_iterator_base(const _Safe_local_iterator_base&); 00079 00080 ~_Safe_local_iterator_base() { this->_M_detach(); } 00081 00082 _Safe_unordered_container_base* 00083 _M_get_container() const _GLIBCXX_NOEXCEPT; 00084 00085 public: 00086 /** Attaches this iterator to the given container, detaching it 00087 * from whatever container it was attached to originally. If the 00088 * new container is the NULL pointer, the iterator is left 00089 * unattached. 00090 */ 00091 void _M_attach(_Safe_sequence_base* __seq, bool __constant); 00092 00093 /** Likewise, but not thread-safe. */ 00094 void _M_attach_single(_Safe_sequence_base* __seq, bool __constant) throw (); 00095 00096 /** Detach the iterator for whatever container it is attached to, 00097 * if any. 00098 */ 00099 void _M_detach(); 00100 00101 /** Likewise, but not thread-safe. */ 00102 void _M_detach_single() throw (); 00103 }; 00104 00105 /** 00106 * @brief Base class that supports tracking of local iterators that 00107 * reference an unordered container. 00108 * 00109 * The %_Safe_unordered_container_base class provides basic support for 00110 * tracking iterators into an unordered container. Containers that track 00111 * iterators must derived from %_Safe_unordered_container_base publicly, so 00112 * that safe iterators (which inherit _Safe_iterator_base) can 00113 * attach to them. This class contains four linked lists of 00114 * iterators, one for constant iterators, one for mutable 00115 * iterators, one for constant local iterators, one for mutable local 00116 * iterators and a version number that allows very fast 00117 * invalidation of all iterators that reference the container. 00118 * 00119 * This class must ensure that no operation on it may throw an 00120 * exception, otherwise @a safe containers may fail to provide the 00121 * exception-safety guarantees required by the C++ standard. 00122 */ 00123 class _Safe_unordered_container_base : public _Safe_sequence_base 00124 { 00125 typedef _Safe_sequence_base _Base; 00126 public: 00127 /// The list of mutable local iterators that reference this container 00128 _Safe_iterator_base* _M_local_iterators; 00129 00130 /// The list of constant local iterators that reference this container 00131 _Safe_iterator_base* _M_const_local_iterators; 00132 00133 protected: 00134 // Initialize with a version number of 1 and no iterators 00135 _Safe_unordered_container_base() 00136 : _M_local_iterators(0), _M_const_local_iterators(0) 00137 { } 00138 00139 /** Notify all iterators that reference this container that the 00140 container is being destroyed. */ 00141 ~_Safe_unordered_container_base() 00142 { this->_M_detach_all(); } 00143 00144 /** Detach all iterators, leaving them singular. */ 00145 void 00146 _M_detach_all(); 00147 00148 /** Swap this container with the given container. This operation 00149 * also swaps ownership of the iterators, so that when the 00150 * operation is complete all iterators that originally referenced 00151 * one container now reference the other container. 00152 */ 00153 void 00154 _M_swap(_Safe_unordered_container_base& __x); 00155 00156 public: 00157 /** Attach an iterator to this container. */ 00158 void 00159 _M_attach_local(_Safe_iterator_base* __it, bool __constant); 00160 00161 /** Likewise but not thread safe. */ 00162 void 00163 _M_attach_local_single(_Safe_iterator_base* __it, bool __constant) throw (); 00164 00165 /** Detach an iterator from this container */ 00166 void 00167 _M_detach_local(_Safe_iterator_base* __it); 00168 00169 /** Likewise but not thread safe. */ 00170 void 00171 _M_detach_local_single(_Safe_iterator_base* __it) throw (); 00172 }; 00173 } // namespace __gnu_debug 00174 00175 #endif