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// Safe container/iterator base implementation -*- C++ -*-
// Copyright (C) 2011-2021 Free Software Foundation, Inc.
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// GNU General Public License for more details.
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
// <>.
/** @file debug/safe_unordered_base.h
* This file is a GNU debug extension to the Standard C++ Library.
#include <debug/safe_base.h>
namespace __gnu_debug
class _Safe_unordered_container_base;
/** \brief Basic functionality for a @a safe iterator.
* The %_Safe_local_iterator_base base class implements the functionality
* of a safe local iterator that is not specific to a particular iterator
* type. It contains a pointer back to the container it references
* along with iterator version information and pointers to form a
* doubly-linked list of local iterators referenced by the container.
* This class must not perform any operations that can throw an
* exception, or the exception guarantees of derived iterators will
* be broken.
class _Safe_local_iterator_base : public _Safe_iterator_base
/** Initializes the iterator and makes it singular. */
{ }
/** Initialize the iterator to reference the container pointed to
* by @p __seq. @p __constant is true when we are initializing a
* constant local iterator, and false if it is a mutable local iterator.
* Note that @p __seq may be NULL, in which case the iterator will be
* singular. Otherwise, the iterator will reference @p __seq and
* be nonsingular.
_Safe_local_iterator_base(const _Safe_sequence_base* __seq, bool __constant)
{ this->_M_attach(const_cast<_Safe_sequence_base*>(__seq), __constant); }
/** Initializes the iterator to reference the same container that
@p __x does. @p __constant is true if this is a constant
iterator, and false if it is mutable. */
_Safe_local_iterator_base(const _Safe_local_iterator_base& __x,
bool __constant)
{ this->_M_attach(__x._M_sequence, __constant); }
~_Safe_local_iterator_base() { this->_M_detach(); }
_M_get_container() const noexcept;
/** Attaches this iterator to the given container, detaching it
* from whatever container it was attached to originally. If the
* new container is the NULL pointer, the iterator is left
* unattached.
_M_attach(_Safe_sequence_base* __seq, bool __constant);
/** Likewise, but not thread-safe. */
_M_attach_single(_Safe_sequence_base* __seq, bool __constant) throw ();
/** Detach the iterator for whatever container it is attached to,
* if any.
/** Likewise, but not thread-safe. */
_M_detach_single() throw ();
* @brief Base class that supports tracking of local iterators that
* reference an unordered container.
* The %_Safe_unordered_container_base class provides basic support for
* tracking iterators into an unordered container. Containers that track
* iterators must derived from %_Safe_unordered_container_base publicly, so
* that safe iterators (which inherit _Safe_iterator_base) can
* attach to them. This class contains four linked lists of
* iterators, one for constant iterators, one for mutable
* iterators, one for constant local iterators, one for mutable local
* iterators and a version number that allows very fast
* invalidation of all iterators that reference the container.
* This class must ensure that no operation on it may throw an
* exception, otherwise @a safe containers may fail to provide the
* exception-safety guarantees required by the C++ standard.
class _Safe_unordered_container_base : public _Safe_sequence_base
friend class _Safe_local_iterator_base;
typedef _Safe_sequence_base _Base;
/// The list of mutable local iterators that reference this container
_Safe_iterator_base* _M_local_iterators;
/// The list of constant local iterators that reference this container
_Safe_iterator_base* _M_const_local_iterators;
// Initialize with a version number of 1 and no iterators
_Safe_unordered_container_base() noexcept
: _M_local_iterators(nullptr), _M_const_local_iterators(nullptr)
{ }
// Copy constructor does not copy iterators.
_Safe_unordered_container_base(const _Safe_unordered_container_base&)
: _Safe_unordered_container_base() { }
// When moved unordered containers iterators are swapped.
_Safe_unordered_container_base(_Safe_unordered_container_base&& __x)
: _Safe_unordered_container_base()
{ this->_M_swap(__x); }
/** Notify all iterators that reference this container that the
container is being destroyed. */
~_Safe_unordered_container_base() noexcept
{ this->_M_detach_all(); }
/** Detach all iterators, leaving them singular. */
/** Swap this container with the given container. This operation
* also swaps ownership of the iterators, so that when the
* operation is complete all iterators that originally referenced
* one container now reference the other container.
_M_swap(_Safe_unordered_container_base& __x) noexcept;
/** Attach an iterator to this container. */
_M_attach_local(_Safe_iterator_base* __it, bool __constant);
/** Likewise but not thread safe. */
_M_attach_local_single(_Safe_iterator_base* __it, bool __constant) throw ();
/** Detach an iterator from this container */
_M_detach_local(_Safe_iterator_base* __it);
/** Likewise but not thread safe. */
_M_detach_local_single(_Safe_iterator_base* __it) throw ();
} // namespace __gnu_debug