safe_unordered_base.h
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// Safe container/iterator base implementation -*- C++ -*-
// Copyright (C) 2011-2013 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
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// 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
// <http://www.gnu.org/licenses/>.
/** @file debug/safe_unordered_base.h
* This file is a GNU debug extension to the Standard C++ Library.
*/
#ifndef _GLIBCXX_DEBUG_SAFE_UNORDERED_BASE_H
#define _GLIBCXX_DEBUG_SAFE_UNORDERED_BASE_H 1
#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
{
protected:
/** Initializes the iterator and makes it singular. */
_Safe_local_iterator_base()
{ }
/** 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&
operator=(const _Safe_local_iterator_base&);
explicit
_Safe_local_iterator_base(const _Safe_local_iterator_base&);
~_Safe_local_iterator_base() { this->_M_detach(); }
_Safe_unordered_container_base*
_M_get_container() const _GLIBCXX_NOEXCEPT;
public:
/** 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.
*/
void _M_attach(_Safe_sequence_base* __seq, bool __constant);
/** Likewise, but not thread-safe. */
void _M_attach_single(_Safe_sequence_base* __seq, bool __constant) throw ();
/** Detach the iterator for whatever container it is attached to,
* if any.
*/
void _M_detach();
/** Likewise, but not thread-safe. */
void _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
{
typedef _Safe_sequence_base _Base;
public:
/// 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;
protected:
// Initialize with a version number of 1 and no iterators
_Safe_unordered_container_base()
: _M_local_iterators(0), _M_const_local_iterators(0)
{ }
/** Notify all iterators that reference this container that the
container is being destroyed. */
~_Safe_unordered_container_base()
{ this->_M_detach_all(); }
/** Detach all iterators, leaving them singular. */
void
_M_detach_all();
/** 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.
*/
void
_M_swap(_Safe_unordered_container_base& __x);
public:
/** Attach an iterator to this container. */
void
_M_attach_local(_Safe_iterator_base* __it, bool __constant);
/** Likewise but not thread safe. */
void
_M_attach_local_single(_Safe_iterator_base* __it, bool __constant) throw ();
/** Detach an iterator from this container */
void
_M_detach_local(_Safe_iterator_base* __it);
/** Likewise but not thread safe. */
void
_M_detach_local_single(_Safe_iterator_base* __it) throw ();
};
} // namespace __gnu_debug
#endif