mirror of
https://github.com/autc04/Retro68.git
synced 2024-09-10 03:54:48 +00:00
270 lines
8.8 KiB
C++
270 lines
8.8 KiB
C++
// Safe sequence/iterator base implementation -*- C++ -*-
|
|
|
|
// Copyright (C) 2003-2016 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_base.h
|
|
* This file is a GNU debug extension to the Standard C++ Library.
|
|
*/
|
|
|
|
#ifndef _GLIBCXX_DEBUG_SAFE_BASE_H
|
|
#define _GLIBCXX_DEBUG_SAFE_BASE_H 1
|
|
|
|
#include <ext/concurrence.h>
|
|
|
|
namespace __gnu_debug
|
|
{
|
|
class _Safe_sequence_base;
|
|
|
|
/** \brief Basic functionality for a @a safe iterator.
|
|
*
|
|
* The %_Safe_iterator_base base class implements the functionality
|
|
* of a safe iterator that is not specific to a particular iterator
|
|
* type. It contains a pointer back to the sequence it references
|
|
* along with iterator version information and pointers to form a
|
|
* doubly-linked list of 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_iterator_base
|
|
{
|
|
public:
|
|
/** The sequence this iterator references; may be NULL to indicate
|
|
a singular iterator. */
|
|
_Safe_sequence_base* _M_sequence;
|
|
|
|
/** The version number of this iterator. The sentinel value 0 is
|
|
* used to indicate an invalidated iterator (i.e., one that is
|
|
* singular because of an operation on the container). This
|
|
* version number must equal the version number in the sequence
|
|
* referenced by _M_sequence for the iterator to be
|
|
* non-singular.
|
|
*/
|
|
unsigned int _M_version;
|
|
|
|
/** Pointer to the previous iterator in the sequence's list of
|
|
iterators. Only valid when _M_sequence != NULL. */
|
|
_Safe_iterator_base* _M_prior;
|
|
|
|
/** Pointer to the next iterator in the sequence's list of
|
|
iterators. Only valid when _M_sequence != NULL. */
|
|
_Safe_iterator_base* _M_next;
|
|
|
|
protected:
|
|
/** Initializes the iterator and makes it singular. */
|
|
_Safe_iterator_base()
|
|
: _M_sequence(0), _M_version(0), _M_prior(0), _M_next(0)
|
|
{ }
|
|
|
|
/** Initialize the iterator to reference the sequence pointed to
|
|
* by @p __seq. @p __constant is true when we are initializing a
|
|
* constant iterator, and false if it is a mutable 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_iterator_base(const _Safe_sequence_base* __seq, bool __constant)
|
|
: _M_sequence(0), _M_version(0), _M_prior(0), _M_next(0)
|
|
{ this->_M_attach(const_cast<_Safe_sequence_base*>(__seq), __constant); }
|
|
|
|
/** Initializes the iterator to reference the same sequence that
|
|
@p __x does. @p __constant is true if this is a constant
|
|
iterator, and false if it is mutable. */
|
|
_Safe_iterator_base(const _Safe_iterator_base& __x, bool __constant)
|
|
: _M_sequence(0), _M_version(0), _M_prior(0), _M_next(0)
|
|
{ this->_M_attach(__x._M_sequence, __constant); }
|
|
|
|
~_Safe_iterator_base() { this->_M_detach(); }
|
|
|
|
/** For use in _Safe_iterator. */
|
|
__gnu_cxx::__mutex&
|
|
_M_get_mutex() throw ();
|
|
|
|
public:
|
|
/** Attaches this iterator to the given sequence, detaching it
|
|
* from whatever sequence it was attached to originally. If the
|
|
* new sequence 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 sequence it is attached to,
|
|
* if any.
|
|
*/
|
|
void
|
|
_M_detach();
|
|
|
|
/** Likewise, but not thread-safe. */
|
|
void
|
|
_M_detach_single() throw ();
|
|
|
|
/** Determines if we are attached to the given sequence. */
|
|
bool
|
|
_M_attached_to(const _Safe_sequence_base* __seq) const
|
|
{ return _M_sequence == __seq; }
|
|
|
|
/** Is this iterator singular? */
|
|
_GLIBCXX_PURE bool
|
|
_M_singular() const throw ();
|
|
|
|
/** Can we compare this iterator to the given iterator @p __x?
|
|
Returns true if both iterators are nonsingular and reference
|
|
the same sequence. */
|
|
_GLIBCXX_PURE bool
|
|
_M_can_compare(const _Safe_iterator_base& __x) const throw ();
|
|
|
|
/** Invalidate the iterator, making it singular. */
|
|
void
|
|
_M_invalidate()
|
|
{ _M_version = 0; }
|
|
|
|
/** Reset all member variables */
|
|
void
|
|
_M_reset() throw ();
|
|
|
|
/** Unlink itself */
|
|
void
|
|
_M_unlink() throw ()
|
|
{
|
|
if (_M_prior)
|
|
_M_prior->_M_next = _M_next;
|
|
if (_M_next)
|
|
_M_next->_M_prior = _M_prior;
|
|
}
|
|
};
|
|
|
|
/** Iterators that derive from _Safe_iterator_base can be determined singular
|
|
* or non-singular.
|
|
**/
|
|
inline bool
|
|
__check_singular_aux(const _Safe_iterator_base* __x)
|
|
{ return __x->_M_singular(); }
|
|
|
|
/**
|
|
* @brief Base class that supports tracking of iterators that
|
|
* reference a sequence.
|
|
*
|
|
* The %_Safe_sequence_base class provides basic support for
|
|
* tracking iterators into a sequence. Sequences that track
|
|
* iterators must derived from %_Safe_sequence_base publicly, so
|
|
* that safe iterators (which inherit _Safe_iterator_base) can
|
|
* attach to them. This class contains two linked lists of
|
|
* iterators, one for constant iterators and one for mutable
|
|
* 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 sequences may fail to provide the
|
|
* exception-safety guarantees required by the C++ standard.
|
|
*/
|
|
class _Safe_sequence_base
|
|
{
|
|
public:
|
|
/// The list of mutable iterators that reference this container
|
|
_Safe_iterator_base* _M_iterators;
|
|
|
|
/// The list of constant iterators that reference this container
|
|
_Safe_iterator_base* _M_const_iterators;
|
|
|
|
/// The container version number. This number may never be 0.
|
|
mutable unsigned int _M_version;
|
|
|
|
protected:
|
|
// Initialize with a version number of 1 and no iterators
|
|
_Safe_sequence_base() _GLIBCXX_NOEXCEPT
|
|
: _M_iterators(0), _M_const_iterators(0), _M_version(1)
|
|
{ }
|
|
|
|
#if __cplusplus >= 201103L
|
|
_Safe_sequence_base(const _Safe_sequence_base&) noexcept
|
|
: _Safe_sequence_base() { }
|
|
#endif
|
|
|
|
/** Notify all iterators that reference this sequence that the
|
|
sequence is being destroyed. */
|
|
~_Safe_sequence_base()
|
|
{ this->_M_detach_all(); }
|
|
|
|
/** Detach all iterators, leaving them singular. */
|
|
void
|
|
_M_detach_all();
|
|
|
|
/** Detach all singular iterators.
|
|
* @post for all iterators i attached to this sequence,
|
|
* i->_M_version == _M_version.
|
|
*/
|
|
void
|
|
_M_detach_singular();
|
|
|
|
/** Revalidates all attached singular iterators. This method may
|
|
* be used to validate iterators that were invalidated before
|
|
* (but for some reason, such as an exception, need to become
|
|
* valid again).
|
|
*/
|
|
void
|
|
_M_revalidate_singular();
|
|
|
|
/** Swap this sequence with the given sequence. 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_sequence_base& __x) _GLIBCXX_USE_NOEXCEPT;
|
|
|
|
/** For use in _Safe_sequence. */
|
|
__gnu_cxx::__mutex&
|
|
_M_get_mutex() throw ();
|
|
|
|
public:
|
|
/** Invalidates all iterators. */
|
|
void
|
|
_M_invalidate_all() const
|
|
{ if (++_M_version == 0) _M_version = 1; }
|
|
|
|
/** Attach an iterator to this sequence. */
|
|
void
|
|
_M_attach(_Safe_iterator_base* __it, bool __constant);
|
|
|
|
/** Likewise but not thread safe. */
|
|
void
|
|
_M_attach_single(_Safe_iterator_base* __it, bool __constant) throw ();
|
|
|
|
/** Detach an iterator from this sequence */
|
|
void
|
|
_M_detach(_Safe_iterator_base* __it);
|
|
|
|
/** Likewise but not thread safe. */
|
|
void
|
|
_M_detach_single(_Safe_iterator_base* __it) throw ();
|
|
};
|
|
} // namespace __gnu_debug
|
|
|
|
#endif
|