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Commit ebd4c354 by François Dumont
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re PR libstdc++/62313 (Data race in debug iterators) 

2014-09-29  François Dumont  <fdumont@gcc.gnu.org>

	PR libstdc++/62313
	* include/debug/safe_base.h
	(_Safe_iterator_base(const _Safe_iterator_base&)): Delete declaration.
	(_Safe_iterator_base& operator=(const _Safe_iterator_base&)): Likewise.
	* include/debug/safe_iterator.h (_Safe_iterator<>): Move normal iterator
	before _Safe_iterator_base in memory. Lock before modifying the iterator
	in numerous places.
	* include/debug/safe_local_iterator.h
	(_Safe_local_iterator_base(const _Safe_local_iterator_base&)): Delete
	declaration.
	(_Safe_local_iterator_base& operator=(const _Safe_local_iterator_base&)):
	Likewise.
	* include/debug/safe_unordered_base.h (_Safe_local_iterator<>):  Move
	normal iterator before _Safe_iterator_base in memory. Lock before
	modifying the iterator in numerous places.
	* include/debug/forward_list (_Safe_forward_list<>::_M_swap_aux): Adapt.
	* include/debug/safe_sequence.tcc
	(_Safe_sequence<>::_M_transfer_from_if): Adapt.

From-SVN: r215693
parent a3052d31
Showing with 247 additions and 112 deletions
libstdc++-v3/ChangeLog
2014-09-29 François Dumont <fdumont@gcc.gnu.org>
PR libstdc++/62313
* include/debug/safe_base.h
(_Safe_iterator_base(const _Safe_iterator_base&)): Delete declaration.
(_Safe_iterator_base& operator=(const _Safe_iterator_base&)): Likewise.
* include/debug/safe_iterator.h (_Safe_iterator<>): Move normal iterator
before _Safe_iterator_base in memory. Lock before modifying the iterator
in numerous places.
* include/debug/safe_local_iterator.h
(_Safe_local_iterator_base(const _Safe_local_iterator_base&)): Delete
declaration.
(_Safe_local_iterator_base& operator=(const _Safe_local_iterator_base&)):
Likewise.
* include/debug/safe_unordered_base.h (_Safe_local_iterator<>): Move
normal iterator before _Safe_iterator_base in memory. Lock before
modifying the iterator in numerous places.
* include/debug/forward_list (_Safe_forward_list<>::_M_swap_aux): Adapt.
* include/debug/safe_sequence.tcc
(_Safe_sequence<>::_M_transfer_from_if): Adapt.
2014-09-25 Jonathan Wakely <jwakely@redhat.com>
DR 1339
......
libstdc++-v3/include/debug/forward_list
......@@ -86,24 +86,26 @@ namespace __gnu_debug
for (_Safe_iterator_base* __iter = __lhs_iterators; __iter;)
{
// Even iterator is cast to const_iterator, not a problem.
const_iterator* __victim = static_cast<const_iterator*>(__iter);
_Safe_iterator_base* __victim_base = __iter;
const_iterator* __victim =
static_cast<const_iterator*>(__victim_base);
__iter = __iter->_M_next;
if (__victim->base() == __rseq._M_base().cbefore_begin())
{
__victim->_M_unlink();
if (__lhs_iterators == __victim)
__lhs_iterators = __victim->_M_next;
if (__lhs_iterators == __victim_base)
__lhs_iterators = __victim_base->_M_next;
if (__bbegin_its)
{
__victim->_M_next = __bbegin_its;
__bbegin_its->_M_prior = __victim;
__victim_base->_M_next = __bbegin_its;
__bbegin_its->_M_prior = __victim_base;
}
else
__last_bbegin = __victim;
__bbegin_its = __victim;
__last_bbegin = __victim_base;
__bbegin_its = __victim_base;
}
else
__victim->_M_sequence = &__lhs;
__victim_base->_M_sequence = &__lhs;
}
if (__bbegin_its)
......
libstdc++-v3/include/debug/safe_base.h
......@@ -95,12 +95,6 @@ namespace __gnu_debug
: _M_sequence(0), _M_version(0), _M_prior(0), _M_next(0)
{ this->_M_attach(__x._M_sequence, __constant); }
_Safe_iterator_base&
operator=(const _Safe_iterator_base&);
explicit
_Safe_iterator_base(const _Safe_iterator_base&);
~_Safe_iterator_base() { this->_M_detach(); }
/** For use in _Safe_iterator. */
......
libstdc++-v3/include/debug/safe_local_iterator.h
......@@ -49,15 +49,15 @@ namespace __gnu_debug
* the iterator's state.
*/
template<typename _Iterator, typename _Sequence>
class _Safe_local_iterator : public _Safe_local_iterator_base
class _Safe_local_iterator
: private _Iterator
, public _Safe_local_iterator_base
{
typedef _Safe_local_iterator _Self;
typedef _Iterator _Iter_base;
typedef _Safe_local_iterator_base _Safe_base;
typedef typename _Sequence::const_local_iterator _Const_local_iterator;
typedef typename _Sequence::size_type size_type;
/// The underlying iterator
_Iterator _M_current;
/// Determine if this is a constant iterator.
bool
_M_constant() const
......@@ -68,6 +68,14 @@ namespace __gnu_debug
typedef std::iterator_traits<_Iterator> _Traits;
struct _Attach_single
{ };
_Safe_local_iterator(const _Iterator& __i, _Safe_sequence_base* __cont,
_Attach_single) noexcept
: _Iter_base(__i)
{ _M_attach_single(__cont); }
public:
typedef _Iterator iterator_type;
typedef typename _Traits::iterator_category iterator_category;
......@@ -77,7 +85,7 @@ namespace __gnu_debug
typedef typename _Traits::pointer pointer;
/// @post the iterator is singular and unattached
_Safe_local_iterator() : _M_current() { }
_Safe_local_iterator() noexcept : _Iter_base() { }
/**
* @brief Safe iterator construction from an unsafe iterator and
......@@ -86,8 +94,9 @@ namespace __gnu_debug
* @pre @p seq is not NULL
* @post this is not singular
*/
_Safe_local_iterator(const _Iterator& __i, const _Sequence* __seq)
: _Safe_local_iterator_base(__seq, _M_constant()), _M_current(__i)
_Safe_local_iterator(const _Iterator& __i,
const _Safe_sequence_base* __cont)
: _Iter_base(__i), _Safe_base(__cont, _M_constant())
{
_GLIBCXX_DEBUG_VERIFY(!this->_M_singular(),
_M_message(__msg_init_singular)
......@@ -97,9 +106,8 @@ namespace __gnu_debug
/**
* @brief Copy construction.
*/
_Safe_local_iterator(const _Safe_local_iterator& __x)
: _Safe_local_iterator_base(__x, _M_constant()),
_M_current(__x._M_current)
_Safe_local_iterator(const _Safe_local_iterator& __x) noexcept
: _Iter_base(__x.base())
{
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// DR 408. Is vector<reverse_iterator<char*> > forbidden?
......@@ -108,6 +116,25 @@ namespace __gnu_debug
_M_message(__msg_init_copy_singular)
._M_iterator(*this, "this")
._M_iterator(__x, "other"));
_M_attach(__x._M_sequence);
}
/**
* @brief Move construction.
* @post __x is singular and unattached
*/
_Safe_local_iterator(_Safe_local_iterator&& __x) noexcept
: _Iter_base()
{
_GLIBCXX_DEBUG_VERIFY(!__x._M_singular()
|| __x.base() == _Iterator(),
_M_message(__msg_init_copy_singular)
._M_iterator(*this, "this")
._M_iterator(__x, "other"));
auto __cont = __x._M_sequence;
__x._M_detach();
std::swap(base(), __x.base());
_M_attach(__cont);
}
/**
......@@ -121,8 +148,7 @@ namespace __gnu_debug
_MutableIterator,
typename _Sequence::local_iterator::iterator_type>::__value,
_Sequence>::__type>& __x)
: _Safe_local_iterator_base(__x, _M_constant()),
_M_current(__x.base())
: _Iter_base(__x.base())
{
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// DR 408. Is vector<reverse_iterator<char*> > forbidden?
......@@ -131,6 +157,7 @@ namespace __gnu_debug
_M_message(__msg_init_const_singular)
._M_iterator(*this, "this")
._M_iterator(__x, "other"));
_M_attach(__x._M_sequence);
}
/**
......@@ -146,8 +173,54 @@ namespace __gnu_debug
_M_message(__msg_copy_singular)
._M_iterator(*this, "this")
._M_iterator(__x, "other"));
_M_current = __x._M_current;
this->_M_attach(__x._M_sequence);
if (this->_M_sequence && this->_M_sequence == __x._M_sequence)
{
__gnu_cxx::__scoped_lock __l(this->_M_get_mutex());
base() = __x.base();
_M_version = __x._M_sequence->_M_version;
}
else
{
_M_detach();
base() = __x.base();
_M_attach(__x._M_sequence);
}
return *this;
}
/**
* @brief Move assignment.
* @post __x is singular and unattached
*/
_Safe_local_iterator&
operator=(_Safe_local_iterator&& __x) noexcept
{
_GLIBCXX_DEBUG_VERIFY(this != &__x,
_M_message(__msg_self_move_assign)
._M_iterator(*this, "this"));
_GLIBCXX_DEBUG_VERIFY(!__x._M_singular()
|| __x.base() == _Iterator(),
_M_message(__msg_copy_singular)
._M_iterator(*this, "this")
._M_iterator(__x, "other"));
if (this->_M_sequence && this->_M_sequence == __x._M_sequence)
{
__gnu_cxx::__scoped_lock __l(this->_M_get_mutex());
base() = __x.base();
_M_version = __x._M_sequence->_M_version;
}
else
{
_M_detach();
base() = __x.base();
_M_attach(__x._M_sequence);
}
__x._M_detach();
__x.base() = _Iterator();
return *this;
}
......@@ -161,7 +234,7 @@ namespace __gnu_debug
_GLIBCXX_DEBUG_VERIFY(this->_M_dereferenceable(),
_M_message(__msg_bad_deref)
._M_iterator(*this, "this"));
return *_M_current;
return *base();
}
/**
......@@ -175,7 +248,7 @@ namespace __gnu_debug
_GLIBCXX_DEBUG_VERIFY(this->_M_dereferenceable(),
_M_message(__msg_bad_deref)
._M_iterator(*this, "this"));
return std::__addressof(*_M_current);
return std::__addressof(*base());
}
// ------ Input iterator requirements ------
......@@ -189,7 +262,8 @@ namespace __gnu_debug
_GLIBCXX_DEBUG_VERIFY(this->_M_incrementable(),
_M_message(__msg_bad_inc)
._M_iterator(*this, "this"));
++_M_current;
__gnu_cxx::__scoped_lock __l(this->_M_get_mutex());
++base();
return *this;
}
......@@ -203,39 +277,42 @@ namespace __gnu_debug
_GLIBCXX_DEBUG_VERIFY(this->_M_incrementable(),
_M_message(__msg_bad_inc)
._M_iterator(*this, "this"));
_Safe_local_iterator __tmp(*this);
++_M_current;
return __tmp;
__gnu_cxx::__scoped_lock __l(this->_M_get_mutex());
return _Safe_local_iterator(base()++, this->_M_sequence,
_Attach_single());
}
// ------ Utilities ------
/**
* @brief Return the underlying iterator
*/
_Iterator
base() const { return _M_current; }
_Iterator&
base() noexcept { return *this; }
const _Iterator&
base() const noexcept { return *this; }
/**
* @brief Return the bucket
*/
size_type
bucket() const { return _M_current._M_get_bucket(); }
bucket() const { return base()._M_get_bucket(); }
/**
* @brief Conversion to underlying non-debug iterator to allow
* better interaction with non-debug containers.
*/
operator _Iterator() const { return _M_current; }
operator _Iterator() const { return *this; }
/** Attach iterator to the given sequence. */
void
_M_attach(_Safe_sequence_base* __seq)
{ _Safe_iterator_base::_M_attach(__seq, _M_constant()); }
{ _Safe_base::_M_attach(__seq, _M_constant()); }
/** Likewise, but not thread-safe. */
void
_M_attach_single(_Safe_sequence_base* __seq)
{ _Safe_iterator_base::_M_attach_single(__seq, _M_constant()); }
{ _Safe_base::_M_attach_single(__seq, _M_constant()); }
/// Is the iterator dereferenceable?
bool
......
libstdc++-v3/include/debug/safe_sequence.tcc
......@@ -81,42 +81,45 @@ namespace __gnu_debug
for (_Safe_iterator_base* __iter = __from._M_iterators; __iter;)
{
iterator* __victim = static_cast<iterator*>(__iter);
_Safe_iterator_base* __victim_base = __iter;
iterator* __victim = static_cast<iterator*>(__victim_base);
__iter = __iter->_M_next;
if (!__victim->_M_singular() && __pred(__victim->base()))
{
__victim->_M_detach_single();
if (__transfered_iterators)
{
__victim->_M_next = __transfered_iterators;
__transfered_iterators->_M_prior = __victim;
__victim_base->_M_next = __transfered_iterators;
__transfered_iterators->_M_prior = __victim_base;
}
else
__last_iterator = __victim;
__victim->_M_sequence = this;
__victim->_M_version = this->_M_version;
__transfered_iterators = __victim;
__last_iterator = __victim_base;
__victim_base->_M_sequence = this;
__victim_base->_M_version = this->_M_version;
__transfered_iterators = __victim_base;
}
}
for (_Safe_iterator_base* __iter2 = __from._M_const_iterators;
__iter2;)
{
const_iterator* __victim = static_cast<const_iterator*>(__iter2);
_Safe_iterator_base* __victim_base = __iter2;
const_iterator* __victim =
static_cast<const_iterator*>(__victim_base);
__iter2 = __iter2->_M_next;
if (!__victim->_M_singular() && __pred(__victim->base()))
{
__victim->_M_detach_single();
if (__transfered_const_iterators)
{
__victim->_M_next = __transfered_const_iterators;
__transfered_const_iterators->_M_prior = __victim;
__victim_base->_M_next = __transfered_const_iterators;
__transfered_const_iterators->_M_prior = __victim_base;
}
else
__last_const_iterator = __victim;
__victim->_M_sequence = this;
__victim->_M_version = this->_M_version;
__transfered_const_iterators = __victim;
__victim_base->_M_sequence = this;
__victim_base->_M_version = this->_M_version;
__transfered_const_iterators = __victim_base;
}
}
}
......
libstdc++-v3/include/debug/safe_unordered_base.h
......@@ -71,12 +71,6 @@ namespace __gnu_debug
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*
......
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