Source code repo: http://github.com/khizmax/libcds/
Download: http://sourceforge.net/projects/libcds/files/
-
+
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef CDSLIB_INTRUSIVE_DETAILS_SKIP_LIST_BASE_H
typedef typename gc::template atomic_marked_ptr< marked_ptr> atomic_marked_ptr; ///< atomic marked pointer specific for GC
//@cond
typedef atomic_marked_ptr tower_item_type;
+
+ enum state {
+ clean, // initial state
+ removed, // final state
+ hand_off // temp state
+ };
//@endcond
protected:
- atomic_marked_ptr m_pNext; ///< Next item in bottom-list (list at level 0)
- unsigned int m_nHeight; ///< Node height (size of m_arrNext array). For node at level 0 the height is 1.
- atomic_marked_ptr * m_arrNext; ///< Array of next items for levels 1 .. m_nHeight - 1. For node at level 0 \p m_arrNext is \p nullptr
+ //@cond
+ atomic_marked_ptr m_pNext; ///< Next item in bottom-list (list at level 0)
+ unsigned int m_nHeight; ///< Node height (size of \p m_arrNext array). For node at level 0 the height is 1.
+ atomic_marked_ptr * m_arrNext; ///< Array of next items for levels 1 .. m_nHeight - 1. For node at level 0 \p m_arrNext is \p nullptr
+ atomics::atomic< state > m_state;
+ //@endcond
public:
- /// Constructs a node of height 1 (a bottom-list node)
node()
: m_pNext( nullptr )
- , m_nHeight(1)
+ , m_nHeight( 1 )
, m_arrNext( nullptr )
+ , m_state( clean )
{}
- /// Constructs a node of height \p nHeight
+
+ /// Constructs a node's tower of height \p nHeight
void make_tower( unsigned int nHeight, atomic_marked_ptr * nextTower )
{
assert( nHeight > 0 );
- assert( (nHeight == 1 && nextTower == nullptr) // bottom-list node
- || (nHeight > 1 && nextTower != nullptr) // node at level of more than 0
+ assert( (nHeight == 1 && nextTower == nullptr) // bottom-list node
+ || (nHeight > 1 && nextTower != nullptr) // node at level of more than 0
);
m_arrNext = nextTower;
m_nHeight = nHeight;
+ atomics::atomic_thread_fence( atomics::memory_order_release );
}
//@cond
{
return m_arrNext;
}
+
+ bool has_tower() const
+ {
+ return m_nHeight > 1;
+ }
//@endcond
/// Access to element of next pointer array
atomic_marked_ptr& next( unsigned int nLevel )
{
- assert( nLevel < height() );
- assert( nLevel == 0 || (nLevel > 0 && m_arrNext != nullptr) );
-
-# ifdef CDS_THREAD_SANITIZER_ENABLED
- // TSan false positive: m_arrNext is read-only array
- CDS_TSAN_ANNOTATE_IGNORE_READS_BEGIN;
- atomic_marked_ptr& r = nLevel ? m_arrNext[ nLevel - 1] : m_pNext;
- CDS_TSAN_ANNOTATE_IGNORE_READS_END;
- return r;
-# else
+ assert( nLevel < height());
+ assert( nLevel == 0 || (nLevel > 0 && m_arrNext != nullptr));
+
return nLevel ? m_arrNext[ nLevel - 1] : m_pNext;
-# endif
}
/// Access to element of next pointer array (const version)
atomic_marked_ptr const& next( unsigned int nLevel ) const
{
- assert( nLevel < height() );
+ assert( nLevel < height());
assert( nLevel == 0 || nLevel > 0 && m_arrNext != nullptr );
-# ifdef CDS_THREAD_SANITIZER_ENABLED
- // TSan false positive: m_arrNext is read-only array
- CDS_TSAN_ANNOTATE_IGNORE_READS_BEGIN;
- atomic_marked_ptr const& r = nLevel ? m_arrNext[ nLevel - 1] : m_pNext;
- CDS_TSAN_ANNOTATE_IGNORE_READS_END;
- return r;
-# else
return nLevel ? m_arrNext[ nLevel - 1] : m_pNext;
-# endif
}
- /// Access to element of next pointer array (same as \ref next function)
+ /// Access to element of next pointer array (synonym for \p next() function)
atomic_marked_ptr& operator[]( unsigned int nLevel )
{
return next( nLevel );
}
- /// Access to element of next pointer array (same as \ref next function)
+ /// Access to element of next pointer array (synonym for \p next() function)
atomic_marked_ptr const& operator[]( unsigned int nLevel ) const
{
return next( nLevel );
&& m_arrNext == nullptr
&& m_nHeight <= 1;
}
+
+ bool set_state( state& cur_state, state new_state, atomics::memory_order order )
+ {
+ return m_state.compare_exchange_strong( cur_state, new_state, order, atomics::memory_order_relaxed );
+ }
+
+ void clear_state( atomics::memory_order order )
+ {
+ m_state.store( clean, order );
+ }
//@endcond
};
event_counter m_nExtractMaxRetries ; ///< Count of retries of \p extract_max call
event_counter m_nEraseWhileFind ; ///< Count of erased item while searching
event_counter m_nExtractWhileFind ; ///< Count of extracted item while searching (RCU only)
+ event_counter m_nNodeHandOffFailed ; ///< Cannot set "hand-off" node state
//@cond
void onAddNode( unsigned int nHeight )
void onExtractMaxSuccess() { ++m_nExtractMaxSuccess; }
void onExtractMaxFailed() { ++m_nExtractMaxFailed; }
void onExtractMaxRetry() { ++m_nExtractMaxRetries; }
+ void onNodeHandOffFailed() { ++m_nNodeHandOffFailed; }
//@endcond
};
void onExtractMaxSuccess() const {}
void onExtractMaxFailed() const {}
void onExtractMaxRetry() const {}
-
+ void onNodeHandOffFailed() const {}
//@endcond
};
static node_type * make_tower( node_type * pNode, unsigned int nHeight )
{
if ( nHeight > 1 )
- pNode->make_tower( nHeight, tower_allocator().NewArray( nHeight - 1, nullptr ) );
+ pNode->make_tower( nHeight, tower_allocator().NewArray( nHeight - 1, nullptr ));
return pNode;
}
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