-//$$CDS-header$$
-
-#ifndef __CDS_URCU_EXEMPT_PTR_H
-#define __CDS_URCU_EXEMPT_PTR_H
-
+/*
+ This file is a part of libcds - Concurrent Data Structures library
+
+ (C) Copyright Maxim Khizhinsky (libcds.dev@gmail.com) 2006-2016
+
+ 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:
+
+ * Redistributions of source code must retain the above copyright notice, this
+ list of conditions and the following disclaimer.
+
+ * Redistributions in binary form must reproduce the above copyright notice,
+ this list of conditions and the following disclaimer in the documentation
+ and/or other materials provided with the distribution.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ 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.
+*/
+
+#ifndef CDSLIB_URCU_EXEMPT_PTR_H
+#define CDSLIB_URCU_EXEMPT_PTR_H
+
+#include <type_traits>
#include <cds/details/defs.h>
namespace cds { namespace urcu {
For non-intrusive containers from \p cds::container namespace \p Disposer is usually an invocation
of node deallocator. For intrusive containers the disposer can be empty or it can trigger an event "node can be reused safely".
In any case, the exempt pointer concept keeps RCU semantics.
+ The destructor or \p release() should be called outside the RCU lock of current thread.
You don't need use this helper class directly. Any RCU-based container typedefs a simplified version of this template.
- \p NodeType - container's node type
- \p ValueType - value type stored in container's node. For intrusive containers it is the same as \p NodeType
- \p Disposer - a disposer functor
- - \p Cast - a functor for casting from \p NodeType to \p ValueType. For intrusive containers
+ - \p Cast - a functor for casting from \p NodeType to \p ValueType. For intrusive containers
the casting is usually disabled, i.e. \p Cast is \p void.
*/
template <
>
class exempt_ptr
{
+ //@cond
+ struct trivial_cast {
+ ValueType * operator()( NodeType * p ) const
+ {
+ return p;
+ }
+ };
+ //@endcond
public:
typedef RCU rcu ; ///< RCU type - one of <tt>cds::urcu::gc< ... ></tt>
typedef NodeType node_type ; ///< Node type
typedef ValueType value_type ; ///< Value type
typedef Disposer disposer ; ///< Disposer calling when release
- typedef Cast node_to_value_cast ; ///< Functor converting \p node_type to \p value_type
+ /// Functor converting \p node_type to \p value_type
+ typedef typename std::conditional< std::is_same< Cast, void >::value, trivial_cast, Cast>::type node_to_value_cast;
private:
//@cond
/// The exempt pointer is not copy-constructible
exempt_ptr( exempt_ptr const& ) = delete;
- /// Releases the pointer
+ /// Releases the pointer, see \p release()
~exempt_ptr()
{
release();
/// Disposes the pointer. Should be called only outside of RCU critical section
void release()
{
- assert( !rcu::is_locked() );
if ( !empty() ) {
+ assert( !rcu::is_locked() );
rcu::template retire_ptr<disposer>( m_pNode );
m_pNode = nullptr;
}
}
};
-
- //@cond
- // Intrusive container specialization
- template <
- class RCU,
- typename NodeType,
- typename Disposer
- >
- class exempt_ptr< RCU, NodeType, NodeType, Disposer, void >
- {
- public:
- typedef RCU rcu ; ///< RCU type - one of <tt>cds::urcu::gc< ... ></tt>
- typedef NodeType node_type ; ///< Node type
- typedef NodeType value_type ; ///< Node type
- typedef Disposer disposer ; ///< Disposer calling when release
- typedef void node_to_value_cast; ///< No casting is needed
-
- private:
- node_type * m_pNode;
-
- public:
- /// Constructs empty pointer
- exempt_ptr() CDS_NOEXCEPT
- : m_pNode( nullptr )
- {}
-
- /// Creates exempt pointer for \p pNode. Only for internal use.
- explicit exempt_ptr( node_type * pNode ) CDS_NOEXCEPT
- : m_pNode( pNode )
- {}
- explicit exempt_ptr( std::nullptr_t ) CDS_NOEXCEPT
- : m_pNode( nullptr )
- {}
-
- /// Move ctor
- exempt_ptr( exempt_ptr&& p ) CDS_NOEXCEPT
- : m_pNode( p.m_pNode )
- {
- p.m_pNode = nullptr;
- }
-
-
- /// The exempt pointer is not copy-constructible
- exempt_ptr( exempt_ptr const& ) = delete;
-
- /// Releases the pointer
- ~exempt_ptr()
- {
- release();
- }
-
- /// Checks if the pointer is \p nullptr
- bool empty() const CDS_NOEXCEPT
- {
- return m_pNode == nullptr;
- }
-
- /// \p bool operator returns <tt>!empty()</tt>
- explicit operator bool() const CDS_NOEXCEPT
- {
- return !empty();
- }
-
- /// Dereference operator.
- value_type * operator->() const CDS_NOEXCEPT
- {
- return !empty() ? m_pNode : nullptr;
- }
-
- /// Returns a reference to the value
- value_type& operator *() CDS_NOEXCEPT
- {
- assert( !empty());
- return *m_pNode;
- }
-
- /// Move assignment. Can be called only outside of RCU critical section
- exempt_ptr& operator =(exempt_ptr&& p) CDS_NOEXCEPT
- {
- release();
- m_pNode = p.m_pNode;
- p.m_pNode = nullptr;
- return *this;
- }
-
- /// The exempt pointer is not copy-assignable
- exempt_ptr& operator=(exempt_ptr const&) = delete;
-
- /// Disposes the pointer. Should be called only outside of RCU critical section
- void release()
- {
- assert( !rcu::is_locked() );
- if ( !empty() ) {
- rcu::template retire_ptr<disposer>( m_pNode );
- m_pNode = nullptr;
- }
- }
- };
- //@endcond
-
}} // namespace cds::urcu
-#endif //#ifndef __CDS_URCU_EXEMPT_PTR_H
+#endif //#ifndef CDSLIB_URCU_EXEMPT_PTR_H
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