--- /dev/null
+/*
+ This file is a part of libcds - Concurrent Data Structures library
+
+ (C) Copyright Maxim Khizhinsky (libcds.dev@gmail.com) 2006-2017
+
+ 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_RAW_PTR_H
+#define CDSLIB_URCU_RAW_PTR_H
+
+#include <utility> // std::move
+#include <type_traits>
+#include <cds/details/defs.h>
+
+namespace cds { namespace urcu {
+
+ /// Raw pointer to node of RCU-based container
+ /**
+ This class is intented for returning a pointer to node of RCU-based container.
+ The objects of \p %raw_ptr class is returned by functions like \p get() of that containers.
+ Those functions must be called only under RCU-lock, otherwise the node returned can be reclaimed.
+ On the other hand, traversing the container can remove a lot of nodes marked as deleted ones.
+ Since RCU is locked, such nodes cannot be reclaimed immediately and must be retired only
+ outside RCU lock.
+
+ The object of \p %raw_ptr solves that problem: it contains the pointer to the node found
+ and a chain of nodes that were be reclaimed during traversing. The \p %raw_ptr object destructor
+ frees the chain (but not the node found) passing it to RCU \p batch_retire().
+
+ The object of \p %raw_ptr class must be destructed only outside RCU-lock of current thread.
+
+ Usually, you do not need to use \p %raw_ptr class directly. Each RCU container declares
+ a \p %raw_ptr typedef suitable for the container.
+
+ Template arguments:
+ - \p RCU - one of \ref cds_urcu_gc "RCU type"
+ - \p ValueType - type of values stored in container
+ - \p ReclaimedEnumerator - implementation-defined for each type of container
+
+ Example: let \p Container is an RCU container
+ @code
+ Container c;
+ // ...
+ // Find a key
+ typename Container::raw_ptr pRaw;
+
+ // RCU locked section
+ {
+ typename Container::rcu_lock l;
+ pRaw = c.get( key );
+ if ( pRaw ) {
+ // Deal with pRaw
+ }
+ }
+ // Release outside RCU-lock
+ pRaw.release();
+ @endcode
+ */
+ template <
+ class RCU,
+ typename ValueType,
+ typename ReclaimedEnumerator
+ >
+ class raw_ptr
+ {
+ public:
+ typedef RCU rcu; ///< RCU type - one of <tt>cds::urcu::gc< ... ></tt>
+ typedef ValueType value_type; ///< Value type pointed by \p %raw_ptr
+ typedef ReclaimedEnumerator reclaimed_enumerator; ///< implementation-defined, for internal use only
+
+ private:
+ //@cond
+ value_type * m_ptr; ///< pointer to node
+ reclaimed_enumerator m_Enum; ///< reclaimed node enumerator
+ //@endcond
+
+ public:
+ /// Constructs an empty raw pointer
+ raw_ptr()
+ : m_ptr( nullptr )
+ {}
+
+ /// Move ctor
+ raw_ptr( raw_ptr&& p )
+ : m_ptr( p.m_ptr )
+ , m_Enum(std::move( p.m_Enum ))
+ {
+ p.m_ptr = nullptr;
+ }
+
+ /// Copy ctor is prohibited
+ raw_ptr( raw_ptr const& ) = delete;
+
+ //@cond
+ // Only for internal use
+ raw_ptr( value_type * p, reclaimed_enumerator&& e )
+ : m_ptr( p )
+ , m_Enum(std::move( e ))
+ {}
+ raw_ptr( reclaimed_enumerator&& e )
+ : m_ptr( nullptr )
+ , m_Enum(std::move( e ))
+ {}
+ //@endcond
+
+ /// Releases the raw pointer
+ ~raw_ptr()
+ {
+ release();
+ }
+
+ public:
+ /// Move assignment operator
+ /**
+ This operator may be called only inside RCU-lock.
+ */
+ raw_ptr& operator=( raw_ptr&& p ) noexcept
+ {
+ assert( rcu::is_locked());
+ m_ptr = p.m_ptr;
+ m_Enum.combine( std::move( p.m_Enum ));
+ p.m_ptr = nullptr;
+ return *this;
+ }
+
+ /// Copy assignment is prohibited
+ raw_ptr& operator=( raw_ptr const& ) = delete;
+
+ /// Returns a pointer to stored value
+ value_type * operator ->() const noexcept
+ {
+ return m_ptr;
+ }
+
+ /// Returns a reference to stored value
+ value_type& operator *()
+ {
+ assert( m_ptr != nullptr );
+ return *m_ptr;
+ }
+
+ /// Returns a reference to stored value
+ value_type const& operator *() const
+ {
+ assert( m_ptr != nullptr );
+ return *m_ptr;
+ }
+
+ /// Checks if the \p %raw_ptr is \p nullptr
+ bool empty() const noexcept
+ {
+ return m_ptr == nullptr;
+ }
+
+ /// Checks if the \p %raw_ptr is not empty
+ explicit operator bool() const noexcept
+ {
+ return !empty();
+ }
+
+ /// Releases the \p %raw_ptr object
+ /**
+ This function may be called only outside RCU locked region.
+ After \p %release() the object becomes empty and can be reused.
+ */
+ void release()
+ {
+ m_Enum.apply();
+ m_ptr = nullptr;
+ }
+ };
+
+ //@cond
+ // Adapter of \p raw_ptr for non-intrusive containers based on intrusive counterpart
+ template <
+ typename ValueType,
+ typename RawPtr,
+ typename Converter
+ >
+ class raw_ptr_adaptor: private RawPtr
+ {
+ public:
+ typedef RawPtr intrusive_raw_ptr;
+ typedef ValueType value_type;
+ typedef typename intrusive_raw_ptr::value_type node_type;
+ typedef Converter converter_type;
+
+ public:
+ // Constructs an empty raw pointer
+ raw_ptr_adaptor()
+ : intrusive_raw_ptr()
+ {}
+
+ // Move ctor
+ raw_ptr_adaptor( intrusive_raw_ptr&& p )
+ : intrusive_raw_ptr( std::move(p))
+ {}
+
+ // Move ctor
+ raw_ptr_adaptor( raw_ptr_adaptor&& p )
+ : intrusive_raw_ptr( std::move(p))
+ {}
+
+ // Copy ctor is prohibited
+ raw_ptr_adaptor( raw_ptr_adaptor const& ) = delete;
+
+ // Releases the raw pointer
+ ~raw_ptr_adaptor()
+ {
+ release();
+ }
+
+ public:
+ // Move assignment operator
+ /*
+ This operator may be called only inside RCU-lock.
+ The \p this should be empty.
+
+ In general, move assignment is intented for internal use.
+ */
+ raw_ptr_adaptor& operator=( raw_ptr_adaptor&& p ) noexcept
+ {
+ intrusive_raw_ptr::operator =(std::move(p));
+ return *this;
+ }
+
+ // Copy assignment is prohibited
+ raw_ptr_adaptor& operator=( raw_ptr_adaptor const& ) = delete;
+
+ // Returns a pointer to stored value
+ value_type * operator ->() const noexcept
+ {
+ return converter_type()( intrusive_raw_ptr::operator->());
+ }
+
+ // Returns a reference to stored value
+ value_type& operator *()
+ {
+ return converter_type()( intrusive_raw_ptr::operator*());
+ }
+
+ // Returns a reference to stored value
+ value_type const& operator *() const
+ {
+ return converter_type()( intrusive_raw_ptr::operator*());
+ }
+
+ // Checks if the \p %raw_ptr is \p nullptr
+ bool empty() const noexcept
+ {
+ return intrusive_raw_ptr::empty();
+ }
+
+ // Checks if the \p %raw_ptr is not empty
+ explicit operator bool() const noexcept
+ {
+ return !empty();
+ }
+
+ // Releases the \p %raw_ptr object
+ /*
+ This function may be called only outside RCU section.
+ After \p %release() the object can be reused.
+ */
+ void release()
+ {
+ intrusive_raw_ptr::release();
+ }
+ };
+ //@endcond
+
+}} // namespace cds::urcu
+
+#endif // #ifndef CDSLIB_URCU_RAW_PTR_H
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