X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=cds%2Fcontainer%2Fskip_list_set_rcu.h;h=9c9b4f0e6cc28cfe44d1a62aaa92c4fe1a169098;hb=056d289619d45ccf1055c18d63cb3bad072a71a0;hp=e57a803673fde31a7f46c76b329fc88393b3db6a;hpb=4ca7a52111a504c05818a718a21081fb04fea00e;p=libcds.git

diff --git a/cds/container/skip_list_set_rcu.h b/cds/container/skip_list_set_rcu.h
index e57a8036..9c9b4f0e 100644
--- a/cds/container/skip_list_set_rcu.h
+++ b/cds/container/skip_list_set_rcu.h
@@ -1,4 +1,32 @@
-//$$CDS-header$$
+/*
+    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_CONTAINER_SKIP_LIST_SET_RCU_H
 #define CDSLIB_CONTAINER_SKIP_LIST_SET_RCU_H
@@ -171,10 +199,6 @@ namespace cds { namespace container {
         typedef typename traits::stat              stat            ;   ///< internal statistics type
         typedef typename traits::rcu_check_deadlock    rcu_check_deadlock ; ///< Deadlock checking policy
 
-        //@cond
-        typedef cds::container::skip_list::implementation_tag implementation_tag;
-        //@endcond
-
     protected:
         //@cond
         typedef typename maker::node_type           node_type;
@@ -191,17 +215,37 @@ namespace cds { namespace container {
         /// pointer to extracted node
         using exempt_ptr = cds::urcu::exempt_ptr< gc, node_type, value_type, typename maker::intrusive_traits::disposer >;
 
+    private:
+        //@cond
+        struct raw_ptr_converter
+        {
+            value_type * operator()( node_type * p ) const
+            {
+               return p ? &p->m_Value : nullptr;
+            }
+
+            value_type& operator()( node_type& n ) const
+            {
+                return n.m_Value;
+            }
+
+            value_type const& operator()( node_type const& n ) const
+            {
+                return n.m_Value;
+            }
+        };
+        //@endcond
+
+    public:
+        /// Result of \p get(), \p get_with() functions - pointer to the node found
+        typedef cds::urcu::raw_ptr_adaptor< value_type, typename base_class::raw_ptr, raw_ptr_converter > raw_ptr;
+
     protected:
         //@cond
         unsigned int random_level()
         {
             return base_class::random_level();
         }
-
-        value_type * to_value_ptr( node_type * pNode ) const CDS_NOEXCEPT
-        {
-            return pNode ? &pNode->m_Value : nullptr;
-        }
         //@endcond
 
     public:
@@ -215,7 +259,17 @@ namespace cds { namespace container {
         {}
 
     public:
-        /// Iterator type
+    ///@name Forward ordered iterators (thread-safe under RCU lock)
+    //@{
+        /// Forward iterator
+        /**
+            The forward iterator has some features:
+            - it has no post-increment operator
+            - it depends on iterator of underlying \p OrderedList
+
+            You may safely use iterators in multi-threaded environment only under RCU lock.
+            Otherwise, a crash is possible if another thread deletes the element the iterator points to.
+        */
         typedef skip_list::details::iterator< typename base_class::iterator >  iterator;
 
         /// Const iterator type
@@ -224,38 +278,39 @@ namespace cds { namespace container {
         /// Returns a forward iterator addressing the first element in a set
         iterator begin()
         {
-            return iterator( base_class::begin() );
+            return iterator( base_class::begin());
         }
 
         /// Returns a forward const iterator addressing the first element in a set
-        //@{
         const_iterator begin() const
         {
-            return const_iterator( base_class::begin() );
+            return const_iterator( base_class::begin());
         }
+
+        /// Returns a forward const iterator addressing the first element in a set
         const_iterator cbegin() const
         {
-            return const_iterator( base_class::cbegin() );
+            return const_iterator( base_class::cbegin());
         }
-        //@}
 
         /// Returns a forward iterator that addresses the location succeeding the last element in a set.
         iterator end()
         {
-            return iterator( base_class::end() );
+            return iterator( base_class::end());
         }
 
         /// Returns a forward const iterator that addresses the location succeeding the last element in a set.
-        //@{
         const_iterator end() const
         {
-            return const_iterator( base_class::end() );
+            return const_iterator( base_class::end());
         }
+
+        /// Returns a forward const iterator that addresses the location succeeding the last element in a set.
         const_iterator cend() const
         {
-            return const_iterator( base_class::cend() );
+            return const_iterator( base_class::cend());
         }
-        //@}
+    //@}
 
     public:
         /// Inserts new node
@@ -275,7 +330,7 @@ namespace cds { namespace container {
         bool insert( Q const& val )
         {
             scoped_node_ptr sp( node_allocator().New( random_level(), val ));
-            if ( base_class::insert( *sp.get() )) {
+            if ( base_class::insert( *sp.get())) {
                 sp.release();
                 return true;
             }
@@ -310,47 +365,51 @@ namespace cds { namespace container {
             return false;
         }
 
-        /// Ensures that the item exists in the set
+        /// Updates the item
         /**
             The operation performs inserting or changing data with lock-free manner.
 
-            If the \p val key not found in the set, then the new item created from \p val
-            is inserted into the set. Otherwise, the functor \p func is called with the item found.
-            The functor \p Func should be a function with signature:
-            \code
-                void func( bool bNew, value_type& item, const Q& val );
-            \endcode
-            or a functor:
+            If \p val not found in the set, then the new item created from \p val
+            is inserted into the set iff \p bInsert is \p true.
+            Otherwise, the functor \p func is called with the item found.
+            The functor \p Func signature:
             \code
                 struct my_functor {
                     void operator()( bool bNew, value_type& item, const Q& val );
                 };
             \endcode
-
-            with arguments:
+            where:
             - \p bNew - \p true if the item has been inserted, \p false otherwise
-            - \p item - item of the set
-            - \p val - argument \p key passed into the \p ensure function
+            - \p item - an item of the set
+            - \p val - argument \p val passed into the \p %update() function
 
             The functor may change non-key fields of the \p item; however, \p func must guarantee
             that during changing no any other modifications could be made on this item by concurrent threads.
 
             RCU \p synchronize method can be called. RCU should not be locked.
 
-            Returns <tt> std::pair<bool, bool> </tt> where \p first is true if operation is successfull,
+            Returns <tt> std::pair<bool, bool> </tt> where \p first is true if operation is successful,
             \p second is true if new item has been added or \p false if the item with \p key
-            already is in the set.
+            already exists.
         */
         template <typename Q, typename Func>
-        std::pair<bool, bool> ensure( const Q& val, Func func )
+        std::pair<bool, bool> update( const Q& val, Func func, bool bInsert = true )
         {
             scoped_node_ptr sp( node_allocator().New( random_level(), val ));
-            std::pair<bool, bool> bRes = base_class::ensure( *sp,
-                [&func, &val](bool bNew, node_type& node, node_type&){ func( bNew, node.m_Value, val ); });
+            std::pair<bool, bool> bRes = base_class::update( *sp,
+                [&func, &val](bool bNew, node_type& node, node_type&){ func( bNew, node.m_Value, val );}, bInsert );
             if ( bRes.first && bRes.second )
                 sp.release();
             return bRes;
         }
+        //@cond
+        template <typename Q, typename Func>
+        CDS_DEPRECATED("ensure() is deprecated, use update()")
+        std::pair<bool, bool> ensure( const Q& val, Func func )
+        {
+            return update( val, func, true );
+        }
+        //@endcond
 
         /// Inserts data of type \ref value_type constructed with <tt>std::forward<Args>(args)...</tt>
         /**
@@ -362,7 +421,7 @@ namespace cds { namespace container {
         bool emplace( Args&&... args )
         {
             scoped_node_ptr sp( node_allocator().New( random_level(), std::forward<Args>(args)... ));
-            if ( base_class::insert( *sp.get() )) {
+            if ( base_class::insert( *sp.get())) {
                 sp.release();
                 return true;
             }
@@ -573,45 +632,56 @@ namespace cds { namespace container {
         {
             CDS_UNUSED( pred );
             return base_class::find_with( val, cds::details::predicate_wrapper< node_type, Less, typename maker::value_accessor >(),
-                                          [&f]( node_type& node, Q& v ) { f( node.m_Value, v ); } );
+                                          [&f]( node_type& node, Q const& v ) { f( node.m_Value, v ); } );
         }
         //@endcond
 
-        /// Find the key \p val
-        /** @anchor cds_nonintrusive_SkipListSet_rcu_find_val
-
-            The function searches the item with key equal to \p val
+        /// Checks whether the set contains \p key
+        /**
+            The function searches the item with key equal to \p key
             and returns \p true if it is found, and \p false otherwise.
 
-            Note the hash functor specified for class \p Traits template parameter
-            should accept a parameter of type \p Q that may be not the same as \ref value_type.
-
             The function applies RCU lock internally.
         */
         template <typename Q>
-        bool find( Q const & val )
+        bool contains( Q const & key )
+        {
+            return base_class::contains( key );
+        }
+        //@cond
+        template <typename Q>
+        CDS_DEPRECATED("deprecated, use contains()")
+        bool find( Q const & key )
         {
-            return base_class::find( val );
+            return contains( key );
         }
+        //@endcond
 
-        /// Finds the key \p val using \p pred predicate for searching
+        /// Checks whether the set contains \p key using \p pred predicate for searching
         /**
-            The function is an analog of \ref cds_nonintrusive_SkipListSet_rcu_find_val "find(Q const&)"
-            but \p pred is used for key comparing.
+            The function is similar to <tt>contains( key )</tt> but \p pred is used for key comparing.
             \p Less functor has the interface like \p std::less.
             \p Less must imply the same element order as the comparator used for building the set.
         */
         template <typename Q, typename Less>
-        bool find_with( Q const& val, Less pred )
+        bool contains( Q const& key, Less pred )
         {
             CDS_UNUSED( pred );
-            return base_class::find_with( val, cds::details::predicate_wrapper< node_type, Less, typename maker::value_accessor >());
+            return base_class::contains( key, cds::details::predicate_wrapper< node_type, Less, typename maker::value_accessor >());
+        }
+        //@cond
+        template <typename Q, typename Less>
+        CDS_DEPRECATED("deprecated, use contains()")
+        bool find_with( Q const& key, Less pred )
+        {
+            return contains( key, pred );
         }
+        //@endcond
 
         /// Finds \p key and return the item found
         /** \anchor cds_nonintrusive_SkipListSet_rcu_get
-            The function searches the item with key equal to \p key and returns the pointer to item found.
-            If \p key is not found it returns \p nullptr.
+            The function searches the item with key equal to \p key and returns a \p raw_ptr object pointed to item found.
+            If \p key is not found it returns empty \p raw_ptr.
 
             Note the compare functor in \p Traits class' template argument
             should accept a parameter of type \p Q that can be not the same as \p value_type.
@@ -622,26 +692,25 @@ namespace cds { namespace container {
             typedef cds::container::SkipListSet< cds::urcu::gc< cds::urcu::general_buffered<> >, foo, my_traits > skip_list;
             skip_list theList;
             // ...
+            typename skip_list::raw_ptr pVal;
             {
                 // Lock RCU
                 skip_list::rcu_lock lock;
 
-                foo * pVal = theList.get( 5 );
-                // Deal with pVal
-                //...
-
-                // Unlock RCU by rcu_lock destructor
-                // pVal can be freed at any time after RCU unlocking
+                pVal = theList.get( 5 );
+                if ( pVal ) {
+                    // Deal with pVal
+                    //...
+                }
             }
+            // You can manually release pVal after RCU-locked section
+            pVal.release();
             \endcode
-
-            After RCU unlocking the \p %force_dispose member function can be called manually,
-            see \ref force_dispose for explanation.
         */
         template <typename Q>
-        value_type * get( Q const& key )
+        raw_ptr get( Q const& key )
         {
-            return to_value_ptr( base_class::get( key ));
+            return raw_ptr( base_class::get( key ));
         }
 
         /// Finds the key \p val and return the item found
@@ -654,10 +723,10 @@ namespace cds { namespace container {
             \p pred must imply the same element order as the comparator used for building the set.
         */
         template <typename Q, typename Less>
-        value_type * get_with( Q const& val, Less pred )
+        raw_ptr get_with( Q const& val, Less pred )
         {
             CDS_UNUSED( pred );
-            return to_value_ptr( base_class::get_with( val, cds::details::predicate_wrapper< node_type, Less, typename maker::value_accessor >() ));
+            return raw_ptr( base_class::get_with( val, cds::details::predicate_wrapper< node_type, Less, typename maker::value_accessor >()));
         }
 
         /// Clears the set (non-atomic).
@@ -667,7 +736,7 @@ namespace cds { namespace container {
             this sequence
             \code
             set.clear();
-            assert( set.empty() );
+            assert( set.empty());
             \endcode
             the assertion could be raised.
 
@@ -701,15 +770,6 @@ namespace cds { namespace container {
         {
             return base_class::statistics();
         }
-
-        /// Clears internal list of ready-to-delete items passing them to RCU reclamation cycle
-        /**
-            See \ref cds_intrusive_SkipListSet_rcu_force_dispose "intrusive SkipListSet" for explanation
-        */
-        void force_dispose()
-        {
-            return base_class::force_dispose();
-        }
     };
 
 }} // namespace cds::container