Merge branch 'flat_combinig_add_stress_and_unint_tests' of https://github.com/mgalimu...

[libcds.git] / cds / intrusive / lazy_list_nogc.h

diff --git a/cds/intrusive/lazy_list_nogc.h b/cds/intrusive/lazy_list_nogc.h
index d65dc84aafe77e8027e7d0307b83ae8ae6985c99..01fc656e4528ce6a6827a844e32a8d1f95fa086d 100644 (file)
--- a/cds/intrusive/lazy_list_nogc.h
+++ b/cds/intrusive/lazy_list_nogc.h
@@ -1,7 +1,35 @@
-//$$CDS-header$$
+/*
+    This file is a part of libcds - Concurrent Data Structures library

 
 

-#ifndef __CDS_INTRUSIVE_LAZY_LIST_NOGC_H
-#define __CDS_INTRUSIVE_LAZY_LIST_NOGC_H
+    (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_INTRUSIVE_LAZY_LIST_NOGC_H
+#define CDSLIB_INTRUSIVE_LAZY_LIST_NOGC_H

 
 #include <mutex>        // unique_lock
 #include <cds/intrusive/details/lazy_list_base.h>
 
 #include <mutex>        // unique_lock
 #include <cds/intrusive/details/lazy_list_base.h>


@@ -12,12 +40,12 @@ namespace cds { namespace intrusive {
         /// Lazy list node for \p gc::nogc
         /**
             Template parameters:
         /// Lazy list node for \p gc::nogc
         /**
             Template parameters:

-             - Lock - lock type. Default is \p cds::lock::Spin
+             - Lock - lock type. Default is \p cds::sync::spin

              - Tag - a \ref cds_intrusive_hook_tag "tag"
         */
         template <
 #ifdef CDS_DOXYGEN_INVOKED
              - Tag - a \ref cds_intrusive_hook_tag "tag"
         */
         template <
 #ifdef CDS_DOXYGEN_INVOKED

-            typename Lock = cds::lock::Spin,
+            typename Lock = cds::sync::spin,

             typename Tag = opt::none
 #else
             typename Lock,
             typename Tag = opt::none
 #else
             typename Lock,


@@ -40,13 +68,18 @@ namespace cds { namespace intrusive {
     }   // namespace lazy_list
 
 
     }   // namespace lazy_list
 
 

-    /// Lazy ordered single-linked list (template specialization for \p gc::nogc)
+    /// Lazy single-linked list (template specialization for \p gc::nogc)

     /** @ingroup cds_intrusive_list
         \anchor cds_intrusive_LazyList_nogc
 
         This specialization is append-only list when no item
         reclamation may be performed. The class does not support deleting of list item.
 
     /** @ingroup cds_intrusive_list
         \anchor cds_intrusive_LazyList_nogc
 
         This specialization is append-only list when no item
         reclamation may be performed. The class does not support deleting of list item.
 

+        The list can be ordered if \p Traits::sort is \p true that is default
+        or unordered otherwise. Unordered list can be maintained by \p equal_to
+        relationship (\p Traits::equal_to), but for the ordered list \p less
+        or \p compare relations should be specified in \p Traits.
+

         See \ref cds_intrusive_LazyList_hp "LazyList" for description of template parameters.
     */
     template <
         See \ref cds_intrusive_LazyList_hp "LazyList" for description of template parameters.
     */
     template <


@@ -66,21 +99,33 @@ namespace cds { namespace intrusive {
 
         typedef typename traits::hook    hook;      ///< hook type
         typedef typename hook::node_type node_type; ///< node type
 
         typedef typename traits::hook    hook;      ///< hook type
         typedef typename hook::node_type node_type; ///< node type

+        static CDS_CONSTEXPR bool const c_bSort = traits::sort; ///< List type: ordered (\p true) or unordered (\p false)

 
 #   ifdef CDS_DOXYGEN_INVOKED
 
 #   ifdef CDS_DOXYGEN_INVOKED

-        typedef implementation_defined key_comparator  ;    ///< key comparison functor based on opt::compare and opt::less option setter.
+        /// Key comparing functor
+        /**
+            - for ordered list, the functor is based on \p traits::compare or \p traits::less
+            - for unordered list, the functor is based on \p traits::equal_to, \p traits::compare or \p traits::less
+        */
+        typedef implementation_defined key_comparator;

 #   else
 #   else

-        typedef typename opt::details::make_comparator< value_type, traits >::type key_comparator;
+        typedef typename std::conditional< c_bSort,
+            typename opt::details::make_comparator< value_type, traits >::type,
+            typename opt::details::make_equal_to< value_type, traits >::type
+        >::type key_comparator;

 #   endif
         typedef typename traits::back_off  back_off;   ///< Back-off strategy
         typedef typename traits::disposer  disposer;   ///< disposer
         typedef typename get_node_traits< value_type, node_type, hook>::type node_traits;    ///< node traits
         typedef typename lazy_list::get_link_checker< node_type, traits::link_checker >::type link_checker;   ///< link checker
 
 #   endif
         typedef typename traits::back_off  back_off;   ///< Back-off strategy
         typedef typename traits::disposer  disposer;   ///< disposer
         typedef typename get_node_traits< value_type, node_type, hook>::type node_traits;    ///< node traits
         typedef typename lazy_list::get_link_checker< node_type, traits::link_checker >::type link_checker;   ///< link checker
 

-        typedef typename traits::item_counter item_counter;  ///< Item counting policy used
-        typedef typename traits::memory_model  memory_model; ///< C++ memory ordering (see lazy_list::traits::memory_model)
+        typedef typename traits::item_counter item_counter; ///< Item counting policy used
+        typedef typename traits::memory_model memory_model; ///< C++ memory ordering (see \p lazy_list::traits::memory_model)
+        typedef typename traits::stat         stat;         ///< Internal statistics

 
         //@cond
 
         //@cond

+        static_assert((std::is_same< gc, typename node_type::gc >::value), "GC and node_type::gc must be the same type");
+

         // Rebind traits (split-list support)
         template <typename... Options>
         struct rebind_traits {
         // Rebind traits (split-list support)
         template <typename... Options>
         struct rebind_traits {


@@ -90,6 +135,10 @@ namespace cds { namespace intrusive {
                 , typename cds::opt::make_options< traits, Options...>::type
             >   type;
         };
                 , typename cds::opt::make_options< traits, Options...>::type
             >   type;
         };

+
+        // Stat selector
+        template <typename Stat>
+        using select_stat_wrapper = lazy_list::select_stat_wrapper< Stat >;

         //@endcond
 
     protected:
         //@endcond
 
     protected:


@@ -99,6 +148,7 @@ namespace cds { namespace intrusive {
         node_type       m_Head;        ///< List head (dummy node)
         node_type       m_Tail;        ///< List tail (dummy node)
         item_counter    m_ItemCounter; ///< Item counter
         node_type       m_Head;        ///< List head (dummy node)
         node_type       m_Tail;        ///< List tail (dummy node)
         item_counter    m_ItemCounter; ///< Item counter

+        mutable stat    m_Stat;        ///< Internal statistics

 
         //@cond
 
 
         //@cond
 


@@ -159,6 +209,7 @@ namespace cds { namespace intrusive {
 
         void link_node( node_type * pNode, node_type * pPred, node_type * pCur )
         {
 
         void link_node( node_type * pNode, node_type * pPred, node_type * pCur )
         {

+            link_checker::is_empty( pNode );

             assert( pPred->m_pNext.load(memory_model::memory_order_relaxed) == pCur );
 
             pNode->m_pNext.store( pCur, memory_model::memory_order_release );
             assert( pPred->m_pNext.load(memory_model::memory_order_relaxed) == pCur );
 
             pNode->m_pNext.store( pCur, memory_model::memory_order_release );


@@ -285,7 +336,7 @@ namespace cds { namespace intrusive {
         /// Returns a forward const iterator addressing the first element in a list
         const_iterator cbegin() const
         {
         /// Returns a forward const iterator addressing the first element in a list
         const_iterator cbegin() const
         {

-            const_iterator it( const_cast<node_type *>(&m_Head) );
+            const_iterator it( const_cast<node_type *>(&m_Head));

             ++it;   // skip dummy head
             return it;
         }
             ++it;   // skip dummy head
             return it;
         }


@@ -298,17 +349,25 @@ namespace cds { namespace intrusive {
         /// Returns an const iterator that addresses the location succeeding the last element in a list
         const_iterator cend() const
         {
         /// Returns an const iterator that addresses the location succeeding the last element in a list
         const_iterator cend() const
         {

-            return const_iterator( const_cast<node_type *>(&m_Tail) );
+            return const_iterator( const_cast<node_type *>(&m_Tail));

         }
 
     public:
         /// Default constructor initializes empty list
         LazyList()
         {
         }
 
     public:
         /// Default constructor initializes empty list
         LazyList()
         {

-            static_assert( (std::is_same< gc, typename node_type::gc >::value), "GC and node_type::gc must be the same type" );

             m_Head.m_pNext.store( &m_Tail, memory_model::memory_order_relaxed );
         }
 
             m_Head.m_pNext.store( &m_Tail, memory_model::memory_order_relaxed );
         }
 

+        //@cond
+        template <typename Stat, typename = std::enable_if<std::is_same<stat, lazy_list::wrapped_stat<Stat>>::value >>
+        explicit LazyList( Stat& st )
+            : m_Stat( st )
+        {
+            m_Head.m_pNext.store( &m_Tail, memory_model::memory_order_relaxed );
+        }
+        //@endcond
+

         /// Destroys the list object
         ~LazyList()
         {
         /// Destroys the list object
         ~LazyList()
         {


@@ -329,11 +388,12 @@ namespace cds { namespace intrusive {
             return insert_at( &m_Head, val );
         }
 
             return insert_at( &m_Head, val );
         }
 

-        /// Ensures that the \p item exists in the list
+        /// Updates the item

         /**
             The operation performs inserting or changing data with lock-free manner.
 
         /**
             The operation performs inserting or changing data with lock-free manner.
 

-            If the item \p val not found in the list, then \p val is inserted into the list.
+            If the item \p val not found in the list, then \p val is inserted into the list
+            iff \p bAllowInsert is \p true.

             Otherwise, the functor \p func is called with item found.
             The functor signature is:
             \code
             Otherwise, the functor \p func is called with item found.
             The functor signature is:
             \code


@@ -344,23 +404,30 @@ namespace cds { namespace intrusive {
             with arguments:
             - \p bNew - \p true if the item has been inserted, \p false otherwise
             - \p item - item of the list
             with arguments:
             - \p bNew - \p true if the item has been inserted, \p false otherwise
             - \p item - item of the list

-            - \p val - argument \p val passed into the \p ensure function
+            - \p val - argument \p val passed into the \p update() function

             If new item has been inserted (i.e. \p bNew is \p true) then \p item and \p val arguments
             If new item has been inserted (i.e. \p bNew is \p true) then \p item and \p val arguments

-            refers to the same thing.
+            refer to the same thing.

 
             The functor may change non-key fields of the \p item.
             While the functor \p f is calling the item \p item is locked.
 
 
             The functor may change non-key fields of the \p item.
             While the functor \p f is calling the item \p item is locked.
 

-            Returns <tt> std::pair<bool, bool>  </tt> where \p first is true if operation is successfull,
-            \p second is true if new item has been added or \p false if the item with \p key
+            Returns <tt> std::pair<bool, bool>  </tt> where \p first is \p true if operation is successful,
+            \p second is \p true if new item has been added or \p false if the item with \p key

             already is in the list.
         */
             already is in the list.
         */

-

         template <typename Func>
         template <typename Func>

+        std::pair<bool, bool> update( value_type& val, Func func, bool bAllowInsert = true )
+        {
+            return update_at( &m_Head, val, func, bAllowInsert );
+        }
+        //@cond
+        template <typename Func>
+        CDS_DEPRECATED("ensure() is deprecated, use update()")

         std::pair<bool, bool> ensure( value_type& val, Func func )
         {
         std::pair<bool, bool> ensure( value_type& val, Func func )
         {

-            return ensure_at( &m_Head, val, func );
+            return update( val, func, true );

         }
         }

+        //@endcond

 
         /// Finds the key \p key
         /** \anchor cds_intrusive_LazyList_nogc_find_func
 
         /// Finds the key \p key
         /** \anchor cds_intrusive_LazyList_nogc_find_func


@@ -384,43 +451,114 @@ namespace cds { namespace intrusive {
         {
             return find_at( &m_Head, key, key_comparator(), f );
         }
         {
             return find_at( &m_Head, key, key_comparator(), f );
         }

+        //@cond
+        template <typename Q, typename Func>
+        bool find( Q const& key, Func f )
+        {
+            return find_at( &m_Head, key, key_comparator(), f );
+        }
+        //@endcond

 
 

-        /// Finds the key \p key using \p pred predicate for searching
+        /// Finds the key \p key using \p less predicate for searching. Disabled for unordered lists.

         /**
             The function is an analog of \ref cds_intrusive_LazyList_nogc_find_func "find(Q&, Func)"
             but \p pred is used for key comparing.
             \p Less functor has the interface like \p std::less.
             \p pred must imply the same element order as the comparator used for building the list.
         */
         /**
             The function is an analog of \ref cds_intrusive_LazyList_nogc_find_func "find(Q&, Func)"
             but \p pred is used for key comparing.
             \p Less functor has the interface like \p std::less.
             \p pred must imply the same element order as the comparator used for building the list.
         */

-        template <typename Q, typename Less, typename Func>
-        bool find_with( Q& key, Less pred, Func f )
+        template <typename Q, typename Less, typename Func, bool Sort = c_bSort>
+        typename std::enable_if<Sort, bool>::type find_with( Q& key, Less less, Func f )

         {
         {

+            CDS_UNUSED( less );

             return find_at( &m_Head, key, cds::opt::details::make_comparator_from_less<Less>(), f );
         }
 
             return find_at( &m_Head, key, cds::opt::details::make_comparator_from_less<Less>(), f );
         }
 

-        /// Finds the key \p key
-        /** \anchor cds_intrusive_LazyList_nogc_find_val
+        /// Finds the key \p key using \p equal predicate for searching. Disabled for ordered lists.
+        /**
+            The function is an analog of \ref cds_intrusive_LazyList_nogc_find_func "find(Q&, Func)"
+            but \p equal is used for key comparing.
+            \p Equal functor has the interface like \p std::equal_to.
+        */
+        template <typename Q, typename Equal, typename Func, bool Sort = c_bSort>
+        typename std::enable_if<!Sort, bool>::type find_with( Q& key, Equal equal, Func f )
+        {
+            CDS_UNUSED( equal );
+            return find_at( &m_Head, key, equal, f );
+        }
+        //@cond
+        template <typename Q, typename Less, typename Func, bool Sort = c_bSort>
+        typename std::enable_if<Sort, bool>::type find_with( Q const& key, Less pred, Func f )
+        {
+            CDS_UNUSED( pred );
+            return find_at( &m_Head, key, cds::opt::details::make_comparator_from_less<Less>(), f );
+        }
+
+        template <typename Q, typename Equal, typename Func, bool Sort = c_bSort>
+        typename std::enable_if<!Sort, bool>::type find_with( Q const& key, Equal equal, Func f )
+        {
+            CDS_UNUSED( equal );
+            return find_at( &m_Head, key, equal, f );
+        }
+        //@endcond
+
+        /// Checks whether the list contains \p key
+        /**

             The function searches the item with key equal to \p key
             The function searches the item with key equal to \p key

-            and returns pointer to value found or \p nullptr.
+            and returns \p true if it is found, and \p false otherwise.

         */
         template <typename Q>
         */
         template <typename Q>

+        value_type * contains( Q const& key )
+        {
+            return find_at( &m_Head, key, key_comparator());
+        }
+        //@cond
+        template <typename Q>
+        CDS_DEPRECATED("deprecated, use contains()")

         value_type * find( Q const& key )
         {
         value_type * find( Q const& key )
         {

-            return find_at( &m_Head, key, key_comparator() );
+            return contains( key );

         }
         }

+        //@endcond

 
 

-        /// Finds the key \p key using \p pred predicate for searching
+        /// Checks whether the map contains \p key using \p pred predicate for searching (ordered list version)

         /**
         /**

-            The function is an analog of \ref cds_intrusive_LazyList_nogc_find_val "find(Q const&)"
-            but \p pred is used for key comparing.
+            The function is an analog of <tt>contains( key )</tt> but \p pred is used for key comparing.

             \p Less functor has the interface like \p std::less.
             \p Less functor has the interface like \p std::less.

-            \p pred must imply the same element order as the comparator used for building the list.
+            \p Less must imply the same element order as the comparator used for building the list.
+        */
+        template <typename Q, typename Less, bool Sort = c_bSort>
+        typename std::enable_if<Sort, value_type *>::type contains( Q const& key, Less pred )
+        {
+            CDS_UNUSED( pred );
+            return find_at( &m_Head, key, cds::opt::details::make_comparator_from_less<Less>());
+        }
+        //@cond
+        template <typename Q, typename Less, bool Sort = c_bSort>
+        CDS_DEPRECATED("deprecated, use contains()")
+        typename std::enable_if<Sort, value_type *>::type find_with( Q const& key, Less pred )
+        {
+            return contains( key, pred );
+        }
+        //@endcond
+
+        /// Checks whether the map contains \p key using \p equal predicate for searching (unordered list version)
+        /**
+            The function is an analog of <tt>contains( key )</tt> but \p equal is used for key comparing.
+            \p Equal functor has the interface like \p std::equal_to.

         */
         */

-        template <typename Q, typename Less>
-        value_type * find_with( Q const & key, Less pred )
+        template <typename Q, typename Equal, bool Sort = c_bSort>
+        typename std::enable_if<!Sort, value_type *>::type contains( Q const& key, Equal equal )
+        {
+            return find_at( &m_Head, key, equal );
+        }
+        //@cond
+        template <typename Q, typename Equal, bool Sort = c_bSort>
+        CDS_DEPRECATED("deprecated, use contains()")
+        typename std::enable_if<!Sort, value_type *>::type find_with( Q const& key, Equal equal )

         {
         {

-            return find_at( &m_Head, key, cds::opt::details::make_comparator_from_less<Less>() );
+            return contains( key, equal );

         }
         }

+        //@endcond

 
         /// Clears the list
         /**
 
         /// Clears the list
         /**


@@ -437,6 +575,7 @@ namespace cds { namespace intrusive {
             while ( pHead != &m_Tail ) {
                 node_type * p = pHead->m_pNext.load(memory_model::memory_order_relaxed);
                 dispose_node( pHead, disp );
             while ( pHead != &m_Tail ) {
                 node_type * p = pHead->m_pNext.load(memory_model::memory_order_relaxed);
                 dispose_node( pHead, disp );

+                --m_ItemCounter;

                 pHead = p;
             }
         }
                 pHead = p;
             }
         }


@@ -447,7 +586,7 @@ namespace cds { namespace intrusive {
         */
         void clear()
         {
         */
         void clear()
         {

-            clear( disposer() );
+            clear( disposer());

         }
 
         /// Checks if the list is empty
         }
 
         /// Checks if the list is empty


@@ -469,6 +608,12 @@ namespace cds { namespace intrusive {
             return m_ItemCounter.value();
         }
 
             return m_ItemCounter.value();
         }
 

+        /// Returns const reference to internal statistics
+        stat const& statistics() const
+        {
+            return m_Stat;
+        }
+

     protected:
         //@cond
         // split-list support
     protected:
         //@cond
         // split-list support


@@ -486,32 +631,37 @@ namespace cds { namespace intrusive {
             // Hack: convert node_type to value_type.
             // In principle, auxiliary node can be non-reducible to value_type
             // We assume that comparator can correctly distinguish aux and regular node.
             // Hack: convert node_type to value_type.
             // In principle, auxiliary node can be non-reducible to value_type
             // We assume that comparator can correctly distinguish aux and regular node.

-            return insert_at( pHead, *node_traits::to_value_ptr( pNode ) );
+            return insert_at( pHead, *node_traits::to_value_ptr( pNode ));

         }
 
         bool insert_at( node_type * pHead, value_type& val )
         {
         }
 
         bool insert_at( node_type * pHead, value_type& val )
         {

-            link_checker::is_empty( node_traits::to_node_ptr( val ) );

             position pos;
             position pos;

-            key_comparator  cmp;
+            key_comparator pred;

 
             while ( true ) {
 
             while ( true ) {

-                search( pHead, val, pos, key_comparator() );
+                search( pHead, val, pos, pred );

                 {
                     auto_lock_position alp( pos );
                     if ( validate( pos.pPred, pos.pCur )) {
                 {
                     auto_lock_position alp( pos );
                     if ( validate( pos.pPred, pos.pCur )) {

-                        if ( pos.pCur != &m_Tail && cmp( *node_traits::to_value_ptr( *pos.pCur ), val ) == 0 ) {
+                        if ( pos.pCur != &m_Tail && equal( *node_traits::to_value_ptr( *pos.pCur ), val, pred )) {

                             // failed: key already in list
                             // failed: key already in list

+                            m_Stat.onInsertFailed();

                             return false;
                         }
                         else {
                             link_node( node_traits::to_node_ptr( val ), pos.pPred, pos.pCur );
                             return false;
                         }
                         else {
                             link_node( node_traits::to_node_ptr( val ), pos.pPred, pos.pCur );

-                            ++m_ItemCounter;
-                            return true;
+                            break;

                         }
                     }
                 }
                         }
                     }
                 }

+
+                m_Stat.onInsertRetry();

             }
             }

+
+            ++m_ItemCounter;
+            m_Stat.onInsertSuccess();
+            return true;

         }
 
         iterator insert_at_( node_type * pHead, value_type& val )
         }
 
         iterator insert_at_( node_type * pHead, value_type& val )


@@ -523,82 +673,95 @@ namespace cds { namespace intrusive {
 
 
         template <typename Func>
 
 
         template <typename Func>

-        std::pair<iterator, bool> ensure_at_( node_type * pHead, value_type& val, Func func )
+        std::pair<iterator, bool> update_at_( node_type * pHead, value_type& val, Func func, bool bAllowInsert )

         {
             position pos;
         {
             position pos;

-            key_comparator  cmp;
+            key_comparator pred;

 
             while ( true ) {
 
             while ( true ) {

-                search( pHead, val, pos, key_comparator() );
+                search( pHead, val, pos, pred );

                 {
                     auto_lock_position alp( pos );
                     if ( validate( pos.pPred, pos.pCur )) {
                 {
                     auto_lock_position alp( pos );
                     if ( validate( pos.pPred, pos.pCur )) {

-                        if ( pos.pCur != &m_Tail && cmp( *node_traits::to_value_ptr( *pos.pCur ), val ) == 0 ) {
+                        if ( pos.pCur != &m_Tail && equal( *node_traits::to_value_ptr( *pos.pCur ), val, pred )) {

                             // key already in the list
 
                             func( false, *node_traits::to_value_ptr( *pos.pCur ) , val );
                             // key already in the list
 
                             func( false, *node_traits::to_value_ptr( *pos.pCur ) , val );

+                            m_Stat.onUpdateExisting();

                             return std::make_pair( iterator( pos.pCur ), false );
                         }
                         else {
                             // new key
                             return std::make_pair( iterator( pos.pCur ), false );
                         }
                         else {
                             // new key

-                            link_checker::is_empty( node_traits::to_node_ptr( val ) );
+                            if ( !bAllowInsert ) {
+                                m_Stat.onUpdateFailed();
+                                return std::make_pair( end(), false );
+                            }

 
                             link_node( node_traits::to_node_ptr( val ), pos.pPred, pos.pCur );
                             func( true, val, val );
 
                             link_node( node_traits::to_node_ptr( val ), pos.pPred, pos.pCur );
                             func( true, val, val );

-                            ++m_ItemCounter;
-                            return std::make_pair( iterator( node_traits::to_node_ptr( val )), true );
+                            break;

                         }
                     }
                         }
                     }

+
+                    m_Stat.onUpdateRetry();

                 }
             }
                 }
             }

+
+            ++m_ItemCounter;
+            m_Stat.onUpdateNew();
+            return std::make_pair( iterator( node_traits::to_node_ptr( val )), true );

         }
 
         template <typename Func>
         }
 
         template <typename Func>

-        std::pair<bool, bool> ensure_at( node_type * pHead, value_type& val, Func func )
+        std::pair<bool, bool> update_at( node_type * pHead, value_type& val, Func func, bool bAllowInsert )

         {
         {

-            std::pair<iterator, bool> ret = ensure_at_( pHead, val, func );
+            std::pair<iterator, bool> ret = update_at_( pHead, val, func, bAllowInsert );

             return std::make_pair( ret.first != end(), ret.second );
         }
 
             return std::make_pair( ret.first != end(), ret.second );
         }
 

-        template <typename Q, typename Compare, typename Func>
-        bool find_at( node_type * pHead, Q& val, Compare cmp, Func f )
+        template <typename Q, typename Pred, typename Func>
+        bool find_at( node_type * pHead, Q& val, Pred pred, Func f )

         {
             position pos;
 
         {
             position pos;
 

-            search( pHead, val, pos, cmp );
+            search( pHead, val, pos, pred );

             if ( pos.pCur != &m_Tail ) {
                 std::unique_lock< typename node_type::lock_type> al( pos.pCur->m_Lock );
             if ( pos.pCur != &m_Tail ) {
                 std::unique_lock< typename node_type::lock_type> al( pos.pCur->m_Lock );

-                if ( cmp( *node_traits::to_value_ptr( *pos.pCur ), val ) == 0 )
+                if ( equal( *node_traits::to_value_ptr( *pos.pCur ), val, pred ))

                 {
                     f( *node_traits::to_value_ptr( *pos.pCur ), val );
                 {
                     f( *node_traits::to_value_ptr( *pos.pCur ), val );

+                    m_Stat.onFindSuccess();

                     return true;
                 }
             }
                     return true;
                 }
             }

+
+            m_Stat.onFindFailed();

             return false;
         }
 
             return false;
         }
 

-        template <typename Q, typename Compare>
-        value_type * find_at( node_type * pHead, Q& val, Compare cmp)
+        template <typename Q, typename Pred>
+        value_type * find_at( node_type * pHead, Q& val, Pred pred)

         {
         {

-            iterator it = find_at_( pHead, val, cmp );
-            if ( it != end() )
+            iterator it = find_at_( pHead, val, pred );
+            if ( it != end())

                 return &*it;
             return nullptr;
         }
 
                 return &*it;
             return nullptr;
         }
 

-        template <typename Q, typename Compare>
-        iterator find_at_( node_type * pHead, Q& val, Compare cmp)
+        template <typename Q, typename Pred>
+        iterator find_at_( node_type * pHead, Q& val, Pred pred)

         {
             position pos;
 
         {
             position pos;
 

-            search( pHead, val, pos, cmp );
+            search( pHead, val, pos, pred );

             if ( pos.pCur != &m_Tail ) {
             if ( pos.pCur != &m_Tail ) {

-                std::unique_lock< typename node_type::lock_type> al( pos.pCur->m_Lock );
-                if ( cmp( *node_traits::to_value_ptr( *pos.pCur ), val ) == 0 )
-                {
+                if ( equal( *node_traits::to_value_ptr( *pos.pCur ), val, pred )) {
+                    m_Stat.onFindSuccess();

                     return iterator( pos.pCur );
                 }
             }
                     return iterator( pos.pCur );
                 }
             }

+
+            m_Stat.onFindFailed();

             return end();
         }
 
             return end();
         }
 


@@ -606,8 +769,25 @@ namespace cds { namespace intrusive {
 
     protected:
         //@cond
 
     protected:
         //@cond

-        template <typename Q, typename Compare>
-        void search( node_type * pHead, const Q& key, position& pos, Compare cmp )
+        template <typename Q, typename Equal, bool Sort = c_bSort>
+        typename std::enable_if<!Sort, void>::type search( node_type * pHead, const Q& key, position& pos, Equal eq )
+        {
+            const node_type * pTail = &m_Tail;
+
+            node_type * pCur = pHead;
+            node_type * pPrev = pHead;
+
+            while ( pCur != pTail && ( pCur == pHead || !equal( *node_traits::to_value_ptr( *pCur ), key, eq ))) {
+                pPrev = pCur;
+                pCur = pCur->m_pNext.load(memory_model::memory_order_acquire);
+            }
+
+            pos.pCur = pCur;
+            pos.pPred = pPrev;
+        }
+
+        template <typename Q, typename Compare, bool Sort = c_bSort>
+        typename std::enable_if<Sort, void>::type search( node_type * pHead, const Q& key, position& pos, Compare cmp )

         {
             const node_type * pTail = &m_Tail;
 
         {
             const node_type * pTail = &m_Tail;
 


@@ -623,14 +803,51 @@ namespace cds { namespace intrusive {
             pos.pPred = pPrev;
         }
 
             pos.pPred = pPrev;
         }
 

-        static bool validate( node_type * pPred, node_type * pCur )
+        template <typename L, typename R, typename Equal, bool Sort = c_bSort>
+        static typename std::enable_if<!Sort, bool>::type equal( L const& l, R const& r, Equal eq )
+        {
+            return eq(l, r);
+        }
+
+        template <typename L, typename R, typename Compare, bool Sort = c_bSort>
+        static typename std::enable_if<Sort, bool>::type equal( L const& l, R const& r, Compare cmp )

         {
         {

-            return pPred->m_pNext.load(memory_model::memory_order_acquire) == pCur;
+            return cmp(l, r) == 0;

         }
 
         }
 

+        bool validate( node_type * pPred, node_type * pCur )
+        {
+            if ( pPred->m_pNext.load(memory_model::memory_order_acquire) == pCur ) {
+                m_Stat.onValidationSuccess();
+                return true;
+            }
+
+            m_Stat.onValidationFailed();
+            return false;
+        }
+
+        // for split-list
+        template <typename Predicate>
+        void erase_for( Predicate pred )
+        {
+            node_type * pPred = nullptr;
+            node_type * pHead = m_Head.m_pNext.load( memory_model::memory_order_relaxed );
+
+            while ( pHead != &m_Tail ) {
+                node_type * p = pHead->m_pNext.load( memory_model::memory_order_relaxed );
+                if ( pred( *node_traits::to_value_ptr( pHead ))) {
+                    assert( pPred != nullptr );
+                    pPred->m_pNext.store( p, memory_model::memory_order_relaxed );
+                    dispose_node( pHead, disposer());
+                }
+                else
+                    pPred = pHead;
+                pHead = p;
+            }
+        }

         //@endcond
     };
 
 }}  // namespace cds::intrusive
 
         //@endcond
     };
 
 }}  // namespace cds::intrusive
 

-#endif  // #ifndef __CDS_INTRUSIVE_LAZY_LIST_NOGC_H
+#endif  // #ifndef CDSLIB_INTRUSIVE_LAZY_LIST_NOGC_H