Only tests with max load factor for parallel maps

[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 a50e742a5608b183505f1e6a761caf87c6c12b71..2c9761f54fb209b02a807badb233f6366b0fef74 100644 (file)
--- a/cds/intrusive/lazy_list_nogc.h
+++ b/cds/intrusive/lazy_list_nogc.h
@@ -1,27 +1,65 @@
-//$$CDS-header$$
+/*
+    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 <cds/gc/nogc.h>
 
 namespace cds { namespace intrusive {
     namespace lazy_list {
 #include <cds/intrusive/details/lazy_list_base.h>
 #include <cds/gc/nogc.h>
 
 namespace cds { namespace intrusive {
     namespace lazy_list {

-        /// Lazy list node for gc::nogc
+        /// Lazy list node for \p gc::nogc

         /**
             Template parameters:
         /**
             Template parameters:

-            - Tag - a tag used to distinguish between different implementation
+             - Lock - lock type. Default is \p cds::sync::spin
+             - Tag - a \ref cds_intrusive_hook_tag "tag"

         */
         */

-        template <typename Lock, typename Tag>
+        template <
+#ifdef CDS_DOXYGEN_INVOKED
+            typename Lock = cds::sync::spin,
+            typename Tag = opt::none
+#else
+            typename Lock,
+            typename Tag
+#endif
+        >

         struct node<gc::nogc, Lock, Tag>
         {
         struct node<gc::nogc, Lock, Tag>
         {

-            typedef gc::nogc    gc          ;   ///< Garbage collector
-            typedef Lock        lock_type   ;   ///< Lock type
-            typedef Tag         tag         ;   ///< tag
+            typedef gc::nogc    gc;   ///< Garbage collector
+            typedef Lock        lock_type;  ///< Lock type
+            typedef Tag         tag;  ///< tag

 
 

-            atomics::atomic<node *> m_pNext ; ///< pointer to the next node in the list
-            mutable lock_type   m_Lock  ; ///< Node lock
+            atomics::atomic<node *> m_pNext; ///< pointer to the next node in the list
+            mutable lock_type   m_Lock;      ///< Node lock

 
             node()
                 : m_pNext( nullptr )
 
             node()
                 : m_pNext( nullptr )


@@ -30,39 +68,24 @@ namespace cds { namespace intrusive {
     }   // namespace lazy_list
 
 
     }   // namespace lazy_list
 
 

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

     /** @ingroup cds_intrusive_list
         \anchor cds_intrusive_LazyList_nogc
 
     /** @ingroup cds_intrusive_list
         \anchor cds_intrusive_LazyList_nogc
 

-        This specialization is intended for so-called persistent usage when no item
+        This specialization is append-only list when no item

         reclamation may be performed. The class does not support deleting of list item.
 
         reclamation may be performed. The class does not support deleting of list item.
 

-        See \ref cds_intrusive_LazyList_hp "LazyList" for description of template parameters.
-
-        The interface of the specialization is a slightly different.
-
-        The gc::nogc specialization of LazyList accepts following template argument list
-        \p Options of cds::intrusive::lazy_list::make_traits metafunction:
-        - opt::hook - hook used. Possible values are: lazy_list::base_hook, lazy_list::member_hook, lazy_list::traits_hook.
-            If the option is not specified, <tt>lazy_list::base_hook<></tt> and gc::HP is used.
-        - opt::compare - key comparison functor. No default functor is provided.
-            If the option is not specified, the opt::less is used.
-        - opt::less - specifies binary predicate used for key comparison. Default is \p std::less<T>.
-        - opt::back_off - back-off strategy used. If the option is not specified, the cds::backoff::empty is used.
-        - opt::disposer - the functor used for dispose removed items. Default is opt::v::empty_disposer. The disposer
-            provided is used only in \ref clear() function.
-        - opt::link_checker - the type of node's link fields checking. Default is \ref opt::debug_check_link
-        - opt::item_counter - the type of item counting feature. Default is \ref atomicity::empty_item_counter that is no item counting.
-        - opt::memory_model - C++ memory ordering model. Can be opt::v::relaxed_ordering (relaxed memory model, the default)
-            or opt::v::sequential_consistent (sequentially consisnent memory model).
-
-        The opt::allocator and opt::back_off is not used for this specialization.
+        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 <
         typename T
 #ifdef CDS_DOXYGEN_INVOKED
     */
     template <
         typename T
 #ifdef CDS_DOXYGEN_INVOKED

-        ,class Traits = lazy_list::type_traits
+        ,class Traits = lazy_list::traits

 #else
         ,class Traits
 #endif
 #else
         ,class Traits
 #endif


@@ -70,46 +93,62 @@ namespace cds { namespace intrusive {
     class LazyList<gc::nogc, T, Traits>
     {
     public:
     class LazyList<gc::nogc, T, Traits>
     {
     public:

-        typedef T       value_type      ;   ///< type of value stored in the list
-        typedef Traits  options         ;   ///< Traits template parameter
+        typedef gc::nogc gc;         ///< Garbage collector
+        typedef T        value_type; ///< type of value stored in the list
+        typedef Traits   traits;    ///< Traits template parameter

 
 

-        typedef typename options::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, options >::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
 #   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 options::disposer  disposer    ;   ///< disposer used
-        typedef typename get_node_traits< value_type, node_type, hook>::type node_traits ;    ///< node traits
-        typedef typename lazy_list::get_link_checker< node_type, options::link_checker >::type link_checker   ;   ///< link checker
-
-        typedef gc::nogc  gc    ;   ///< Garbage collector
-        typedef typename options::back_off  back_off        ;   ///< back-off strategy (not used)
-        typedef typename options::item_counter item_counter ;   ///< Item counting policy used
-        typedef typename options::memory_model  memory_model;   ///< C++ memory ordering (see lazy_list::type_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

-        // Rebind options (split-list support)
+        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>
         template <typename... Options>

-        struct rebind_options {
+        struct rebind_traits {

             typedef LazyList<
                 gc
                 , value_type
             typedef LazyList<
                 gc
                 , value_type

-                , typename cds::opt::make_options< options, Options...>::type
+                , typename cds::opt::make_options< traits, Options...>::type

             >   type;
         };
             >   type;
         };

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

         //@endcond
 
     protected:
         typedef node_type *     auxiliary_head   ;   ///< Auxiliary head type (for split-list support)
 
     protected:
         //@endcond
 
     protected:
         typedef node_type *     auxiliary_head   ;   ///< Auxiliary head type (for split-list support)
 
     protected:

-        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
 


@@ -170,6 +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 );


@@ -291,31 +331,47 @@ namespace cds { namespace intrusive {
         /// Returns a forward const iterator addressing the first element in a list
         const_iterator begin() const
         {
         /// Returns a forward const iterator addressing the first element in a list
         const_iterator begin() const
         {

-            const_iterator it( const_cast<node_type *>( &m_Head ));
-            ++it        ;   // skip dummy head
+            return cbegin();
+        }
+        /// 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));
+            ++it;   // skip dummy head

             return it;
         }
 
         /// Returns an const iterator that addresses the location succeeding the last element in a list
         const_iterator end() const
         {
             return it;
         }
 
         /// Returns an const iterator that addresses the location succeeding the last element in a list
         const_iterator end() const
         {

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

         }
 
     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 );
+        }

 
 

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

+        //@endcond

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

-

             assert( m_Head.m_pNext.load(memory_model::memory_order_relaxed) == &m_Tail );
             m_Head.m_pNext.store( nullptr, memory_model::memory_order_relaxed );
         }
             assert( m_Head.m_pNext.load(memory_model::memory_order_relaxed) == &m_Tail );
             m_Head.m_pNext.store( nullptr, memory_model::memory_order_relaxed );
         }


@@ -332,11 +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


@@ -347,125 +404,161 @@ 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.
 

-            You may pass \p func argument by reference using \p std::ref.
-
-            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 val
+        /// Finds the key \p key

         /** \anchor cds_intrusive_LazyList_nogc_find_func
         /** \anchor cds_intrusive_LazyList_nogc_find_func

-            The function searches the item with key equal to \p val
+            The function searches the item with key equal to \p key

             and calls the functor \p f for item found.
             The interface of \p Func functor is:
             \code
             struct functor {
             and calls the functor \p f for item found.
             The interface of \p Func functor is:
             \code
             struct functor {

-                void operator()( value_type& item, Q& val );
+                void operator()( value_type& item, Q& key );

             };
             \endcode
             };
             \endcode

-            where \p item is the item found, \p val is the <tt>find</tt> function argument.
-
-            You may pass \p f argument by reference using \p std::ref.
+            where \p item is the item found, \p key is the <tt>find</tt> function argument.

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

-            The function returns \p true if \p val is found, \p false otherwise.
+            The function returns \p true if \p key is found, \p false otherwise.

         */
         template <typename Q, typename Func>
         */
         template <typename Q, typename Func>

-        bool find( Q& val, Func f )
+        bool find( Q& key, Func f )

         {
         {

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

         }
         }

-
-        /// Finds the key \p val
-        /** \anchor cds_intrusive_LazyList_nogc_find_cfunc
-            The function searches the item with key equal to \p val
-            and calls the functor \p f for item found.
-            The interface of \p Func functor is:
-            \code
-            struct functor {
-                void operator()( value_type& item, Q const& val );
-            };
-            \endcode
-            where \p item is the item found, \p val is the <tt>find</tt> function argument.
-
-            You may pass \p f argument by reference using \p std::ref.
-
-            The functor may change non-key fields of \p item.
-            While the functor \p f is calling the item found \p item is locked.
-
-            The function returns \p true if \p val is found, \p false otherwise.
-        */
+        //@cond

         template <typename Q, typename Func>
         template <typename Q, typename Func>

-        bool find( Q const& val, Func f )
+        bool find( Q const& key, Func f )

         {
         {

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

         }
         }

+        //@endcond

 
 

-        /// Finds the key \p val 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_cfunc "find(Q const&, Func)"
+            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.
         */
             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 const& val, 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 )

         {
         {

-            return find_at( &m_Head, val, cds::opt::details::make_comparator_from_less<Less>(), f );
+            CDS_UNUSED( less );
+            return find_at( &m_Head, key, cds::opt::details::make_comparator_from_less<Less>(), f );

         }
 
         }
 

-        /// Finds the key \p val using \p pred predicate for searching
+        /// 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)"
         /**
             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.
+            but \p equal is used for key comparing.
+            \p Equal functor has the interface like \p std::equal_to.

         */
         */

-        template <typename Q, typename Less, typename Func>
-        bool find_with( Q& val, Less pred, Func f )
+        template <typename Q, typename Equal, typename Func, bool Sort = c_bSort>
+        typename std::enable_if<!Sort, bool>::type find_with( Q& key, Equal eq, Func f )
+        {
+            //CDS_UNUSED( eq );
+            return find_at( &m_Head, key, eq, 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 )

         {
         {

-            return find_at( &m_Head, val, cds::opt::details::make_comparator_from_less<Less>(), f );
+            CDS_UNUSED( pred );
+            return find_at( &m_Head, key, cds::opt::details::make_comparator_from_less<Less>(), f );

         }
 
         }
 

-        /// Finds the key \p val
-        /** \anchor cds_intrusive_LazyList_nogc_find_val
-            The function searches the item with key equal to \p val
-            and returns pointer to value found or \p nullptr.
+        template <typename Q, typename Equal, typename Func, bool Sort = c_bSort>
+        typename std::enable_if<!Sort, bool>::type find_with( Q const& key, Equal eq, Func f )
+        {
+            //CDS_UNUSED( eq );
+            return find_at( &m_Head, key, eq, f );
+        }
+        //@endcond
+
+        /// Checks whether the list 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.

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

-        value_type * find( Q const& val )
+        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 )

         {
         {

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

         }
         }

+        //@endcond

 
 

-        /// Finds the key \p val 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>
-        value_type * find_with( Q const & val, Less pred )
+        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 find_at( &m_Head, val, cds::opt::details::make_comparator_from_less<Less>() );
+            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 Equal, bool Sort = c_bSort>
+        typename std::enable_if<!Sort, value_type *>::type contains( Q const& key, Equal eq )
+        {
+            return find_at( &m_Head, key, eq );
+        }
+        //@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 eq )
+        {
+            return contains( key, eq );
+        }
+        //@endcond

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


@@ -482,6 +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;
             }
         }


@@ -492,7 +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


@@ -514,6 +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


@@ -531,32 +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 )


@@ -568,82 +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 ) {
             if ( pos.pCur != &m_Tail ) {

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

-                cds::lock::scoped_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();
         }
 


@@ -651,8 +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;
 


@@ -668,14 +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 pPred->m_pNext.load(memory_model::memory_order_acquire) == pCur;
+            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 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