X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=cds%2Fintrusive%2Fmichael_set.h;h=79b2b8cbf7264f41ea6be1c0df33698c5b95a39a;hb=6924946ceeaae28bc227fe7c9d8e939963bb9d69;hp=a2aac0b46f4e124b6252cc9e0a3d2bb88b195d5c;hpb=40e34e6d0b104b6f5aff506ad67d43fd410e52bc;p=libcds.git

diff --git a/cds/intrusive/michael_set.h b/cds/intrusive/michael_set.h
index a2aac0b4..79b2b8cb 100644
--- a/cds/intrusive/michael_set.h
+++ b/cds/intrusive/michael_set.h
@@ -271,10 +271,6 @@ namespace cds { namespace intrusive {
         // GC and OrderedList::gc must be the same
         static_assert(std::is_same<gc, typename ordered_list::gc>::value, "GC and OrderedList::gc must be the same");
 
-        // atomicity::empty_item_counter is not allowed as a item counter
-        static_assert(!std::is_same<item_counter, atomicity::empty_item_counter>::value,
-            "cds::atomicity::empty_item_counter is not allowed as a item counter");
-
     protected:
         //@cond
         typedef typename ordered_list::template select_stat_wrapper< typename ordered_list::stat > bucket_stat;
@@ -626,6 +622,34 @@ namespace cds { namespace intrusive {
             return false;
         }
 
+        /// Deletes the item pointed by iterator \p iter (only for \p IterableList based set)
+        /**
+            Returns \p true if the operation is successful, \p false otherwise.
+            The function can return \p false if the node the iterator points to has already been deleted
+            by other thread.
+
+            The function does not invalidate the iterator, it remains valid and can be used for further traversing.
+
+            @note \p %erase_at() is supported only for \p %MichaelHashSet based on \p IterableList.
+        */
+#ifdef CDS_DOXYGEN_INVOKED
+        bool erase_at( iterator const& iter )
+#else
+        template <typename Iterator>
+        typename std::enable_if< std::is_same<Iterator, iterator>::value && is_iterable_list< ordered_list >::value, bool >::type
+        erase_at( Iterator const& iter )
+#endif
+        {
+            assert( iter != end());
+            assert( iter.bucket() != nullptr );
+
+            if ( iter.bucket()->erase_at( iter.underlying_iterator())) {
+                --m_ItemCounter;
+                return true;
+            }
+            return false;
+        }
+
         /// Extracts the item with specified \p key
         /** \anchor cds_intrusive_MichaelHashSet_hp_extract
             The function searches an item with key equal to \p key,
@@ -901,8 +925,8 @@ namespace cds { namespace intrusive {
 
         /// Checks if the set is empty
         /**
-            Emptiness is checked by item counting: if item count is zero then the set is empty.
-            Thus, the correct item counting feature is an important part of Michael's set implementation.
+            @warning If you use \p atomicity::empty_item_counter in \p traits::item_counter,
+            the function always returns \p true.
         */
         bool empty() const
         {
@@ -910,6 +934,10 @@ namespace cds { namespace intrusive {
         }
 
         /// Returns item count in the set
+        /**
+            If you use \p atomicity::empty_item_counter in \p traits::item_counter,
+            the function always returns 0.
+        */
         size_t size() const
         {
             return m_ItemCounter;
@@ -954,15 +982,15 @@ namespace cds { namespace intrusive {
         }
 
         template <typename Stat>
-        typename std::enable_if< Stat::empty >::type construct_bucket( internal_bucket_type * bucket )
+        typename std::enable_if< Stat::empty >::type construct_bucket( internal_bucket_type * b )
         {
-            new (bucket) internal_bucket_type;
+            new (b) internal_bucket_type;
         }
 
         template <typename Stat>
-        typename std::enable_if< !Stat::empty >::type construct_bucket( internal_bucket_type * bucket )
+        typename std::enable_if< !Stat::empty >::type construct_bucket( internal_bucket_type * b )
         {
-            new (bucket) internal_bucket_type( m_Stat );
+            new (b) internal_bucket_type( m_Stat );
         }
 
         /// Calculates hash value of \p key