reformatting

[libcds.git] / cds / intrusive / details / michael_set_base.h

diff --git a/cds/intrusive/details/michael_set_base.h b/cds/intrusive/details/michael_set_base.h
index 757d05e33f4d9eab9d8f2d0811f6cbf08f19c762..8e63cf3849b49d5f38382cb7badd601b047d734c 100644 (file)
--- a/cds/intrusive/details/michael_set_base.h
+++ b/cds/intrusive/details/michael_set_base.h
@@ -1,7 +1,35 @@
-//$$CDS-header$$
+/*
+    This file is a part of libcds - Concurrent Data Structures library
 
-#ifndef __CDS_INTRUSIVE_DETAILS_MICHAEL_SET_BASE_H
-#define __CDS_INTRUSIVE_DETAILS_MICHAEL_SET_BASE_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_DETAILS_MICHAEL_SET_BASE_H
+#define CDSLIB_INTRUSIVE_DETAILS_MICHAEL_SET_BASE_H
 
 #include <cds/intrusive/details/base.h>
 #include <cds/opt/compare.h>
@@ -15,7 +43,6 @@ namespace cds { namespace intrusive {
     /** @ingroup cds_intrusive_helper
     */
     namespace michael_set {
-
         /// MichaelHashSet traits
         struct traits {
             /// Hash function
@@ -31,9 +58,10 @@ namespace cds { namespace intrusive {
             /**
                 The item counting is an important part of \p MichaelHashSet algorithm:
                 the \p empty() member function depends on correct item counting.
-                Therefore, \p atomicity::empty_item_counter is not allowed as a type of the option.
+                You may use \p atomicity::empty_item_counter if don't need \p empty() and \p size()
+                member functions.
 
-                Default is \p atomicity::item_counter.
+                Default is \p atomicity::item_counter; to avoid false sharing you may use \p atomicity::cache_friendly_item_counter
             */
             typedef cds::atomicity::item_counter item_counter;
 
@@ -67,10 +95,10 @@ namespace cds { namespace intrusive {
                     nLoadFactor = 1;
                 if ( nMaxItemCount == 0 )
                     nMaxItemCount = 4;
-                const size_t nBucketCount = (size_t)( nMaxItemCount / nLoadFactor );
-                const size_t nLog2 = cds::bitop::MSB( nBucketCount );
+                const size_t nBucketCount = nMaxItemCount / nLoadFactor;
+                const size_t exp2 = size_t( 1 ) << cds::bitop::MSB( nBucketCount );
 
-                return (( size_t( 1 << nLog2 ) < nBucketCount ? size_t( 1 << (nLog2 + 1) ) : size_t( 1 << nLog2 ))) - 1;
+                return ( exp2 < nBucketCount ? exp2 * 2 : exp2 ) - 1;
             }
 
             template <typename OrderedList, bool IsConst>
@@ -93,7 +121,8 @@ namespace cds { namespace intrusive {
             template <typename OrderedList, bool IsConst>
             class iterator
             {
-                friend class iterator < OrderedList, !IsConst >;
+                friend class iterator< OrderedList, !IsConst >;
+
             protected:
                 typedef OrderedList bucket_type;
                 typedef typename list_iterator_selector< bucket_type, IsConst>::bucket_ptr bucket_ptr;
@@ -106,11 +135,11 @@ namespace cds { namespace intrusive {
                 void next()
                 {
                     if ( m_pCurBucket < m_pEndBucket ) {
-                        if ( ++m_itList != m_pCurBucket->end() )
+                        if ( ++m_itList != m_pCurBucket->end())
                             return;
                         while ( ++m_pCurBucket < m_pEndBucket ) {
                             m_itList = m_pCurBucket->begin();
-                            if ( m_itList != m_pCurBucket->end() )
+                            if ( m_itList != m_pCurBucket->end())
                                 return;
                         }
                     }
@@ -134,7 +163,7 @@ namespace cds { namespace intrusive {
                     , m_itList( it )
                     , m_pEndBucket( pLast )
                 {
-                    if ( it == pFirst->end() )
+                    if ( it == pFirst->end())
                         next();
                 }
 
@@ -176,6 +205,11 @@ namespace cds { namespace intrusive {
                     return m_pCurBucket != m_pEndBucket ? m_pCurBucket : nullptr;
                 }
 
+                list_iterator const& underlying_iterator() const
+                {
+                    return m_itList;
+                }
+
                 template <bool C>
                 bool operator ==(iterator<bucket_type, C> const& i) const
                 {
@@ -186,11 +220,10 @@ namespace cds { namespace intrusive {
                 {
                     return !( *this == i );
                 }
-
             };
         }
         //@endcond
-    }
+    } // namespace michael_set
 
     //@cond
     // Forward declarations
@@ -200,4 +233,4 @@ namespace cds { namespace intrusive {
 
 }} // namespace cds::intrusive
 
-#endif // #ifndef __CDS_INTRUSIVE_DETAILS_MICHAEL_SET_BASE_H
+#endif // #ifndef CDSLIB_INTRUSIVE_DETAILS_MICHAEL_SET_BASE_H