-//$$CDS-header$$
+/*
+ This file is a part of libcds - Concurrent Data Structures library
-#ifndef __CDS_CONTAINER_MICHAEL_SET_NOGC_H
-#define __CDS_CONTAINER_MICHAEL_SET_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_CONTAINER_MICHAEL_SET_NOGC_H
+#define CDSLIB_CONTAINER_MICHAEL_SET_NOGC_H
#include <cds/container/details/michael_set_base.h>
#include <cds/gc/nogc.h>
-#include <cds/details/allocator.h>
namespace cds { namespace container {
/** @ingroup cds_nonintrusive_set
\anchor cds_nonintrusive_MichaelHashSet_nogc
- This specialization is intended for so-called persistent usage when no item
+ This specialization is so-called append-only when no item
reclamation may be performed. The class does not support deleting of list item.
See \ref cds_nonintrusive_MichaelHashSet_hp "MichaelHashSet" for description of template parameters.
- The template parameter \p OrderedList should be any gc::nogc-derived ordered list, for example,
- \ref cds_nonintrusive_MichaelList_nogc "persistent MichaelList".
-
- The interface of the specialization is a slightly different.
+ The template parameter \p OrderedList should be any \p gc::nogc -derived ordered list, for example,
+ \ref cds_nonintrusive_MichaelList_nogc "append-only MichaelList".
*/
template <
class OrderedList,
#ifdef CDS_DOXYGEN_INVOKED
- class Traits = michael_set::type_traits
+ class Traits = michael_set::traits
#else
class Traits
#endif
>
- class MichaelHashSet< gc::nogc, OrderedList, Traits >
+ class MichaelHashSet< cds::gc::nogc, OrderedList, Traits >
{
public:
- typedef OrderedList bucket_type ; ///< type of ordered list used as a bucket implementation
- typedef Traits options ; ///< Traits template parameters
+ typedef cds::gc::nogc gc; ///< Garbage collector
+ typedef OrderedList ordered_list; ///< type of ordered list to be used as a bucket implementation
+ typedef Traits traits; ///< Set traits
- typedef typename bucket_type::value_type value_type ; ///< type of value stored in the list
- typedef gc::nogc gc ; ///< Garbage collector
- typedef typename bucket_type::key_comparator key_comparator ; ///< key comparison functor
+ typedef typename ordered_list::value_type value_type; ///< type of value stored in the list
+ typedef typename ordered_list::key_comparator key_comparator; ///< key comparison functor
+#ifdef CDS_DOXYGEN_INVOKED
+ typedef typename ordered_list::stat stat; ///< Internal statistics
+#endif
/// Hash functor for \ref value_type and all its derivatives that you use
- typedef typename cds::opt::v::hash_selector< typename options::hash >::type hash;
- typedef typename options::item_counter item_counter ; ///< Item counter type
+ typedef typename cds::opt::v::hash_selector< typename traits::hash >::type hash;
+ typedef typename traits::item_counter item_counter; ///< Item counter type
+ typedef typename traits::allocator allocator; ///< Bucket table allocator
- /// Bucket table allocator
- typedef cds::details::Allocator< bucket_type, typename options::allocator > bucket_table_allocator;
+ // 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 bucket_type::iterator bucket_iterator;
- typedef typename bucket_type::const_iterator bucket_const_iterator;
- //@endcond
+ typedef typename ordered_list::template select_stat_wrapper< typename ordered_list::stat > bucket_stat;
- protected:
- item_counter m_ItemCounter ; ///< Item counter
- hash m_HashFunctor ; ///< Hash functor
+ typedef typename ordered_list::template rebind_traits<
+ cds::opt::item_counter< cds::atomicity::empty_item_counter >
+ , cds::opt::stat< typename bucket_stat::wrapped_stat >
+ >::type internal_bucket_type_;
- bucket_type * m_Buckets ; ///< bucket table
+ class internal_bucket_type: public internal_bucket_type_
+ {
+ typedef internal_bucket_type_ base_class;
+ public:
+ using base_class::base_class;
+ using typename base_class::node_type;
+ using base_class::alloc_node;
+ using base_class::insert_node;
+ using base_class::node_to_value;
+ };
- private:
+ /// Bucket table allocator
+ typedef typename allocator::template rebind< internal_bucket_type >::other bucket_table_allocator;
+
+ typedef typename internal_bucket_type::iterator bucket_iterator;
+ typedef typename internal_bucket_type::const_iterator bucket_const_iterator;
+ //@endcond
+
+ public:
//@cond
- const size_t m_nHashBitmask;
+ typedef typename bucket_stat::stat stat;
//@endcond
protected:
- /// Calculates hash value of \p key
- template <typename Q>
- size_t hash_value( const Q& key ) const
- {
- return m_HashFunctor( key ) & m_nHashBitmask;
- }
-
- /// Returns the bucket (ordered list) for \p key
- template <typename Q>
- bucket_type& bucket( const Q& key )
- {
- return m_Buckets[ hash_value( key ) ];
- }
+ //@cond
+ const size_t m_nHashBitmask;
+ item_counter m_ItemCounter; ///< Item counter
+ hash m_HashFunctor; ///< Hash functor
+ internal_bucket_type* m_Buckets; ///< bucket table
+ stat m_Stat; ///< Internal statistics
+ //@endcond
public:
+ ///@name Forward iterators
+ //@{
/// Forward iterator
/**
The forward iterator for Michael's set is based on \p OrderedList forward iterator and has some features:
- it has no post-increment operator
- it iterates items in unordered fashion
+
+ The iterator interface:
+ \code
+ class iterator {
+ public:
+ // Default constructor
+ iterator();
+
+ // Copy construtor
+ iterator( iterator const& src );
+
+ // Dereference operator
+ value_type * operator ->() const;
+
+ // Dereference operator
+ value_type& operator *() const;
+
+ // Preincrement operator
+ iterator& operator ++();
+
+ // Assignment operator
+ iterator& operator = (iterator const& src);
+
+ // Equality operators
+ bool operator ==(iterator const& i ) const;
+ bool operator !=(iterator const& i ) const;
+ };
+ \endcode
*/
- typedef michael_set::details::iterator< bucket_type, false > iterator;
+ typedef michael_set::details::iterator< internal_bucket_type, false > iterator;
/// Const forward iterator
/**
For iterator's features and requirements see \ref iterator
*/
- typedef michael_set::details::iterator< bucket_type, true > const_iterator;
+ typedef michael_set::details::iterator< internal_bucket_type, true > const_iterator;
/// Returns a forward iterator addressing the first element in a set
/**
*/
iterator begin()
{
- return iterator( m_Buckets[0].begin(), m_Buckets, m_Buckets + bucket_count() );
+ return iterator( m_Buckets[0].begin(), m_Buckets, m_Buckets + bucket_count());
}
/// Returns an iterator that addresses the location succeeding the last element in a set
*/
iterator end()
{
- return iterator( m_Buckets[bucket_count() - 1].end(), m_Buckets + bucket_count() - 1, m_Buckets + bucket_count() );
+ return iterator( m_Buckets[bucket_count() - 1].end(), m_Buckets + bucket_count() - 1, m_Buckets + bucket_count());
}
/// Returns a forward const iterator addressing the first element in a set
- //@{
const_iterator begin() const
{
return get_const_begin();
}
- const_iterator cbegin()
+
+ /// Returns a forward const iterator addressing the first element in a set
+ const_iterator cbegin() const
{
return get_const_begin();
}
- //@}
/// Returns an const iterator that addresses the location succeeding the last element in a set
- //@{
const_iterator end() const
{
return get_const_end();
}
- const_iterator cend()
- {
- return get_const_end();
- }
- //@}
- private:
- //@{
- const_iterator get_const_begin() const
- {
- return const_iterator( const_cast<bucket_type const&>(m_Buckets[0]).begin(), m_Buckets, m_Buckets + bucket_count() );
- }
- const_iterator get_const_end() const
+ /// Returns an const iterator that addresses the location succeeding the last element in a set
+ const_iterator cend() const
{
- return const_iterator( const_cast<bucket_type const&>(m_Buckets[bucket_count() - 1]).end(), m_Buckets + bucket_count() - 1, m_Buckets + bucket_count() );
+ return get_const_end();
}
- //@}
+ //@}
public:
/// Initialize hash set
/**
- See \ref cds_nonintrusive_MichaelHashSet_hp "MichaelHashSet" ctor for explanation
+ The Michael's hash set is non-expandable container. You should point the average count of items \p nMaxItemCount
+ when you create an object.
+ \p nLoadFactor parameter defines average count of items per bucket and it should be small number between 1 and 10.
+ Remember, since the bucket implementation is an ordered list, searching in the bucket is linear [<tt>O(nLoadFactor)</tt>].
+
+ The ctor defines hash table size as rounding <tt>nMaxItemCount / nLoadFactor</tt> up to nearest power of two.
*/
MichaelHashSet(
size_t nMaxItemCount, ///< estimation of max item count in the hash set
size_t nLoadFactor ///< load factor: estimation of max number of items in the bucket
) : m_nHashBitmask( michael_set::details::init_hash_bitmask( nMaxItemCount, nLoadFactor ))
+ , m_Buckets( bucket_table_allocator().allocate( bucket_count()))
{
- // GC and OrderedList::gc must be the same
- static_assert(( std::is_same<gc, typename bucket_type::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 ), "atomicity::empty_item_counter is not allowed as a item counter");
-
- m_Buckets = bucket_table_allocator().NewArray( bucket_count() );
+ for ( auto it = m_Buckets, itEnd = m_Buckets + bucket_count(); it != itEnd; ++it )
+ construct_bucket<bucket_stat>( it );
}
- /// Clear hash set and destroy it
+ /// Clears hash set and destroys it
~MichaelHashSet()
{
clear();
- bucket_table_allocator().Delete( m_Buckets, bucket_count() );
+ for ( auto it = m_Buckets, itEnd = m_Buckets + bucket_count(); it != itEnd; ++it )
+ it->~internal_bucket_type();
+ bucket_table_allocator().deallocate( m_Buckets, bucket_count());
}
/// Inserts new node
template <typename Q>
iterator insert( const Q& val )
{
- bucket_type& refBucket = bucket( val );
+ internal_bucket_type& refBucket = bucket( val );
bucket_iterator it = refBucket.insert( val );
- if ( it != refBucket.end() ) {
+ if ( it != refBucket.end()) {
++m_ItemCounter;
- return iterator( it, &refBucket, m_Buckets + bucket_count() );
+ return iterator( it, &refBucket, m_Buckets + bucket_count());
}
return end();
template <typename... Args>
iterator emplace( Args&&... args )
{
- bucket_type& refBucket = bucket( value_type(std::forward<Args>(args)...));
- bucket_iterator it = refBucket.emplace( std::forward<Args>(args)... );
-
- if ( it != refBucket.end() ) {
+ typename internal_bucket_type::node_type * pNode = internal_bucket_type::alloc_node( std::forward<Args>( args )... );
+ internal_bucket_type& refBucket = bucket( internal_bucket_type::node_to_value( *pNode ));
+ bucket_iterator it = refBucket.insert_node( pNode );
+ if ( it != refBucket.end()) {
++m_ItemCounter;
- return iterator( it, &refBucket, m_Buckets + bucket_count() );
+ return iterator( it, &refBucket, m_Buckets + bucket_count());
}
return end();
}
- /// Ensures that the item \p val exists in the set
+ /// Updates the element
/**
- The operation inserts new item if the key \p val is not found in the set.
- Otherwise, the function returns an iterator that points to item found.
+ The operation performs inserting or changing data with lock-free manner.
+
+ If the item \p val not found in the set, then \p val is inserted iff \p bAllowInsert is \p true.
+
+ Returns <tt> std::pair<iterator, bool> </tt> where \p first is an iterator pointing to
+ item found or inserted, or \p end() if \p bAllowInsert is \p false,
+
+ \p second is true if new item has been added or \p false if the item is already in the set.
- Returns <tt> std::pair<iterator, bool> </tt> where \p first is an iterator pointing to
- item found or inserted, \p second is true if new item has been added or \p false if the item
- already is in the set.
+ @warning For \ref cds_intrusive_MichaelList_hp "MichaelList" as the bucket see \ref cds_intrusive_item_creating "insert item troubleshooting".
+ \ref cds_intrusive_LazyList_hp "LazyList" provides exclusive access to inserted item and does not require any node-level
+ synchronization.
*/
template <typename Q>
- std::pair<iterator, bool> ensure( const Q& val )
+ std::pair<iterator, bool> update( Q const& val, bool bAllowInsert = true )
{
- bucket_type& refBucket = bucket( val );
- std::pair<bucket_iterator, bool> ret = refBucket.ensure( val );
+ internal_bucket_type& refBucket = bucket( val );
+ std::pair<bucket_iterator, bool> ret = refBucket.update( val, bAllowInsert );
- if ( ret.first != refBucket.end() ) {
+ if ( ret.first != refBucket.end()) {
if ( ret.second )
++m_ItemCounter;
- return std::make_pair( iterator( ret.first, &refBucket, m_Buckets + bucket_count() ), ret.second );
+ return std::make_pair( iterator( ret.first, &refBucket, m_Buckets + bucket_count()), ret.second );
}
-
return std::make_pair( end(), ret.second );
}
+ //@cond
+ template <typename Q>
+ CDS_DEPRECATED("ensure() is deprecated, use update()")
+ std::pair<iterator, bool> ensure( Q const& val )
+ {
+ return update( val, true );
+ }
+ //@endcond
- /// Find the key \p key
- /** \anchor cds_nonintrusive_MichealSet_nogc_find
+ /// Checks whether the set contains \p key
+ /**
The function searches the item with key equal to \p key
and returns an iterator pointed to item found if the key is found,
- and \ref end() otherwise
+ or \ref end() otherwise.
+
+ Note the hash functor specified for class \p Traits template parameter
+ should accept a parameter of type \p Q that can be not the same as \p value_type.
*/
template <typename Q>
- iterator find( Q const& key )
+ iterator contains( Q const& key )
{
- bucket_type& refBucket = bucket( key );
- bucket_iterator it = refBucket.find( key );
- if ( it != refBucket.end() )
- return iterator( it, &refBucket, m_Buckets + bucket_count() );
+ internal_bucket_type& refBucket = bucket( key );
+ bucket_iterator it = refBucket.contains( key );
+ if ( it != refBucket.end())
+ return iterator( it, &refBucket, m_Buckets + bucket_count());
return end();
}
+ //@cond
+ template <typename Q>
+ CDS_DEPRECATED("use contains()")
+ iterator find( Q const& key )
+ {
+ 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_MichealSet_nogc_find "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 must imply the same element order as the comparator used for building the set.
*/
template <typename Q, typename Less>
- iterator find_with( Q const& key, Less pred )
+ iterator contains( Q const& key, Less pred )
{
- bucket_type& refBucket = bucket( key );
- bucket_iterator it = refBucket.find_with( key, pred );
- if ( it != refBucket.end() )
- return iterator( it, &refBucket, m_Buckets + bucket_count() );
+ internal_bucket_type& refBucket = bucket( key );
+ bucket_iterator it = refBucket.contains( key, pred );
+ if ( it != refBucket.end())
+ return iterator( it, &refBucket, m_Buckets + bucket_count());
return end();
}
+ //@cond
+ template <typename Q, typename Less>
+ CDS_DEPRECATED("use contains()")
+ iterator find_with( Q const& key, Less pred )
+ {
+ return contains( key, pred );
+ }
+ //@endcond
-
- /// Clears the set (non-atomic, not thread-safe)
- /**
- The function deletes all items from the set.
- The function is not atomic and even not thread-safe.
- It cleans up each bucket and then resets the item counter to zero.
- If there are a thread that performs insertion while \p clear is working the result is undefined in general case:
- <tt> empty() </tt> may return \p true but the set may contain item(s).
- */
+ /// Clears the set (not atomic)
void clear()
{
for ( size_t i = 0; i < bucket_count(); ++i )
m_ItemCounter.reset();
}
-
/// Checks if the set is empty
/**
- Emptiness is checked by item counting: if item count is zero then the set is empty.
+ The emptiness is checked by the 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.
*/
bool empty() const
return m_ItemCounter;
}
+ /// Returns const reference to internal statistics
+ stat const& statistics() const
+ {
+ return m_Stat;
+ }
+
/// Returns the size of hash table
/**
- Since MichaelHashSet cannot dynamically extend the hash table size,
+ Since \p %MichaelHashSet cannot dynamically extend the hash table size,
the value returned is an constant depending on object initialization parameters;
see MichaelHashSet::MichaelHashSet for explanation.
*/
{
return m_nHashBitmask + 1;
}
+
+ protected:
+ //@cond
+ /// Calculates hash value of \p key
+ template <typename Q>
+ size_t hash_value( const Q& key ) const
+ {
+ return m_HashFunctor( key ) & m_nHashBitmask;
+ }
+
+ /// Returns the bucket (ordered list) for \p key
+ template <typename Q>
+ internal_bucket_type& bucket( const Q& key )
+ {
+ return m_Buckets[hash_value( key )];
+ }
+ //@endcond
+
+ private:
+ //@cond
+ template <typename Stat>
+ typename std::enable_if< Stat::empty >::type construct_bucket( internal_bucket_type* bucket )
+ {
+ new (bucket) internal_bucket_type;
+ }
+
+ template <typename Stat>
+ typename std::enable_if< !Stat::empty >::type construct_bucket( internal_bucket_type* bucket )
+ {
+ new (bucket) internal_bucket_type( m_Stat );
+ }
+
+ const_iterator get_const_begin() const
+ {
+ return const_iterator( const_cast<internal_bucket_type const&>(m_Buckets[0]).begin(), m_Buckets, m_Buckets + bucket_count());
+ }
+ const_iterator get_const_end() const
+ {
+ return const_iterator( const_cast<internal_bucket_type const&>(m_Buckets[bucket_count() - 1]).end(), m_Buckets + bucket_count() - 1, m_Buckets + bucket_count());
+ }
+ //@endcond
};
}} // cds::container
-#endif // ifndef __CDS_CONTAINER_MICHAEL_SET_NOGC_H
+#endif // ifndef CDSLIB_CONTAINER_MICHAEL_SET_NOGC_H