-//$$CDS-header$$
+/*
+ This file is a part of libcds - Concurrent Data Structures library
-#ifndef __CDS_INTRUSIVE_MICHAEL_SET_NOGC_H
-#define __CDS_INTRUSIVE_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_INTRUSIVE_MICHAEL_SET_NOGC_H
+#define CDSLIB_INTRUSIVE_MICHAEL_SET_NOGC_H
#include <cds/intrusive/details/michael_set_base.h>
#include <cds/gc/nogc.h>
-#include <cds/details/allocator.h>
namespace cds { namespace intrusive {
/** @ingroup cds_intrusive_map
\anchor cds_intrusive_MichaelHashSet_nogc
- This specialization is intended for so-called persistent usage when no item
- reclamation may be performed. The class does not support deleting of list item.
+ This specialization is so-called append-only when no item
+ reclamation may be performed. The set does not support deleting of list item.
See \ref cds_intrusive_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_intrusive_MichaelList_nogc "persistent MichaelList".
-
- The interface of the specialization is a slightly different.
+ The template parameter \p OrderedList should be any \p cds::gc::nogc -derived ordered list, for example,
+ \ref cds_intrusive_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 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 bucket_type::disposer disposer ; ///< Node disposer functor
+ typedef typename ordered_list::value_type value_type; ///< type of value to be stored in the set
+ typedef typename ordered_list::key_comparator key_comparator; ///< key comparing functor
+ typedef typename ordered_list::disposer disposer; ///< Node disposer 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
+ /// Hash functor for \p value_type and all its derivatives that you use
+ 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");
protected:
- item_counter m_ItemCounter ; ///< Item counter
- hash m_HashFunctor ; ///< Hash functor
+ //@cond
+ typedef typename ordered_list::template select_stat_wrapper< typename ordered_list::stat > bucket_stat;
- bucket_type * m_Buckets ; ///< bucket table
+ 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;
- private:
+ typedef typename allocator::template rebind< internal_bucket_type >::other bucket_table_allocator;
+ //@endcond
+
+ public:
//@cond
- const size_t m_nHashBitmask;
+ typedef typename bucket_stat::stat stat;
//@endcond
protected:
+ //@cond
+ hash m_HashFunctor; ///< Hash functor
+ const size_t m_nHashBitmask;
+ internal_bucket_type * m_Buckets; ///< bucket table
+ item_counter m_ItemCounter; ///< Item counter
+ stat m_Stat; ///< Internal statistics
+ //@endcond
+
+ protected:
+ //@cond
/// Calculates hash value of \p key
template <typename Q>
size_t hash_value( Q const & key ) const
/// Returns the bucket (ordered list) for \p key
template <typename Q>
- bucket_type& bucket( Q const & key )
+ internal_bucket_type& bucket( Q const & key )
{
return m_Buckets[ hash_value( key ) ];
}
+ //@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();
+ return cbegin();
}
- const_iterator cbegin()
+ /// Returns a forward const iterator addressing the first element in a set
+ const_iterator cbegin() const
{
- return get_const_begin();
+ return const_iterator( m_Buckets[0].cbegin(), m_Buckets, m_Buckets + bucket_count());
}
- //@}
/// 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:
- //@cond
- const_iterator get_const_begin() const
- {
- return const_iterator( m_Buckets[0].begin(), m_Buckets, m_Buckets + bucket_count() );
+ return cend();
}
- 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( m_Buckets[bucket_count() - 1].end(), m_Buckets + bucket_count() - 1, m_Buckets + bucket_count() );
+ return const_iterator( m_Buckets[bucket_count() - 1].cend(), m_Buckets + bucket_count() - 1, m_Buckets + bucket_count());
}
- //@endcond
+ //@}
public:
/// Initializes hash set
/**
- See \ref cds_intrusive_MichaelHashSet_hp "MichaelHashSet" ctor for explanation
+ The Michael's hash set is an unbounded container, but its hash table is non-expandable.
+ At construction time you should pass estimated maximum item count and a load factor.
+ The load factor is average size of one bucket - a small number between 1 and 10.
+ The bucket is an ordered single-linked list, searching in the bucket has linear complexity <tt>O(nLoadFactor)</tt>.
+ The constructor 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 );
}
/// Clears hash set object 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
return bRet;
}
- /// Ensures that the \p item exists in the set
+ /// Updates the element
/**
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 into the set.
+ If the item \p val not found in the set, then \p val is inserted iff \p bAllowInsert is \p true.
Otherwise, the functor \p func is called with item found.
The functor signature is:
\code
- void func( bool bNew, value_type& item, value_type& val );
+ struct functor {
+ void operator()( bool bNew, value_type& item, value_type& val );
+ };
\endcode
with arguments:
- \p bNew - \p true if the item has been inserted, \p false otherwise
- \p item - item of the set
- - \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
refers to the same thing.
- The functor can change non-key fields of the \p item; however, \p func must guarantee
- that during changing no any other modifications could be made on this item by concurrent threads.
-
- You can pass \p func argument by value or by reference using <tt>boost::ref</tt> or cds::ref.
+ The functor may change non-key fields of the \p item.
- Returns std::pair<bool, bool> where \p first is \p true if operation is successfull,
+ 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 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 Func>
- std::pair<bool, bool> ensure( value_type& val, Func func )
+ std::pair<bool, bool> update( value_type& val, Func func, bool bAllowInsert = true )
{
- std::pair<bool, bool> bRet = bucket( val ).ensure( val, func );
- if ( bRet.first && bRet.second )
+ std::pair<bool, bool> bRet = bucket( val ).update( val, func, bAllowInsert );
+ if ( bRet.second )
++m_ItemCounter;
return bRet;
}
+ //@cond
+ template <typename Func>
+ CDS_DEPRECATED("ensure() is deprecated, use update()")
+ std::pair<bool, bool> ensure( value_type& val, Func func )
+ {
+ return update( val, func, true );
+ }
+ //@endcond
- /// Finds the key \p val
- /** \anchor cds_intrusive_MichaelHashSet_nogc_find_val
- The function searches the item with key equal to \p val
- and returns pointer to item found, otherwise \p nullptr.
+ /// Checks whether the set contains \p key
+ /**
+
+ The function searches the item with key equal to \p key
+ and returns the pointer to an element found or \p nullptr.
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>
- value_type * find( Q const& val )
+ value_type * contains( Q const& key )
+ {
+ return bucket( key ).contains( key );
+ }
+ //@cond
+ template <typename Q>
+ CDS_DEPRECATED("use contains()")
+ value_type * find( Q const& key )
{
- return bucket( val ).find( val );
+ 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_intrusive_MichaelHashSet_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 pred must imply the same element order as the comparator used for building the set.
+ \p Less must imply the same element order as the comparator used for building the set.
*/
template <typename Q, typename Less>
- value_type * find_with( Q const& val, Less pred )
+ value_type * contains( Q const& key, Less pred )
+ {
+ return bucket( key ).contains( key, pred );
+ }
+ //@cond
+ template <typename Q, typename Less>
+ CDS_DEPRECATED("use contains()")
+ value_type * find_with( Q const& key, Less pred )
{
- return bucket( val ).find_with( val, pred );
+ return contains( key, pred );
}
+ //@endcond
- /// Finds the key \p val
+ /// Finds the key \p key
/** \anchor cds_intrusive_MichaelHashSet_nogc_find_func
- The function searches the item with key equal to \p val and calls the functor \p f for item found.
+ 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 {
- void operator()( value_type& item, Q& val );
+ void operator()( value_type& item, Q& key );
};
\endcode
- where \p item is the item found, \p val is the <tt>find</tt> function argument.
-
- You can pass \p f argument by value or by reference using <tt>boost::ref</tt> or cds::ref.
+ where \p item is the item found, \p key is the <tt>find</tt> function argument.
The functor can change non-key fields of \p item.
The functor does not serialize simultaneous access to the set \p item. If such access is
possible you must provide your own synchronization schema on item level to exclude unsafe item modifications.
- The \p val argument is non-const since it can be used as \p f functor destination i.e., the functor
+ The \p key argument is non-const since it can be used as \p f functor destination i.e., the functor
can modify both arguments.
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.
- 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>
- bool find( Q& val, Func f )
+ bool find( Q& key, Func f )
+ {
+ return bucket( key ).find( key, f );
+ }
+ //@cond
+ template <typename Q, typename Func>
+ bool find( Q const& key, Func f )
{
- return bucket( val ).find( val, f );
+ return bucket( key ).find( key, f );
}
+ //@endcond
- /// Finds the key \p val using \p pred predicate for searching
+ /// Finds the key \p key using \p pred predicate for searching
/**
The function is an analog of \ref cds_intrusive_MichaelHashSet_nogc_find_func "find(Q&, Func)"
but \p pred is used for key comparing.
\p pred must imply the same element order as the comparator used for building the set.
*/
template <typename Q, typename Less, typename Func>
- bool find( Q& val, Less pred, Func f )
- {
- return bucket( val ).find_with( val, pred, f );
- }
-
- /// Finds the key \p val
- /** \anchor cds_intrusive_MichaelHashSet_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 can pass \p f argument by value or by reference using <tt>boost::ref</tt> or cds::ref.
-
- The functor can change non-key fields of \p item.
- The functor does not serialize simultaneous access to the set \p item. If such access is
- possible you must provide your own synchronization schema on item level to exclude unsafe item modifications.
-
- 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.
-
- The function returns \p true if \p val is found, \p false otherwise.
- */
- template <typename Q, typename Func>
- bool find( Q const& val, Func f )
+ bool find_with( Q& key, Less pred, Func f )
{
- return bucket( val ).find( val, f );
+ return bucket( key ).find_with( key, pred, f );
}
-
- /// Finds the key \p val using \p pred predicate for searching
- /**
- The function is an analog of \ref cds_intrusive_MichaelHashSet_nogc_find_cfunc "find(Q const&, 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 set.
- */
+ //@cond
template <typename Q, typename Less, typename Func>
- bool find_with( Q const& val, Less pred, Func f )
+ bool find_with( Q const& key, Less pred, Func f )
{
- return bucket( val ).find_with( val, pred, f );
+ return bucket( key ).find_with( key, pred, f );
}
+ //@endcond
/// Clears the set (non-atomic)
/**
The function unlink all items from the set.
The function is not atomic. 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:
+ 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).
- Therefore, \p clear may be used only for debugging purposes.
+ Therefore, \p %clear() may be used only for debugging purposes.
For each item the \p disposer is called after unlinking.
*/
/// 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
{
}
/// 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;
/// 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;
}
+ /// Returns const reference to internal statistics
+ stat const& statistics() const
+ {
+ return m_Stat;
+ }
+
+ private:
+ //@cond
+ template <typename Stat>
+ typename std::enable_if< Stat::empty >::type construct_bucket( internal_bucket_type * b )
+ {
+ new (b) internal_bucket_type;
+ }
+
+ template <typename Stat>
+ typename std::enable_if< !Stat::empty >::type construct_bucket( internal_bucket_type * b )
+ {
+ new (b) internal_bucket_type( m_Stat );
+ }
+ //@endcond
};
}} // namespace cds::intrusive
-#endif // #ifndef __CDS_INTRUSIVE_MICHAEL_SET_NOGC_H
+#endif // #ifndef CDSLIB_INTRUSIVE_MICHAEL_SET_NOGC_H
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