--- /dev/null
+/*
+ This file is a part of libcds - Concurrent Data Structures library
+
+ (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_MAP_H
+#define CDSLIB_CONTAINER_MICHAEL_MAP_H
+
+#include <cds/container/details/michael_map_base.h>
+#include <cds/container/details/iterable_list_base.h>
+#include <cds/details/allocator.h>
+
+namespace cds { namespace container {
+
+ /// Michael's hash map
+ /** @ingroup cds_nonintrusive_map
+ \anchor cds_nonintrusive_MichaelHashMap_hp
+
+ Source:
+ - [2002] Maged Michael "High performance dynamic lock-free hash tables and list-based sets"
+
+ Michael's hash table algorithm is based on lock-free ordered list and it is very simple.
+ The main structure is an array \p T of size \p M. Each element in \p T is basically a pointer
+ to a hash bucket, implemented as a singly linked list. The array of buckets cannot be dynamically expanded.
+ However, each bucket may contain unbounded number of items.
+
+ Template parameters are:
+ - \p GC - Garbage collector used. You may use any \ref cds_garbage_collector "Garbage collector"
+ from the \p libcds library.
+ Note the \p GC must be the same as the GC used for \p OrderedList
+ - \p OrderedList - ordered key-value list implementation used as bucket for hash map, for example, \p MichaelKVList,
+ \p LazyKVList, \p IterableKVList. The ordered list implementation specifies the \p Key and \p Value types
+ stored in the hash-map, the reclamation schema \p GC used by hash-map, the comparison functor for the type \p Key
+ and other features specific for the ordered list.
+ - \p Traits - map traits, default is \p michael_map::traits.
+ Instead of defining \p Traits struct you may use option-based syntax with \p michael_map::make_traits metafunction.
+
+ Many of the class function take a key argument of type \p K that in general is not \p key_type.
+ \p key_type and an argument of template type \p K must meet the following requirements:
+ - \p key_type should be constructible from value of type \p K;
+ - the hash functor should be able to calculate correct hash value from argument \p key of type \p K:
+ <tt> hash( key_type(key)) == hash( key ) </tt>
+ - values of type \p key_type and \p K should be comparable
+
+ There are the specializations:
+ - for \ref cds_urcu_desc "RCU" - declared in <tt>cds/container/michael_map_rcu.h</tt>,
+ see \ref cds_nonintrusive_MichaelHashMap_rcu "MichaelHashMap<RCU>".
+ - for \p cds::gc::nogc declared in <tt>cds/container/michael_map_nogc.h</tt>,
+ see \ref cds_nonintrusive_MichaelHashMap_nogc "MichaelHashMap<gc::nogc>".
+
+ \anchor cds_nonintrusive_MichaelHashMap_how_touse
+ <b>How to use</b>
+
+ Suppose, you want to make \p int to \p int map for Hazard Pointer garbage collector. You should
+ choose suitable ordered list class that will be used as a bucket for the map; it may be \p MichaelKVList.
+ \code
+ #include <cds/container/michael_kvlist_hp.h> // MichaelKVList for gc::HP
+ #include <cds/container/michael_map.h> // MichaelHashMap
+
+ // List traits based on std::less predicate
+ struct list_traits: public cds::container::michael_list::traits
+ {
+ typedef std::less<int> less;
+ };
+
+ // Ordered list
+ typedef cds::container::MichaelKVList< cds::gc::HP, int, int, list_traits> int2int_list;
+
+ // Map traits
+ struct map_traits: public cds::container::michael_map::traits
+ {
+ struct hash {
+ size_t operator()( int i ) const
+ {
+ return cds::opt::v::hash<int>()( i );
+ }
+ }
+ };
+
+ // Your map
+ typedef cds::container::MichaelHashMap< cds::gc::HP, int2int_list, map_traits > int2int_map;
+
+ // Now you can use int2int_map class
+
+ int main()
+ {
+ int2int_map theMap;
+
+ theMap.insert( 100 );
+ ...
+ }
+ \endcode
+
+ You may use option-based declaration:
+ \code
+ #include <cds/container/michael_kvlist_hp.h> // MichaelKVList for gc::HP
+ #include <cds/container/michael_map.h> // MichaelHashMap
+
+ // Ordered list
+ typedef cds::container::MichaelKVList< cds::gc::HP, int, int,
+ typename cds::container::michael_list::make_traits<
+ cds::container::opt::less< std::less<int> > // item comparator option
+ >::type
+ > int2int_list;
+
+ // Map
+ typedef cds::container::MichaelHashMap< cds::gc::HP, int2int_list,
+ cds::container::michael_map::make_traits<
+ cc::opt::hash< cds::opt::v::hash<int> >
+ >
+ > int2int_map;
+ \endcode
+ */
+ template <
+ class GC,
+ class OrderedList,
+#ifdef CDS_DOXYGEN_INVOKED
+ class Traits = michael_map::traits
+#else
+ class Traits
+#endif
+ >
+ class MichaelHashMap
+ {
+ public:
+ typedef GC gc; ///< Garbage collector
+ typedef OrderedList ordered_list; ///< type of ordered list to be used as a bucket
+ typedef Traits traits; ///< Map traits
+
+ typedef typename ordered_list::key_type key_type; ///< key type
+ typedef typename ordered_list::mapped_type mapped_type; ///< value type
+ typedef typename ordered_list::value_type value_type; ///< key/value pair stored in the map
+ typedef typename traits::allocator allocator; ///< Bucket table allocator
+
+ typedef typename ordered_list::key_comparator key_comparator; ///< key compare functor
+#ifdef CDS_DOXYGEN_INVOKED
+ typedef typename ordered_list::stat stat; ///< Internal statistics
+ /// Guarded pointer - a result of \p get() and \p extract() functions
+ typedef typename ordered_list::guarded_ptr guarded_ptr;
+#endif
+
+ /// Hash functor for \ref key_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
+
+ // 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");
+
+ static constexpr const size_t c_nHazardPtrCount = ordered_list::c_nHazardPtrCount; ///< Count of hazard pointer required
+
+ //@cond
+ typedef typename ordered_list::template select_stat_wrapper< typename ordered_list::stat > bucket_stat;
+
+ 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;
+
+ typedef typename internal_bucket_type::guarded_ptr guarded_ptr;
+ typedef typename allocator::template rebind< internal_bucket_type >::other bucket_table_allocator;
+ typedef typename bucket_stat::stat stat;
+ //@endcond
+
+ protected:
+ //@cond
+ const size_t m_nHashBitmask;
+ internal_bucket_type* m_Buckets; ///< bucket table
+ hash m_HashFunctor; ///< Hash functor
+ item_counter m_ItemCounter; ///< Item counter
+ stat m_Stat; ///< Internal statistics
+ //@endcond
+
+ protected:
+ //@cond
+ /// Forward iterator
+ template <bool IsConst>
+ class iterator_type: protected cds::intrusive::michael_set::details::iterator< internal_bucket_type, IsConst >
+ {
+ typedef cds::intrusive::michael_set::details::iterator< internal_bucket_type, IsConst > base_class;
+ friend class MichaelHashMap;
+
+ protected:
+ typedef typename base_class::bucket_ptr bucket_ptr;
+ typedef typename base_class::list_iterator list_iterator;
+
+ public:
+ /// Value pointer type (const for const_iterator)
+ typedef typename cds::details::make_const_type<typename MichaelHashMap::mapped_type, IsConst>::pointer value_ptr;
+ /// Value reference type (const for const_iterator)
+ typedef typename cds::details::make_const_type<typename MichaelHashMap::mapped_type, IsConst>::reference value_ref;
+
+ /// Key-value pair pointer type (const for const_iterator)
+ typedef typename cds::details::make_const_type<typename MichaelHashMap::value_type, IsConst>::pointer pair_ptr;
+ /// Key-value pair reference type (const for const_iterator)
+ typedef typename cds::details::make_const_type<typename MichaelHashMap::value_type, IsConst>::reference pair_ref;
+
+ protected:
+ iterator_type( list_iterator const& it, bucket_ptr pFirst, bucket_ptr pLast )
+ : base_class( it, pFirst, pLast )
+ {}
+
+ public:
+ /// Default ctor
+ iterator_type()
+ : base_class()
+ {}
+
+ /// Copy ctor
+ iterator_type( const iterator_type& src )
+ : base_class( src )
+ {}
+
+ /// Dereference operator
+ pair_ptr operator ->() const
+ {
+ assert( base_class::m_pCurBucket != nullptr );
+ return base_class::m_itList.operator ->();
+ }
+
+ /// Dereference operator
+ pair_ref operator *() const
+ {
+ assert( base_class::m_pCurBucket != nullptr );
+ return base_class::m_itList.operator *();
+ }
+
+ /// Pre-increment
+ iterator_type& operator ++()
+ {
+ base_class::operator++();
+ return *this;
+ }
+
+ /// Assignment operator
+ iterator_type& operator = (const iterator_type& src)
+ {
+ base_class::operator =(src);
+ return *this;
+ }
+
+ /// Returns current bucket (debug function)
+ bucket_ptr bucket() const
+ {
+ return base_class::bucket();
+ }
+
+ /// Equality operator
+ template <bool C>
+ bool operator ==(iterator_type<C> const& i ) const
+ {
+ return base_class::operator ==( i );
+ }
+ /// Equality operator
+ template <bool C>
+ bool operator !=(iterator_type<C> const& i ) const
+ {
+ return !( *this == i );
+ }
+ };
+ //@endcond
+
+ public:
+ ///@name Forward iterators (only for debugging purpose)
+ //@{
+ /// Forward iterator
+ /**
+ The forward iterator for Michael's map has some features:
+ - it has no post-increment operator
+ - to protect the value, the iterator contains a GC-specific guard + another guard is required locally for increment operator.
+ For some GC (like as \p gc::HP), a guard is a limited resource per thread, so an exception (or assertion) "no free guard"
+ may be thrown if the limit of guard count per thread is exceeded.
+ - The iterator cannot be moved across thread boundary because it contains thread-private GC's guard.
+
+ Iterator thread safety depends on type of \p OrderedList:
+ - for \p MichaelKVList and \p LazyKVList: iterator guarantees safety even if you delete the item that iterator points to
+ because that item is guarded by hazard pointer.
+ However, in case of concurrent deleting operations it is no guarantee that you iterate all item in the map.
+ Moreover, a crash is possible when you try to iterate the next element that has been deleted by concurrent thread.
+ Use this iterator on the concurrent container for debugging purpose only.
+ - for \p IterableList: iterator is thread-safe. You may use it freely in concurrent environment.
+
+ 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
+
+ @note The iterator object returned by \p end(), \p cend() member functions points to \p nullptr and should not be dereferenced.
+ */
+ typedef iterator_type< false > iterator;
+
+ /// Const forward iterator
+ typedef iterator_type< true > const_iterator;
+
+ /// Returns a forward iterator addressing the first element in a map
+ /**
+ For empty map \code begin() == end() \endcode
+ */
+ iterator begin()
+ {
+ return iterator( bucket_begin()->begin(), bucket_begin(), bucket_end());
+ }
+
+ /// Returns an iterator that addresses the location succeeding the last element in a map
+ /**
+ Do not use the value returned by <tt>end</tt> function to access any item.
+ The returned value can be used only to control reaching the end of the map.
+ For empty map \code begin() == end() \endcode
+ */
+ iterator end()
+ {
+ return iterator( bucket_end()[-1].end(), bucket_end() - 1, bucket_end());
+ }
+
+ /// Returns a forward const iterator addressing the first element in a map
+ const_iterator begin() const
+ {
+ return get_const_begin();
+ }
+ /// Returns a forward const iterator addressing the first element in a map
+ const_iterator cbegin() const
+ {
+ return get_const_begin();
+ }
+
+ /// Returns an const iterator that addresses the location succeeding the last element in a map
+ const_iterator end() const
+ {
+ return get_const_end();
+ }
+ /// Returns an const iterator that addresses the location succeeding the last element in a map
+ const_iterator cend() const
+ {
+ return get_const_end();
+ }
+ //@}
+
+ public:
+ /// Initializes the map
+ /** @anchor cds_nonintrusive_MichaelHashMap_hp_ctor
+ The Michael's hash map 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>].
+ Note, that many popular STL hash map implementation uses load factor 1.
+
+ The ctor defines hash table size as rounding <tt>nMacItemCount / nLoadFactor</tt> up to nearest power of two.
+ */
+ MichaelHashMap(
+ size_t nMaxItemCount, ///< estimation of max item count in the hash map
+ size_t nLoadFactor ///< load factor: estimation of max number of items in the bucket
+ )
+ : m_nHashBitmask( michael_map::details::init_hash_bitmask( nMaxItemCount, nLoadFactor ))
+ , m_Buckets( bucket_table_allocator().allocate( bucket_count()))
+ {
+ for ( auto it = m_Buckets, itEnd = m_Buckets + bucket_count(); it != itEnd; ++it )
+ construct_bucket<bucket_stat>( it );
+ }
+
+ /// Clears hash map and destroys it
+ ~MichaelHashMap()
+ {
+ clear();
+
+ 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 with key and default value
+ /**
+ The function creates a node with \p key and default value, and then inserts the node created into the map.
+
+ Preconditions:
+ - The \p key_type should be constructible from value of type \p K.
+ In trivial case, \p K is equal to \p key_type.
+ - The \p mapped_type should be default-constructible.
+
+ Returns \p true if inserting successful, \p false otherwise.
+ */
+ template <typename K>
+ bool insert( K&& key )
+ {
+ const bool bRet = bucket( key ).insert( std::forward<K>( key ));
+ if ( bRet )
+ ++m_ItemCounter;
+ return bRet;
+ }
+
+ /// Inserts new node
+ /**
+ The function creates a node with copy of \p val value
+ and then inserts the node created into the map.
+
+ Preconditions:
+ - The \p key_type should be constructible from \p key of type \p K.
+ - The \p mapped_type should be constructible from \p val of type \p V.
+
+ Returns \p true if \p val is inserted into the map, \p false otherwise.
+ */
+ template <typename K, typename V>
+ bool insert( K&& key, V&& val )
+ {
+ const bool bRet = bucket( key ).insert( std::forward<K>( key ), std::forward<V>( val ));
+ if ( bRet )
+ ++m_ItemCounter;
+ return bRet;
+ }
+
+ /// Inserts new node and initialize it by a functor
+ /**
+ This function inserts new node with key \p key and if inserting is successful then it calls
+ \p func functor with signature
+ \code
+ struct functor {
+ void operator()( value_type& item );
+ };
+ \endcode
+
+ The argument \p item of user-defined functor \p func is the reference
+ to the map's item inserted:
+ - <tt>item.first</tt> is a const reference to item's key that cannot be changed.
+ - <tt>item.second</tt> is a reference to item's value that may be changed.
+
+ The user-defined functor is called only if inserting is successful.
+
+ The \p key_type should be constructible from value of type \p K.
+
+ The function allows to split creating of new item into two part:
+ - create item from \p key;
+ - insert new item into the map;
+ - if inserting is successful, initialize the value of item by calling \p func functor
+
+ This can be useful if complete initialization of object of \p mapped_type is heavyweight and
+ it is preferable that the initialization should be completed only if inserting is successful.
+
+ @warning For \ref cds_nonintrusive_MichaelKVList_gc "MichaelKVList" as the bucket see \ref cds_intrusive_item_creating "insert item troubleshooting".
+ \ref cds_nonintrusive_LazyKVList_gc "LazyKVList" provides exclusive access to inserted item and does not require any node-level
+ synchronization.
+ */
+ template <typename K, typename Func>
+ bool insert_with( K&& key, Func func )
+ {
+ const bool bRet = bucket( key ).insert_with( std::forward<K>( key ), func );
+ if ( bRet )
+ ++m_ItemCounter;
+ return bRet;
+ }
+
+ /// Updates data by \p key
+ /**
+ The operation performs inserting or replacing the element with lock-free manner.
+
+ If the \p key not found in the map, then the new item created from \p key
+ will be inserted into the map iff \p bAllowInsert is \p true.
+ (note that in this case the \ref key_type should be constructible from type \p K).
+ Otherwise, if \p key is found, the functor \p func is called with item found.
+
+ The functor \p func signature depends on \p OrderedList:
+
+ <b>for \p MichaelKVList, \p LazyKVList</b>
+ \code
+ struct my_functor {
+ void operator()( bool bNew, value_type& item );
+ };
+ \endcode
+ with arguments:
+ - \p bNew - \p true if the item has been inserted, \p false otherwise
+ - \p item - the item found or inserted
+
+ The functor may change any fields of the \p item.second that is \p mapped_type.
+
+ <b>for \p IterableKVList</b>
+ \code
+ void func( value_type& val, value_type * old );
+ \endcode
+ where
+ - \p val - a new data constructed from \p key
+ - \p old - old value that will be retired. If new item has been inserted then \p old is \p nullptr.
+
+ The functor may change non-key fields of \p val; however, \p func must guarantee
+ that during changing no any other modifications could be made on this item by concurrent threads.
+
+ @return <tt> std::pair<bool, bool> </tt> where \p first is true if operation is successful,
+ \p second is true if new item has been added or \p false if the item with \p key
+ already exists.
+
+ @warning For \ref cds_nonintrusive_MichaelKVList_gc "MichaelKVList" and \ref cds_nonintrusive_IterableKVList_gc "IterableKVList"
+ as the bucket see \ref cds_intrusive_item_creating "insert item troubleshooting".
+ \ref cds_nonintrusive_LazyKVList_gc "LazyKVList" provides exclusive access to inserted item and does not require any node-level
+ synchronization.
+ */
+ template <typename K, typename Func >
+ std::pair<bool, bool> update( K&& key, Func func, bool bAllowInsert = true )
+ {
+ std::pair<bool, bool> bRet = bucket( key ).update( std::forward<K>( key ), func, bAllowInsert );
+ if ( bRet.first && bRet.second )
+ ++m_ItemCounter;
+ return bRet;
+ }
+ //@cond
+ template <typename K, typename Func>
+ CDS_DEPRECATED("ensure() is deprecated, use update()")
+ std::pair<bool, bool> ensure( K const& key, Func func )
+ {
+ std::pair<bool, bool> bRet = bucket( key ).update( key, func, true );
+ if ( bRet.first && bRet.second )
+ ++m_ItemCounter;
+ return bRet;
+ }
+ //@endcond
+
+ /// Inserts or updates the node (only for \p IterableKVList)
+ /**
+ The operation performs inserting or changing data with lock-free manner.
+
+ If \p key is not found in the map, then \p key is inserted iff \p bAllowInsert is \p true.
+ Otherwise, the current element is changed to \p val, the old element will be retired later.
+
+ Returns std::pair<bool, bool> where \p first is \p true if operation is successful,
+ \p second is \p true if \p val has been added or \p false if the item with that key
+ already in the map.
+ */
+ template <typename Q, typename V>
+#ifdef CDS_DOXYGEN_INVOKED
+ std::pair<bool, bool>
+#else
+ typename std::enable_if<
+ std::is_same< Q, Q>::value && is_iterable_list< ordered_list >::value,
+ std::pair<bool, bool>
+ >::type
+#endif
+ upsert( Q&& key, V&& val, bool bAllowInsert = true )
+ {
+ std::pair<bool, bool> bRet = bucket( val ).upsert( std::forward<Q>( key ), std::forward<V>( val ), bAllowInsert );
+ if ( bRet.second )
+ ++m_ItemCounter;
+ return bRet;
+ }
+
+ /// For key \p key inserts data of type \p mapped_type created from \p args
+ /**
+ \p key_type should be constructible from type \p K
+
+ Returns \p true if inserting successful, \p false otherwise.
+ */
+ template <typename K, typename... Args>
+ bool emplace( K&& key, Args&&... args )
+ {
+ const bool bRet = bucket( key ).emplace( std::forward<K>(key), std::forward<Args>(args)... );
+ if ( bRet )
+ ++m_ItemCounter;
+ return bRet;
+ }
+
+ /// Deletes \p key from the map
+ /** \anchor cds_nonintrusive_MichaelMap_erase_val
+
+ Return \p true if \p key is found and deleted, \p false otherwise
+ */
+ template <typename K>
+ bool erase( K const& key )
+ {
+ const bool bRet = bucket( key ).erase( key );
+ if ( bRet )
+ --m_ItemCounter;
+ return bRet;
+ }
+
+ /// Deletes the item from the map using \p pred predicate for searching
+ /**
+ The function is an analog of \ref cds_nonintrusive_MichaelMap_erase_val "erase(K const&)"
+ 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 map.
+ */
+ template <typename K, typename Less>
+ bool erase_with( K const& key, Less pred )
+ {
+ const bool bRet = bucket( key ).erase_with( key, pred );
+ if ( bRet )
+ --m_ItemCounter;
+ return bRet;
+ }
+
+ /// Deletes \p key from the map
+ /** \anchor cds_nonintrusive_MichaelMap_erase_func
+
+ The function searches an item with key \p key, calls \p f functor
+ and deletes the item. If \p key is not found, the functor is not called.
+
+ The functor \p Func interface:
+ \code
+ struct extractor {
+ void operator()(value_type& item) { ... }
+ };
+ \endcode
+
+ Return \p true if key is found and deleted, \p false otherwise
+ */
+ template <typename K, typename Func>
+ bool erase( K const& key, Func f )
+ {
+ const bool bRet = bucket( key ).erase( key, f );
+ if ( bRet )
+ --m_ItemCounter;
+ return bRet;
+ }
+
+ /// Deletes the item from the map using \p pred predicate for searching
+ /**
+ The function is an analog of \ref cds_nonintrusive_MichaelMap_erase_func "erase(K const&, Func)"
+ 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 map.
+ */
+ template <typename K, typename Less, typename Func>
+ bool erase_with( K const& key, Less pred, Func f )
+ {
+ const bool bRet = bucket( key ).erase_with( key, pred, f );
+ if ( bRet )
+ --m_ItemCounter;
+ return bRet;
+ }
+
+ /// Deletes the item pointed by iterator \p iter (only for \p IterableList based map)
+ /**
+ 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 %MichaelHashMap 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_nonintrusive_MichaelHashMap_hp_extract
+ The function searches an item with key equal to \p key,
+ unlinks it from the map, and returns it as \p guarded_ptr.
+ If \p key is not found the function returns an empty guarded pointer.
+
+ Note the compare functor should accept a parameter of type \p K that may be not the same as \p key_type.
+
+ The extracted item is freed automatically when returned \p guarded_ptr object will be destroyed or released.
+ @note Each \p guarded_ptr object uses the GC's guard that can be limited resource.
+
+ Usage:
+ \code
+ typedef cds::container::MichaelHashMap< your_template_args > michael_map;
+ michael_map theMap;
+ // ...
+ {
+ michael_map::guarded_ptr gp( theMap.extract( 5 ));
+ if ( gp ) {
+ // Deal with gp
+ // ...
+ }
+ // Destructor of gp releases internal HP guard
+ }
+ \endcode
+ */
+ template <typename K>
+ guarded_ptr extract( K const& key )
+ {
+ guarded_ptr gp( bucket( key ).extract( key ));
+ if ( gp )
+ --m_ItemCounter;
+ return gp;
+ }
+
+ /// Extracts the item using compare functor \p pred
+ /**
+ The function is an analog of \ref cds_nonintrusive_MichaelHashMap_hp_extract "extract(K const&)"
+ but \p pred predicate is used for key comparing.
+
+ \p Less functor has the semantics like \p std::less but should take arguments of type \p key_type and \p K
+ in any order.
+ \p pred must imply the same element order as the comparator used for building the map.
+ */
+ template <typename K, typename Less>
+ guarded_ptr extract_with( K const& key, Less pred )
+ {
+ guarded_ptr gp( bucket( key ).extract_with( key, pred ));
+ if ( gp )
+ --m_ItemCounter;
+ return gp;
+ }
+
+ /// Finds the key \p key
+ /** \anchor cds_nonintrusive_MichaelMap_find_cfunc
+
+ 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 );
+ };
+ \endcode
+ where \p item is the item found.
+
+ The functor may change \p item.second. Note that the functor is only guarantee
+ that \p item cannot be disposed during functor is executing.
+ The functor does not serialize simultaneous access to the map's \p item. If such access is
+ possible you must provide your own synchronization schema on item level to exclude unsafe item modifications.
+
+ The function returns \p true if \p key is found, \p false otherwise.
+ */
+ template <typename K, typename Func>
+ bool find( K const& key, Func f )
+ {
+ return bucket( key ).find( key, f );
+ }
+
+ /// Finds \p key and returns iterator pointed to the item found (only for \p IterableList)
+ /**
+ If \p key is not found the function returns \p end().
+
+ @note This function is supported only for map based on \p IterableList
+ */
+ template <typename K>
+#ifdef CDS_DOXYGEN_INVOKED
+ iterator
+#else
+ typename std::enable_if< std::is_same<K,K>::value && is_iterable_list< ordered_list >::value, iterator >::type
+#endif
+ find( K const& key )
+ {
+ auto& b = bucket( key );
+ auto it = b.find( key );
+ if ( it == b.end())
+ return end();
+ return iterator( it, &b, bucket_end());
+ }
+
+
+ /// Finds the key \p val using \p pred predicate for searching
+ /**
+ The function is an analog of \ref cds_nonintrusive_MichaelMap_find_cfunc "find(K const&, Func)"
+ 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 map.
+ */
+ template <typename K, typename Less, typename Func>
+ bool find_with( K const& key, Less pred, Func f )
+ {
+ return bucket( key ).find_with( key, pred, f );
+ }
+
+ /// Finds \p key using \p pred predicate and returns iterator pointed to the item found (only for \p IterableList)
+ /**
+ The function is an analog of \p find(K&) 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.
+
+ If \p key is not found the function returns \p end().
+
+ @note This function is supported only for map based on \p IterableList
+ */
+ template <typename K, typename Less>
+#ifdef CDS_DOXYGEN_INVOKED
+ iterator
+#else
+ typename std::enable_if< std::is_same<K, K>::value && is_iterable_list< ordered_list >::value, iterator >::type
+#endif
+ find_with( K const& key, Less pred )
+ {
+ auto& b = bucket( key );
+ auto it = b.find_with( key, pred );
+ if ( it == b.end())
+ return end();
+ return iterator( it, &b, bucket_end());
+ }
+
+ /// Checks whether the map 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 K>
+ bool contains( K const& key )
+ {
+ return bucket( key ).contains( key );
+ }
+
+ /// Checks whether the map contains \p key using \p pred predicate for searching
+ /**
+ 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 map.
+ */
+ template <typename K, typename Less>
+ bool contains( K const& key, Less pred )
+ {
+ return bucket( key ).contains( key, pred );
+ }
+
+ /// Finds \p key and return the item found
+ /** \anchor cds_nonintrusive_MichaelHashMap_hp_get
+ The function searches the item with key equal to \p key
+ and returns the guarded pointer to the item found.
+ If \p key is not found the function returns an empty guarded pointer,
+
+ @note Each \p guarded_ptr object uses one GC's guard which can be limited resource.
+
+ Usage:
+ \code
+ typedef cds::container::MichaeHashMap< your_template_params > michael_map;
+ michael_map theMap;
+ // ...
+ {
+ michael_map::guarded_ptr gp( theMap.get( 5 ));
+ if ( gp ) {
+ // Deal with gp
+ //...
+ }
+ // Destructor of guarded_ptr releases internal HP guard
+ }
+ \endcode
+
+ Note the compare functor specified for \p OrderedList template parameter
+ should accept a parameter of type \p K that can be not the same as \p key_type.
+ */
+ template <typename K>
+ guarded_ptr get( K const& key )
+ {
+ return bucket( key ).get( key );
+ }
+
+ /// Finds \p key and return the item found
+ /**
+ The function is an analog of \ref cds_nonintrusive_MichaelHashMap_hp_get "get( K const&)"
+ but \p pred is used for comparing the keys.
+
+ \p Less functor has the semantics like \p std::less but should take arguments of type \p key_type and \p K
+ in any order.
+ \p pred must imply the same element order as the comparator used for building the map.
+ */
+ template <typename K, typename Less>
+ guarded_ptr get_with( K const& key, Less pred )
+ {
+ return bucket( key ).get_with( key, pred );
+ }
+
+ /// Clears the map (not atomic)
+ void clear()
+ {
+ for ( size_t i = 0; i < bucket_count(); ++i )
+ m_Buckets[i].clear();
+ m_ItemCounter.reset();
+ }
+
+ /// Checks if the map is empty
+ /**
+ @warning If you use \p atomicity::empty_item_counter in \p traits::item_counter,
+ the function always returns \p true.
+ */
+ bool empty() const
+ {
+ return size() == 0;
+ }
+
+ /// Returns item count in the map
+ /**
+ 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 \p %MichaelHashMap cannot dynamically extend the hash table size,
+ the value returned is an constant depending on object initialization parameters;
+ see \p MichaelHashMap::MichaelHashMap for explanation.
+ */
+ size_t bucket_count() const
+ {
+ return m_nHashBitmask + 1;
+ }
+
+ /// Returns const reference to internal statistics
+ stat const& statistics() const
+ {
+ return m_Stat;
+ }
+
+ protected:
+ //@cond
+ /// Calculates hash value of \p key
+ template <typename Q>
+ size_t hash_value( Q const& key ) const
+ {
+ return m_HashFunctor( key ) & m_nHashBitmask;
+ }
+
+ /// Returns the bucket (ordered list) for \p key
+ template <typename Q>
+ internal_bucket_type& bucket( Q const& key )
+ {
+ return m_Buckets[hash_value( key )];
+ }
+ //@endcond
+
+ private:
+ //@cond
+ internal_bucket_type* bucket_begin() const
+ {
+ return m_Buckets;
+ }
+
+ internal_bucket_type* bucket_end() const
+ {
+ return m_Buckets + bucket_count();
+ }
+
+ const_iterator get_const_begin() const
+ {
+ return const_iterator( bucket_begin()->cbegin(), bucket_begin(), bucket_end());
+ }
+ const_iterator get_const_end() const
+ {
+ return const_iterator( (bucket_end() - 1)->cend(), bucket_end() - 1, bucket_end());
+ }
+
+ 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::container
+
+#endif // ifndef CDSLIB_CONTAINER_MICHAEL_MAP_H
projects / c11concurrency-benchmarks.git / blobdiff