--- /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_INTRUSIVE_MICHAEL_SET_H
+#define CDSLIB_INTRUSIVE_MICHAEL_SET_H
+
+#include <cds/intrusive/details/michael_set_base.h>
+#include <cds/intrusive/details/iterable_list_base.h>
+
+namespace cds { namespace intrusive {
+
+ /// Michael's hash set
+ /** @ingroup cds_intrusive_map
+ \anchor cds_intrusive_MichaelHashSet_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. Note the \p GC must be the same as the GC used for \p OrderedList
+ - \p OrderedList - ordered list implementation used as bucket for hash set, possible implementations:
+ \p MichaelList, \p LazyList, \p IterableList.
+ The intrusive ordered list implementation specifies the type \p T stored in the hash-set, the reclamation
+ schema \p GC used by hash-set, the comparison functor for the type \p T and other features specific for
+ the ordered list.
+ - \p Traits - type traits. See \p michael_set::traits for explanation.
+ Instead of defining \p Traits struct you can use option-based syntax with \p michael_set::make_traits metafunction.
+
+ There are several specializations of \p %MichaelHashSet for each GC. You should include:
+ - <tt><cds/intrusive/michael_set_rcu.h></tt> for \ref cds_intrusive_MichaelHashSet_rcu "RCU type"
+ - <tt><cds/intrusive/michael_set_nogc.h></tt> for \ref cds_intrusive_MichaelHashSet_nogc for append-only set
+ - <tt><cds/intrusive/michael_set.h></tt> for \p gc::HP, \p gc::DHP
+
+ <b>Hash functor</b>
+
+ Some member functions of Michael's hash set accept the key parameter of type \p Q which differs from \p value_type.
+ It is expected that type \p Q contains full key of \p value_type, and for equal keys of type \p Q and \p value_type
+ the hash values of these keys must be equal.
+ The hash functor \p Traits::hash should accept parameters of both type:
+ \code
+ // Our node type
+ struct Foo {
+ std::string key_; // key field
+ // ... other fields
+ };
+
+ // Hash functor
+ struct fooHash {
+ size_t operator()( const std::string& s ) const
+ {
+ return std::hash( s );
+ }
+
+ size_t operator()( const Foo& f ) const
+ {
+ return (*this)( f.key_ );
+ }
+ };
+ \endcode
+
+ <b>How to use</b>
+
+ First, you should define ordered list type to use in your hash set:
+ \code
+ // For gc::HP-based MichaelList implementation
+ #include <cds/intrusive/michael_list_hp.h>
+
+ // cds::intrusive::MichaelHashSet declaration
+ #include <cds/intrusive/michael_set.h>
+
+ // Type of hash-set items
+ struct Foo: public cds::intrusive::michael_list::node< cds::gc::HP >
+ {
+ std::string key_ ; // key field
+ unsigned val_ ; // value field
+ // ... other value fields
+ };
+
+ // Declare comparator for the item
+ struct FooCmp
+ {
+ int operator()( const Foo& f1, const Foo& f2 ) const
+ {
+ return f1.key_.compare( f2.key_ );
+ }
+ };
+
+ // Declare bucket type for Michael's hash set
+ // The bucket type is any ordered list type like MichaelList, LazyList
+ typedef cds::intrusive::MichaelList< cds::gc::HP, Foo,
+ typename cds::intrusive::michael_list::make_traits<
+ // hook option
+ cds::intrusive::opt::hook< cds::intrusive::michael_list::base_hook< cds::opt::gc< cds::gc::HP > > >
+ // item comparator option
+ ,cds::opt::compare< FooCmp >
+ >::type
+ > Foo_bucket;
+ \endcode
+
+ Second, you should declare Michael's hash set container:
+ \code
+
+ // Declare hash functor
+ // Note, the hash functor accepts parameter type Foo and std::string
+ struct FooHash {
+ size_t operator()( const Foo& f ) const
+ {
+ return cds::opt::v::hash<std::string>()( f.key_ );
+ }
+ size_t operator()( const std::string& f ) const
+ {
+ return cds::opt::v::hash<std::string>()( f );
+ }
+ };
+
+ // Michael's set typedef
+ typedef cds::intrusive::MichaelHashSet<
+ cds::gc::HP
+ ,Foo_bucket
+ ,typename cds::intrusive::michael_set::make_traits<
+ cds::opt::hash< FooHash >
+ >::type
+ > Foo_set;
+ \endcode
+
+ Now, you can use \p Foo_set in your application.
+
+ Like other intrusive containers, you may build several containers on single item structure:
+ \code
+ #include <cds/intrusive/michael_list_hp.h>
+ #include <cds/intrusive/michael_list_dhp.h>
+ #include <cds/intrusive/michael_set.h>
+
+ struct tag_key1_idx;
+ struct tag_key2_idx;
+
+ // Your two-key data
+ // The first key is maintained by gc::HP, second key is maintained by gc::DHP garbage collectors
+ // (I don't know what is needed for, but it is correct)
+ struct Foo
+ : public cds::intrusive::michael_list::node< cds::gc::HP, tag_key1_idx >
+ , public cds::intrusive::michael_list::node< cds::gc::DHP, tag_key2_idx >
+ {
+ std::string key1_ ; // first key field
+ unsigned int key2_ ; // second key field
+
+ // ... value fields and fields for controlling item's lifetime
+ };
+
+ // Declare comparators for the item
+ struct Key1Cmp
+ {
+ int operator()( const Foo& f1, const Foo& f2 ) const { return f1.key1_.compare( f2.key1_ ) ; }
+ };
+ struct Key2Less
+ {
+ bool operator()( const Foo& f1, const Foo& f2 ) const { return f1.key2_ < f2.key1_ ; }
+ };
+
+ // Declare bucket type for Michael's hash set indexed by key1_ field and maintained by gc::HP
+ typedef cds::intrusive::MichaelList< cds::gc::HP, Foo,
+ typename cds::intrusive::michael_list::make_traits<
+ // hook option
+ cds::intrusive::opt::hook< cds::intrusive::michael_list::base_hook< cds::opt::gc< cds::gc::HP >, tag_key1_idx > >
+ // item comparator option
+ ,cds::opt::compare< Key1Cmp >
+ >::type
+ > Key1_bucket;
+
+ // Declare bucket type for Michael's hash set indexed by key2_ field and maintained by gc::DHP
+ typedef cds::intrusive::MichaelList< cds::gc::DHP, Foo,
+ typename cds::intrusive::michael_list::make_traits<
+ // hook option
+ cds::intrusive::opt::hook< cds::intrusive::michael_list::base_hook< cds::opt::gc< cds::gc::DHP >, tag_key2_idx > >
+ // item comparator option
+ ,cds::opt::less< Key2Less >
+ >::type
+ > Key2_bucket;
+
+ // Declare hash functor
+ struct Key1Hash {
+ size_t operator()( const Foo& f ) const { return cds::opt::v::hash<std::string>()( f.key1_ ) ; }
+ size_t operator()( const std::string& s ) const { return cds::opt::v::hash<std::string>()( s ) ; }
+ };
+ inline size_t Key2Hash( const Foo& f ) { return (size_t) f.key2_ ; }
+
+ // Michael's set indexed by key1_ field
+ typedef cds::intrusive::MichaelHashSet<
+ cds::gc::HP
+ ,Key1_bucket
+ ,typename cds::intrusive::michael_set::make_traits<
+ cds::opt::hash< Key1Hash >
+ >::type
+ > key1_set;
+
+ // Michael's set indexed by key2_ field
+ typedef cds::intrusive::MichaelHashSet<
+ cds::gc::DHP
+ ,Key2_bucket
+ ,typename cds::intrusive::michael_set::make_traits<
+ cds::opt::hash< Key2Hash >
+ >::type
+ > key2_set;
+ \endcode
+ */
+ template <
+ class GC,
+ class OrderedList,
+#ifdef CDS_DOXYGEN_INVOKED
+ class Traits = michael_set::traits
+#else
+ class Traits
+#endif
+ >
+ class MichaelHashSet
+ {
+ public:
+ typedef GC gc; ///< Garbage collector
+ typedef OrderedList ordered_list; ///< type of ordered list used as a bucket implementation
+ typedef Traits traits; ///< Set traits
+
+ 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 \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
+
+ typedef typename ordered_list::guarded_ptr guarded_ptr; ///< Guarded pointer
+
+ /// Count of hazard pointer required for the algorithm
+ static constexpr const size_t c_nHazardPtrCount = ordered_list::c_nHazardPtrCount;
+
+ // 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:
+ //@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 allocator::template rebind< internal_bucket_type >::other bucket_table_allocator;
+ //@endcond
+
+ public:
+ //@cond
+ typedef typename bucket_stat::stat stat;
+ //@endcond
+
+ protected:
+ //@cond
+ hash m_HashFunctor; ///< Hash functor
+ size_t const m_nHashBitmask;
+ internal_bucket_type* m_Buckets; ///< bucket table
+ item_counter m_ItemCounter; ///< Item counter
+ 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 cannot be moved across thread boundary because it may contain GC's guard that is thread-private GC data.
+
+ Iterator thread safety depends on type of \p OrderedList:
+ - for \p MichaelList and \p LazyList: 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 set.
+ 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.
+ */
+ 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< internal_bucket_type, true > const_iterator;
+
+ /// Returns a forward iterator addressing the first element in a set
+ /**
+ For empty set \code begin() == end() \endcode
+ */
+ iterator begin()
+ {
+ return iterator( m_Buckets[0].begin(), bucket_begin(), bucket_end());
+ }
+
+ /// Returns an iterator that addresses the location succeeding the last element in a set
+ /**
+ 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 set.
+ For empty set \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 set
+ const_iterator begin() const
+ {
+ return get_const_begin();
+ }
+
+ /// 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();
+ }
+
+ /// Returns an const iterator that addresses the location succeeding the last element in a set
+ const_iterator cend() const
+ {
+ return get_const_end();
+ }
+ //@}
+
+ public:
+ /// Initializes hash set
+ /**
+ 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. Small integer up to 10.
+ ) : m_nHashBitmask( michael_set::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 set object and destroys it
+ ~MichaelHashSet()
+ {
+ 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
+ /**
+ The function inserts \p val in the set if it does not contain
+ an item with key equal to \p val.
+
+ Returns \p true if \p val is placed into the set, \p false otherwise.
+ */
+ bool insert( value_type& val )
+ {
+ bool bRet = bucket( val ).insert( val );
+ if ( bRet )
+ ++m_ItemCounter;
+ return bRet;
+ }
+
+ /// Inserts new node
+ /**
+ This function is intended for derived non-intrusive containers.
+
+ The function allows to split creating of new item into two part:
+ - create item with key only
+ - insert new item into the set
+ - if inserting is success, calls \p f functor to initialize value-field of \p val.
+
+ The functor signature is:
+ \code
+ void func( value_type& val );
+ \endcode
+ where \p val is the item inserted.
+
+ The user-defined functor is called only if the inserting is success.
+
+ @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>
+ bool insert( value_type& val, Func f )
+ {
+ bool bRet = bucket( val ).insert( val, f );
+ if ( bRet )
+ ++m_ItemCounter;
+ return bRet;
+ }
+
+ /// 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 iff \p bAllowInsert is \p true.
+ Otherwise, the functor \p func is called with item found.
+
+ The functor signature depends of the type of \p OrderedList:
+
+ <b>for \p MichaelList, \p LazyList</b>
+ \code
+ 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 %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 may change non-key fields of the \p item.
+ @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.
+
+ <b>for \p IterableList</b>
+ \code
+ void func( value_type& val, value_type * old );
+ \endcode
+ where
+ - \p val - argument \p val passed into the \p %update() function
+ - \p old - old value that will be retired. If new item has been inserted then \p old is \p nullptr.
+
+ 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.
+ */
+ template <typename Func>
+ std::pair<bool, bool> update( value_type& val, Func func, bool bAllowInsert = true )
+ {
+ 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
+
+ /// Inserts or updates the node (only for \p IterableList)
+ /**
+ The operation performs inserting or changing data with lock-free manner.
+
+ If the item \p val is not found in the set, then \p val is inserted iff \p bAllowInsert is \p true.
+ Otherwise, the current element is changed to \p val, the old element will be retired later
+ by call \p Traits::disposer.
+
+ 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 set.
+ */
+#ifdef CDS_DOXYGEN_INVOKED
+ std::pair<bool, bool> upsert( value_type& val, bool bAllowInsert = true )
+#else
+ template <typename Q>
+ typename std::enable_if<
+ std::is_same< Q, value_type>::value && is_iterable_list< ordered_list >::value,
+ std::pair<bool, bool>
+ >::type
+ upsert( Q& val, bool bAllowInsert = true )
+#endif
+ {
+ std::pair<bool, bool> bRet = bucket( val ).upsert( val, bAllowInsert );
+ if ( bRet.second )
+ ++m_ItemCounter;
+ return bRet;
+ }
+
+ /// Unlinks the item \p val from the set
+ /**
+ The function searches the item \p val in the set and unlink it
+ if it is found and is equal to \p val.
+
+ The function returns \p true if success and \p false otherwise.
+ */
+ bool unlink( value_type& val )
+ {
+ bool bRet = bucket( val ).unlink( val );
+ if ( bRet )
+ --m_ItemCounter;
+ return bRet;
+ }
+
+ /// Deletes the item from the set
+ /** \anchor cds_intrusive_MichaelHashSet_hp_erase
+ The function searches an item with key equal to \p key in the set,
+ unlinks it, and returns \p true.
+ If the item with key equal to \p key is not found the function return \p false.
+
+ Note the hash functor should accept a parameter of type \p Q that can be not the same as \p value_type.
+ */
+ template <typename Q>
+ bool erase( Q const& key )
+ {
+ if ( bucket( key ).erase( key )) {
+ --m_ItemCounter;
+ return true;
+ }
+ return false;
+ }
+
+ /// Deletes the item from the set using \p pred predicate for searching
+ /**
+ The function is an analog of \ref cds_intrusive_MichaelHashSet_hp_erase "erase(Q const&)"
+ 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.
+ */
+ template <typename Q, typename Less>
+ bool erase_with( Q const& key, Less pred )
+ {
+ if ( bucket( key ).erase_with( key, pred )) {
+ --m_ItemCounter;
+ return true;
+ }
+ return false;
+ }
+
+ /// Deletes the item from the set
+ /** \anchor cds_intrusive_MichaelHashSet_hp_erase_func
+ The function searches an item with key equal to \p key in the set,
+ call \p f functor with item found, and unlinks it from the set.
+ The \ref disposer specified in \p OrderedList class template parameter is called
+ by garbage collector \p GC asynchronously.
+
+ The \p Func interface is
+ \code
+ struct functor {
+ void operator()( value_type const& item );
+ };
+ \endcode
+
+ If the item with key equal to \p key is not found the function return \p false.
+
+ Note the hash functor should accept a parameter of type \p Q that can be not the same as \p value_type.
+ */
+ template <typename Q, typename Func>
+ bool erase( Q const& key, Func f )
+ {
+ if ( bucket( key ).erase( key, f )) {
+ --m_ItemCounter;
+ return true;
+ }
+ return false;
+ }
+
+ /// Deletes the item from the set using \p pred predicate for searching
+ /**
+ The function is an analog of \ref cds_intrusive_MichaelHashSet_hp_erase_func "erase(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.
+ */
+ template <typename Q, typename Less, typename Func>
+ bool erase_with( Q const& key, Less pred, Func f )
+ {
+ if ( bucket( key ).erase_with( key, pred, f )) {
+ --m_ItemCounter;
+ return true;
+ }
+ 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,
+ unlinks it from the set, and returns an guarded pointer to the item extracted.
+ If \p key is not found the function returns an empty guarded pointer.
+
+ Note the compare functor should accept a parameter of type \p Q that may be not the same as \p value_type.
+
+ The \p disposer specified in \p OrderedList class' template parameter is called automatically
+ by garbage collector \p GC when returned \ref 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::intrusive::MichaelHashSet< your_template_args > michael_set;
+ michael_set theSet;
+ // ...
+ {
+ michael_set::guarded_ptr gp( theSet.extract( 5 ));
+ if ( gp ) {
+ // Deal with gp
+ // ...
+ }
+ // Destructor of gp releases internal HP guard
+ }
+ \endcode
+ */
+ template <typename Q>
+ guarded_ptr extract( Q 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_intrusive_MichaelHashSet_hp_extract "extract(Q 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 \ref value_type and \p Q
+ in any order.
+ \p pred must imply the same element order as the comparator used for building the list.
+ */
+ template <typename Q, typename Less>
+ guarded_ptr extract_with( Q 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_intrusive_MichaelHashSet_hp_find_func
+ 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& key );
+ };
+ \endcode
+ where \p item is the item found, \p key is the <tt>find</tt> function argument.
+
+ The functor may change non-key fields of \p item. 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 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 key argument is non-const since it can be used as \p f functor destination i.e., the functor
+ may 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 key is found, \p false otherwise.
+ */
+ template <typename Q, typename Func>
+ 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( key ).find( key, f );
+ }
+ //@endcond
+
+ /// 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 the set based on \p IterableList
+ */
+ template <typename Q>
+#ifdef CDS_DOXYGEN_INVOKED
+ iterator
+#else
+ typename std::enable_if< std::is_same<Q,Q>::value && is_iterable_list< ordered_list >::value, iterator >::type
+#endif
+ find( Q& key )
+ {
+ internal_bucket_type& b = bucket( key );
+ typename internal_bucket_type::iterator it = b.find( key );
+ if ( it == b.end())
+ return end();
+ return iterator( it, &b, bucket_end());
+ }
+ //@cond
+ template <typename Q>
+ typename std::enable_if< std::is_same<Q, Q>::value && is_iterable_list< ordered_list >::value, iterator >::type
+ find( Q const& key )
+ {
+ internal_bucket_type& b = bucket( key );
+ typename internal_bucket_type::iterator it = b.find( key );
+ if ( it == b.end())
+ return end();
+ return iterator( it, &b, bucket_end());
+ }
+ //@endcond
+
+
+ /// Finds the key \p key using \p pred predicate for searching
+ /**
+ The function is an analog of \ref cds_intrusive_MichaelHashSet_hp_find_func "find(Q&, 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.
+ */
+ template <typename Q, typename Less, typename Func>
+ bool find_with( Q& key, Less pred, Func f )
+ {
+ return bucket( key ).find_with( key, pred, f );
+ }
+ //@cond
+ template <typename Q, typename Less, typename Func>
+ bool find_with( Q const& key, Less pred, Func f )
+ {
+ return bucket( key ).find_with( key, pred, f );
+ }
+ //@endcond
+
+ /// 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(Q&) 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 the set based on \p IterableList
+ */
+ template <typename Q, typename Less>
+#ifdef CDS_DOXYGEN_INVOKED
+ iterator
+#else
+ typename std::enable_if< std::is_same<Q, Q>::value && is_iterable_list< ordered_list >::value, iterator >::type
+#endif
+ find_with( Q& key, Less pred )
+ {
+ internal_bucket_type& b = bucket( key );
+ typename internal_bucket_type::iterator it = b.find_with( key, pred );
+ if ( it == b.end())
+ return end();
+ return iterator( it, &b, bucket_end());
+ }
+ //@cond
+ template <typename Q, typename Less>
+ typename std::enable_if< std::is_same<Q, Q>::value && is_iterable_list< ordered_list >::value, iterator >::type
+ find_with( Q const& key, Less pred )
+ {
+ internal_bucket_type& b = bucket( key );
+ typename internal_bucket_type::iterator it = b.find_with( key, pred );
+ if ( it == b.end())
+ return end();
+ return iterator( it, &b, bucket_end());
+ }
+ //@endcond
+
+ /// Checks whether the set contains \p key
+ /**
+
+ The function searches the item with key equal to \p key
+ and returns \p true if the key is found, and \p false 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>
+ bool contains( Q const& key )
+ {
+ return bucket( key ).contains( key );
+ }
+
+ /// Checks whether the set 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 set.
+ */
+ template <typename Q, typename Less>
+ bool contains( Q const& key, Less pred )
+ {
+ return bucket( key ).contains( key, pred );
+ }
+
+ /// Finds the key \p key and return the item found
+ /** \anchor cds_intrusive_MichaelHashSet_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 \p guarded_ptr.
+
+ @note Each \p guarded_ptr object uses one GC's guard which can be limited resource.
+
+ Usage:
+ \code
+ typedef cds::intrusive::MichaelHashSet< your_template_params > michael_set;
+ michael_set theSet;
+ // ...
+ {
+ michael_set::guarded_ptr gp( theSet.get( 5 ));
+ if ( theSet.get( 5 )) {
+ // 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 Q that can be not the same as \p value_type.
+ */
+ template <typename Q>
+ guarded_ptr get( Q const& key )
+ {
+ return bucket( key ).get( key );
+ }
+
+ /// Finds the key \p key and return the item found
+ /**
+ The function is an analog of \ref cds_intrusive_MichaelHashSet_hp_get "get( Q 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 \ref value_type and \p Q
+ in any order.
+ \p pred must imply the same element order as the comparator used for building the set.
+ */
+ template <typename Q, typename Less>
+ guarded_ptr get_with( Q const& key, Less pred )
+ {
+ return bucket( key ).get_with( key, pred );
+ }
+
+ /// 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:
+ \p empty() may return \p true but the set may contain item(s).
+ Therefore, \p %clear() may be used only for debugging purposes.
+
+ For each item the \p disposer is called after unlinking.
+ */
+ void clear()
+ {
+ for ( size_t i = 0; i < bucket_count(); ++i )
+ m_Buckets[i].clear();
+ m_ItemCounter.reset();
+ }
+
+ /// Checks if the set 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 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 const reference to internal statistics
+ stat const& statistics() const
+ {
+ return m_Stat;
+ }
+
+ /// Returns the size of hash table
+ /**
+ Since \p %MichaelHashSet cannot dynamically extend the hash table size,
+ the value returned is an constant depending on object initialization parameters,
+ see \p MichaelHashSet::MichaelHashSet.
+ */
+ size_t bucket_count() const
+ {
+ return m_nHashBitmask + 1;
+ }
+
+ 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( m_Buckets[0].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 );
+ }
+
+ /// 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
+ };
+
+}} // namespace cds::intrusive
+
+#endif // ifndef CDSLIB_INTRUSIVE_MICHAEL_SET_H
projects / c11concurrency-benchmarks.git / blobdiff