3 #ifndef __CDS_CONTAINER_SPLIT_LIST_SET_RCU_H
4 #define __CDS_CONTAINER_SPLIT_LIST_SET_RCU_H
6 #include <cds/intrusive/split_list_rcu.h>
7 #include <cds/container/details/make_split_list_set.h>
8 #include <cds/details/functor_wrapper.h>
10 namespace cds { namespace container {
12 /// Split-ordered list set (template specialization for \ref cds_urcu_desc "RCU")
13 /** @ingroup cds_nonintrusive_set
14 \anchor cds_nonintrusive_SplitListSet_rcu
16 Hash table implementation based on split-ordered list algorithm discovered by Ori Shalev and Nir Shavit, see
17 - [2003] Ori Shalev, Nir Shavit "Split-Ordered Lists - Lock-free Resizable Hash Tables"
18 - [2008] Nir Shavit "The Art of Multiprocessor Programming"
20 See intrusive::SplitListSet for a brief description of the split-list algorithm.
23 - \p RCU - one of \ref cds_urcu_gc "RCU type"
24 - \p T - type stored in the split-list. The type must be default- and copy-constructible.
25 - \p Traits - type traits, default is split_list::type_traits. Instead of declaring split_list::type_traits -based
26 struct you may apply option-based notation with split_list::make_traits metafunction.
30 The class supports a forward iterator (\ref iterator and \ref const_iterator).
31 The iteration is ordered.
33 You may iterate over split-list set items only under RCU lock.
34 Only in this case the iterator is thread-safe since
35 while RCU is locked any set's item cannot be reclaimed.
37 The requirement of RCU lock during iterating means that deletion of the elements (i.e. \ref erase)
40 @warning The iterator object cannot be passed between threads
42 \warning Due to concurrent nature of skip-list set it is not guarantee that you can iterate
43 all elements in the set: any concurrent deletion can exclude the element
44 pointed by the iterator from the set, and your iteration can be terminated
45 before end of the set. Therefore, such iteration is more suitable for debugging purposes
47 The iterator class supports the following minimalistic interface:
54 iterator( iterator const& s);
56 value_type * operator ->() const;
57 value_type& operator *() const;
60 iterator& operator ++();
63 iterator& operator = (const iterator& src);
65 bool operator ==(iterator const& i ) const;
66 bool operator !=(iterator const& i ) const;
69 Note, the iterator object returned by \ref end, \p cend member functions points to \p nullptr and should not be dereferenced.
73 You should decide what garbage collector you want, and what ordered list you want to use. Split-ordered list
74 is an original data structure based on an ordered list. Suppose, you want construct split-list set based on cds::urcu::general_buffered<> GC
75 and LazyList as ordered list implementation. So, you beginning your program with following include:
77 #include <cds/urcu/general_buffered.h>
78 #include <cds/container/lazy_list_rcu.h>
79 #include <cds/container/split_list_set_rcu.h>
81 namespace cc = cds::container;
83 // The data belonged to split-ordered list
85 int nKey; // key field
86 std::string strValue ; // value field
89 The inclusion order is important:
90 - first, include one of \ref cds_urcu_gc "RCU implementation" (<tt>cds/urcu/general_buffered.h</tt> in our case)
91 - second, include file for ordered-list implementation (for this example, <tt>cds/container/lazy_list_rcu.h</tt>),
92 - then, the header for RCU-based split-list set <tt>cds/container/split_list_set_rcu.h</tt>.
94 Now, you should declare traits for split-list set. The main parts of traits are a hash functor for the set and a comparing functor for ordered list.
95 Note that we define several function in <tt>foo_hash</tt> and <tt>foo_less</tt> functors for different argument types since we want call our \p %SplitListSet
96 object by the key of type <tt>int</tt> and by the value of type <tt>foo</tt>.
98 The second attention: instead of using LazyList in SplitListSet traits we use a tag <tt>cds::contaner::lazy_list_tag</tt> for the lazy list.
99 The split-list requires significant support from underlying ordered list class and it is not good idea to dive you
100 into deep implementation details of split-list and ordered list interrelations. The tag paradigm simplifies split-list interface.
105 size_t operator()( int key ) const { return std::hash( key ) ; }
106 size_t operator()( foo const& item ) const { return std::hash( item.nKey ) ; }
111 bool operator()(int i, foo const& f ) const { return i < f.nKey ; }
112 bool operator()(foo const& f, int i ) const { return f.nKey < i ; }
113 bool operator()(foo const& f1, foo const& f2) const { return f1.nKey < f2.nKey; }
116 // SplitListSet traits
117 struct foo_set_traits: public cc::split_list::type_traits
119 typedef cc::lazy_list_tag ordered_list ; // what type of ordered list we want to use
120 typedef foo_hash hash ; // hash functor for our data stored in split-list set
122 // Type traits for our LazyList class
123 struct ordered_list_traits: public cc::lazy_list::type_traits
125 typedef foo_less less ; // use our foo_less as comparator to order list nodes
130 Now you are ready to declare our set class based on \p %SplitListSet:
132 typedef cc::SplitListSet< cds::urcu::gc<cds::urcu::general_buffered<> >, foo, foo_set_traits > foo_set;
135 You may use the modern option-based declaration instead of classic type-traits-based one:
137 typedef cc:SplitListSet<
138 cds::urcu::gc<cds::urcu::general_buffered<> > // RCU type used
139 ,foo // type of data stored
140 ,cc::split_list::make_traits< // metafunction to build split-list traits
141 cc::split_list::ordered_list<cc::lazy_list_tag> // tag for underlying ordered list implementation
142 ,cc::opt::hash< foo_hash > // hash functor
143 ,cc::split_list::ordered_list_traits< // ordered list traits desired
144 cc::lazy_list::make_traits< // metafunction to build lazy list traits
145 cc::opt::less< foo_less > // less-based compare functor
151 In case of option-based declaration using split_list::make_traits metafunction
152 the struct \p foo_set_traits is not required.
154 Now, the set of type \p foo_set is ready to use in your program.
156 Note that in this example we show only mandatory type_traits parts, optional ones is the default and they are inherited
157 from cds::container::split_list::type_traits.
158 The <b>cds</b> library contains many other options for deep tuning of behavior of the split-list and
159 ordered-list containers.
164 #ifdef CDS_DOXYGEN_INVOKED
165 class Traits = split_list::type_traits
170 class SplitListSet< cds::urcu::gc< RCU >, T, Traits >:
171 #ifdef CDS_DOXYGEN_INVOKED
172 protected intrusive::SplitListSet< cds::urcu::gc< RCU >, typename Traits::ordered_list, Traits >
174 protected details::make_split_list_set< cds::urcu::gc< RCU >, T, typename Traits::ordered_list, split_list::details::wrap_set_traits<T, Traits> >::type
179 typedef details::make_split_list_set< cds::urcu::gc< RCU >, T, typename Traits::ordered_list, split_list::details::wrap_set_traits<T, Traits> > maker;
180 typedef typename maker::type base_class;
184 typedef Traits options ; ///< \p Traits template argument
185 typedef typename maker::gc gc ; ///< Garbage collector
186 typedef typename maker::value_type value_type ; ///< type of value stored in the list
187 typedef typename maker::ordered_list ordered_list ; ///< Underlying ordered list class
188 typedef typename base_class::key_comparator key_comparator; ///< key compare functor
190 /// Hash functor for \ref value_type and all its derivatives that you use
191 typedef typename base_class::hash hash;
192 typedef typename base_class::item_counter item_counter ; ///< Item counter type
194 typedef typename base_class::rcu_lock rcu_lock ; ///< RCU scoped lock
195 /// Group of \p extract_xxx functions require external locking if underlying ordered list requires that
196 static CDS_CONSTEXPR_CONST bool c_bExtractLockExternal = base_class::c_bExtractLockExternal;
200 typedef typename maker::cxx_node_allocator cxx_node_allocator;
201 typedef typename maker::node_type node_type;
205 /// pointer to extracted node
206 typedef cds::urcu::exempt_ptr< gc, node_type, value_type, typename maker::ordered_list_traits::disposer > exempt_ptr;
211 template <typename Q>
212 static node_type * alloc_node(Q const& v )
214 return cxx_node_allocator().New( v );
217 template <typename Q, typename Func>
218 bool find_( Q& val, Func f )
220 # ifdef CDS_CXX11_LAMBDA_SUPPORT
221 return base_class::find( val, [&f]( node_type& item, Q& val ) { cds::unref(f)(item.m_Value, val) ; } );
223 find_functor_wrapper<Func> fw(f);
224 return base_class::find( val, cds::ref(fw) );
228 template <typename Q, typename Less, typename Func>
229 bool find_with_( Q& val, Less pred, Func f )
231 # ifdef CDS_CXX11_LAMBDA_SUPPORT
232 return base_class::find_with( val, typename maker::template predicate_wrapper<Less>::type(),
233 [&f]( node_type& item, Q& val ) { cds::unref(f)(item.m_Value, val) ; } );
235 find_functor_wrapper<Func> fw(f);
236 return base_class::find_with( val, typename maker::template predicate_wrapper<Less>::type(), cds::ref(fw) );
241 template <typename... Args>
242 static node_type * alloc_node( Args&&... args )
244 return cxx_node_allocator().MoveNew( std::forward<Args>(args)...);
247 static void free_node( node_type * pNode )
249 cxx_node_allocator().Delete( pNode );
252 struct node_disposer {
253 void operator()( node_type * pNode )
258 typedef std::unique_ptr< node_type, node_disposer > scoped_node_ptr;
260 bool insert_node( node_type * pNode )
262 assert( pNode != nullptr );
263 scoped_node_ptr p(pNode);
265 if ( base_class::insert( *pNode ) ) {
277 # ifndef CDS_CXX11_LAMBDA_SUPPORT
278 template <typename Func>
279 class insert_functor_wrapper: protected cds::details::functor_wrapper<Func>
281 typedef cds::details::functor_wrapper<Func> base_class;
283 insert_functor_wrapper( Func f ): base_class(f) {}
285 void operator()(node_type& node)
287 base_class::get()( node.m_Value );
291 template <typename Func, typename Q>
292 class ensure_functor_wrapper: protected cds::details::functor_wrapper<Func>
294 typedef cds::details::functor_wrapper<Func> base_class;
297 ensure_functor_wrapper( Func f, Q const& v ): base_class(f), m_val(v) {}
299 void operator()( bool bNew, node_type& item, node_type const& /*val*/ )
301 base_class::get()( bNew, item.m_Value, m_val );
305 template <typename Func>
306 class find_functor_wrapper: protected cds::details::functor_wrapper<Func>
308 typedef cds::details::functor_wrapper<Func> base_class;
310 find_functor_wrapper( Func f ): base_class(f) {}
312 template <typename Q>
313 void operator()( node_type& item, Q& val )
315 base_class::get()( item.m_Value, val );
319 struct empty_find_functor
321 template <typename Q>
322 void operator()( node_type&, Q& )
326 template <typename Func>
327 class erase_functor_wrapper: protected cds::details::functor_wrapper<Func>
329 typedef cds::details::functor_wrapper<Func> base_class;
331 erase_functor_wrapper( Func f ): base_class( f ) {}
333 void operator()(node_type& node)
335 base_class::get()( node.m_Value );
338 # endif // ifndef CDS_CXX11_LAMBDA_SUPPORT
344 \p IsConst - constness boolean flag
346 The forward iterator for a split-list has the following features:
347 - it has no post-increment operator
348 - it depends on underlying ordered list iterator
349 - it is safe to iterate only inside RCU critical section
350 - deleting an item pointed by the iterator can cause to deadlock
352 Therefore, the use of iterators in concurrent environment is not good idea.
353 Use it for debug purpose only.
355 template <bool IsConst>
356 class iterator_type: protected base_class::template iterator_type<IsConst>
359 typedef typename base_class::template iterator_type<IsConst> iterator_base_class;
360 friend class SplitListSet;
363 /// Value pointer type (const for const iterator)
364 typedef typename cds::details::make_const_type<value_type, IsConst>::pointer value_ptr;
365 /// Value reference type (const for const iterator)
366 typedef typename cds::details::make_const_type<value_type, IsConst>::reference value_ref;
374 iterator_type( iterator_type const& src )
375 : iterator_base_class( src )
380 explicit iterator_type( iterator_base_class const& src )
381 : iterator_base_class( src )
386 /// Dereference operator
387 value_ptr operator ->() const
389 return &(iterator_base_class::operator->()->m_Value);
392 /// Dereference operator
393 value_ref operator *() const
395 return iterator_base_class::operator*().m_Value;
399 iterator_type& operator ++()
401 iterator_base_class::operator++();
405 /// Assignment operator
406 iterator_type& operator = (iterator_type const& src)
408 iterator_base_class::operator=(src);
412 /// Equality operator
414 bool operator ==(iterator_type<C> const& i ) const
416 return iterator_base_class::operator==(i);
419 /// Equality operator
421 bool operator !=(iterator_type<C> const& i ) const
423 return iterator_base_class::operator!=(i);
428 /// Initializes split-ordered list of default capacity
430 The default capacity is defined in bucket table constructor.
431 See intrusive::split_list::expandable_bucket_table, intrusive::split_list::static_bucket_table
432 which selects by intrusive::split_list::dynamic_bucket_table option.
438 /// Initializes split-ordered list
440 size_t nItemCount ///< estimate average of item count
441 , size_t nLoadFactor = 1 ///< load factor - average item count per bucket. Small integer up to 8, default is 1.
443 : base_class( nItemCount, nLoadFactor )
447 typedef iterator_type<false> iterator ; ///< Forward iterator
448 typedef iterator_type<true> const_iterator ; ///< Forward const iterator
450 /// Returns a forward iterator addressing the first element in a set
452 For empty set \code begin() == end() \endcode
456 return iterator( base_class::begin() );
459 /// Returns an iterator that addresses the location succeeding the last element in a set
461 Do not use the value returned by <tt>end</tt> function to access any item.
462 The returned value can be used only to control reaching the end of the set.
463 For empty set \code begin() == end() \endcode
467 return iterator( base_class::end() );
470 /// Returns a forward const iterator addressing the first element in a set
471 const_iterator begin() const
473 return const_iterator( base_class::begin() );
476 /// Returns an const iterator that addresses the location succeeding the last element in a set
477 const_iterator end() const
479 return const_iterator( base_class::end() );
485 The function creates a node with copy of \p val value
486 and then inserts the node created into the set.
488 The type \p Q should contain as minimum the complete key for the node.
489 The object of \p value_type should be constructible from a value of type \p Q.
490 In trivial case, \p Q is equal to \p value_type.
492 The function applies RCU lock internally.
494 Returns \p true if \p val is inserted into the set, \p false otherwise.
496 template <typename Q>
497 bool insert( Q const& val )
499 return insert_node( alloc_node( val ) );
504 The function allows to split creating of new item into two part:
505 - create item with key only
506 - insert new item into the set
507 - if inserting is success, calls \p f functor to initialize value-field of \p val.
509 The functor signature is:
511 void func( value_type& val );
513 where \p val is the item inserted. User-defined functor \p f should guarantee that during changing
514 \p val no any other changes could be made on this set's item by concurrent threads.
515 The user-defined functor is called only if the inserting is success. It may be passed by reference
516 using <tt>boost::ref</tt>
518 The function applies RCU lock internally.
520 template <typename Q, typename Func>
521 bool insert( Q const& val, Func f )
523 scoped_node_ptr pNode( alloc_node( val ));
525 # ifdef CDS_CXX11_LAMBDA_SUPPORT
526 if ( base_class::insert( *pNode, [&f](node_type& node) { cds::unref(f)( node.m_Value ) ; } ))
528 insert_functor_wrapper<Func> fw(f);
529 if ( base_class::insert( *pNode, cds::ref(fw) ) )
538 /// Inserts data of type \p value_type constructed with <tt>std::forward<Args>(args)...</tt>
540 Returns \p true if inserting successful, \p false otherwise.
542 The function applies RCU lock internally.
544 template <typename... Args>
545 bool emplace( Args&&... args )
547 return insert_node( alloc_node( std::forward<Args>(args)...));
550 /// Ensures that the \p item exists in the set
552 The operation performs inserting or changing data with lock-free manner.
554 If the \p val key not found in the set, then the new item created from \p val
555 is inserted into the set. Otherwise, the functor \p func is called with the item found.
556 The functor \p Func should be a function with signature:
558 void func( bool bNew, value_type& item, const Q& val );
563 void operator()( bool bNew, value_type& item, const Q& val );
568 - \p bNew - \p true if the item has been inserted, \p false otherwise
569 - \p item - item of the set
570 - \p val - argument \p val passed into the \p ensure function
572 The functor may change non-key fields of the \p item; however, \p func must guarantee
573 that during changing no any other modifications could be made on this item by concurrent threads.
575 You may pass \p func argument by reference using <tt>boost::ref</tt>.
577 The function applies RCU lock internally.
579 Returns <tt> std::pair<bool, bool> </tt> where \p first is true if operation is successfull,
580 \p second is true if new item has been added or \p false if the item with \p key
581 already is in the set.
583 template <typename Q, typename Func>
584 std::pair<bool, bool> ensure( Q const& val, Func func )
586 scoped_node_ptr pNode( alloc_node( val ));
588 # ifdef CDS_CXX11_LAMBDA_SUPPORT
589 std::pair<bool, bool> bRet = base_class::ensure( *pNode,
590 [&func, &val]( bool bNew, node_type& item, node_type const& /*val*/ ) {
591 cds::unref(func)( bNew, item.m_Value, val );
594 ensure_functor_wrapper<Func, Q> fw( func, val );
595 std::pair<bool, bool> bRet = base_class::ensure( *pNode, cds::ref(fw) );
598 if ( bRet.first && bRet.second )
603 /// Deletes \p key from the set
604 /** \anchor cds_nonintrusive_SplitListSet_rcu_erase_val
606 Since the key of SplitListSet's item type \p value_type is not explicitly specified,
607 template parameter \p Q defines the key type searching in the list.
608 The set item comparator should be able to compare the values of type \p value_type
611 RCU \p synchronize method can be called. RCU should not be locked.
613 Return \p true if key is found and deleted, \p false otherwise
615 template <typename Q>
616 bool erase( Q const& key )
618 return base_class::erase( key );
621 /// Deletes the item from the set using \p pred predicate for searching
623 The function is an analog of \ref cds_nonintrusive_SplitListSet_rcu_erase_val "erase(Q const&)"
624 but \p pred is used for key comparing.
625 \p Less functor has the interface like \p std::less.
626 \p Less must imply the same element order as the comparator used for building the set.
628 template <typename Q, typename Less>
629 bool erase_with( Q const& key, Less pred )
631 return base_class::erase_with( key, typename maker::template predicate_wrapper<Less>::type() );
634 /// Deletes \p key from the set
635 /** \anchor cds_nonintrusive_SplitListSet_rcu_erase_func
637 The function searches an item with key \p key, calls \p f functor
638 and deletes the item. If \p key is not found, the functor is not called.
640 The functor \p Func interface:
643 void operator()(value_type const& val);
646 The functor may be passed by reference using <tt>boost:ref</tt>
648 Since the key of SplitListSet's \p value_type is not explicitly specified,
649 template parameter \p Q defines the key type searching in the list.
650 The list item comparator should be able to compare the values of the type \p value_type
653 RCU \p synchronize method can be called. RCU should not be locked.
655 Return \p true if key is found and deleted, \p false otherwise
657 template <typename Q, typename Func>
658 bool erase( Q const& key, Func f )
660 # ifdef CDS_CXX11_LAMBDA_SUPPORT
661 return base_class::erase( key, [&f](node_type& node) { cds::unref(f)( node.m_Value ); } );
663 erase_functor_wrapper<Func> fw( f );
664 return base_class::erase( key, cds::ref(fw) );
668 /// Deletes the item from the set using \p pred predicate for searching
670 The function is an analog of \ref cds_nonintrusive_SplitListSet_rcu_erase_func "erase(Q const&, Func)"
671 but \p pred is used for key comparing.
672 \p Less functor has the interface like \p std::less.
673 \p Less must imply the same element order as the comparator used for building the set.
675 template <typename Q, typename Less, typename Func>
676 bool erase_with( Q const& key, Less pred, Func f )
678 # ifdef CDS_CXX11_LAMBDA_SUPPORT
679 return base_class::erase_with( key, typename maker::template predicate_wrapper<Less>::type(),
680 [&f](node_type& node) { cds::unref(f)( node.m_Value ); } );
682 erase_functor_wrapper<Func> fw( f );
683 return base_class::erase_with( key, typename maker::template predicate_wrapper<Less>::type(), cds::ref(fw) );
687 /// Extracts an item from the set
688 /** \anchor cds_nonintrusive_SplitListSet_rcu_extract
689 The function searches an item with key equal to \p val in the set,
690 unlinks it from the set, places item pointer into \p dest argument, and returns \p true.
691 If the item with the key equal to \p val is not found the function return \p false.
693 @note The function does NOT call RCU read-side lock or synchronization,
694 and does NOT dispose the item found. It just excludes the item from the set
695 and returns a pointer to item found.
696 You should lock RCU before calling of the function, and you should synchronize RCU
697 outside the RCU lock to free extracted item
700 typedef cds::urcu::gc< general_buffered<> > rcu;
701 typedef cds::container::SplitListSet< rcu, Foo > splitlist_set;
703 splitlist_set theSet;
706 splitlist_set::exempt_ptr p;
708 // first, we should lock RCU
709 splitlist_set::rcu_lock lock;
711 // Now, you can apply extract function
712 // Note that you must not delete the item found inside the RCU lock
713 if ( theSet.extract( p, 10 )) {
714 // do something with p
719 // We may safely release p here
720 // release() passes the pointer to RCU reclamation cycle
724 template <typename Q>
725 bool extract( exempt_ptr& dest, Q const& val )
727 node_type * pNode = base_class::extract_( val, key_comparator() );
735 /// Extracts an item from the set using \p pred predicate for searching
737 The function is an analog of \ref cds_nonintrusive_SplitListSet_rcu_extract "extract(exempt_ptr&, Q const&)"
738 but \p pred is used for key comparing.
739 \p Less functor has the interface like \p std::less.
740 \p pred must imply the same element order as the comparator used for building the set.
742 template <typename Q, typename Less>
743 bool extract_with( exempt_ptr& dest, Q const& val, Less pred )
745 node_type * pNode = base_class::extract_with_( val, typename maker::template predicate_wrapper<Less>::type());
753 /// Finds the key \p val
754 /** \anchor cds_nonintrusive_SplitListSet_rcu_find_func
756 The function searches the item with key equal to \p val and calls the functor \p f for item found.
757 The interface of \p Func functor is:
760 void operator()( value_type& item, Q& val );
763 where \p item is the item found, \p val is the <tt>find</tt> function argument.
765 You may pass \p f argument by reference using <tt>boost::ref</tt> or cds::ref.
767 The functor may change non-key fields of \p item. Note that the functor is only guarantee
768 that \p item cannot be disposed during functor is executing.
769 The functor does not serialize simultaneous access to the set's \p item. If such access is
770 possible you must provide your own synchronization schema on item level to exclude unsafe item modifications.
772 The \p val argument is non-const since it can be used as \p f functor destination i.e., the functor
773 may modify both arguments.
775 Note the hash functor specified for class \p Traits template parameter
776 should accept a parameter of type \p Q that can be not the same as \p value_type.
778 The function makes RCU lock internally.
780 The function returns \p true if \p val is found, \p false otherwise.
782 template <typename Q, typename Func>
783 bool find( Q& val, Func f )
785 return find_( val, f );
788 /// Finds the key \p val using \p pred predicate for searching
790 The function is an analog of \ref cds_nonintrusive_SplitListSet_rcu_find_func "find(Q&, Func)"
791 but \p pred is used for key comparing.
792 \p Less functor has the interface like \p std::less.
793 \p Less must imply the same element order as the comparator used for building the set.
795 template <typename Q, typename Less, typename Func>
796 bool find_with( Q& val, Less pred, Func f )
798 return find_with_( val, pred, f );
801 /// Find the key \p val
802 /** \anchor cds_nonintrusive_SplitListSet_rcu_find_cfunc
804 The function searches the item with key equal to \p val and calls the functor \p f for item found.
805 The interface of \p Func functor is:
808 void operator()( value_type& item, Q const& val );
811 where \p item is the item found, \p val is the <tt>find</tt> function argument.
813 You may pass \p f argument by reference using <tt>boost::ref</tt> or cds::ref.
815 The functor may change non-key fields of \p item. Note that the functor is only guarantee
816 that \p item cannot be disposed during functor is executing.
817 The functor does not serialize simultaneous access to the set's \p item. If such access is
818 possible you must provide your own synchronization schema on item level to exclude unsafe item modifications.
820 Note the hash functor specified for class \p Traits template parameter
821 should accept a parameter of type \p Q that can be not the same as \p value_type.
823 The function makes RCU lock internally.
825 The function returns \p true if \p val is found, \p false otherwise.
827 template <typename Q, typename Func>
828 bool find( Q const& val, Func f )
830 return find_( val, f );
833 /// Finds the key \p val using \p pred predicate for searching
835 The function is an analog of \ref cds_nonintrusive_SplitListSet_rcu_find_cfunc "find(Q const&, Func)"
836 but \p pred is used for key comparing.
837 \p Less functor has the interface like \p std::less.
838 \p Less must imply the same element order as the comparator used for building the set.
840 template <typename Q, typename Less, typename Func>
841 bool find_with( Q const& val, Less pred, Func f )
843 return find_with_( val, pred, f );
846 /// Finds the key \p val
847 /** \anchor cds_nonintrusive_SplitListSet_rcu_find_val
849 The function searches the item with key equal to \p val
850 and returns \p true if it is found, and \p false otherwise.
852 Note the hash functor specified for class \p Traits template parameter
853 should accept a parameter of type \p Q that can be not the same as \p value_type.
855 The function makes RCU lock internally.
857 template <typename Q>
858 bool find( Q const& val )
860 return base_class::find( val );
863 /// Finds the key \p val using \p pred predicate for searching
865 The function is an analog of \ref cds_nonintrusive_SplitListSet_rcu_find_val "find(Q const&)"
866 but \p pred is used for key comparing.
867 \p Less functor has the interface like \p std::less.
868 \p Less must imply the same element order as the comparator used for building the set.
870 template <typename Q, typename Less>
871 bool find_with( Q const& val, Less pred )
873 return base_class::find_with( val, typename maker::template predicate_wrapper<Less>::type() );
876 /// Finds the key \p val and return the item found
877 /** \anchor cds_nonintrusive_SplitListSet_rcu_get
878 The function searches the item with key equal to \p val and returns the pointer to item found.
879 If \p val is not found it returns \p nullptr.
881 Note the compare functor should accept a parameter of type \p Q that can be not the same as \p value_type.
883 RCU should be locked before call of this function.
884 Returned item is valid only while RCU is locked:
886 typedef cds::urcu::gc< general_buffered<> > rcu;
887 typedef cds::container::SplitListSet< rcu, Foo > splitlist_set;
888 splitlist_set theSet;
892 splitlist_set::rcu_lock lock;
894 foo * pVal = theSet.get( 5 );
899 // Unlock RCU by rcu_lock destructor
900 // pVal can be retired by disposer at any time after RCU has been unlocked
904 template <typename Q>
905 value_type * get( Q const& val )
907 node_type * pNode = base_class::get( val );
908 return pNode ? &pNode->m_Value : nullptr;
911 /// Finds the key \p val and return the item found
913 The function is an analog of \ref cds_nonintrusive_SplitListSet_rcu_get "get(Q const&)"
914 but \p pred is used for comparing the keys.
916 \p Less functor has the semantics like \p std::less but should take arguments of type \ref value_type and \p Q
918 \p pred must imply the same element order as the comparator used for building the set.
920 template <typename Q, typename Less>
921 value_type * get_with( Q const& val, Less pred )
923 node_type * pNode = base_class::get_with( val, typename maker::template predicate_wrapper<Less>::type());
924 return pNode ? &pNode->m_Value : nullptr;
927 /// Clears the set (non-atomic)
929 The function unlink all items from the set.
930 The function is not atomic and not lock-free and should be used for debugging only.
932 RCU \p synchronize method can be called. RCU should not be locked.
939 /// Checks if the set is empty
941 Emptiness is checked by item counting: if item count is zero then assume that the set is empty.
942 Thus, the correct item counting feature is an important part of split-list set implementation.
946 return base_class::empty();
949 /// Returns item count in the set
952 return base_class::size();
957 }} // namespace cds::container
959 #endif // #ifndef __CDS_CONTAINER_SPLIT_LIST_SET_RCU_H