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 # ifdef CDS_EMPLACE_SUPPORT
242 template <typename... Args>
243 static node_type * alloc_node( Args&&... args )
245 return cxx_node_allocator().MoveNew( std::forward<Args>(args)...);
249 static void free_node( node_type * pNode )
251 cxx_node_allocator().Delete( pNode );
254 struct node_disposer {
255 void operator()( node_type * pNode )
260 typedef std::unique_ptr< node_type, node_disposer > scoped_node_ptr;
262 bool insert_node( node_type * pNode )
264 assert( pNode != nullptr );
265 scoped_node_ptr p(pNode);
267 if ( base_class::insert( *pNode ) ) {
279 # ifndef CDS_CXX11_LAMBDA_SUPPORT
280 template <typename Func>
281 class insert_functor_wrapper: protected cds::details::functor_wrapper<Func>
283 typedef cds::details::functor_wrapper<Func> base_class;
285 insert_functor_wrapper( Func f ): base_class(f) {}
287 void operator()(node_type& node)
289 base_class::get()( node.m_Value );
293 template <typename Func, typename Q>
294 class ensure_functor_wrapper: protected cds::details::functor_wrapper<Func>
296 typedef cds::details::functor_wrapper<Func> base_class;
299 ensure_functor_wrapper( Func f, Q const& v ): base_class(f), m_val(v) {}
301 void operator()( bool bNew, node_type& item, node_type const& /*val*/ )
303 base_class::get()( bNew, item.m_Value, m_val );
307 template <typename Func>
308 class find_functor_wrapper: protected cds::details::functor_wrapper<Func>
310 typedef cds::details::functor_wrapper<Func> base_class;
312 find_functor_wrapper( Func f ): base_class(f) {}
314 template <typename Q>
315 void operator()( node_type& item, Q& val )
317 base_class::get()( item.m_Value, val );
321 struct empty_find_functor
323 template <typename Q>
324 void operator()( node_type&, Q& )
328 template <typename Func>
329 class erase_functor_wrapper: protected cds::details::functor_wrapper<Func>
331 typedef cds::details::functor_wrapper<Func> base_class;
333 erase_functor_wrapper( Func f ): base_class( f ) {}
335 void operator()(node_type& node)
337 base_class::get()( node.m_Value );
340 # endif // ifndef CDS_CXX11_LAMBDA_SUPPORT
346 \p IsConst - constness boolean flag
348 The forward iterator for a split-list has the following features:
349 - it has no post-increment operator
350 - it depends on underlying ordered list iterator
351 - it is safe to iterate only inside RCU critical section
352 - deleting an item pointed by the iterator can cause to deadlock
354 Therefore, the use of iterators in concurrent environment is not good idea.
355 Use it for debug purpose only.
357 template <bool IsConst>
358 class iterator_type: protected base_class::template iterator_type<IsConst>
361 typedef typename base_class::template iterator_type<IsConst> iterator_base_class;
362 friend class SplitListSet;
365 /// Value pointer type (const for const iterator)
366 typedef typename cds::details::make_const_type<value_type, IsConst>::pointer value_ptr;
367 /// Value reference type (const for const iterator)
368 typedef typename cds::details::make_const_type<value_type, IsConst>::reference value_ref;
376 iterator_type( iterator_type const& src )
377 : iterator_base_class( src )
382 explicit iterator_type( iterator_base_class const& src )
383 : iterator_base_class( src )
388 /// Dereference operator
389 value_ptr operator ->() const
391 return &(iterator_base_class::operator->()->m_Value);
394 /// Dereference operator
395 value_ref operator *() const
397 return iterator_base_class::operator*().m_Value;
401 iterator_type& operator ++()
403 iterator_base_class::operator++();
407 /// Assignment operator
408 iterator_type& operator = (iterator_type const& src)
410 iterator_base_class::operator=(src);
414 /// Equality operator
416 bool operator ==(iterator_type<C> const& i ) const
418 return iterator_base_class::operator==(i);
421 /// Equality operator
423 bool operator !=(iterator_type<C> const& i ) const
425 return iterator_base_class::operator!=(i);
430 /// Initializes split-ordered list of default capacity
432 The default capacity is defined in bucket table constructor.
433 See intrusive::split_list::expandable_bucket_table, intrusive::split_list::static_bucket_table
434 which selects by intrusive::split_list::dynamic_bucket_table option.
440 /// Initializes split-ordered list
442 size_t nItemCount ///< estimate average of item count
443 , size_t nLoadFactor = 1 ///< load factor - average item count per bucket. Small integer up to 8, default is 1.
445 : base_class( nItemCount, nLoadFactor )
449 typedef iterator_type<false> iterator ; ///< Forward iterator
450 typedef iterator_type<true> const_iterator ; ///< Forward const iterator
452 /// Returns a forward iterator addressing the first element in a set
454 For empty set \code begin() == end() \endcode
458 return iterator( base_class::begin() );
461 /// Returns an iterator that addresses the location succeeding the last element in a set
463 Do not use the value returned by <tt>end</tt> function to access any item.
464 The returned value can be used only to control reaching the end of the set.
465 For empty set \code begin() == end() \endcode
469 return iterator( base_class::end() );
472 /// Returns a forward const iterator addressing the first element in a set
473 const_iterator begin() const
475 return const_iterator( base_class::begin() );
478 /// Returns an const iterator that addresses the location succeeding the last element in a set
479 const_iterator end() const
481 return const_iterator( base_class::end() );
487 The function creates a node with copy of \p val value
488 and then inserts the node created into the set.
490 The type \p Q should contain as minimum the complete key for the node.
491 The object of \p value_type should be constructible from a value of type \p Q.
492 In trivial case, \p Q is equal to \p value_type.
494 The function applies RCU lock internally.
496 Returns \p true if \p val is inserted into the set, \p false otherwise.
498 template <typename Q>
499 bool insert( Q const& val )
501 return insert_node( alloc_node( val ) );
506 The function allows to split creating of new item into two part:
507 - create item with key only
508 - insert new item into the set
509 - if inserting is success, calls \p f functor to initialize value-field of \p val.
511 The functor signature is:
513 void func( value_type& val );
515 where \p val is the item inserted. User-defined functor \p f should guarantee that during changing
516 \p val no any other changes could be made on this set's item by concurrent threads.
517 The user-defined functor is called only if the inserting is success. It may be passed by reference
518 using <tt>boost::ref</tt>
520 The function applies RCU lock internally.
522 template <typename Q, typename Func>
523 bool insert( Q const& val, Func f )
525 scoped_node_ptr pNode( alloc_node( val ));
527 # ifdef CDS_CXX11_LAMBDA_SUPPORT
528 if ( base_class::insert( *pNode, [&f](node_type& node) { cds::unref(f)( node.m_Value ) ; } ))
530 insert_functor_wrapper<Func> fw(f);
531 if ( base_class::insert( *pNode, cds::ref(fw) ) )
540 # ifdef CDS_EMPLACE_SUPPORT
541 /// Inserts data of type \p value_type constructed with <tt>std::forward<Args>(args)...</tt>
543 Returns \p true if inserting successful, \p false otherwise.
545 The function applies RCU lock internally.
547 @note This function is available only for compiler that supports
548 variadic template and move semantics.
550 template <typename... Args>
551 bool emplace( Args&&... args )
553 return insert_node( alloc_node( std::forward<Args>(args)...));
557 /// Ensures that the \p item exists in the set
559 The operation performs inserting or changing data with lock-free manner.
561 If the \p val key not found in the set, then the new item created from \p val
562 is inserted into the set. Otherwise, the functor \p func is called with the item found.
563 The functor \p Func should be a function with signature:
565 void func( bool bNew, value_type& item, const Q& val );
570 void operator()( bool bNew, value_type& item, const Q& val );
575 - \p bNew - \p true if the item has been inserted, \p false otherwise
576 - \p item - item of the set
577 - \p val - argument \p val passed into the \p ensure function
579 The functor may change non-key fields of the \p item; however, \p func must guarantee
580 that during changing no any other modifications could be made on this item by concurrent threads.
582 You may pass \p func argument by reference using <tt>boost::ref</tt>.
584 The function applies RCU lock internally.
586 Returns <tt> std::pair<bool, bool> </tt> where \p first is true if operation is successfull,
587 \p second is true if new item has been added or \p false if the item with \p key
588 already is in the set.
590 template <typename Q, typename Func>
591 std::pair<bool, bool> ensure( Q const& val, Func func )
593 scoped_node_ptr pNode( alloc_node( val ));
595 # ifdef CDS_CXX11_LAMBDA_SUPPORT
596 std::pair<bool, bool> bRet = base_class::ensure( *pNode,
597 [&func, &val]( bool bNew, node_type& item, node_type const& /*val*/ ) {
598 cds::unref(func)( bNew, item.m_Value, val );
601 ensure_functor_wrapper<Func, Q> fw( func, val );
602 std::pair<bool, bool> bRet = base_class::ensure( *pNode, cds::ref(fw) );
605 if ( bRet.first && bRet.second )
610 /// Deletes \p key from the set
611 /** \anchor cds_nonintrusive_SplitListSet_rcu_erase_val
613 Since the key of SplitListSet's item type \p value_type is not explicitly specified,
614 template parameter \p Q defines the key type searching in the list.
615 The set item comparator should be able to compare the values of type \p value_type
618 RCU \p synchronize method can be called. RCU should not be locked.
620 Return \p true if key is found and deleted, \p false otherwise
622 template <typename Q>
623 bool erase( Q const& key )
625 return base_class::erase( key );
628 /// Deletes the item from the set using \p pred predicate for searching
630 The function is an analog of \ref cds_nonintrusive_SplitListSet_rcu_erase_val "erase(Q const&)"
631 but \p pred is used for key comparing.
632 \p Less functor has the interface like \p std::less.
633 \p Less must imply the same element order as the comparator used for building the set.
635 template <typename Q, typename Less>
636 bool erase_with( Q const& key, Less pred )
638 return base_class::erase_with( key, typename maker::template predicate_wrapper<Less>::type() );
641 /// Deletes \p key from the set
642 /** \anchor cds_nonintrusive_SplitListSet_rcu_erase_func
644 The function searches an item with key \p key, calls \p f functor
645 and deletes the item. If \p key is not found, the functor is not called.
647 The functor \p Func interface:
650 void operator()(value_type const& val);
653 The functor may be passed by reference using <tt>boost:ref</tt>
655 Since the key of SplitListSet's \p value_type is not explicitly specified,
656 template parameter \p Q defines the key type searching in the list.
657 The list item comparator should be able to compare the values of the type \p value_type
660 RCU \p synchronize method can be called. RCU should not be locked.
662 Return \p true if key is found and deleted, \p false otherwise
664 template <typename Q, typename Func>
665 bool erase( Q const& key, Func f )
667 # ifdef CDS_CXX11_LAMBDA_SUPPORT
668 return base_class::erase( key, [&f](node_type& node) { cds::unref(f)( node.m_Value ); } );
670 erase_functor_wrapper<Func> fw( f );
671 return base_class::erase( key, cds::ref(fw) );
675 /// Deletes the item from the set using \p pred predicate for searching
677 The function is an analog of \ref cds_nonintrusive_SplitListSet_rcu_erase_func "erase(Q const&, Func)"
678 but \p pred is used for key comparing.
679 \p Less functor has the interface like \p std::less.
680 \p Less must imply the same element order as the comparator used for building the set.
682 template <typename Q, typename Less, typename Func>
683 bool erase_with( Q const& key, Less pred, Func f )
685 # ifdef CDS_CXX11_LAMBDA_SUPPORT
686 return base_class::erase_with( key, typename maker::template predicate_wrapper<Less>::type(),
687 [&f](node_type& node) { cds::unref(f)( node.m_Value ); } );
689 erase_functor_wrapper<Func> fw( f );
690 return base_class::erase_with( key, typename maker::template predicate_wrapper<Less>::type(), cds::ref(fw) );
694 /// Extracts an item from the set
695 /** \anchor cds_nonintrusive_SplitListSet_rcu_extract
696 The function searches an item with key equal to \p val in the set,
697 unlinks it from the set, places item pointer into \p dest argument, and returns \p true.
698 If the item with the key equal to \p val is not found the function return \p false.
700 @note The function does NOT call RCU read-side lock or synchronization,
701 and does NOT dispose the item found. It just excludes the item from the set
702 and returns a pointer to item found.
703 You should lock RCU before calling of the function, and you should synchronize RCU
704 outside the RCU lock to free extracted item
707 typedef cds::urcu::gc< general_buffered<> > rcu;
708 typedef cds::container::SplitListSet< rcu, Foo > splitlist_set;
710 splitlist_set theSet;
713 splitlist_set::exempt_ptr p;
715 // first, we should lock RCU
716 splitlist_set::rcu_lock lock;
718 // Now, you can apply extract function
719 // Note that you must not delete the item found inside the RCU lock
720 if ( theSet.extract( p, 10 )) {
721 // do something with p
726 // We may safely release p here
727 // release() passes the pointer to RCU reclamation cycle
731 template <typename Q>
732 bool extract( exempt_ptr& dest, Q const& val )
734 node_type * pNode = base_class::extract_( val, key_comparator() );
742 /// Extracts an item from the set using \p pred predicate for searching
744 The function is an analog of \ref cds_nonintrusive_SplitListSet_rcu_extract "extract(exempt_ptr&, Q const&)"
745 but \p pred is used for key comparing.
746 \p Less functor has the interface like \p std::less.
747 \p pred must imply the same element order as the comparator used for building the set.
749 template <typename Q, typename Less>
750 bool extract_with( exempt_ptr& dest, Q const& val, Less pred )
752 node_type * pNode = base_class::extract_with_( val, typename maker::template predicate_wrapper<Less>::type());
760 /// Finds the key \p val
761 /** \anchor cds_nonintrusive_SplitListSet_rcu_find_func
763 The function searches the item with key equal to \p val and calls the functor \p f for item found.
764 The interface of \p Func functor is:
767 void operator()( value_type& item, Q& val );
770 where \p item is the item found, \p val is the <tt>find</tt> function argument.
772 You may pass \p f argument by reference using <tt>boost::ref</tt> or cds::ref.
774 The functor may change non-key fields of \p item. Note that the functor is only guarantee
775 that \p item cannot be disposed during functor is executing.
776 The functor does not serialize simultaneous access to the set's \p item. If such access is
777 possible you must provide your own synchronization schema on item level to exclude unsafe item modifications.
779 The \p val argument is non-const since it can be used as \p f functor destination i.e., the functor
780 may modify both arguments.
782 Note the hash functor specified for class \p Traits template parameter
783 should accept a parameter of type \p Q that can be not the same as \p value_type.
785 The function makes RCU lock internally.
787 The function returns \p true if \p val is found, \p false otherwise.
789 template <typename Q, typename Func>
790 bool find( Q& val, Func f )
792 return find_( val, f );
795 /// Finds the key \p val using \p pred predicate for searching
797 The function is an analog of \ref cds_nonintrusive_SplitListSet_rcu_find_func "find(Q&, Func)"
798 but \p pred is used for key comparing.
799 \p Less functor has the interface like \p std::less.
800 \p Less must imply the same element order as the comparator used for building the set.
802 template <typename Q, typename Less, typename Func>
803 bool find_with( Q& val, Less pred, Func f )
805 return find_with_( val, pred, f );
808 /// Find the key \p val
809 /** \anchor cds_nonintrusive_SplitListSet_rcu_find_cfunc
811 The function searches the item with key equal to \p val and calls the functor \p f for item found.
812 The interface of \p Func functor is:
815 void operator()( value_type& item, Q const& val );
818 where \p item is the item found, \p val is the <tt>find</tt> function argument.
820 You may pass \p f argument by reference using <tt>boost::ref</tt> or cds::ref.
822 The functor may change non-key fields of \p item. Note that the functor is only guarantee
823 that \p item cannot be disposed during functor is executing.
824 The functor does not serialize simultaneous access to the set's \p item. If such access is
825 possible you must provide your own synchronization schema on item level to exclude unsafe item modifications.
827 Note the hash functor specified for class \p Traits template parameter
828 should accept a parameter of type \p Q that can be not the same as \p value_type.
830 The function makes RCU lock internally.
832 The function returns \p true if \p val is found, \p false otherwise.
834 template <typename Q, typename Func>
835 bool find( Q const& val, Func f )
837 return find_( val, f );
840 /// Finds the key \p val using \p pred predicate for searching
842 The function is an analog of \ref cds_nonintrusive_SplitListSet_rcu_find_cfunc "find(Q const&, Func)"
843 but \p pred is used for key comparing.
844 \p Less functor has the interface like \p std::less.
845 \p Less must imply the same element order as the comparator used for building the set.
847 template <typename Q, typename Less, typename Func>
848 bool find_with( Q const& val, Less pred, Func f )
850 return find_with_( val, pred, f );
853 /// Finds the key \p val
854 /** \anchor cds_nonintrusive_SplitListSet_rcu_find_val
856 The function searches the item with key equal to \p val
857 and returns \p true if it is found, and \p false otherwise.
859 Note the hash functor specified for class \p Traits template parameter
860 should accept a parameter of type \p Q that can be not the same as \p value_type.
862 The function makes RCU lock internally.
864 template <typename Q>
865 bool find( Q const& val )
867 return base_class::find( val );
870 /// Finds the key \p val using \p pred predicate for searching
872 The function is an analog of \ref cds_nonintrusive_SplitListSet_rcu_find_val "find(Q const&)"
873 but \p pred is used for key comparing.
874 \p Less functor has the interface like \p std::less.
875 \p Less must imply the same element order as the comparator used for building the set.
877 template <typename Q, typename Less>
878 bool find_with( Q const& val, Less pred )
880 return base_class::find_with( val, typename maker::template predicate_wrapper<Less>::type() );
883 /// Finds the key \p val and return the item found
884 /** \anchor cds_nonintrusive_SplitListSet_rcu_get
885 The function searches the item with key equal to \p val and returns the pointer to item found.
886 If \p val is not found it returns \p nullptr.
888 Note the compare functor should accept a parameter of type \p Q that can be not the same as \p value_type.
890 RCU should be locked before call of this function.
891 Returned item is valid only while RCU is locked:
893 typedef cds::urcu::gc< general_buffered<> > rcu;
894 typedef cds::container::SplitListSet< rcu, Foo > splitlist_set;
895 splitlist_set theSet;
899 splitlist_set::rcu_lock lock;
901 foo * pVal = theSet.get( 5 );
906 // Unlock RCU by rcu_lock destructor
907 // pVal can be retired by disposer at any time after RCU has been unlocked
911 template <typename Q>
912 value_type * get( Q const& val )
914 node_type * pNode = base_class::get( val );
915 return pNode ? &pNode->m_Value : nullptr;
918 /// Finds the key \p val and return the item found
920 The function is an analog of \ref cds_nonintrusive_SplitListSet_rcu_get "get(Q const&)"
921 but \p pred is used for comparing the keys.
923 \p Less functor has the semantics like \p std::less but should take arguments of type \ref value_type and \p Q
925 \p pred must imply the same element order as the comparator used for building the set.
927 template <typename Q, typename Less>
928 value_type * get_with( Q const& val, Less pred )
930 node_type * pNode = base_class::get_with( val, typename maker::template predicate_wrapper<Less>::type());
931 return pNode ? &pNode->m_Value : nullptr;
934 /// Clears the set (non-atomic)
936 The function unlink all items from the set.
937 The function is not atomic and not lock-free and should be used for debugging only.
939 RCU \p synchronize method can be called. RCU should not be locked.
946 /// Checks if the set is empty
948 Emptiness is checked by item counting: if item count is zero then assume that the set is empty.
949 Thus, the correct item counting feature is an important part of split-list set implementation.
953 return base_class::empty();
956 /// Returns item count in the set
959 return base_class::size();
964 }} // namespace cds::container
966 #endif // #ifndef __CDS_CONTAINER_SPLIT_LIST_SET_RCU_H