3 #ifndef __CDS_CONTAINER_SPLIT_LIST_SET_H
4 #define __CDS_CONTAINER_SPLIT_LIST_SET_H
6 #include <cds/intrusive/split_list.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
13 /** @ingroup cds_nonintrusive_set
14 \anchor cds_nonintrusive_SplitListSet_hp
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 GC - Garbage collector used
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.
28 There are the specializations:
29 - for \ref cds_urcu_desc "RCU" - declared in <tt>cd/container/split_list_set_rcu.h</tt>,
30 see \ref cds_nonintrusive_SplitListSet_rcu "SplitListSet<RCU>".
31 - for \ref cds::gc::nogc declared in <tt>cds/container/split_list_set_nogc.h</tt>,
32 see \ref cds_nonintrusive_SplitListSet_nogc "SplitListSet<gc::nogc>".
36 You should decide what garbage collector you want, and what ordered list you want to use. Split-ordered list
37 is original data structure based on an ordered list. Suppose, you want construct split-list set based on gc::PTB GC
38 and LazyList as ordered list implementation. So, you beginning your program with following include:
40 #include <cds/container/lazy_list_ptb.h>
41 #include <cds/container/split_list_set.h>
43 namespace cc = cds::container;
45 // The data belonged to split-ordered list
47 int nKey; // key field
48 std::string strValue ; // value field
51 The inclusion order is important: first, include header for ordered-list implementation (for this example, <tt>cds/container/lazy_list_ptb.h</tt>),
52 then the header for split-list set <tt>cds/container/split_list_set.h</tt>.
54 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.
55 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
56 object by the key of type <tt>int</tt> and by the value of type <tt>foo</tt>.
58 The second attention: instead of using \p %LazyList in \p %SplitListSet traits we use a tag <tt>cds::contaner::lazy_list_tag</tt> for the lazy list.
59 The split-list requires significant support from underlying ordered list class and it is not good idea to dive you
60 into deep implementation details of split-list and ordered list interrelations. The tag paradigm simplifies split-list interface.
65 size_t operator()( int key ) const { return std::hash( key ) ; }
66 size_t operator()( foo const& item ) const { return std::hash( item.nKey ) ; }
71 bool operator()(int i, foo const& f ) const { return i < f.nKey ; }
72 bool operator()(foo const& f, int i ) const { return f.nKey < i ; }
73 bool operator()(foo const& f1, foo const& f2) const { return f1.nKey < f2.nKey; }
76 // SplitListSet traits
77 struct foo_set_traits: public cc::split_list::type_traits
79 typedef cc::lazy_list_tag ordered_list ; // what type of ordered list we want to use
80 typedef foo_hash hash ; // hash functor for our data stored in split-list set
82 // Type traits for our LazyList class
83 struct ordered_list_traits: public cc::lazy_list::type_traits
85 typedef foo_less less ; // use our foo_less as comparator to order list nodes
90 Now you are ready to declare our set class based on \p %SplitListSet:
92 typedef cc::SplitListSet< cds::gc::PTB, foo, foo_set_traits > foo_set;
95 You may use the modern option-based declaration instead of classic type-traits-based one:
97 typedef cc:SplitListSet<
98 cs::gc::PTB // GC used
99 ,foo // type of data stored
100 ,cc::split_list::make_traits< // metafunction to build split-list traits
101 cc::split_list::ordered_list<cc::lazy_list_tag> // tag for underlying ordered list implementation
102 ,cc::opt::hash< foo_hash > // hash functor
103 ,cc::split_list::ordered_list_traits< // ordered list traits desired
104 cc::lazy_list::make_traits< // metafunction to build lazy list traits
105 cc::opt::less< foo_less > // less-based compare functor
111 In case of option-based declaration using split_list::make_traits metafunction
112 the struct \p foo_set_traits is not required.
114 Now, the set of type \p foo_set is ready to use in your program.
116 Note that in this example we show only mandatory type_traits parts, optional ones is the default and they are inherited
117 from cds::container::split_list::type_traits.
118 The <b>cds</b> library contains many other options for deep tuning of behavior of the split-list and
119 ordered-list containers.
124 #ifdef CDS_DOXYGEN_INVOKED
125 class Traits = split_list::type_traits
131 #ifdef CDS_DOXYGEN_INVOKED
132 protected intrusive::SplitListSet<GC, typename Traits::ordered_list, Traits>
134 protected details::make_split_list_set< GC, T, typename Traits::ordered_list, split_list::details::wrap_set_traits<T, Traits> >::type
139 typedef details::make_split_list_set< GC, T, typename Traits::ordered_list, split_list::details::wrap_set_traits<T, Traits> > maker;
140 typedef typename maker::type base_class;
144 typedef Traits options ; ///< \p Traits template argument
145 typedef typename maker::gc gc ; ///< Garbage collector
146 typedef typename maker::value_type value_type ; ///< type of value stored in the list
147 typedef typename maker::ordered_list ordered_list ; ///< Underlying ordered list class
148 typedef typename base_class::key_comparator key_comparator; ///< key compare functor
150 /// Hash functor for \p %value_type and all its derivatives that you use
151 typedef typename base_class::hash hash;
152 typedef typename base_class::item_counter item_counter ; ///< Item counter type
156 typedef typename maker::cxx_node_allocator cxx_node_allocator;
157 typedef typename maker::node_type node_type;
162 typedef cds::gc::guarded_ptr< gc, node_type, value_type, details::guarded_ptr_cast_set<node_type, value_type> > guarded_ptr;
166 template <typename Q>
167 static node_type * alloc_node(Q const& v )
169 return cxx_node_allocator().New( v );
172 template <typename Q, typename Func>
173 bool find_( Q& val, Func f )
175 return base_class::find( val, [&f]( node_type& item, Q& val ) { cds::unref(f)(item.m_Value, val) ; } );
178 template <typename Q, typename Less, typename Func>
179 bool find_with_( Q& val, Less pred, Func f )
181 return base_class::find_with( val, typename maker::template predicate_wrapper<Less>::type(),
182 [&f]( node_type& item, Q& val ) { cds::unref(f)(item.m_Value, val) ; } );
185 template <typename... Args>
186 static node_type * alloc_node( Args&&... args )
188 return cxx_node_allocator().MoveNew( std::forward<Args>(args)...);
191 static void free_node( node_type * pNode )
193 cxx_node_allocator().Delete( pNode );
196 struct node_disposer {
197 void operator()( node_type * pNode )
202 typedef std::unique_ptr< node_type, node_disposer > scoped_node_ptr;
204 bool insert_node( node_type * pNode )
206 assert( pNode != nullptr );
207 scoped_node_ptr p(pNode);
209 if ( base_class::insert( *pNode ) ) {
222 \p IsConst - constness boolean flag
224 The forward iterator for a split-list has the following features:
225 - it has no post-increment operator
226 - it depends on underlying ordered list iterator
227 - The iterator object cannot be moved across thread boundary since it contains GC's guard that is thread-private GC data.
228 - Iterator ensures thread-safety even if you delete the item that iterator points to. However, in case of concurrent
229 deleting operations it is no guarantee that you iterate all item in the split-list.
231 Therefore, the use of iterators in concurrent environment is not good idea. Use it for debug purpose only.
233 template <bool IsConst>
234 class iterator_type: protected base_class::template iterator_type<IsConst>
237 typedef typename base_class::template iterator_type<IsConst> iterator_base_class;
238 friend class SplitListSet;
241 /// Value pointer type (const for const iterator)
242 typedef typename cds::details::make_const_type<value_type, IsConst>::pointer value_ptr;
243 /// Value reference type (const for const iterator)
244 typedef typename cds::details::make_const_type<value_type, IsConst>::reference value_ref;
252 iterator_type( iterator_type const& src )
253 : iterator_base_class( src )
258 explicit iterator_type( iterator_base_class const& src )
259 : iterator_base_class( src )
264 /// Dereference operator
265 value_ptr operator ->() const
267 return &(iterator_base_class::operator->()->m_Value);
270 /// Dereference operator
271 value_ref operator *() const
273 return iterator_base_class::operator*().m_Value;
277 iterator_type& operator ++()
279 iterator_base_class::operator++();
283 /// Assignment operator
284 iterator_type& operator = (iterator_type const& src)
286 iterator_base_class::operator=(src);
290 /// Equality operator
292 bool operator ==(iterator_type<C> const& i ) const
294 return iterator_base_class::operator==(i);
297 /// Equality operator
299 bool operator !=(iterator_type<C> const& i ) const
301 return iterator_base_class::operator!=(i);
306 /// Initializes split-ordered list of default capacity
308 The default capacity is defined in bucket table constructor.
309 See intrusive::split_list::expandable_bucket_table, intrusive::split_list::static_bucket_table
310 which selects by intrusive::split_list::dynamic_bucket_table option.
316 /// Initializes split-ordered list
318 size_t nItemCount ///< estimate average of item count
319 , size_t nLoadFactor = 1 ///< load factor - average item count per bucket. Small integer up to 8, default is 1.
321 : base_class( nItemCount, nLoadFactor )
326 typedef iterator_type<false> iterator;
328 /// Const forward iterator
329 typedef iterator_type<true> const_iterator;
331 /// Returns a forward iterator addressing the first element in a set
333 For empty set \code begin() == end() \endcode
337 return iterator( base_class::begin() );
340 /// Returns an iterator that addresses the location succeeding the last element in a set
342 Do not use the value returned by <tt>end</tt> function to access any item.
343 The returned value can be used only to control reaching the end of the set.
344 For empty set \code begin() == end() \endcode
348 return iterator( base_class::end() );
351 /// Returns a forward const iterator addressing the first element in a set
352 const_iterator begin() const
354 return const_iterator( base_class::begin() );
357 /// Returns an const iterator that addresses the location succeeding the last element in a set
358 const_iterator end() const
360 return const_iterator( base_class::end() );
366 The function creates a node with copy of \p val value
367 and then inserts the node created into the set.
369 The type \p Q should contain as minimum the complete key for the node.
370 The object of \ref value_type should be constructible from a value of type \p Q.
371 In trivial case, \p Q is equal to \ref value_type.
373 Returns \p true if \p val is inserted into the set, \p false otherwise.
375 template <typename Q>
376 bool insert( Q const& val )
378 return insert_node( alloc_node( val ) );
383 The function allows to split creating of new item into two part:
384 - create item with key only
385 - insert new item into the set
386 - if inserting is success, calls \p f functor to initialize value-field of \p val.
388 The functor signature is:
390 void func( value_type& val );
392 where \p val is the item inserted. User-defined functor \p f should guarantee that during changing
393 \p val no any other changes could be made on this set's item by concurrent threads.
394 The user-defined functor is called only if the inserting is success. It may be passed by reference
395 using <tt>boost::ref</tt>
397 template <typename Q, typename Func>
398 bool insert( Q const& val, Func f )
400 scoped_node_ptr pNode( alloc_node( val ));
402 if ( base_class::insert( *pNode, [&f](node_type& node) { cds::unref(f)( node.m_Value ) ; } )) {
409 /// Inserts data of type \p %value_type constructed with <tt>std::forward<Args>(args)...</tt>
411 Returns \p true if inserting successful, \p false otherwise.
413 template <typename... Args>
414 bool emplace( Args&&... args )
416 return insert_node( alloc_node( std::forward<Args>(args)...));
419 /// Ensures that the \p item exists in the set
421 The operation performs inserting or changing data with lock-free manner.
423 If the \p val key not found in the set, then the new item created from \p val
424 is inserted into the set. Otherwise, the functor \p func is called with the item found.
425 The functor \p Func should be a function with signature:
427 void func( bool bNew, value_type& item, const Q& val );
432 void operator()( bool bNew, value_type& item, const Q& val );
437 - \p bNew - \p true if the item has been inserted, \p false otherwise
438 - \p item - item of the set
439 - \p val - argument \p val passed into the \p ensure function
441 The functor may change non-key fields of the \p item; however, \p func must guarantee
442 that during changing no any other modifications could be made on this item by concurrent threads.
444 You may pass \p func argument by reference using <tt>boost::ref</tt>.
446 Returns <tt> std::pair<bool, bool> </tt> where \p first is true if operation is successfull,
447 \p second is true if new item has been added or \p false if the item with \p key
448 already is in the set.
450 template <typename Q, typename Func>
451 std::pair<bool, bool> ensure( Q const& val, Func func )
453 scoped_node_ptr pNode( alloc_node( val ));
455 std::pair<bool, bool> bRet = base_class::ensure( *pNode,
456 [&func, &val]( bool bNew, node_type& item, node_type const& /*val*/ ) {
457 cds::unref(func)( bNew, item.m_Value, val );
460 if ( bRet.first && bRet.second )
465 /// Deletes \p key from the set
466 /** \anchor cds_nonintrusive_SplitListSet_erase_val
468 The item comparator should be able to compare the values of type \p value_type
471 Return \p true if key is found and deleted, \p false otherwise
473 template <typename Q>
474 bool erase( Q const& key )
476 return base_class::erase( key );
479 /// Deletes the item from the set using \p pred predicate for searching
481 The function is an analog of \ref cds_nonintrusive_SplitListSet_erase_val "erase(Q const&)"
482 but \p pred is used for key comparing.
483 \p Less functor has the interface like \p std::less.
484 \p Less must imply the same element order as the comparator used for building the set.
486 template <typename Q, typename Less>
487 bool erase_with( Q const& key, Less pred )
489 return base_class::erase_with( key, typename maker::template predicate_wrapper<Less>::type() );
492 /// Deletes \p key from the set
493 /** \anchor cds_nonintrusive_SplitListSet_erase_func
495 The function searches an item with key \p key, calls \p f functor
496 and deletes the item. If \p key is not found, the functor is not called.
498 The functor \p Func interface:
501 void operator()(value_type const& val);
504 The functor may be passed by reference using <tt>boost:ref</tt>
506 Since the key of SplitListSet's \p value_type is not explicitly specified,
507 template parameter \p Q defines the key type searching in the list.
508 The list item comparator should be able to compare the values of the type \p value_type
511 Return \p true if key is found and deleted, \p false otherwise
513 template <typename Q, typename Func>
514 bool erase( Q const& key, Func f )
516 return base_class::erase( key, [&f](node_type& node) { cds::unref(f)( node.m_Value ); } );
519 /// Deletes the item from the set using \p pred predicate for searching
521 The function is an analog of \ref cds_nonintrusive_SplitListSet_erase_func "erase(Q const&, Func)"
522 but \p pred is used for key comparing.
523 \p Less functor has the interface like \p std::less.
524 \p Less must imply the same element order as the comparator used for building the set.
526 template <typename Q, typename Less, typename Func>
527 bool erase_with( Q const& key, Less pred, Func f )
529 return base_class::erase_with( key, typename maker::template predicate_wrapper<Less>::type(),
530 [&f](node_type& node) { cds::unref(f)( node.m_Value ); } );
533 /// Extracts the item with specified \p key
534 /** \anchor cds_nonintrusive_SplitListSet_hp_extract
535 The function searches an item with key equal to \p key,
536 unlinks it from the set, and returns it in \p dest parameter.
537 If the item with key equal to \p key is not found the function returns \p false.
539 Note the compare functor should accept a parameter of type \p Q that may be not the same as \p value_type.
541 The extracted item is freed automatically when returned \ref guarded_ptr object will be destroyed or released.
542 @note Each \p guarded_ptr object uses the GC's guard that can be limited resource.
546 typedef cds::container::SplitListSet< your_template_args > splitlist_set;
547 splitlist_set theSet;
550 splitlist_set::guarded_ptr gp;
551 theSet.extract( gp, 5 );
555 // Destructor of gp releases internal HP guard
559 template <typename Q>
560 bool extract( guarded_ptr& dest, Q const& key )
562 return extract_( dest.guard(), key );
565 /// Extracts the item using compare functor \p pred
567 The function is an analog of \ref cds_nonintrusive_SplitListSet_hp_extract "extract(guarded_ptr&, Q const&)"
568 but \p pred predicate is used for key comparing.
570 \p Less functor has the semantics like \p std::less but should take arguments of type \ref value_type and \p Q
572 \p pred must imply the same element order as the comparator used for building the set.
574 template <typename Q, typename Less>
575 bool extract_with( guarded_ptr& dest, Q const& key, Less pred )
577 return extract_with_( dest.guard(), key, pred );
580 /// Finds the key \p val
581 /** \anchor cds_nonintrusive_SplitListSet_find_func
583 The function searches the item with key equal to \p val and calls the functor \p f for item found.
584 The interface of \p Func functor is:
587 void operator()( value_type& item, Q& val );
590 where \p item is the item found, \p val is the <tt>find</tt> function argument.
592 You may pass \p f argument by reference using <tt>boost::ref</tt> or cds::ref.
594 The functor may change non-key fields of \p item. Note that the functor is only guarantee
595 that \p item cannot be disposed during functor is executing.
596 The functor does not serialize simultaneous access to the set's \p item. If such access is
597 possible you must provide your own synchronization schema on item level to exclude unsafe item modifications.
599 The \p val argument is non-const since it can be used as \p f functor destination i.e., the functor
600 may modify both arguments.
602 Note the hash functor specified for class \p Traits template parameter
603 should accept a parameter of type \p Q that can be not the same as \p value_type.
605 The function returns \p true if \p val is found, \p false otherwise.
607 template <typename Q, typename Func>
608 bool find( Q& val, Func f )
610 return find_( val, f );
613 /// Finds the key \p val using \p pred predicate for searching
615 The function is an analog of \ref cds_nonintrusive_SplitListSet_find_func "find(Q&, Func)"
616 but \p pred is used for key comparing.
617 \p Less functor has the interface like \p std::less.
618 \p Less must imply the same element order as the comparator used for building the set.
620 template <typename Q, typename Less, typename Func>
621 bool find_with( Q& val, Less pred, Func f )
623 return find_with_( val, pred, f );
626 /// Finds the key \p val
627 /** \anchor cds_nonintrusive_SplitListSet_find_cfunc
629 The function searches the item with key equal to \p val and calls the functor \p f for item found.
630 The interface of \p Func functor is:
633 void operator()( value_type& item, Q const& val );
636 where \p item is the item found, \p val is the <tt>find</tt> function argument.
638 You may pass \p f argument by reference using <tt>boost::ref</tt> or cds::ref.
640 The functor may change non-key fields of \p item. Note that the functor is only guarantee
641 that \p item cannot be disposed during functor is executing.
642 The functor does not serialize simultaneous access to the set's \p item. If such access is
643 possible you must provide your own synchronization schema on item level to exclude unsafe item modifications.
645 Note the hash functor specified for class \p Traits template parameter
646 should accept a parameter of type \p Q that can be not the same as \p value_type.
648 The function returns \p true if \p val is found, \p false otherwise.
650 template <typename Q, typename Func>
651 bool find( Q const& val, Func f )
653 return find_( val, f );
656 /// Finds the key \p val using \p pred predicate for searching
658 The function is an analog of \ref cds_nonintrusive_SplitListSet_find_cfunc "find(Q const&, Func)"
659 but \p pred is used for key comparing.
660 \p Less functor has the interface like \p std::less.
661 \p Less must imply the same element order as the comparator used for building the set.
663 template <typename Q, typename Less, typename Func>
664 bool find_with( Q const& val, Less pred, Func f )
666 return find_with_( val, pred, f );
669 /// Finds the key \p val
670 /** \anchor cds_nonintrusive_SplitListSet_find_val
672 The function searches the item with key equal to \p val
673 and returns \p true if it is found, and \p false otherwise.
675 Note the hash functor specified for class \p Traits template parameter
676 should accept a parameter of type \p Q that can be not the same as \ref value_type.
678 template <typename Q>
679 bool find( Q const& val )
681 return base_class::find( val );
684 /// Finds the key \p val using \p pred predicate for searching
686 The function is an analog of \ref cds_nonintrusive_SplitListSet_find_val "find(Q const&)"
687 but \p pred is used for key comparing.
688 \p Less functor has the interface like \p std::less.
689 \p Less must imply the same element order as the comparator used for building the set.
691 template <typename Q, typename Less>
692 bool find_with( Q const& val, Less pred )
694 return base_class::find_with( val, typename maker::template predicate_wrapper<Less>::type() );
697 /// Finds the key \p key and return the item found
698 /** \anchor cds_nonintrusive_SplitListSet_hp_get
699 The function searches the item with key equal to \p key
700 and assigns the item found to guarded pointer \p ptr.
701 The function returns \p true if \p key is found, and \p false otherwise.
702 If \p key is not found the \p ptr parameter is not changed.
704 @note Each \p guarded_ptr object uses one GC's guard which can be limited resource.
708 typedef cds::container::SplitListSet< your_template_params > splitlist_set;
709 splitlist_set theSet;
712 splitlist_set::guarded_ptr gp;
713 if ( theSet.get( gp, 5 )) {
717 // Destructor of guarded_ptr releases internal HP guard
721 Note the compare functor specified for split-list set
722 should accept a parameter of type \p Q that can be not the same as \p value_type.
724 template <typename Q>
725 bool get( guarded_ptr& ptr, Q const& key )
727 return get_( ptr.guard(), key );
730 /// Finds \p key and return the item found
732 The function is an analog of \ref cds_nonintrusive_SplitListSet_hp_get "get( guarded_ptr&, Q const&)"
733 but \p pred is used for comparing the keys.
735 \p Less functor has the semantics like \p std::less but should take arguments of type \ref value_type and \p Q
737 \p pred must imply the same element order as the comparator used for building the set.
739 template <typename Q, typename Less>
740 bool get_with( guarded_ptr& ptr, Q const& key, Less pred )
742 return get_with_( ptr.guard(), key, pred );
745 /// Clears the set (non-atomic)
747 The function unlink all items from the set.
748 The function is not atomic and not lock-free and should be used for debugging only.
755 /// Checks if the set is empty
757 Emptiness is checked by item counting: if item count is zero then assume that the set is empty.
758 Thus, the correct item counting feature is an important part of split-list set implementation.
762 return base_class::empty();
765 /// Returns item count in the set
768 return base_class::size();
773 using base_class::extract_;
774 using base_class::get_;
776 template <typename Q, typename Less>
777 bool extract_with_( typename gc::Guard& guard, Q const& key, Less pred )
779 return base_class::extract_with_( guard, key, typename maker::template predicate_wrapper<Less>::type() );
782 template <typename Q, typename Less>
783 bool get_with_( typename gc::Guard& guard, Q const& key, Less pred )
785 return base_class::get_with_( guard, key, typename maker::template predicate_wrapper<Less>::type() );
793 }} // namespace cds::container
795 #endif // #ifndef __CDS_CONTAINER_SPLIT_LIST_SET_H