3 #ifndef CDSLIB_INTRUSIVE_STRIPED_SET_H
4 #define CDSLIB_INTRUSIVE_STRIPED_SET_H
6 #include <cds/intrusive/details/base.h>
7 #include <cds/intrusive/striped_set/adapter.h>
8 #include <cds/intrusive/striped_set/striping_policy.h>
10 namespace cds { namespace intrusive {
11 /// StripedSet related definitions
12 namespace striped_set {
14 /** @defgroup cds_striped_resizing_policy Resizing policy for striped/refinable set/map
16 Resizing policy for \p intrusive::StripedSet, \p container::StripedSet and \p container::StripedMap.
19 } // namespace striped_set
22 /** @ingroup cds_intrusive_map
25 - [2008] Maurice Herlihy, Nir Shavit "The Art of Multiprocessor Programming"
27 Lock striping is very simple technique.
28 The set consists of the bucket table and the array of locks.
29 Initially, the capacity of lock array and bucket table is the same.
30 When set is resized, bucket table capacity will be doubled but lock array will not.
31 The lock \p i protects each bucket \p j, where <tt> j = i mod L </tt>,
32 where \p L - the size of lock array.
35 - \p Container - the container class that is used as bucket table entry. The \p Container class should support
36 an uniform interface described below.
37 - \p Options - options
39 The \p %StripedSet class does not exactly dictate the type of container that should be used as a \p Container bucket.
40 Instead, the class supports different intrusive container type for the bucket, for exampe,
41 \p boost::intrusive::list, \p boost::intrusive::set and others.
43 Remember that \p %StripedSet class algorithm ensures sequential blocking access to its bucket through the mutex type you specify
44 among \p Options template arguments.
47 - \p opt::mutex_policy - concurrent access policy.
48 Available policies: \p striped_set::striping, \p striped_set::refinable.
49 Default is \p %striped_set::striping.
50 - \p cds::opt::hash - hash functor. Default option value see <tt>opt::v::hash_selector <opt::none></tt>
51 which selects default hash functor for your compiler.
52 - \p cds::opt::compare - key comparison functor. No default functor is provided.
53 If the option is not specified, the \p opt::less is used.
54 - \p cds::opt::less - specifies binary predicate used for key comparison. Default is \p std::less<T>.
55 - \p cds::opt::item_counter - item counter type. Default is \p atomicity::item_counter since some operation on the counter is performed
56 without locks. Note that item counting is an essential part of the set algorithm, so dummy counter like \p atomicity::empty_item_counter
58 - \p cds::opt::allocator - the allocator type using for memory allocation of bucket table and lock array. Default is \ref CDS_DEFAULT_ALLOCATOR.
59 - \p cds::opt::resizing_policy - the resizing policy - a functor that decides when to resize the hash set.
60 Default option value depends on bucket container type:
61 for sequential containers like \p boost::intrusive::list the resizing policy is <tt>cds::container::striped_set::load_factor_resizing<4> </tt>;
62 for other type of containers like \p boost::intrusive::set the resizing policy is cds::container::striped_set::no_resizing.
63 See \ref cds_striped_resizing_policy "available resizing policy".
64 Note that the choose of resizing policy depends of \p Container type:
65 for sequential containers like \p boost::intrusive::list the right policy can significantly improve performance.
66 For other, non-sequential types of \p Container (like a \p boost::intrusive::set) the resizing policy is not so important.
67 - \p cds::opt::buffer - a buffer type used only for \p boost::intrusive::unordered_set.
68 Default is <tt>cds::opt::v::static_buffer< cds::any_type, 256 > </tt>.
70 \p opt::compare or \p opt::less options are used in some \p Container class for ordering.
71 \p %opt::compare option has the highest priority: if \p %opt::compare is specified, \p %opt::less is not used.
73 You can pass other option that would be passed to \p adapt metafunction, see below.
75 <b>Internal details</b>
77 The \p %StripedSet class cannot utilize the \p Container specified directly, but only its adapted variant which
78 supports an unified interface. Internally, the adaptation is made via \p intrusive::striped_set::adapt metafunction that wraps bucket container
79 and provides the unified bucket interface suitable for \p %StripedSet. Such adaptation is completely transparent for you -
80 you don't need to call \p adapt metafunction directly, \p %StripedSet class's internal machinery itself invokes appropriate
81 \p adapt metafunction specialization to adjust your \p Container container class to \p %StripedSet bucket's internal interface.
82 All you need is to include a right header before <tt>striped_set.h</tt>.
84 By default, <tt>intrusive::striped_set::adapt<AnyContainer, OptionPack> </tt> metafunction does not make any wrapping to \p AnyContainer,
85 so, the result <tt>intrusive::striped_set::adapt<AnyContainer, OptionPack>::type </tt> is the same as \p AnyContainer.
86 However, there are a lot of specializations of \p %intrusive::striped_set::adapt for \p boost::intrusive containers, see table below.
87 Any of this specialization wraps corresponding container making it suitable for the set's bucket.
88 Remember, you should include the proper header file for \p adapt <b>before</b> including <tt>striped_set.h</tt>.
90 \note It is important to specify <tt>boost::intrusive::constant_time_size<true></tt> option
91 for all \p boost::intrusive container that supports this option. Fast item counting feature is essential part of
92 \p %StripedSet resizing algorithm.
97 <th>.h-file for \p adapt</th>
102 <td> \p boost::intrusive::list</td>
103 <td><tt><cds/intrusive/striped_set/boost_list.h></tt></td>
105 #include <cds/intrusive/striped_set/boost_list.h>
106 #include <cds/intrusive/striped_set.h>
107 typedef cds::intrusive::StripedSet<
108 boost::intrusive::list<T, boost::intrusive::constant_time_size<true> >,
109 cds::opt::less< std::less<T> >
115 Template argument pack \p Options <b>must</b> contain cds::opt::less or cds::opt::compare for type \p T stored in the list
119 <td> \p boost::intrusive::slist</td>
120 <td><tt><cds/intrusive/striped_set/boost_slist.h></tt></td>
122 #include <cds/intrusive/striped_set/boost_slist.h>
123 #include <cds/intrusive/striped_set.h>
124 typedef cds::intrusive::StripedSet<
125 boost::intrusive::slist<T, boost::intrusive::constant_time_size<true> >,
126 cds::opt::less< std::less<T> >
132 Template argument pack \p Options <b>must</b> contain \p cds::opt::less or \p cds::opt::compare for type \p T stored in the list
136 <td> \p boost::intrusive::set</td>
137 <td><tt><cds/intrusive/striped_set/boost_set.h></tt></td>
139 #include <cds/intrusive/striped_set/boost_set.h>
140 #include <cds/intrusive/striped_set.h>
141 typedef cds::intrusive::StripedSet<
142 boost::intrusive::set<T, boost::intrusive::constant_time_size<true> >
147 Note that \p boost::intrusive::compare option using in \p boost::intrusive::set
148 should support \p T type stored in the set and any type \p Q that you can use
149 in \p erase() and \p find() member functions.
153 <td> \p boost::intrusive::unordered_set</td>
154 <td><tt><cds/intrusive/striped_set/boost_unordered_set.h></tt></td>
156 #include <cds/intrusive/striped_set/boost_unordered_set.h>
157 #include <cds/intrusive/striped_set.h>
158 typedef cds::intrusive::StripedSet<
159 boost::intrusive::unordered_set<T
160 ,boost::intrusive::constant_time_size<true>
161 ,boost::intrusive::hash< user_provided_hash_functor >
167 You should provide two different hash function \p h1 and \p h2 - one for \p boost::intrusive::unordered_set
168 and other for \p %StripedSet. For the best result, \p h1 and \p h2 must be orthogonal i.e. <tt>h1(X) != h2(X)</tt> for any value \p X
170 The option \p opt::buffer is used for \p boost::intrusive::bucket_traits. Default is <tt> cds::opt::v::static_buffer< cds::any_type, 256 > </tt>.
171 The resizing policy should correlate with the buffer capacity.
172 The default resizing policy is <tt>cds::container::striped_set::load_factor_resizing<256> </tt> what gives load factor 1 for
173 default bucket buffer that is the best for \p boost::intrusive::unordered_set.
177 <td> \p boost::intrusive::avl_set</td>
178 <td><tt><cds/intrusive/striped_set/boost_avl_set.h></tt></td>
180 #include <cds/intrusive/striped_set/boost_avl_set.h>
181 #include <cds/intrusive/striped_set.h>
182 typedef cds::intrusive::StripedSet<
183 boost::intrusive::avl_set<T, boost::intrusive::constant_time_size<true> >
188 Note that \p boost::intrusive::compare option using in \p boost::intrusive::avl_set
189 should support \p T type stored in the set and any type \p Q that you can use
190 in \p erase() and \p find() member functions.
194 <td> \p boost::intrusive::sg_set</td>
195 <td><tt><cds/intrusive/striped_set/boost_sg_set.h></tt></td>
197 #include <cds/intrusive/striped_set/boost_sg_set.h>
198 #include <cds/intrusive/striped_set.h>
199 typedef cds::intrusive::StripedSet<
200 boost::intrusive::sg_set<T, boost::intrusive::constant_time_size<true> >
205 Note that \p boost::intrusive::compare option using in \p boost::intrusive::sg_set
206 should support \p T type stored in the set and any type \p Q that you can use
207 in \p erase() and \p find() member functions.
211 <td> \p boost::intrusive::splay_set</td>
212 <td><tt><cds/intrusive/striped_set/boost_splay_set.h></tt></td>
214 #include <cds/intrusive/striped_set/boost_splay_set.h>
215 #include <cds/intrusive/striped_set.h>
216 typedef cds::intrusive::StripedSet<
217 boost::intrusive::splay_set<T, boost::intrusive::constant_time_size<true> >
222 Note that \p boost::intrusive::compare option using in \p boost::intrusive::splay_set
223 should support \p T type stored in the set and any type \p Q that you can use
224 in \p erase() and \p find() member functions.
228 <td> \p boost::intrusive::treap_set</td>
229 <td><tt><cds/intrusive/striped_set/boost_treap_set.h></tt></td>
231 #include <cds/intrusive/striped_set/boost_treap_set.h>
232 #include <cds/intrusive/striped_set.h>
233 typedef cds::intrusive::StripedSet<
234 boost::intrusive::treap_set<T, boost::intrusive::constant_time_size<true> >
239 Note that \p boost::intrusive::compare option using in \p boost::intrusive::treap_set
240 should support \p T type stored in the set and any type \p Q that you can use
241 in \p erase() and \p find() member functions.
246 You can use another intrusive container type as striped set's bucket.
247 Suppose, you have a container class \p MyBestContainer and you want to integrate it with \p StripedSet as bucket type.
248 There are two possibility:
249 - either your \p MyBestContainer class has native support of bucket's interface;
250 in this case, you can use default \p intrusive::striped_set::adapt metafunction;
251 - or your \p MyBestContainer class does not support bucket's interface, which means, that you should create a specialization of
252 <tt>cds::intrusive::striped_set::adapt<MyBestContainer> </tt> metafunction providing necessary interface.
254 The <tt>intrusive::striped_set::adapt< Container, OptionPack ></tt> metafunction has two template argument:
255 - \p Container is the class that should be used as the bucket, for example, <tt>boost::intrusive::list< T ></tt>.
256 - \p OptionPack is the packed options from \p %StripedSet declaration. The \p adapt metafunction can use
257 any option from \p OptionPack for its internal use. For example, a \p compare option can be passed to \p adapt
258 metafunction via \p OptionPack argument of \p %StripedSet declaration.
260 See \p intrusive::striped_set::adapt metafunction for the description of interface that the bucket container must provide
261 to be \p %StripedSet compatible.
263 template <class Container, typename... Options>
268 struct default_options {
269 typedef striped_set::striping<> mutex_policy;
270 typedef typename cds::opt::v::hash_selector< cds::opt::none >::type hash;
271 typedef cds::atomicity::item_counter item_counter;
272 typedef CDS_DEFAULT_ALLOCATOR allocator;
273 typedef cds::opt::none resizing_policy;
274 typedef cds::opt::none compare;
275 typedef cds::opt::none less;
278 typedef typename cds::opt::make_options<
279 typename cds::opt::find_type_traits< default_options, Options... >::type
284 typedef Container underlying_container_type ; ///< original intrusive container type for the bucket
285 typedef typename cds::intrusive::striped_set::adapt< underlying_container_type, Options... >::type bucket_type ; ///< container type adapted for hash set
286 typedef typename bucket_type::value_type value_type ; ///< value type stored in the set
288 typedef typename options::hash hash ; ///< Hash functor
289 typedef typename options::item_counter item_counter ; ///< Item counter
290 typedef typename cds::opt::select_default<
291 typename options::resizing_policy,
292 typename bucket_type::default_resizing_policy
293 >::type resizing_policy ; ///< Resizing policy
294 typedef typename options::allocator allocator_type ; ///< allocator type specified in options.
295 typedef typename options::mutex_policy mutex_policy ; ///< Mutex policy
297 typedef cds::details::Allocator< bucket_type, allocator_type > bucket_allocator; ///< bucket allocator type based on allocator_type
300 bucket_type * m_Buckets ; ///< Bucket table
301 size_t m_nBucketMask ; ///< Bucket table size - 1. m_nBucketMask + 1 should be power of two.
302 item_counter m_ItemCounter ; ///< Item counter
303 hash m_Hash ; ///< Hash functor
305 mutex_policy m_MutexPolicy ; ///< Mutex policy
306 resizing_policy m_ResizingPolicy; ///< Resizing policy
308 static const size_t c_nMinimalCapacity = 16 ; ///< Minimal capacity
312 typedef typename mutex_policy::scoped_cell_lock scoped_cell_lock;
313 typedef typename mutex_policy::scoped_full_lock scoped_full_lock;
314 typedef typename mutex_policy::scoped_resize_lock scoped_resize_lock;
319 static size_t calc_init_capacity( size_t nCapacity )
321 nCapacity = cds::beans::ceil2( nCapacity );
322 return nCapacity < c_nMinimalCapacity ? c_nMinimalCapacity : nCapacity;
325 void alloc_bucket_table( size_t nSize )
327 assert( cds::beans::is_power2( nSize ));
328 m_nBucketMask = nSize - 1;
329 m_Buckets = bucket_allocator().NewArray( nSize );
332 static void free_bucket_table( bucket_type * pBuckets, size_t nSize )
334 bucket_allocator().Delete( pBuckets, nSize );
337 template <typename Q>
338 size_t hashing( Q const& v ) const
343 bucket_type * bucket( size_t nHash ) const CDS_NOEXCEPT
345 return m_Buckets + (nHash & m_nBucketMask);
348 template <typename Q, typename Func>
349 bool find_( Q& val, Func f )
351 size_t nHash = hashing( val );
353 scoped_cell_lock sl( m_MutexPolicy, nHash );
354 return bucket( nHash )->find( val, f );
357 template <typename Q, typename Less, typename Func>
358 bool find_with_( Q& val, Less pred, Func f )
360 size_t nHash = hashing( val );
361 scoped_cell_lock sl( m_MutexPolicy, nHash );
362 return bucket( nHash )->find( val, pred, f );
365 void internal_resize( size_t nNewCapacity )
367 // All locks are already locked!
368 m_MutexPolicy.resize( nNewCapacity );
370 size_t nOldCapacity = bucket_count();
371 bucket_type * pOldBuckets = m_Buckets;
373 alloc_bucket_table( nNewCapacity );
375 typedef typename bucket_type::iterator bucket_iterator;
376 bucket_type * pEnd = pOldBuckets + nOldCapacity;
377 for ( bucket_type * pCur = pOldBuckets; pCur != pEnd; ++pCur ) {
378 bucket_iterator itEnd = pCur->end();
379 bucket_iterator itNext;
380 for ( bucket_iterator it = pCur->begin(); it != itEnd; it = itNext ) {
383 bucket( m_Hash( *it ) )->move_item( *pCur, it );
388 free_bucket_table( pOldBuckets, nOldCapacity );
390 m_ResizingPolicy.reset();
395 size_t nOldCapacity = bucket_count();
396 size_t volatile& refBucketMask = m_nBucketMask;
398 scoped_resize_lock al( m_MutexPolicy );
399 if ( al.success() ) {
400 if ( nOldCapacity != refBucketMask + 1 ) {
401 // someone resized already
405 internal_resize( nOldCapacity * 2 );
412 /// Default ctor. The initial capacity is 16.
414 : m_Buckets( nullptr )
415 , m_nBucketMask( c_nMinimalCapacity - 1 )
416 , m_MutexPolicy( c_nMinimalCapacity )
418 alloc_bucket_table( m_nBucketMask + 1 );
421 /// Ctor with initial capacity specified
423 size_t nCapacity ///< Initial size of bucket table and lock array. Must be power of two, the minimum is 16.
425 : m_Buckets( nullptr )
426 , m_nBucketMask( calc_init_capacity(nCapacity) - 1 )
427 , m_MutexPolicy( m_nBucketMask + 1 )
429 alloc_bucket_table( m_nBucketMask + 1 );
432 /// Ctor with resizing policy (copy semantics)
434 This constructor initializes m_ResizingPolicy member with copy of \p resizingPolicy parameter
437 size_t nCapacity ///< Initial size of bucket table and lock array. Must be power of two, the minimum is 16.
438 ,resizing_policy const& resizingPolicy ///< Resizing policy
440 : m_Buckets( nullptr )
441 , m_nBucketMask( ( nCapacity ? calc_init_capacity(nCapacity) : c_nMinimalCapacity ) - 1 )
442 , m_MutexPolicy( m_nBucketMask + 1 )
443 , m_ResizingPolicy( resizingPolicy )
445 alloc_bucket_table( m_nBucketMask + 1 );
448 /// Ctor with resizing policy (move semantics)
450 This constructor initializes m_ResizingPolicy member moving \p resizingPolicy parameter
451 Move semantics is used.
454 size_t nCapacity ///< Initial size of bucket table and lock array. Must be power of two, the minimum is 16.
455 ,resizing_policy&& resizingPolicy ///< Resizing policy
457 : m_Buckets( nullptr )
458 , m_nBucketMask( ( nCapacity ? calc_init_capacity(nCapacity) : c_nMinimalCapacity ) - 1 )
459 , m_MutexPolicy( m_nBucketMask + 1 )
460 , m_ResizingPolicy( std::forward<resizing_policy>( resizingPolicy ) )
462 alloc_bucket_table( m_nBucketMask + 1 );
465 /// Destructor destroys internal data
468 free_bucket_table( m_Buckets, m_nBucketMask + 1 );
474 The function inserts \p val in the set if it does not contain
475 an item with key equal to \p val.
477 Returns \p true if \p val is placed into the set, \p false otherwise.
479 bool insert( value_type& val )
481 return insert( val, []( value_type& ) {} );
486 The function allows to split creating of new item into two part:
487 - create item with key only
488 - insert new item into the set
489 - if inserting is success, calls \p f functor to initialize value-field of \p val.
491 The functor signature is:
493 void func( value_type& val );
495 where \p val is the item inserted.
497 template <typename Func>
498 bool insert( value_type& val, Func f )
502 size_t nHash = hashing( val );
503 bucket_type * pBucket;
505 scoped_cell_lock sl( m_MutexPolicy, nHash );
506 pBucket = bucket( nHash );
507 bOk = pBucket->insert( val, f );
508 bResize = bOk && m_ResizingPolicy( ++m_ItemCounter, *this, *pBucket );
516 /// Ensures that the \p val exists in the set
518 The operation performs inserting or changing data with lock-free manner.
520 If the item \p val not found in the set, then \p val is inserted into the set.
521 Otherwise, the functor \p func is called with item found.
522 The functor signature is:
524 void func( bool bNew, value_type& item, value_type& val );
527 - \p bNew - \p true if the item has been inserted, \p false otherwise
528 - \p item - item of the set
529 - \p val - argument \p val passed into the \p ensure function
530 If new item has been inserted (i.e. \p bNew is \p true) then \p item and \p val arguments
531 refers to the same thing.
533 The functor may change non-key fields of the \p item.
535 Returns <tt> std::pair<bool, bool> </tt> where \p first is \p true if operation is successful,
536 \p second is \p true if new item has been added or \p false if the item with \p key
537 already is in the set.
539 template <typename Func>
540 std::pair<bool, bool> ensure( value_type& val, Func func )
542 std::pair<bool, bool> result;
544 size_t nHash = hashing( val );
545 bucket_type * pBucket;
547 scoped_cell_lock sl( m_MutexPolicy, nHash );
548 pBucket = bucket( nHash );
550 result = pBucket->ensure( val, func );
551 bResize = result.first && result.second && m_ResizingPolicy( ++m_ItemCounter, *this, *pBucket );
559 /// Unlink the item \p val from the set
561 The function searches the item \p val in the set and unlink it
562 if it is found and is equal to \p val (here, the equality means that
563 \p val belongs to the set: if \p item is an item found then
564 unlink is successful iif <tt>&val == &item</tt>)
566 The function returns \p true if success and \p false otherwise.
568 bool unlink( value_type& val )
571 size_t nHash = hashing( val );
573 scoped_cell_lock sl( m_MutexPolicy, nHash );
574 bOk = bucket( nHash )->unlink( val );
582 /// Deletes the item from the set
583 /** \anchor cds_intrusive_StripedSet_erase
584 The function searches an item with key equal to \p val in the set,
585 unlinks it from the set, and returns a pointer to unlinked item.
587 If the item with key equal to \p val is not found the function return \p nullptr.
589 Note the hash functor should accept a parameter of type \p Q that can be not the same as \p value_type.
591 template <typename Q>
592 value_type * erase( Q const& val )
594 return erase( val, [](value_type const&) {} );
597 /// Deletes the item from the set using \p pred predicate for searching
599 The function is an analog of \ref cds_intrusive_StripedSet_erase "erase(Q const&)"
600 but \p pred is used for key comparing
601 \p Less has the interface like \p std::less.
602 \p pred must imply the same element order as the comparator used for building the set.
604 template <typename Q, typename Less>
605 value_type * erase_with( Q const& val, Less pred )
607 return erase_with( val, pred, [](value_type const&) {} );
610 /// Deletes the item from the set
611 /** \anchor cds_intrusive_StripedSet_erase_func
613 The function searches an item with key equal to \p val in the set,
614 call \p f functor with item found, unlinks it from the set, and returns a pointer to unlinked item.
616 The \p Func interface is
619 void operator()( value_type const& item );
623 If the item with key equal to \p val is not found the function return \p false.
625 Note the hash functor should accept a parameter of type \p Q that can be not the same as \p value_type.
627 template <typename Q, typename Func>
628 value_type * erase( Q const& val, Func f )
630 size_t nHash = hashing( val );
633 scoped_cell_lock sl( m_MutexPolicy, nHash );
634 pVal = bucket( nHash )->erase( val, f );
642 /// Deletes the item from the set using \p pred predicate for searching
644 The function is an analog of \ref cds_intrusive_StripedSet_erase_func "erase(Q const&, Func)"
645 but \p pred is used for key comparing
646 \p Less has the interface like \p std::less.
647 \p pred must imply the same element order as the comparator used for building the set.
649 template <typename Q, typename Less, typename Func>
650 value_type * erase_with( Q const& val, Less pred, Func f )
652 size_t nHash = hashing( val );
655 scoped_cell_lock sl( m_MutexPolicy, nHash );
656 pVal = bucket( nHash )->erase( val, pred, f );
664 /// Find the key \p val
665 /** \anchor cds_intrusive_StripedSet_find_func
666 The function searches the item with key equal to \p val and calls the functor \p f for item found.
667 The interface of \p Func functor is:
670 void operator()( value_type& item, Q& val );
673 where \p item is the item found, \p val is the <tt>find</tt> function argument.
675 The functor may change non-key fields of \p item.
677 The \p val argument is non-const since it can be used as \p f functor destination i.e., the functor
678 may modify both arguments.
680 Note the hash functor specified for class \p Traits template parameter
681 should accept a parameter of type \p Q that can be not the same as \p value_type.
683 The function returns \p true if \p val is found, \p false otherwise.
685 template <typename Q, typename Func>
686 bool find( Q& val, Func f )
688 return find_( val, f );
691 /// Find the key \p val using \p pred predicate
693 The function is an analog of \ref cds_intrusive_StripedSet_find_func "find(Q&, Func)"
694 but \p pred is used for key comparing
695 \p Less has the interface like \p std::less.
696 \p pred must imply the same element order as the comparator used for building the set.
698 template <typename Q, typename Less, typename Func>
699 bool find_with( Q& val, Less pred, Func f )
701 return find_with_( val, pred, f );
704 /// Find the key \p val
705 /** \anchor cds_intrusive_StripedSet_find_cfunc
706 The function searches the item with key equal to \p val and calls the functor \p f for item found.
707 The interface of \p Func functor is:
710 void operator()( value_type& item, Q const& val );
713 where \p item is the item found, \p val is the <tt>find</tt> function argument.
715 The functor may change non-key fields of \p item.
717 The \p val argument is non-const since it can be used as \p f functor destination i.e., the functor
718 may modify both arguments.
720 The function returns \p true if \p val is found, \p false otherwise.
722 template <typename Q, typename Func>
723 bool find( Q const& val, Func f )
725 return find_( val, f );
728 /// Find the key \p val using \p pred predicate
730 The function is an analog of \ref cds_intrusive_StripedSet_find_cfunc "find(Q const&, Func)"
731 but \p pred is used for key comparing
732 \p Less has the interface like \p std::less.
733 \p pred must imply the same element order as the comparator used for building the set.
735 template <typename Q, typename Less, typename Func>
736 bool find_with( Q const& val, Less pred, Func f )
738 return find_with_( val, pred, f );
741 /// Find the key \p val
742 /** \anchor cds_intrusive_StripedSet_find_val
743 The function searches the item with key equal to \p val
744 and returns \p true if it is found, and \p false otherwise.
746 Note the hash functor specified for class \p Traits template parameter
747 should accept a parameter of type \p Q that can be not the same as \p value_type.
749 template <typename Q>
750 bool find( Q const& val )
752 return find( val, [](value_type&, Q const& ) {} );
755 /// Find the key \p val using \p pred predicate
757 The function is an analog of \ref cds_intrusive_StripedSet_find_val "find(Q const&)"
758 but \p pred is used for key comparing
759 \p Less has the interface like \p std::less.
760 \p pred must imply the same element order as the comparator used for building the set.
762 template <typename Q, typename Less>
763 bool find_with( Q const& val, Less pred )
765 return find_with( val, pred, [](value_type& , Q const& ) {} );
770 The function unlinks all items from the set.
774 // locks entire array
775 scoped_full_lock sl( m_MutexPolicy );
777 size_t nBucketCount = bucket_count();
778 bucket_type * pBucket = m_Buckets;
779 for ( size_t i = 0; i < nBucketCount; ++i, ++pBucket )
781 m_ItemCounter.reset();
784 /// Clears the set and calls \p disposer for each item
786 The function unlinks all items from the set calling \p disposer for each item.
787 \p Disposer functor interface is:
790 void operator()( value_type * p );
794 template <typename Disposer>
795 void clear_and_dispose( Disposer disposer )
797 // locks entire array
798 scoped_full_lock sl( m_MutexPolicy );
800 size_t nBucketCount = bucket_count();
801 bucket_type * pBucket = m_Buckets;
802 for ( size_t i = 0; i < nBucketCount; ++i, ++pBucket )
803 pBucket->clear( disposer );
804 m_ItemCounter.reset();
807 /// Checks if the set is empty
809 Emptiness is checked by item counting: if item count is zero then the set is empty.
816 /// Returns item count in the set
819 return m_ItemCounter;
822 /// Returns the size of hash table
824 The hash table size is non-constant and can be increased via resizing.
826 size_t bucket_count() const
828 return m_nBucketMask + 1;
831 /// Returns lock array size
832 size_t lock_count() const
834 return m_MutexPolicy.lock_count();
837 /// Returns resizing policy object
838 resizing_policy& get_resizing_policy()
840 return m_ResizingPolicy;
843 /// Returns resizing policy (const version)
844 resizing_policy const& get_resizing_policy() const
846 return m_ResizingPolicy;
849 }} // namespace cds::itrusive
851 #endif // #ifndef CDSLIB_INTRUSIVE_STRIPED_SET_H