3 #ifndef CDSLIB_CONTAINER_SKIP_LIST_SET_NOGC_H
4 #define CDSLIB_CONTAINER_SKIP_LIST_SET_NOGC_H
6 #include <cds/intrusive/skip_list_nogc.h>
7 #include <cds/container/details/skip_list_base.h>
8 #include <cds/details/binary_functor_wrapper.h>
9 #include <cds/gc/nogc.h>
10 #include <cds/details/allocator.h>
12 namespace cds { namespace container {
14 namespace skip_list { namespace details {
15 struct set_key_accessor
17 template <typename NodeType>
18 typename NodeType::stored_value_type const& operator()( NodeType const& node ) const
23 }} // namespace skip_list::details
26 template <typename T, typename Traits >
27 struct make_skip_list_set_nogc
29 typedef cds::gc::nogc gc;
31 typedef Traits traits;
33 typedef cds::intrusive::skip_list::node< gc > intrusive_node_type;
34 struct node_type: public intrusive_node_type
36 typedef intrusive_node_type base_class;
37 typedef typename base_class::atomic_ptr atomic_ptr;
38 typedef atomic_ptr tower_item_type;
39 typedef value_type stored_value_type;
42 //atomic_ptr m_arrTower[] ; // allocated together with node_type in single memory block
45 node_type( unsigned int nHeight, atomic_ptr * pTower, Q const& v )
49 new (pTower) atomic_ptr[ nHeight - 1 ];
50 base_class::make_tower( nHeight, pTower );
54 template <typename Q, typename... Args>
55 node_type( unsigned int nHeight, atomic_ptr * pTower, Q&& q, Args&&... args )
56 : m_Value( std::forward<Q>(q), std::forward<Args>(args)... )
59 new (pTower) atomic_ptr[ nHeight - 1 ];
60 base_class::make_tower( nHeight, pTower );
64 node_type() = delete; // no default ctor
67 typedef skip_list::details::node_allocator< node_type, traits> node_allocator;
69 struct node_deallocator {
70 void operator ()( node_type * pNode )
72 node_allocator().Delete( pNode );
76 typedef skip_list::details::dummy_node_builder<intrusive_node_type> dummy_node_builder;
78 typedef typename traits::key_accessor key_accessor;
79 typedef typename opt::details::make_comparator< value_type, traits >::type key_comparator;
82 template <typename Less>
84 typedef compare_wrapper< node_type, cds::opt::details::make_comparator_from_less<Less>, key_accessor > type;
88 typedef typename cds::intrusive::skip_list::make_traits<
89 cds::opt::type_traits< traits >
90 ,cds::intrusive::opt::hook< intrusive::skip_list::base_hook< cds::opt::gc< gc > > >
91 ,cds::intrusive::opt::disposer< node_deallocator >
92 ,cds::intrusive::skip_list::internal_node_builder< dummy_node_builder >
93 ,cds::opt::compare< cds::details::compare_wrapper< node_type, key_comparator, key_accessor > >
94 >::type intrusive_type_traits;
96 typedef cds::intrusive::SkipListSet< gc, node_type, intrusive_type_traits> type;
98 } // namespace details
101 /// Lock-free skip-list set (template specialization for gc::nogc)
102 /** @ingroup cds_nonintrusive_set
103 \anchor cds_nonintrusive_SkipListSet_nogc
105 This specialization is intended for so-called persistent usage when no item
106 reclamation may be performed. The class does not support deleting of list item.
107 See \ref cds_nonintrusive_SkipListSet_hp "SkipListSet" for detailed description.
110 - \p T - type to be stored in the list.
111 - \p Traits - type traits. See skip_list::traits for explanation.
113 It is possible to declare option-based list with cds::container::skip_list::make_traits metafunction istead of \p Traits template
114 argument. \p Options template arguments of cds::container::skip_list::make_traits metafunction are:
115 - opt::compare - key comparison functor. No default functor is provided.
116 If the option is not specified, the opt::less is used.
117 - opt::less - specifies binary predicate used for key comparison. Default is \p std::less<T>.
118 - opt::item_counter - the type of item counting feature. Default is \ref atomicity::empty_item_counter that is no item counting.
119 - opt::memory_model - C++ memory ordering model. Can be opt::v::relaxed_ordering (relaxed memory model, the default)
120 or opt::v::sequential_consistent (sequentially consisnent memory model).
121 - skip_list::random_level_generator - random level generator. Can be skip_list::xorshift, skip_list::turbo_pascal or
122 user-provided one. See skip_list::random_level_generator option description for explanation.
123 Default is \p %skip_list::turbo_pascal.
124 - opt::allocator - allocator for skip-list node. Default is \ref CDS_DEFAULT_ALLOCATOR.
125 - opt::back_off - back-off strategy used. If the option is not specified, the cds::backoff::Default is used.
126 - opt::stat - internal statistics. Available types: skip_list::stat, skip_list::empty_stat (the default)
130 #ifdef CDS_DOXYGEN_INVOKED
131 class Traits = skip_list::traits
136 class SkipListSet< gc::nogc, T, Traits >:
137 #ifdef CDS_DOXYGEN_INVOKED
138 protected intrusive::SkipListSet< cds::gc::nogc, T, Traits >
140 protected details::make_skip_list_set_nogc< T, typename cds::opt::replace_key_accessor< Traits, skip_list::details::set_key_accessor >::type >::type
144 typedef details::make_skip_list_set_nogc< T, typename cds::opt::replace_key_accessor< Traits, skip_list::details::set_key_accessor >::type > maker;
145 typedef typename maker::type base_class;
148 typedef typename base_class::gc gc ; ///< Garbage collector used
149 typedef T value_type ; ///< Value type stored in the set
150 typedef Traits options ; ///< Options specified
152 typedef typename base_class::back_off back_off ; ///< Back-off strategy used
153 typedef typename options::allocator allocator_type ; ///< Allocator type used for allocate/deallocate the skip-list nodes
154 typedef typename base_class::item_counter item_counter ; ///< Item counting policy used
155 typedef typename maker::key_comparator key_comparator ; ///< key compare functor
156 typedef typename base_class::memory_model memory_model ; ///< Memory ordering. See cds::opt::memory_model option
157 typedef typename options::stat stat ; ///< internal statistics type
158 typedef typename base_class::random_level_generator random_level_generator ; ///< random level generator
161 typedef cds::container::skip_list::implementation_tag implementation_tag;
166 typedef typename maker::node_type node_type;
167 typedef typename maker::node_allocator node_allocator;
168 typedef typename std::conditional<
169 std::is_same< typename options::key_accessor, opt::none >::value,
170 skip_list::details::set_key_accessor,
171 typename options::key_accessor
172 >::type key_accessor;
174 typedef std::unique_ptr< node_type, typename maker::node_deallocator > scoped_node_ptr;
179 typedef skip_list::details::iterator< typename base_class::iterator > iterator;
181 /// Const iterator type
182 typedef skip_list::details::iterator< typename base_class::const_iterator > const_iterator;
184 /// Returns a forward iterator addressing the first element in a set
187 return iterator( base_class::begin() );
190 /// Returns a forward const iterator addressing the first element in a set
192 const_iterator begin() const
194 return const_iterator( base_class::begin() );
196 const_iterator cbegin() const
198 return const_iterator( base_class::cbegin() );
202 /// Returns a forward iterator that addresses the location succeeding the last element in a set.
205 return iterator( base_class::end() );
208 /// Returns a forward const iterator that addresses the location succeeding the last element in a set.
210 const_iterator end() const
212 return const_iterator( base_class::end() );
214 const_iterator cend() const
216 return const_iterator( base_class::cend() );
222 static iterator node_to_iterator( node_type * pNode )
225 return iterator( base_class::iterator::from_node( pNode ));
235 /// Destructor destroys the set object
241 The function inserts \p val in the set if it does not contain
242 an item with key equal to \p val.
244 Return an iterator pointing to inserted item if success, otherwise \ref end()
246 template <typename Q>
247 iterator insert( const Q& val )
249 scoped_node_ptr sp( node_allocator().New( base_class::random_level(), val ));
250 if ( base_class::insert( *sp.get() )) {
251 return node_to_iterator( sp.release() );
256 /// Inserts data of type \ref value_type constructed with <tt>std::forward<Args>(args)...</tt>
258 Return an iterator pointing to inserted item if success \ref end() otherwise
260 template <typename... Args>
261 iterator emplace( Args&&... args )
263 scoped_node_ptr sp( node_allocator().New( base_class::random_level(), std::forward<Args>(args)... ));
264 if ( base_class::insert( *sp.get() )) {
265 return node_to_iterator( sp.release() );
270 /// Ensures that the item \p val exists in the set
272 The operation inserts new item if the key \p val is not found in the set.
273 Otherwise, the function returns an iterator that points to item found.
275 Returns <tt> std::pair<iterator, bool> </tt> where \p first is an iterator pointing to
276 item found or inserted, \p second is true if new item has been added or \p false if the item
277 already is in the set.
279 template <typename Q>
280 std::pair<iterator, bool> ensure( const Q& val )
282 scoped_node_ptr sp( node_allocator().New( base_class::random_level(), val ));
284 std::pair<bool, bool> bRes = base_class::ensure( *sp, [&pNode](bool, node_type& item, node_type&) { pNode = &item; } );
285 if ( bRes.first && bRes.second )
288 return std::make_pair( node_to_iterator( pNode ), bRes.second );
292 /** \anchor cds_nonintrusive_SkipListSet_nogc_find_val
294 The function searches the item with key equal to \p key
295 and returns an iterator pointed to item found if the key is found,
296 and \ref end() otherwise
298 template <typename Q>
299 iterator find( Q const& key ) const
301 node_type * pNode = base_class::find( key );
303 return node_to_iterator( pNode );
304 return base_class::nonconst_end();
307 /// Finds the key \p val using \p pred predicate for searching
309 The function is an analog of \ref cds_nonintrusive_SkipListSet_nogc_find_val "find(Q const&)"
310 but \p pred is used for key comparing.
311 \p Less functor has the interface like \p std::less.
312 \p Less must imply the same element order as the comparator used for building the set.
314 template <typename Q, typename Less>
315 iterator find_with( Q const& key, Less pred ) const
318 node_type * pNode = base_class::find_with( key, cds::details::predicate_wrapper< node_type, Less, key_accessor>() );
320 return node_to_iterator( pNode );
321 return base_class::nonconst_end();
324 /// Gets minimum key from the set
326 If the set is empty the function returns \p nullptr
328 value_type * get_min() const
330 node_type * pNode = base_class::get_min();
331 return pNode ? &pNode->m_Value : nullptr;
334 /// Gets maximum key from the set
336 The function returns \p nullptr if the set is empty
338 value_type * get_max() const
340 node_type * pNode = base_class::get_max();
341 return pNode ? &pNode->m_Value : nullptr;
344 /// Clears the set (non-atomic)
346 The function is not atomic.
347 Finding and/or inserting is prohibited while clearing.
348 Otherwise an unpredictable result may be encountered.
349 Thus, \p clear() may be used only for debugging purposes.
356 /// Checks if the set is empty
359 return base_class::empty();
362 /// Returns item count in the set
364 The value returned depends on item counter type provided by \p Traits template parameter.
365 If it is atomicity::empty_item_counter this function always returns 0.
366 The function is not suitable for checking the set emptiness, use \ref empty
367 member function for this purpose.
371 return base_class::size();
374 /// Returns maximum height of skip-list. The max height is a constant for each object and does not exceed 32.
375 static CDS_CONSTEXPR unsigned int max_height() CDS_NOEXCEPT
377 return base_class::max_height();
380 /// Returns const reference to internal statistics
381 stat const& statistics() const
383 return base_class::statistics();
389 #endif // ifndef CDSLIB_CONTAINER_SKIP_LIST_SET_NOGC_H