3 #ifndef __CDS_CONTAINER_SKIP_LIST_SET_NOGC_H
4 #define __CDS_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 type_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, 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 type_traits::key_accessor key_accessor;
79 typedef typename opt::details::make_comparator< value_type, 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< type_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::type_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::type_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
162 typedef typename maker::node_type node_type;
163 typedef typename maker::node_allocator node_allocator;
164 typedef typename std::conditional<
165 std::is_same< typename options::key_accessor, opt::none >::value,
166 skip_list::details::set_key_accessor,
167 typename options::key_accessor
168 >::type key_accessor;
170 typedef std::unique_ptr< node_type, typename maker::node_deallocator > scoped_node_ptr;
175 typedef skip_list::details::iterator< typename base_class::iterator > iterator;
177 /// Const iterator type
178 typedef skip_list::details::iterator< typename base_class::const_iterator > const_iterator;
180 /// Returns a forward iterator addressing the first element in a set
183 return iterator( base_class::begin() );
186 /// Returns a forward const iterator addressing the first element in a set
188 const_iterator begin() const
190 return const_iterator( base_class::begin() );
192 const_iterator cbegin()
194 return const_iterator( base_class::cbegin() );
198 /// Returns a forward iterator that addresses the location succeeding the last element in a set.
201 return iterator( base_class::end() );
204 /// Returns a forward const iterator that addresses the location succeeding the last element in a set.
206 const_iterator end() const
208 return const_iterator( base_class::end() );
210 const_iterator cend()
212 return const_iterator( base_class::cend() );
218 static iterator node_to_iterator( node_type * pNode )
221 return iterator( base_class::iterator::from_node( pNode ));
231 /// Destructor destroys the set object
237 The function inserts \p val in the set if it does not contain
238 an item with key equal to \p val.
240 Return an iterator pointing to inserted item if success, otherwise \ref end()
242 template <typename Q>
243 iterator insert( const Q& val )
245 scoped_node_ptr sp( node_allocator().New( base_class::random_level(), val ));
246 if ( base_class::insert( *sp.get() )) {
247 return node_to_iterator( sp.release() );
252 /// Inserts data of type \ref value_type constructed with <tt>std::forward<Args>(args)...</tt>
254 Return an iterator pointing to inserted item if success \ref end() otherwise
256 template <typename... Args>
257 iterator emplace( Args&&... args )
259 scoped_node_ptr sp( node_allocator().New( base_class::random_level(), std::forward<Args>(args)... ));
260 if ( base_class::insert( *sp.get() )) {
261 return node_to_iterator( sp.release() );
266 /// Ensures that the item \p val exists in the set
268 The operation inserts new item if the key \p val is not found in the set.
269 Otherwise, the function returns an iterator that points to item found.
271 Returns <tt> std::pair<iterator, bool> </tt> where \p first is an iterator pointing to
272 item found or inserted, \p second is true if new item has been added or \p false if the item
273 already is in the set.
275 template <typename Q>
276 std::pair<iterator, bool> ensure( const Q& val )
278 scoped_node_ptr sp( node_allocator().New( base_class::random_level(), val ));
280 std::pair<bool, bool> bRes = base_class::ensure( *sp, [&pNode](bool, node_type& item, node_type&) { pNode = &item; } );
281 if ( bRes.first && bRes.second )
284 return std::make_pair( node_to_iterator( pNode ), bRes.second );
288 /** \anchor cds_nonintrusive_SkipListSet_nogc_find_val
290 The function searches the item with key equal to \p key
291 and returns an iterator pointed to item found if the key is found,
292 and \ref end() otherwise
294 template <typename Q>
295 iterator find( Q const& key ) const
297 node_type * pNode = base_class::find( key );
299 return node_to_iterator( pNode );
300 return base_class::nonconst_end();
303 /// Finds the key \p val using \p pred predicate for searching
305 The function is an analog of \ref cds_nonintrusive_SkipListSet_nogc_find_val "find(Q const&)"
306 but \p pred is used for key comparing.
307 \p Less functor has the interface like \p std::less.
308 \p Less must imply the same element order as the comparator used for building the set.
310 template <typename Q, typename Less>
311 iterator find_with( Q const& key, Less pred ) const
313 node_type * pNode = base_class::find_with( key, cds::details::predicate_wrapper< node_type, Less, key_accessor>() );
315 return node_to_iterator( pNode );
316 return base_class::nonconst_end();
319 /// Gets minimum key from the set
321 If the set is empty the function returns \p nullptr
323 value_type * get_min() const
325 node_type * pNode = base_class::get_min();
326 return pNode ? &pNode->m_Value : nullptr;
329 /// Gets maximum key from the set
331 The function returns \p nullptr if the set is empty
333 value_type * get_max() const
335 node_type * pNode = base_class::get_max();
336 return pNode ? &pNode->m_Value : nullptr;
339 /// Clears the set (non-atomic)
341 The function is not atomic.
342 Finding and/or inserting is prohibited while clearing.
343 Otherwise an unpredictable result may be encountered.
344 Thus, \p clear() may be used only for debugging purposes.
351 /// Checks if the set is empty
354 return base_class::empty();
357 /// Returns item count in the set
359 The value returned depends on item counter type provided by \p Traits template parameter.
360 If it is atomicity::empty_item_counter this function always returns 0.
361 The function is not suitable for checking the set emptiness, use \ref empty
362 member function for this purpose.
366 return base_class::size();
369 /// Returns maximum height of skip-list. The max height is a constant for each object and does not exceed 32.
370 static CDS_CONSTEXPR unsigned int max_height() CDS_NOEXCEPT
372 return base_class::max_height();
375 /// Returns const reference to internal statistics
376 stat const& statistics() const
378 return base_class::statistics();
384 #endif // ifndef __CDS_CONTAINER_SKIP_LIST_SET_NOGC_H