3 #ifndef __CDS_CONTAINER_ELLEN_BINTREE_SET_RCU_H
4 #define __CDS_CONTAINER_ELLEN_BINTREE_SET_RCU_H
6 #include <cds/container/ellen_bintree_base.h>
7 #include <cds/intrusive/ellen_bintree_rcu.h>
9 namespace cds { namespace container {
11 /// Set based on Ellen's et al binary search tree (RCU specialization)
12 /** @ingroup cds_nonintrusive_set
13 @ingroup cds_nonintrusive_tree
14 @anchor cds_container_EllenBinTreeSet_rcu
17 - [2010] F.Ellen, P.Fatourou, E.Ruppert, F.van Breugel "Non-blocking Binary Search Tree"
19 %EllenBinTreeSet is an unbalanced leaf-oriented binary search tree that implements the <i>set</i>
20 abstract data type. Nodes maintains child pointers but not parent pointers.
21 Every internal node has exactly two children, and all data of type \p T currently in
22 the tree are stored in the leaves. Internal nodes of the tree are used to direct \p find
23 operation along the path to the correct leaf. The keys (of \p Key type) stored in internal nodes
24 may or may not be in the set. \p Key type is a subset of \p T type.
25 There should be exactly defined a key extracting functor for converting object of type \p T to
26 object of type \p Key.
28 Due to \p extract_min and \p extract_max member functions the \p %EllenBinTreeSet can act as
29 a <i>priority queue</i>. In this case you should provide unique compound key, for example,
30 the priority value plus some uniformly distributed random value.
32 @warning Recall the tree is <b>unbalanced</b>. The complexity of operations is <tt>O(log N)</tt>
33 for uniformly distributed random keys, but in worst case the complexity is <tt>O(N)</tt>.
35 @note In the current implementation we do not use helping technique described in original paper.
36 So, the current implementation is near to fine-grained lock-based tree.
37 Helping will be implemented in future release
39 <b>Template arguments</b> :
40 - \p RCU - one of \ref cds_urcu_gc "RCU type"
41 - \p Key - key type, a subset of \p T
42 - \p T - type to be stored in tree's leaf nodes.
43 - \p Traits - type traits. See ellen_bintree::type_traits for explanation.
45 It is possible to declare option-based tree with ellen_bintree::make_set_traits metafunction
46 instead of \p Traits template argument.
47 Template argument list \p Options of ellen_bintree::make_set_traits metafunction are:
48 - ellen_bintree::key_extractor - key extracting functor, mandatory option. The functor has the following prototype:
50 struct key_extractor {
51 void operator ()( Key& dest, T const& src );
54 It should initialize \p dest key from \p src data. The functor is used to initialize internal nodes.
55 - opt::compare - key compare functor. No default functor is provided.
56 If the option is not specified, \p %opt::less is used.
57 - opt::less - specifies binary predicate used for key compare. At least \p %opt::compare or \p %opt::less should be defined.
58 - opt::item_counter - the type of item counting feature. Default is \ref atomicity::empty_item_counter that is no item counting.
59 - opt::memory_model - C++ memory ordering model. Can be opt::v::relaxed_ordering (relaxed memory model, the default)
60 or opt::v::sequential_consistent (sequentially consisnent memory model).
61 - opt::allocator - the allocator used for \ref ellen_bintree::node "leaf nodes" which contains data.
62 Default is \ref CDS_DEFAULT_ALLOCATOR.
63 - opt::node_allocator - the allocator used for internal nodes. Default is \ref CDS_DEFAULT_ALLOCATOR.
64 - ellen_bintree::update_desc_allocator - an allocator of \ref ellen_bintree::update_desc "update descriptors",
65 default is \ref CDS_DEFAULT_ALLOCATOR.
66 Note that update descriptor is helping data structure with short lifetime and it is good candidate for pooling.
67 The number of simultaneously existing descriptors is a relatively small number limited the number of threads
68 working with the tree and RCU buffer size.
69 Therefore, a bounded lock-free container like \p cds::container::VyukovMPMCCycleQueue is good choice for the free-list
70 of update descriptors, see cds::memory::vyukov_queue_pool free-list implementation.
71 Also notice that size of update descriptor is not dependent on the type of data
72 stored in the tree so single free-list object can be used for several EllenBinTree-based object.
73 - opt::stat - internal statistics. Available types: ellen_bintree::stat, ellen_bintree::empty_stat (the default)
74 - opt::rcu_check_deadlock - a deadlock checking policy. Default is opt::v::rcu_throw_deadlock
76 @note Before including <tt><cds/container/ellen_bintree_set_rcu.h></tt> you should include appropriate RCU header file,
77 see \ref cds_urcu_gc "RCU type" for list of existing RCU class and corresponding header files.
79 @anchor cds_container_EllenBinTreeSet_rcu_less
80 <b>Predicate requirements</b>
82 opt::less, opt::compare and other predicates using with member fuctions should accept at least parameters
83 of type \p T and \p Key in any combination.
84 For example, for \p Foo struct with \p std::string key field the appropiate \p less functor is:
93 bool operator()( Foo const& v1, Foo const& v2 ) const
94 { return v1.m_strKey < v2.m_strKey ; }
96 bool operator()( Foo const& v, std::string const& s ) const
97 { return v.m_strKey < s ; }
99 bool operator()( std::string const& s, Foo const& v ) const
100 { return s < v.m_strKey ; }
102 // Support comparing std::string and char const *
103 bool operator()( std::string const& s, char const * p ) const
104 { return s.compare(p) < 0 ; }
106 bool operator()( Foo const& v, char const * p ) const
107 { return v.m_strKey.compare(p) < 0 ; }
109 bool operator()( char const * p, std::string const& s ) const
110 { return s.compare(p) > 0; }
112 bool operator()( char const * p, Foo const& v ) const
113 { return v.m_strKey.compare(p) > 0; }
122 #ifdef CDS_DOXYGEN_INVOKED
123 class Traits = ellen_bintree::type_traits
128 class EllenBinTreeSet< cds::urcu::gc<RCU>, Key, T, Traits >
129 #ifdef CDS_DOXYGEN_INVOKED
130 : public cds::intrusive::EllenBinTree< cds::urcu::gc<RCU>, Key, T, Traits >
132 : public ellen_bintree::details::make_ellen_bintree_set< cds::urcu::gc<RCU>, Key, T, Traits >::type
136 typedef ellen_bintree::details::make_ellen_bintree_set< cds::urcu::gc<RCU>, Key, T, Traits > maker;
137 typedef typename maker::type base_class;
141 typedef cds::urcu::gc<RCU> gc ; ///< RCU Garbage collector
142 typedef Key key_type ; ///< type of a key stored in internal nodes; key is a part of \p value_type
143 typedef T value_type ; ///< type of value stored in the binary tree
144 typedef Traits options ; ///< Traits template parameter
146 # ifdef CDS_DOXYGEN_INVOKED
147 typedef implementation_defined key_comparator ; ///< key compare functor based on opt::compare and opt::less option setter.
149 typedef typename maker::intrusive_type_traits::compare key_comparator;
151 typedef typename base_class::item_counter item_counter ; ///< Item counting policy used
152 typedef typename base_class::memory_model memory_model ; ///< Memory ordering. See cds::opt::memory_model option
153 typedef typename base_class::stat stat ; ///< internal statistics type
154 typedef typename base_class::rcu_check_deadlock rcu_check_deadlock ; ///< Deadlock checking policy
155 typedef typename options::key_extractor key_extractor ; ///< key extracting functor
157 typedef typename options::allocator allocator_type ; ///< Allocator for leaf nodes
158 typedef typename base_class::node_allocator node_allocator ; ///< Internal node allocator
159 typedef typename base_class::update_desc_allocator update_desc_allocator ; ///< Update descriptor allocator
161 static CDS_CONSTEXPR_CONST bool c_bExtractLockExternal = base_class::c_bExtractLockExternal; ///< Group of \p extract_xxx functions do not require external locking
165 typedef typename maker::cxx_leaf_node_allocator cxx_leaf_node_allocator;
166 typedef typename base_class::value_type leaf_node;
167 typedef typename base_class::internal_node internal_node;
168 typedef std::unique_ptr< leaf_node, typename maker::intrusive_type_traits::disposer > scoped_node_ptr;
172 typedef typename gc::scoped_lock rcu_lock ; ///< RCU scoped lock
174 /// pointer to extracted node
175 typedef cds::urcu::exempt_ptr< gc, leaf_node, value_type, typename maker::intrusive_type_traits::disposer,
176 cds::urcu::details::conventional_exempt_member_cast<leaf_node, value_type>
181 # ifndef CDS_CXX11_LAMBDA_SUPPORT
182 template <typename Func>
183 struct insert_functor
187 insert_functor ( Func f )
191 void operator()( leaf_node& node )
193 cds::unref(m_func)( node.m_Value );
197 template <typename Q, typename Func>
198 struct ensure_functor
203 ensure_functor( Q const& arg, Func f )
208 void operator ()( bool bNew, leaf_node& node, leaf_node& )
210 cds::unref(m_func)( bNew, node.m_Value, m_arg );
214 template <typename Func>
219 erase_functor( Func f )
223 void operator()( leaf_node const& node )
225 cds::unref(m_func)( node.m_Value );
229 template <typename Func>
234 find_functor( Func f )
238 template <typename Q>
239 void operator ()( leaf_node& node, Q& val )
241 cds::unref(m_func)( node.m_Value, val );
248 /// Default constructor
259 The function creates a node with copy of \p val value
260 and then inserts the node created into the set.
262 The type \p Q should contain at least the complete key for the node.
263 The object of \ref value_type should be constructible from a value of type \p Q.
264 In trivial case, \p Q is equal to \ref value_type.
266 RCU \p synchronize method can be called. RCU should not be locked.
268 Returns \p true if \p val is inserted into the set, \p false otherwise.
270 template <typename Q>
271 bool insert( Q const& val )
273 scoped_node_ptr sp( cxx_leaf_node_allocator().New( val ));
274 if ( base_class::insert( *sp.get() )) {
283 The function allows to split creating of new item into two part:
284 - create item with key only
285 - insert new item into the set
286 - if inserting is success, calls \p f functor to initialize value-fields of \p val.
288 The functor signature is:
290 void func( value_type& val );
292 where \p val is the item inserted. User-defined functor \p f should guarantee that during changing
293 \p val no any other changes could be made on this set's item by concurrent threads.
294 The user-defined functor is called only if the inserting is success. It may be passed by reference
295 using <tt>boost::ref</tt>
297 RCU \p synchronize method can be called. RCU should not be locked.
299 template <typename Q, typename Func>
300 bool insert( Q const& val, Func f )
302 scoped_node_ptr sp( cxx_leaf_node_allocator().New( val ));
303 # ifdef CDS_CXX11_LAMBDA_SUPPORT
304 if ( base_class::insert( *sp.get(), [&f]( leaf_node& val ) { cds::unref(f)( val.m_Value ); } ))
306 insert_functor<Func> wrapper(f);
307 if ( base_class::insert( *sp, cds::ref(wrapper) ))
316 /// Ensures that the item exists in the set
318 The operation performs inserting or changing data with lock-free manner.
320 If the \p val key not found in the set, then the new item created from \p val
321 is inserted into the set. Otherwise, the functor \p func is called with the item found.
322 The functor \p Func should be a function with signature:
324 void func( bool bNew, value_type& item, const Q& val );
329 void operator()( bool bNew, value_type& item, const Q& val );
334 - \p bNew - \p true if the item has been inserted, \p false otherwise
335 - \p item - item of the set
336 - \p val - argument \p key passed into the \p ensure function
338 The functor may change non-key fields of the \p item; however, \p func must guarantee
339 that during changing no any other modifications could be made on this item by concurrent threads.
341 You may pass \p func argument by reference using <tt>boost::ref</tt>.
343 RCU \p synchronize method can be called. RCU should not be locked.
345 Returns <tt> std::pair<bool, bool> </tt> where \p first is true if operation is successfull,
346 \p second is true if new item has been added or \p false if the item with \p key
347 already is in the set.
349 template <typename Q, typename Func>
350 std::pair<bool, bool> ensure( const Q& val, Func func )
352 scoped_node_ptr sp( cxx_leaf_node_allocator().New( val ));
353 # ifdef CDS_CXX11_LAMBDA_SUPPORT
354 std::pair<bool, bool> bRes = base_class::ensure( *sp,
355 [&func, &val](bool bNew, leaf_node& node, leaf_node&){ cds::unref(func)( bNew, node.m_Value, val ); });
357 ensure_functor<Q, Func> wrapper( val, func );
358 std::pair<bool, bool> bRes = base_class::ensure( *sp, cds::ref(wrapper));
360 if ( bRes.first && bRes.second )
365 # ifdef CDS_EMPLACE_SUPPORT
366 /// Inserts data of type \ref value_type constructed with <tt>std::forward<Args>(args)...</tt>
368 Returns \p true if inserting successful, \p false otherwise.
370 RCU \p synchronize method can be called. RCU should not be locked.
372 @note This function is available only for compiler that supports
373 variadic template and move semantics
375 template <typename... Args>
376 bool emplace( Args&&... args )
378 scoped_node_ptr sp( cxx_leaf_node_allocator().New( std::forward<Args>(args)... ));
379 if ( base_class::insert( *sp.get() )) {
387 /// Delete \p key from the set
388 /** \anchor cds_nonintrusive_EllenBinTreeSet_rcu_erase_val
390 The item comparator should be able to compare the type \p value_type
393 RCU \p synchronize method can be called. RCU should not be locked.
395 Return \p true if key is found and deleted, \p false otherwise
397 template <typename Q>
398 bool erase( Q const& key )
400 return base_class::erase( key );
403 /// Deletes the item from the set using \p pred predicate for searching
405 The function is an analog of \ref cds_nonintrusive_EllenBinTreeSet_rcu_erase_val "erase(Q const&)"
406 but \p pred is used for key comparing.
407 \p Less functor has the interface like \p std::less.
408 \p Less must imply the same element order as the comparator used for building the set.
410 template <typename Q, typename Less>
411 bool erase_with( Q const& key, Less pred )
413 return base_class::erase_with( key, cds::details::predicate_wrapper< leaf_node, Less, typename maker::value_accessor >());
416 /// Delete \p key from the set
417 /** \anchor cds_nonintrusive_EllenBinTreeSet_rcu_erase_func
419 The function searches an item with key \p key, calls \p f functor
420 and deletes the item. If \p key is not found, the functor is not called.
422 The functor \p Func interface:
425 void operator()(value_type const& val);
428 The functor may be passed by reference using <tt>boost:ref</tt>
430 Since the key of MichaelHashSet's \p value_type is not explicitly specified,
431 template parameter \p Q defines the key type searching in the list.
432 The list item comparator should be able to compare the type \p T of list item
435 RCU \p synchronize method can be called. RCU should not be locked.
437 Return \p true if key is found and deleted, \p false otherwise
441 template <typename Q, typename Func>
442 bool erase( Q const& key, Func f )
444 # ifdef CDS_CXX11_LAMBDA_SUPPORT
445 return base_class::erase( key, [&f]( leaf_node const& node) { cds::unref(f)( node.m_Value ); } );
447 erase_functor<Func> wrapper(f);
448 return base_class::erase( key, cds::ref(wrapper));
452 /// Deletes the item from the set using \p pred predicate for searching
454 The function is an analog of \ref cds_nonintrusive_EllenBinTreeSet_rcu_erase_func "erase(Q const&, Func)"
455 but \p pred is used for key comparing.
456 \p Less functor has the interface like \p std::less.
457 \p Less must imply the same element order as the comparator used for building the set.
459 template <typename Q, typename Less, typename Func>
460 bool erase_with( Q const& key, Less pred, Func f )
462 # ifdef CDS_CXX11_LAMBDA_SUPPORT
463 return base_class::erase_with( key, cds::details::predicate_wrapper< leaf_node, Less, typename maker::value_accessor >(),
464 [&f]( leaf_node const& node) { cds::unref(f)( node.m_Value ); } );
466 erase_functor<Func> wrapper(f);
467 return base_class::erase_with( key, cds::details::predicate_wrapper< leaf_node, Less, typename maker::value_accessor >(), cds::ref(wrapper));
471 /// Extracts an item with minimal key from the set
473 If the set is not empty, the function returns \p true, \p result contains a pointer to value.
474 If the set is empty, the function returns \p false, \p result is left unchanged.
476 @note Due the concurrent nature of the set, the function extracts <i>nearly</i> minimum key.
477 It means that the function gets leftmost leaf of the tree and tries to unlink it.
478 During unlinking, a concurrent thread may insert an item with key less than leftmost item's key.
479 So, the function returns the item with minimum key at the moment of tree traversing.
481 RCU \p synchronize method can be called. RCU should NOT be locked.
482 The function does not free the item.
483 The deallocator will be implicitly invoked when \p result object is destroyed or when
484 <tt>result.release()</tt> is called, see cds::urcu::exempt_ptr for explanation.
485 @note Before reusing \p result object you should call its \p release() method.
487 bool extract_min( exempt_ptr& result )
489 return base_class::extract_min_( result );
492 /// Extracts an item with maximal key from the set
494 If the set is not empty, the function returns \p true, \p result contains a pointer to extracted item.
495 If the set is empty, the function returns \p false, \p result is left unchanged.
497 @note Due the concurrent nature of the set, the function extracts <i>nearly</i> maximal key.
498 It means that the function gets rightmost leaf of the tree and tries to unlink it.
499 During unlinking, a concurrent thread may insert an item with key great than leftmost item's key.
500 So, the function returns the item with maximum key at the moment of tree traversing.
502 RCU \p synchronize method can be called. RCU should NOT be locked.
503 The function does not free the item.
504 The deallocator will be implicitly invoked when \p result object is destroyed or when
505 <tt>result.release()</tt> is called, see cds::urcu::exempt_ptr for explanation.
506 @note Before reusing \p result object you should call its \p release() method.
508 bool extract_max( exempt_ptr& result )
510 return base_class::extract_max_( result );
513 /// Extracts an item from the set
514 /** \anchor cds_nonintrusive_EllenBinTreeSet_rcu_extract
515 The function searches an item with key equal to \p key in the tree,
516 unlinks it, and returns pointer to an item found in \p result parameter.
517 If \p key is not found the function returns \p false.
519 RCU \p synchronize method can be called. RCU should NOT be locked.
520 The function does not destroy the item found.
521 The dealloctor will be implicitly invoked when \p result object is destroyed or when
522 <tt>result.release()</tt> is called, see cds::urcu::exempt_ptr for explanation.
523 @note Before reusing \p result object you should call its \p release() method.
525 template <typename Q>
526 bool extract( exempt_ptr& result, Q const& key )
528 return base_class::extract_( result, key, typename base_class::node_compare());
531 /// Extracts an item from the set using \p pred for searching
533 The function is an analog of \ref cds_nonintrusive_EllenBinTreeSet_rcu_extract "extract(exempt_ptr&, Q const&)"
534 but \p pred is used for key compare.
535 \p Less has the interface like \p std::less and should meet \ref cds_container_EllenBinTreeSet_rcu_less
536 "predicate requirements".
537 \p pred must imply the same element order as the comparator used for building the set.
539 template <typename Q, typename Less>
540 bool extract_with( exempt_ptr& result, Q const& val, Less pred )
542 return base_class::extract_with_( result, val,
543 cds::details::predicate_wrapper< leaf_node, Less, typename maker::value_accessor >() );
546 /// Find the key \p val
548 @anchor cds_nonintrusive_EllenBinTreeSet_rcu_find_func
550 The function searches the item with key equal to \p val and calls the functor \p f for item found.
551 The interface of \p Func functor is:
554 void operator()( value_type& item, Q& val );
557 where \p item is the item found, \p val is the <tt>find</tt> function argument.
559 You may pass \p f argument by reference using <tt>boost::ref</tt> or cds::ref.
561 The functor may change non-key fields of \p item. Note that the functor is only guarantee
562 that \p item cannot be disposed during functor is executing.
563 The functor does not serialize simultaneous access to the set's \p item. If such access is
564 possible you must provide your own synchronization schema on item level to exclude unsafe item modifications.
566 The \p val argument is non-const since it can be used as \p f functor destination i.e., the functor
567 can modify both arguments.
569 Note the hash functor specified for class \p Traits template parameter
570 should accept a parameter of type \p Q that may be not the same as \p value_type.
572 The function applies RCU lock internally.
574 The function returns \p true if \p val is found, \p false otherwise.
576 template <typename Q, typename Func>
577 bool find( Q& val, Func f ) const
579 # ifdef CDS_CXX11_LAMBDA_SUPPORT
580 return base_class::find( val, [&f]( leaf_node& node, Q& v ) { cds::unref(f)( node.m_Value, v ); });
582 find_functor<Func> wrapper(f);
583 return base_class::find( val, cds::ref(wrapper));
587 /// Finds the key \p val using \p pred predicate for searching
589 The function is an analog of \ref cds_nonintrusive_EllenBinTreeSet_rcu_find_func "find(Q&, Func)"
590 but \p pred is used for key comparing.
591 \p Less functor has the interface like \p std::less.
592 \p Less must imply the same element order as the comparator used for building the set.
594 template <typename Q, typename Less, typename Func>
595 bool find_with( Q& val, Less pred, Func f ) const
597 # ifdef CDS_CXX11_LAMBDA_SUPPORT
598 return base_class::find_with( val, cds::details::predicate_wrapper< leaf_node, Less, typename maker::value_accessor >(),
599 [&f]( leaf_node& node, Q& v ) { cds::unref(f)( node.m_Value, v ); } );
601 find_functor<Func> wrapper(f);
602 return base_class::find_with( val, cds::details::predicate_wrapper< leaf_node, Less, typename maker::value_accessor >(),
607 /// Find the key \p val
608 /** @anchor cds_nonintrusive_EllenBinTreeSet_rcu_find_cfunc
610 The function searches the item with key equal to \p val and calls the functor \p f for item found.
611 The interface of \p Func functor is:
614 void operator()( value_type& item, Q const& val );
617 where \p item is the item found, \p val is the <tt>find</tt> function argument.
619 You may pass \p f argument by reference using <tt>boost::ref</tt> or cds::ref.
621 The functor may change non-key fields of \p item. Note that the functor is only guarantee
622 that \p item cannot be disposed during functor is executing.
623 The functor does not serialize simultaneous access to the set's \p item. If such access is
624 possible you must provide your own synchronization schema on item level to exclude unsafe item modifications.
626 Note the hash functor specified for class \p Traits template parameter
627 should accept a parameter of type \p Q that may be not the same as \p value_type.
629 The function applies RCU lock internally.
631 The function returns \p true if \p val is found, \p false otherwise.
633 template <typename Q, typename Func>
634 bool find( Q const& val, Func f ) const
636 # ifdef CDS_CXX11_LAMBDA_SUPPORT
637 return base_class::find( val, [&f]( leaf_node& node, Q const& v ) { cds::unref(f)( node.m_Value, v ); });
639 find_functor<Func> wrapper(f);
640 return base_class::find( val, cds::ref(wrapper));
644 /// Finds the key \p val using \p pred predicate for searching
646 The function is an analog of \ref cds_nonintrusive_EllenBinTreeSet_rcu_find_cfunc "find(Q const&, Func)"
647 but \p pred is used for key comparing.
648 \p Less functor has the interface like \p std::less.
649 \p Less must imply the same element order as the comparator used for building the set.
651 template <typename Q, typename Less, typename Func>
652 bool find_with( Q const& val, Less pred, Func f ) const
654 # ifdef CDS_CXX11_LAMBDA_SUPPORT
655 return base_class::find_with( val, cds::details::predicate_wrapper< leaf_node, Less, typename maker::value_accessor >(),
656 [&f]( leaf_node& node, Q const& v ) { cds::unref(f)( node.m_Value, v ); } );
658 find_functor<Func> wrapper(f);
659 return base_class::find_with( val, cds::details::predicate_wrapper< leaf_node, Less, typename maker::value_accessor >(),
664 /// Find the key \p val
665 /** @anchor cds_nonintrusive_EllenBinTreeSet_rcu_find_val
667 The function searches the item with key equal to \p val
668 and returns \p true if it is found, and \p false otherwise.
670 Note the hash functor specified for class \p Traits template parameter
671 should accept a parameter of type \p Q that may be not the same as \ref value_type.
673 The function applies RCU lock internally.
675 template <typename Q>
676 bool find( Q const & val ) const
678 return base_class::find( val );
681 /// Finds the key \p val using \p pred predicate for searching
683 The function is an analog of \ref cds_nonintrusive_EllenBinTreeSet_rcu_find_val "find(Q const&)"
684 but \p pred is used for key comparing.
685 \p Less functor has the interface like \p std::less.
686 \p Less must imply the same element order as the comparator used for building the set.
688 template <typename Q, typename Less>
689 bool find_with( Q const& val, Less pred ) const
691 return base_class::find_with( val, cds::details::predicate_wrapper< leaf_node, Less, typename maker::value_accessor >());
694 /// Finds \p key and return the item found
695 /** \anchor cds_nonintrusive_EllenBinTreeSet_rcu_get
696 The function searches the item with key equal to \p key and returns the pointer to item found.
697 If \p key is not found it returns \p NULL.
699 RCU should be locked before call the function.
700 Returned pointer is valid while RCU is locked.
702 template <typename Q>
703 value_type * get( Q const& key ) const
705 leaf_node * pNode = base_class::get( key );
706 return pNode ? &pNode->m_Value : nullptr;
709 /// Finds \p key with \p pred predicate and return the item found
711 The function is an analog of \ref cds_nonintrusive_EllenBinTreeSet_rcu_get "get(Q const&)"
712 but \p pred is used for comparing the keys.
714 \p Less functor has the semantics like \p std::less but should take arguments of type \ref value_type
715 and \p Q in any order.
716 \p pred must imply the same element order as the comparator used for building the set.
718 template <typename Q, typename Less>
719 value_type * get_with( Q const& key, Less pred ) const
721 leaf_node * pNode = base_class::get_with( key,
722 cds::details::predicate_wrapper< leaf_node, Less, typename maker::value_accessor >());
723 return pNode ? &pNode->m_Value : nullptr;
726 /// Clears the set (non-atomic)
728 The function unlink all items from the tree.
729 The function is not atomic, thus, in multi-threaded environment with parallel insertions
733 assert( set.empty() );
735 the assertion could be raised.
737 For each leaf the \ref disposer will be called after unlinking.
739 RCU \p synchronize method can be called. RCU should not be locked.
746 /// Checks if the set is empty
749 return base_class::empty();
752 /// Returns item count in the set
754 Only leaf nodes containing user data are counted.
756 The value returned depends on item counter type provided by \p Traits template parameter.
757 If it is atomicity::empty_item_counter this function always returns 0.
758 Therefore, the function is not suitable for checking the tree emptiness, use \ref empty
759 member function for this purpose.
763 return base_class::size();
766 /// Returns const reference to internal statistics
767 stat const& statistics() const
769 return base_class::statistics();
772 /// Checks internal consistency (not atomic, not thread-safe)
774 The debugging function to check internal consistency of the tree.
776 bool check_consistency() const
778 return base_class::check_consistency();
783 }} // namespace cds::container
785 #endif // #ifndef __CDS_CONTAINER_ELLEN_BINTREE_SET_RCU_H