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 /// Inserts data of type \ref value_type constructed with <tt>std::forward<Args>(args)...</tt>
367 Returns \p true if inserting successful, \p false otherwise.
369 RCU \p synchronize method can be called. RCU should not be locked.
371 template <typename... Args>
372 bool emplace( Args&&... args )
374 scoped_node_ptr sp( cxx_leaf_node_allocator().New( std::forward<Args>(args)... ));
375 if ( base_class::insert( *sp.get() )) {
382 /// Delete \p key from the set
383 /** \anchor cds_nonintrusive_EllenBinTreeSet_rcu_erase_val
385 The item comparator should be able to compare the type \p value_type
388 RCU \p synchronize method can be called. RCU should not be locked.
390 Return \p true if key is found and deleted, \p false otherwise
392 template <typename Q>
393 bool erase( Q const& key )
395 return base_class::erase( key );
398 /// Deletes the item from the set using \p pred predicate for searching
400 The function is an analog of \ref cds_nonintrusive_EllenBinTreeSet_rcu_erase_val "erase(Q const&)"
401 but \p pred is used for key comparing.
402 \p Less functor has the interface like \p std::less.
403 \p Less must imply the same element order as the comparator used for building the set.
405 template <typename Q, typename Less>
406 bool erase_with( Q const& key, Less pred )
408 return base_class::erase_with( key, cds::details::predicate_wrapper< leaf_node, Less, typename maker::value_accessor >());
411 /// Delete \p key from the set
412 /** \anchor cds_nonintrusive_EllenBinTreeSet_rcu_erase_func
414 The function searches an item with key \p key, calls \p f functor
415 and deletes the item. If \p key is not found, the functor is not called.
417 The functor \p Func interface:
420 void operator()(value_type const& val);
423 The functor may be passed by reference using <tt>boost:ref</tt>
425 Since the key of MichaelHashSet's \p value_type is not explicitly specified,
426 template parameter \p Q defines the key type searching in the list.
427 The list item comparator should be able to compare the type \p T of list item
430 RCU \p synchronize method can be called. RCU should not be locked.
432 Return \p true if key is found and deleted, \p false otherwise
436 template <typename Q, typename Func>
437 bool erase( Q const& key, Func f )
439 # ifdef CDS_CXX11_LAMBDA_SUPPORT
440 return base_class::erase( key, [&f]( leaf_node const& node) { cds::unref(f)( node.m_Value ); } );
442 erase_functor<Func> wrapper(f);
443 return base_class::erase( key, cds::ref(wrapper));
447 /// Deletes the item from the set using \p pred predicate for searching
449 The function is an analog of \ref cds_nonintrusive_EllenBinTreeSet_rcu_erase_func "erase(Q const&, Func)"
450 but \p pred is used for key comparing.
451 \p Less functor has the interface like \p std::less.
452 \p Less must imply the same element order as the comparator used for building the set.
454 template <typename Q, typename Less, typename Func>
455 bool erase_with( Q const& key, Less pred, Func f )
457 # ifdef CDS_CXX11_LAMBDA_SUPPORT
458 return base_class::erase_with( key, cds::details::predicate_wrapper< leaf_node, Less, typename maker::value_accessor >(),
459 [&f]( leaf_node const& node) { cds::unref(f)( node.m_Value ); } );
461 erase_functor<Func> wrapper(f);
462 return base_class::erase_with( key, cds::details::predicate_wrapper< leaf_node, Less, typename maker::value_accessor >(), cds::ref(wrapper));
466 /// Extracts an item with minimal key from the set
468 If the set is not empty, the function returns \p true, \p result contains a pointer to value.
469 If the set is empty, the function returns \p false, \p result is left unchanged.
471 @note Due the concurrent nature of the set, the function extracts <i>nearly</i> minimum key.
472 It means that the function gets leftmost leaf of the tree and tries to unlink it.
473 During unlinking, a concurrent thread may insert an item with key less than leftmost item's key.
474 So, the function returns the item with minimum key at the moment of tree traversing.
476 RCU \p synchronize method can be called. RCU should NOT be locked.
477 The function does not free the item.
478 The deallocator will be implicitly invoked when \p result object is destroyed or when
479 <tt>result.release()</tt> is called, see cds::urcu::exempt_ptr for explanation.
480 @note Before reusing \p result object you should call its \p release() method.
482 bool extract_min( exempt_ptr& result )
484 return base_class::extract_min_( result );
487 /// Extracts an item with maximal key from the set
489 If the set is not empty, the function returns \p true, \p result contains a pointer to extracted item.
490 If the set is empty, the function returns \p false, \p result is left unchanged.
492 @note Due the concurrent nature of the set, the function extracts <i>nearly</i> maximal key.
493 It means that the function gets rightmost leaf of the tree and tries to unlink it.
494 During unlinking, a concurrent thread may insert an item with key great than leftmost item's key.
495 So, the function returns the item with maximum key at the moment of tree traversing.
497 RCU \p synchronize method can be called. RCU should NOT be locked.
498 The function does not free the item.
499 The deallocator will be implicitly invoked when \p result object is destroyed or when
500 <tt>result.release()</tt> is called, see cds::urcu::exempt_ptr for explanation.
501 @note Before reusing \p result object you should call its \p release() method.
503 bool extract_max( exempt_ptr& result )
505 return base_class::extract_max_( result );
508 /// Extracts an item from the set
509 /** \anchor cds_nonintrusive_EllenBinTreeSet_rcu_extract
510 The function searches an item with key equal to \p key in the tree,
511 unlinks it, and returns pointer to an item found in \p result parameter.
512 If \p key is not found the function returns \p false.
514 RCU \p synchronize method can be called. RCU should NOT be locked.
515 The function does not destroy the item found.
516 The dealloctor will be implicitly invoked when \p result object is destroyed or when
517 <tt>result.release()</tt> is called, see cds::urcu::exempt_ptr for explanation.
518 @note Before reusing \p result object you should call its \p release() method.
520 template <typename Q>
521 bool extract( exempt_ptr& result, Q const& key )
523 return base_class::extract_( result, key, typename base_class::node_compare());
526 /// Extracts an item from the set using \p pred for searching
528 The function is an analog of \ref cds_nonintrusive_EllenBinTreeSet_rcu_extract "extract(exempt_ptr&, Q const&)"
529 but \p pred is used for key compare.
530 \p Less has the interface like \p std::less and should meet \ref cds_container_EllenBinTreeSet_rcu_less
531 "predicate requirements".
532 \p pred must imply the same element order as the comparator used for building the set.
534 template <typename Q, typename Less>
535 bool extract_with( exempt_ptr& result, Q const& val, Less pred )
537 return base_class::extract_with_( result, val,
538 cds::details::predicate_wrapper< leaf_node, Less, typename maker::value_accessor >() );
541 /// Find the key \p val
543 @anchor cds_nonintrusive_EllenBinTreeSet_rcu_find_func
545 The function searches the item with key equal to \p val and calls the functor \p f for item found.
546 The interface of \p Func functor is:
549 void operator()( value_type& item, Q& val );
552 where \p item is the item found, \p val is the <tt>find</tt> function argument.
554 You may pass \p f argument by reference using <tt>boost::ref</tt> or cds::ref.
556 The functor may change non-key fields of \p item. Note that the functor is only guarantee
557 that \p item cannot be disposed during functor is executing.
558 The functor does not serialize simultaneous access to the set's \p item. If such access is
559 possible you must provide your own synchronization schema on item level to exclude unsafe item modifications.
561 The \p val argument is non-const since it can be used as \p f functor destination i.e., the functor
562 can modify both arguments.
564 Note the hash functor specified for class \p Traits template parameter
565 should accept a parameter of type \p Q that may be not the same as \p value_type.
567 The function applies RCU lock internally.
569 The function returns \p true if \p val is found, \p false otherwise.
571 template <typename Q, typename Func>
572 bool find( Q& val, Func f ) const
574 # ifdef CDS_CXX11_LAMBDA_SUPPORT
575 return base_class::find( val, [&f]( leaf_node& node, Q& v ) { cds::unref(f)( node.m_Value, v ); });
577 find_functor<Func> wrapper(f);
578 return base_class::find( val, cds::ref(wrapper));
582 /// Finds the key \p val using \p pred predicate for searching
584 The function is an analog of \ref cds_nonintrusive_EllenBinTreeSet_rcu_find_func "find(Q&, Func)"
585 but \p pred is used for key comparing.
586 \p Less functor has the interface like \p std::less.
587 \p Less must imply the same element order as the comparator used for building the set.
589 template <typename Q, typename Less, typename Func>
590 bool find_with( Q& val, Less pred, Func f ) const
592 # ifdef CDS_CXX11_LAMBDA_SUPPORT
593 return base_class::find_with( val, cds::details::predicate_wrapper< leaf_node, Less, typename maker::value_accessor >(),
594 [&f]( leaf_node& node, Q& v ) { cds::unref(f)( node.m_Value, v ); } );
596 find_functor<Func> wrapper(f);
597 return base_class::find_with( val, cds::details::predicate_wrapper< leaf_node, Less, typename maker::value_accessor >(),
602 /// Find the key \p val
603 /** @anchor cds_nonintrusive_EllenBinTreeSet_rcu_find_cfunc
605 The function searches the item with key equal to \p val and calls the functor \p f for item found.
606 The interface of \p Func functor is:
609 void operator()( value_type& item, Q const& val );
612 where \p item is the item found, \p val is the <tt>find</tt> function argument.
614 You may pass \p f argument by reference using <tt>boost::ref</tt> or cds::ref.
616 The functor may change non-key fields of \p item. Note that the functor is only guarantee
617 that \p item cannot be disposed during functor is executing.
618 The functor does not serialize simultaneous access to the set's \p item. If such access is
619 possible you must provide your own synchronization schema on item level to exclude unsafe item modifications.
621 Note the hash functor specified for class \p Traits template parameter
622 should accept a parameter of type \p Q that may be not the same as \p value_type.
624 The function applies RCU lock internally.
626 The function returns \p true if \p val is found, \p false otherwise.
628 template <typename Q, typename Func>
629 bool find( Q const& val, Func f ) const
631 # ifdef CDS_CXX11_LAMBDA_SUPPORT
632 return base_class::find( val, [&f]( leaf_node& node, Q const& v ) { cds::unref(f)( node.m_Value, v ); });
634 find_functor<Func> wrapper(f);
635 return base_class::find( val, cds::ref(wrapper));
639 /// Finds the key \p val using \p pred predicate for searching
641 The function is an analog of \ref cds_nonintrusive_EllenBinTreeSet_rcu_find_cfunc "find(Q const&, Func)"
642 but \p pred is used for key comparing.
643 \p Less functor has the interface like \p std::less.
644 \p Less must imply the same element order as the comparator used for building the set.
646 template <typename Q, typename Less, typename Func>
647 bool find_with( Q const& val, Less pred, Func f ) const
649 # ifdef CDS_CXX11_LAMBDA_SUPPORT
650 return base_class::find_with( val, cds::details::predicate_wrapper< leaf_node, Less, typename maker::value_accessor >(),
651 [&f]( leaf_node& node, Q const& v ) { cds::unref(f)( node.m_Value, v ); } );
653 find_functor<Func> wrapper(f);
654 return base_class::find_with( val, cds::details::predicate_wrapper< leaf_node, Less, typename maker::value_accessor >(),
659 /// Find the key \p val
660 /** @anchor cds_nonintrusive_EllenBinTreeSet_rcu_find_val
662 The function searches the item with key equal to \p val
663 and returns \p true if it is found, and \p false otherwise.
665 Note the hash functor specified for class \p Traits template parameter
666 should accept a parameter of type \p Q that may be not the same as \ref value_type.
668 The function applies RCU lock internally.
670 template <typename Q>
671 bool find( Q const & val ) const
673 return base_class::find( val );
676 /// Finds the key \p val using \p pred predicate for searching
678 The function is an analog of \ref cds_nonintrusive_EllenBinTreeSet_rcu_find_val "find(Q const&)"
679 but \p pred is used for key comparing.
680 \p Less functor has the interface like \p std::less.
681 \p Less must imply the same element order as the comparator used for building the set.
683 template <typename Q, typename Less>
684 bool find_with( Q const& val, Less pred ) const
686 return base_class::find_with( val, cds::details::predicate_wrapper< leaf_node, Less, typename maker::value_accessor >());
689 /// Finds \p key and return the item found
690 /** \anchor cds_nonintrusive_EllenBinTreeSet_rcu_get
691 The function searches the item with key equal to \p key and returns the pointer to item found.
692 If \p key is not found it returns \p nullptr.
694 RCU should be locked before call the function.
695 Returned pointer is valid while RCU is locked.
697 template <typename Q>
698 value_type * get( Q const& key ) const
700 leaf_node * pNode = base_class::get( key );
701 return pNode ? &pNode->m_Value : nullptr;
704 /// Finds \p key with \p pred predicate and return the item found
706 The function is an analog of \ref cds_nonintrusive_EllenBinTreeSet_rcu_get "get(Q const&)"
707 but \p pred is used for comparing the keys.
709 \p Less functor has the semantics like \p std::less but should take arguments of type \ref value_type
710 and \p Q in any order.
711 \p pred must imply the same element order as the comparator used for building the set.
713 template <typename Q, typename Less>
714 value_type * get_with( Q const& key, Less pred ) const
716 leaf_node * pNode = base_class::get_with( key,
717 cds::details::predicate_wrapper< leaf_node, Less, typename maker::value_accessor >());
718 return pNode ? &pNode->m_Value : nullptr;
721 /// Clears the set (non-atomic)
723 The function unlink all items from the tree.
724 The function is not atomic, thus, in multi-threaded environment with parallel insertions
728 assert( set.empty() );
730 the assertion could be raised.
732 For each leaf the \ref disposer will be called after unlinking.
734 RCU \p synchronize method can be called. RCU should not be locked.
741 /// Checks if the set is empty
744 return base_class::empty();
747 /// Returns item count in the set
749 Only leaf nodes containing user data are counted.
751 The value returned depends on item counter type provided by \p Traits template parameter.
752 If it is atomicity::empty_item_counter this function always returns 0.
753 Therefore, the function is not suitable for checking the tree emptiness, use \ref empty
754 member function for this purpose.
758 return base_class::size();
761 /// Returns const reference to internal statistics
762 stat const& statistics() const
764 return base_class::statistics();
767 /// Checks internal consistency (not atomic, not thread-safe)
769 The debugging function to check internal consistency of the tree.
771 bool check_consistency() const
773 return base_class::check_consistency();
778 }} // namespace cds::container
780 #endif // #ifndef __CDS_CONTAINER_ELLEN_BINTREE_SET_RCU_H