3 #ifndef __CDS_INTRUSIVE_ELLEN_BINTREE_RCU_H
4 #define __CDS_INTRUSIVE_ELLEN_BINTREE_RCU_H
7 #include <cds/intrusive/details/ellen_bintree_base.h>
8 #include <cds/opt/compare.h>
9 #include <cds/details/binary_functor_wrapper.h>
10 #include <cds/urcu/details/check_deadlock.h>
11 #include <cds/urcu/exempt_ptr.h>
13 namespace cds { namespace intrusive {
15 namespace ellen_bintree {
18 struct base_node<cds::urcu::gc<RCU> >: public basic_node
20 typedef basic_node base_class;
22 base_node * m_pNextRetired;
24 typedef cds::urcu::gc<RCU> gc ; ///< Garbage collector
26 /// Constructs leaf (bIntrenal == false) or internal (bInternal == true) node
27 explicit base_node( bool bInternal )
28 : basic_node( bInternal ? internal : 0 )
29 , m_pNextRetired( nullptr )
33 } // namespace ellen_bintree
36 /// Ellen's et al binary search tree (RCU specialization)
37 /** @ingroup cds_intrusive_map
38 @ingroup cds_intrusive_tree
39 @anchor cds_intrusive_EllenBinTree_rcu
42 - [2010] F.Ellen, P.Fatourou, E.Ruppert, F.van Breugel "Non-blocking Binary Search Tree"
44 %EllenBinTree is an unbalanced leaf-oriented binary search tree that implements the <i>set</i>
45 abstract data type. Nodes maintains child pointers but not parent pointers.
46 Every internal node has exactly two children, and all data of type \p T currently in
47 the tree are stored in the leaves. Internal nodes of the tree are used to direct \p find
48 operation along the path to the correct leaf. The keys (of \p Key type) stored in internal nodes
49 may or may not be in the set. \p Key type is a subset of \p T type.
50 There should be exactly defined a key extracting functor for converting object of type \p T to
51 object of type \p Key.
53 Due to \p extract_min and \p extract_max member functions the \p %EllenBinTree can act as
54 a <i>priority queue</i>. In this case you should provide unique compound key, for example,
55 the priority value plus some uniformly distributed random value.
57 @warning Recall the tree is <b>unbalanced</b>. The complexity of operations is <tt>O(log N)</tt>
58 for uniformly distributed random keys, but in worst case the complexity is <tt>O(N)</tt>.
60 @note In the current implementation we do not use helping technique described in the original paper.
61 In Hazard Pointer schema helping is too complicated and does not give any observable benefits.
62 Instead of helping, when a thread encounters a concurrent operation it just spins waiting for
63 the operation done. Such solution allows greatly simplify the implementation of tree.
65 <b>Template arguments</b> :
66 - \p RCU - one of \ref cds_urcu_gc "RCU type"
67 - \p Key - key type, a subset of \p T
68 - \p T - type to be stored in tree's leaf nodes. The type must be based on \p ellen_bintree::node
69 (for \p ellen_bintree::base_hook) or it must have a member of type \p ellen_bintree::node
70 (for \p ellen_bintree::member_hook).
71 - \p Traits - tree traits, default is \p ellen_bintree::traits
72 It is possible to declare option-based tree with \p ellen_bintree::make_traits metafunction
73 instead of \p Traits template argument.
75 @anchor cds_intrusive_EllenBinTree_rcu_less
76 <b>Predicate requirements</b>
78 \p Traits::less, \p Traits::compare and other predicates using with member fuctions should accept at least parameters
79 of type \p T and \p Key in any combination.
80 For example, for \p Foo struct with \p std::string key field the appropiate \p less functor is:
82 struct Foo: public cds::intrusive::ellen_bintree::node< ... >
89 bool operator()( Foo const& v1, Foo const& v2 ) const
90 { return v1.m_strKey < v2.m_strKey ; }
92 bool operator()( Foo const& v, std::string const& s ) const
93 { return v.m_strKey < s ; }
95 bool operator()( std::string const& s, Foo const& v ) const
96 { return s < v.m_strKey ; }
98 // Support comparing std::string and char const *
99 bool operator()( std::string const& s, char const * p ) const
100 { return s.compare(p) < 0 ; }
102 bool operator()( Foo const& v, char const * p ) const
103 { return v.m_strKey.compare(p) < 0 ; }
105 bool operator()( char const * p, std::string const& s ) const
106 { return s.compare(p) > 0; }
108 bool operator()( char const * p, Foo const& v ) const
109 { return v.m_strKey.compare(p) > 0; }
113 @note Before including <tt><cds/intrusive/ellen_bintree_rcu.h></tt> you should include appropriate RCU header file,
114 see \ref cds_urcu_gc "RCU type" for list of existing RCU class and corresponding header files.
116 @anchor cds_intrusive_EllenBinTree_usage
119 Suppose we have the following Foo struct with string key type:
122 std::string m_strKey ; // The key
123 //... // other non-key data
127 We want to utilize RCU-based \p %cds::intrusive::EllenBinTree set for \p Foo data.
128 We may use base hook or member hook. Consider base hook variant.
129 First, we need deriving \p Foo struct from \p cds::intrusive::ellen_bintree::node:
131 #include <cds/urcu/general_buffered.h>
132 #include <cds/intrusive/ellen_bintree_rcu.h>
135 typedef cds::urcu::gc< cds::urcu::general_buffered<> > gpb_rcu;
137 struct Foo: public cds::intrusive:ellen_bintree::node< gpb_rcu >
139 std::string m_strKey ; // The key
140 //... // other non-key data
144 Second, we need to implement auxiliary structures and functors:
145 - key extractor functor for extracting the key from \p Foo object.
146 Such functor is necessary because the tree internal nodes store the keys.
147 - \p less predicate. We want our set should accept \p std::string
148 and <tt>char const *</tt> parameters for searching, so our \p less
149 predicate will not be trivial, see below.
150 - item counting feature: we want our set's \p size() member function
151 returns actual item count.
154 // Key extractor functor
155 struct my_key_extractor
157 void operator ()( std::string& key, Foo const& src ) const
165 bool operator()( Foo const& v1, Foo const& v2 ) const
166 { return v1.m_strKey < v2.m_strKey ; }
168 bool operator()( Foo const& v, std::string const& s ) const
169 { return v.m_strKey < s ; }
171 bool operator()( std::string const& s, Foo const& v ) const
172 { return s < v.m_strKey ; }
174 // Support comparing std::string and char const *
175 bool operator()( std::string const& s, char const * p ) const
176 { return s.compare(p) < 0 ; }
178 bool operator()( Foo const& v, char const * p ) const
179 { return v.m_strKey.compare(p) < 0 ; }
181 bool operator()( char const * p, std::string const& s ) const
182 { return s.compare(p) > 0; }
184 bool operator()( char const * p, Foo const& v ) const
185 { return v.m_strKey.compare(p) > 0; }
188 // Tree traits for our set
189 // It is necessary to specify only those typedefs that differ from
190 // cds::intrusive::ellen_bintree::traits defaults.
191 struct set_traits: public cds::intrusive::ellen_bintree::traits
193 typedef cds::intrusive::ellen_bintree::base_hook< cds::opt::gc<gpb_rcu> > > hook;
194 typedef my_key_extractor key_extractor;
195 typedef my_less less;
196 typedef cds::atomicity::item_counter item_counter;
200 Now we declare \p %EllenBinTree set and use it:
202 typedef cds::intrusive::EllenBinTree< gpb_rcu, std::string, Foo, set_traits > set_type;
208 Instead of declaring \p set_traits type traits we can use option-based syntax with
209 \p ellen_bintree::make_traits metafunction, for example:
211 typedef cds::intrusive::EllenBinTree< gpb_rcu, std::string, Foo,
212 typename cds::intrusive::ellen_bintree::make_traits<
213 cds::opt::hook< cds::intrusive::ellen_bintree::base_hook< cds::opt::gc<gpb_rcu> > >
214 ,cds::intrusive::ellen_bintree::key_extractor< my_key_extractor >
215 ,cds::opt::less< my_less >
216 ,cds::opt::item_counter< cds::atomicity::item_counter >
221 Functionally, \p set_type and \p set_type2 are equivalent.
223 <b>Member-hooked tree</b>
225 Sometimes, we cannot use base hook, for example, when the \p Foo structure is external.
226 In such case we can use member hook feature.
228 #include <cds/urcu/general_buffered.h>
229 #include <cds/intrusive/ellen_bintree_rcu.h>
231 // Struct Foo is external and its declaration cannot be modified.
233 std::string m_strKey ; // The key
234 //... // other non-key data
238 typedef cds::urcu::gc< cds::urcu::general_buffered<> > gpb_rcu;
244 cds::intrusive:ellen_bintree::node< gpb_rcu > set_hook; // member hook
247 // Key extractor functor
248 struct member_key_extractor
250 void operator ()( std::string& key, MyFoo const& src ) const
252 key = src.m_foo.m_strKey;
258 bool operator()( MyFoo const& v1, MyFoo const& v2 ) const
259 { return v1.m_foo.m_strKey < v2.m_foo.m_strKey ; }
261 bool operator()( MyFoo const& v, std::string const& s ) const
262 { return v.m_foo.m_strKey < s ; }
264 bool operator()( std::string const& s, MyFoo const& v ) const
265 { return s < v.m_foo.m_strKey ; }
267 // Support comparing std::string and char const *
268 bool operator()( std::string const& s, char const * p ) const
269 { return s.compare(p) < 0 ; }
271 bool operator()( MyFoo const& v, char const * p ) const
272 { return v.m_foo.m_strKey.compare(p) < 0 ; }
274 bool operator()( char const * p, std::string const& s ) const
275 { return s.compare(p) > 0; }
277 bool operator()( char const * p, MyFoo const& v ) const
278 { return v.m_foo.m_strKey.compare(p) > 0; }
281 // Tree traits for our member-based set
282 struct member_set_traits: public cds::intrusive::ellen_bintree::traits
284 cds::intrusive::ellen_bintree::member_hook< offsetof(MyFoo, set_hook), cds::opt::gc<gpb_rcu> > > hook;
285 typedef member_key_extractor key_extractor;
286 typedef member_less less;
287 typedef cds::atomicity::item_counter item_counter;
290 // Tree containing MyFoo objects
291 typedef cds::intrusive::EllenBinTree< gpb_rcu, std::string, MyFoo, member_set_traits > member_set_type;
293 member_set_type theMemberSet;
296 <b>Multiple containers</b>
298 Sometimes we need that our \p Foo struct should be used in several different containers.
299 Suppose, \p Foo struct has two key fields:
302 std::string m_strKey ; // string key
303 int m_nKey ; // int key
304 //... // other non-key data fields
308 We want to build two intrusive \p %EllenBinTree sets: one indexed on \p Foo::m_strKey field,
309 another indexed on \p Foo::m_nKey field. To decide such case we should use a tag option for
312 #include <cds/urcu/general_buffered.h>
313 #include <cds/intrusive/ellen_bintree_rcu.h>
316 typedef cds::urcu::gc< cds::urcu::general_buffered<> > gpb_rcu;
318 // Declare tag structs
319 struct int_tag ; // int key tag
320 struct string_tag ; // string key tag
322 // Foo struct is derived from two ellen_bintree::node class
323 // with different tags
325 : public cds::intrusive::ellen_bintree::node< gpb_rcu, cds::opt::tag< string_tag > >
326 , public cds::intrusive::ellen_bintree::node< gpb_rcu >, cds::opt::tag< int_tag >
328 std::string m_strKey ; // string key
329 int m_nKey ; // int key
330 //... // other non-key data fields
333 // String key extractor functor
334 struct string_key_extractor
336 void operator ()( std::string& key, Foo const& src ) const
342 // Int key extractor functor
343 struct int_key_extractor
345 void operator ()( int& key, Foo const& src ) const
351 // String less predicate
353 bool operator()( Foo const& v1, Foo const& v2 ) const
354 { return v1.m_strKey < v2.m_strKey ; }
356 bool operator()( Foo const& v, std::string const& s ) const
357 { return v.m_strKey < s ; }
359 bool operator()( std::string const& s, Foo const& v ) const
360 { return s < v.m_strKey ; }
362 // Support comparing std::string and char const *
363 bool operator()( std::string const& s, char const * p ) const
364 { return s.compare(p) < 0 ; }
366 bool operator()( Foo const& v, char const * p ) const
367 { return v.m_strKey.compare(p) < 0 ; }
369 bool operator()( char const * p, std::string const& s ) const
370 { return s.compare(p) > 0; }
372 bool operator()( char const * p, Foo const& v ) const
373 { return v.m_strKey.compare(p) > 0; }
376 // Int less predicate
378 bool operator()( Foo const& v1, Foo const& v2 ) const
379 { return v1.m_nKey < v2.m_nKey ; }
381 bool operator()( Foo const& v, int n ) const
382 { return v.m_nKey < n ; }
384 bool operator()( int n, Foo const& v ) const
385 { return n < v.m_nKey ; }
388 // Type traits for string-indexed set
389 struct string_set_traits: public cds::intrusive::ellen_bintree::traits
391 typedef cds::intrusive::ellen_bintree::base_hook< cds::opt::gc<gpb_rcu> >, cds::opt::tag< string_tag > > hook;
392 typedef string_key_extractor key_extractor;
393 typedef string_less less;
394 typedef cds::atomicity::item_counter item_counter;
397 // Type traits for int-indexed set
398 struct int_set_traits: public cds::intrusive::ellen_bintree::traits
400 typedef cds::intrusive::ellen_bintree::base_hook< cds::opt::gc<gpb_rcu> >, cds::opt::tag< int_tag > > hook;
401 typedef int_key_extractor key_extractor;
402 typedef int_less less;
403 typedef cds::atomicity::item_counter item_counter;
406 // Declare string-indexed set
407 typedef cds::intrusive::EllenBinTree< gpb_rcu, std::string, Foo, string_set_traits > string_set_type;
408 string_set_type theStringSet;
410 // Declare int-indexed set
411 typedef cds::intrusive::EllenBinTree< gpb_rcu, int, Foo, int_set_traits > int_set_type;
412 int_set_type theIntSet;
414 // Now we can use theStringSet and theIntSet in our program
418 template < class RCU,
421 #ifdef CDS_DOXYGEN_INVOKED
422 class Traits = ellen_bintree::traits
427 class EllenBinTree< cds::urcu::gc<RCU>, Key, T, Traits >
430 typedef cds::urcu::gc<RCU> gc; ///< RCU Garbage collector
431 typedef Key key_type; ///< type of a key stored in internal nodes; key is a part of \p value_type
432 typedef T value_type; ///< type of value stored in the binary tree
433 typedef Traits traits; ///< Traits template parameter
435 typedef typename traits::hook hook; ///< hook type
436 typedef typename hook::node_type node_type; ///< node type
438 typedef typename traits::disposer disposer; ///< leaf node disposer
439 typedef typename traits::back_off back_off; ///< back-off strategy
443 typedef ellen_bintree::base_node< gc > tree_node; ///< Base type of tree node
444 typedef node_type leaf_node; ///< Leaf node type
445 typedef ellen_bintree::internal_node< key_type, leaf_node > internal_node; ///< Internal node type
446 typedef ellen_bintree::update_desc< leaf_node, internal_node> update_desc; ///< Update descriptor
447 typedef typename update_desc::update_ptr update_ptr; ///< Marked pointer to update descriptor
451 using exempt_ptr = cds::urcu::exempt_ptr< gc, value_type, value_type, disposer, void >; ///< pointer to extracted node
454 # ifdef CDS_DOXYGEN_INVOKED
455 typedef implementation_defined key_comparator; ///< key compare functor based on \p Traits::compare and \p Traits::less
456 typedef typename get_node_traits< value_type, node_type, hook>::type node_traits; ///< Node traits
458 typedef typename opt::details::make_comparator< value_type, traits >::type key_comparator;
459 struct node_traits: public get_node_traits< value_type, node_type, hook>::type
461 static internal_node const& to_internal_node( tree_node const& n )
463 assert( n.is_internal() );
464 return static_cast<internal_node const&>( n );
467 static leaf_node const& to_leaf_node( tree_node const& n )
469 assert( n.is_leaf() );
470 return static_cast<leaf_node const&>( n );
475 typedef typename traits::item_counter item_counter; ///< Item counting policy used
476 typedef typename traits::memory_model memory_model; ///< Memory ordering. See cds::opt::memory_model option
477 typedef typename traits::stat stat; ///< internal statistics type
478 typedef typename traits::rcu_check_deadlock rcu_check_deadlock; ///< Deadlock checking policy
479 typedef typename traits::key_extractor key_extractor; ///< key extracting functor
481 typedef typename traits::node_allocator node_allocator; ///< Internal node allocator
482 typedef typename traits::update_desc_allocator update_desc_allocator; ///< Update descriptor allocator
484 typedef typename gc::scoped_lock rcu_lock; ///< RCU scoped lock
486 static CDS_CONSTEXPR const bool c_bExtractLockExternal = false; ///< Group of \p extract_xxx functions do not require external locking
490 typedef ellen_bintree::details::compare< key_type, value_type, key_comparator, node_traits > node_compare;
492 typedef cds::urcu::details::check_deadlock_policy< gc, rcu_check_deadlock > check_deadlock_policy;
494 typedef cds::details::Allocator< internal_node, node_allocator > cxx_node_allocator;
495 typedef cds::details::Allocator< update_desc, update_desc_allocator > cxx_update_desc_allocator;
497 struct search_result {
498 internal_node * pGrandParent;
499 internal_node * pParent;
501 update_ptr updParent;
502 update_ptr updGrandParent;
503 bool bRightLeaf ; // true if pLeaf is right child of pParent, false otherwise
504 bool bRightParent ; // true if pParent is right child of pGrandParent, false otherwise
507 :pGrandParent( nullptr )
511 ,bRightParent( false )
518 internal_node m_Root; ///< Tree root node (key= Infinite2)
519 leaf_node m_LeafInf1;
520 leaf_node m_LeafInf2;
523 item_counter m_ItemCounter; ///< item counter
524 mutable stat m_Stat; ///< internal statistics
528 static void free_leaf_node( value_type * p )
533 internal_node * alloc_internal_node() const
535 m_Stat.onInternalNodeCreated();
536 internal_node * pNode = cxx_node_allocator().New();
541 static void free_internal_node( internal_node * pNode )
543 cxx_node_allocator().Delete( pNode );
546 struct internal_node_deleter {
547 void operator()( internal_node * p) const
549 free_internal_node( p );
553 typedef std::unique_ptr< internal_node, internal_node_deleter> unique_internal_node_ptr;
555 update_desc * alloc_update_desc() const
557 m_Stat.onUpdateDescCreated();
558 return cxx_update_desc_allocator().New();
561 static void free_update_desc( update_desc * pDesc )
563 cxx_update_desc_allocator().Delete( pDesc );
568 update_desc * pUpdateHead;
569 tree_node * pNodeHead;
572 class forward_iterator
574 update_desc * m_pUpdate;
578 forward_iterator( retired_list const& l )
579 : m_pUpdate( l.pUpdateHead )
580 , m_pNode( l.pNodeHead )
584 : m_pUpdate( nullptr )
588 cds::urcu::retired_ptr operator *()
591 return cds::urcu::retired_ptr( reinterpret_cast<void *>( m_pUpdate ),
592 reinterpret_cast<cds::urcu::free_retired_ptr_func>( free_update_desc ) );
595 if ( m_pNode->is_leaf() ) {
596 return cds::urcu::retired_ptr( reinterpret_cast<void *>( node_traits::to_value_ptr( static_cast<leaf_node *>( m_pNode ))),
597 reinterpret_cast< cds::urcu::free_retired_ptr_func>( free_leaf_node ) );
600 return cds::urcu::retired_ptr( reinterpret_cast<void *>( static_cast<internal_node *>( m_pNode ) ),
601 reinterpret_cast<cds::urcu::free_retired_ptr_func>( free_internal_node ) );
604 return cds::urcu::retired_ptr( nullptr,
605 reinterpret_cast<cds::urcu::free_retired_ptr_func>( free_update_desc ) );
611 m_pUpdate = m_pUpdate->pNextRetire;
615 m_pNode = m_pNode->m_pNextRetired;
618 friend bool operator ==( forward_iterator const& i1, forward_iterator const& i2 )
620 return i1.m_pUpdate == i2.m_pUpdate && i1.m_pNode == i2.m_pNode;
622 friend bool operator !=( forward_iterator const& i1, forward_iterator const& i2 )
624 return !( i1 == i2 );
630 : pUpdateHead( nullptr )
631 , pNodeHead( nullptr )
636 gc::batch_retire( forward_iterator(*this), forward_iterator() );
639 void push( update_desc * p )
641 p->pNextRetire = pUpdateHead;
645 void push( tree_node * p )
647 p->m_pNextRetired = pNodeHead;
652 void retire_node( tree_node * pNode, retired_list& rl ) const
654 if ( pNode->is_leaf() ) {
655 assert( static_cast<leaf_node *>( pNode ) != &m_LeafInf1 );
656 assert( static_cast<leaf_node *>( pNode ) != &m_LeafInf2 );
659 assert( static_cast<internal_node *>( pNode ) != &m_Root );
660 m_Stat.onInternalNodeDeleted();
665 void retire_update_desc( update_desc * p, retired_list& rl, bool bDirect ) const
667 m_Stat.onUpdateDescDeleted();
669 free_update_desc( p );
674 void make_empty_tree()
676 m_Root.infinite_key( 2 );
677 m_LeafInf1.infinite_key( 1 );
678 m_LeafInf2.infinite_key( 2 );
679 m_Root.m_pLeft.store( &m_LeafInf1, memory_model::memory_order_relaxed );
680 m_Root.m_pRight.store( &m_LeafInf2, memory_model::memory_order_release );
685 /// Default constructor
688 static_assert( !std::is_same< key_extractor, opt::none >::value, "The key extractor option must be specified" );
700 The function inserts \p val in the tree if it does not contain
701 an item with key equal to \p val.
703 The function applies RCU lock internally.
705 Returns \p true if \p val is placed into the set, \p false otherwise.
707 bool insert( value_type& val )
709 return insert( val, []( value_type& ) {} );
714 This function is intended for derived non-intrusive containers.
716 The function allows to split creating of new item into two part:
717 - create item with key only
718 - insert new item into the tree
719 - if inserting is success, calls \p f functor to initialize value-field of \p val.
721 The functor signature is:
723 void func( value_type& val );
725 where \p val is the item inserted. User-defined functor \p f should guarantee that during changing
726 \p val no any other changes could be made on this tree's item by concurrent threads.
727 The user-defined functor is called only if the inserting is success.
729 RCU \p synchronize method can be called. RCU should not be locked.
731 template <typename Func>
732 bool insert( value_type& val, Func f )
734 check_deadlock_policy::check();
736 unique_internal_node_ptr pNewInternal;
737 retired_list updRetire;
745 if ( search( res, val, node_compare() )) {
746 if ( pNewInternal.get() )
747 m_Stat.onInternalNodeDeleted() ; // unique_internal_node_ptr deletes internal node
748 m_Stat.onInsertFailed();
752 if ( res.updParent.bits() != update_desc::Clean )
753 help( res.updParent, updRetire );
755 if ( !pNewInternal.get() )
756 pNewInternal.reset( alloc_internal_node() );
758 if ( try_insert( val, pNewInternal.get(), res, updRetire )) {
760 pNewInternal.release() ; // internal node is linked into the tree and should not be deleted
766 m_Stat.onInsertRetry();
771 m_Stat.onInsertSuccess();
776 /// Ensures that the \p val exists in the tree
778 The operation performs inserting or changing data with lock-free manner.
780 If the item \p val is not found in the tree, then \p val is inserted into the tree.
781 Otherwise, the functor \p func is called with item found.
782 The functor signature is:
784 void func( bool bNew, value_type& item, value_type& val );
787 - \p bNew - \p true if the item has been inserted, \p false otherwise
788 - \p item - item of the tree
789 - \p val - argument \p val passed into the \p ensure function
790 If new item has been inserted (i.e. \p bNew is \p true) then \p item and \p val arguments
791 refer to the same thing.
793 The functor can change non-key fields of the \p item; however, \p func must guarantee
794 that during changing no any other modifications could be made on this item by concurrent threads.
796 RCU \p synchronize method can be called. RCU should not be locked.
798 Returns <tt>std::pair<bool, bool> </tt> where \p first is \p true if operation is successfull,
799 \p second is \p true if new item has been added or \p false if the item with \p key
800 already is in the tree.
802 @warning See \ref cds_intrusive_item_creating "insert item troubleshooting"
804 template <typename Func>
805 std::pair<bool, bool> ensure( value_type& val, Func func )
807 check_deadlock_policy::check();
809 unique_internal_node_ptr pNewInternal;
810 retired_list updRetire;
818 if ( search( res, val, node_compare() )) {
819 func( false, *node_traits::to_value_ptr( res.pLeaf ), val );
820 if ( pNewInternal.get() )
821 m_Stat.onInternalNodeDeleted() ; // unique_internal_node_ptr deletes internal node
822 m_Stat.onEnsureExist();
823 return std::make_pair( true, false );
826 if ( res.updParent.bits() != update_desc::Clean )
827 help( res.updParent, updRetire );
829 if ( !pNewInternal.get() )
830 pNewInternal.reset( alloc_internal_node() );
832 if ( try_insert( val, pNewInternal.get(), res, updRetire )) {
833 func( true, val, val );
834 pNewInternal.release() ; // internal node is linked into the tree and should not be deleted
840 m_Stat.onEnsureRetry();
845 m_Stat.onEnsureNew();
847 return std::make_pair( true, true );
850 /// Unlinks the item \p val from the tree
852 The function searches the item \p val in the tree and unlink it from the tree
853 if it is found and is equal to \p val.
855 Difference between \ref erase and \p unlink functions: \p erase finds <i>a key</i>
856 and deletes the item found. \p unlink finds an item by key and deletes it
857 only if \p val is an item of the tree, i.e. the pointer to item found
858 is equal to <tt> &val </tt>.
860 RCU \p synchronize method can be called. RCU should not be locked.
862 The \ref disposer specified in \p Traits class template parameter is called
863 by garbage collector \p GC asynchronously.
865 The function returns \p true if success and \p false otherwise.
867 bool unlink( value_type& val )
869 return erase_( val, node_compare(),
870 []( value_type const& v, leaf_node const& n ) -> bool { return &v == node_traits::to_value_ptr( n ); },
871 [](value_type const&) {} );
874 /// Deletes the item from the tree
875 /** \anchor cds_intrusive_EllenBinTree_rcu_erase
876 The function searches an item with key equal to \p key in the tree,
877 unlinks it from the tree, and returns \p true.
878 If the item with key equal to \p key is not found the function return \p false.
880 Note the hash functor should accept a parameter of type \p Q that can be not the same as \p value_type.
882 RCU \p synchronize method can be called. RCU should not be locked.
884 template <typename Q>
885 bool erase( const Q& key )
887 return erase_( key, node_compare(),
888 []( Q const&, leaf_node const& ) -> bool { return true; },
889 [](value_type const&) {} );
892 /// Delete the item from the tree with comparing functor \p pred
894 The function is an analog of \ref cds_intrusive_EllenBinTree_rcu_erase "erase(Q const&)"
895 but \p pred predicate is used for key comparing.
896 \p Less has the interface like \p std::less and should meet \ref cds_intrusive_EllenBinTree_rcu_less
897 "Predicate requirements".
898 \p pred must imply the same element order as the comparator used for building the tree.
900 template <typename Q, typename Less>
901 bool erase_with( const Q& key, Less pred )
904 typedef ellen_bintree::details::compare<
907 opt::details::make_comparator_from_less<Less>,
911 return erase_( key, compare_functor(),
912 []( Q const&, leaf_node const& ) -> bool { return true; },
913 [](value_type const&) {} );
916 /// Deletes the item from the tree
917 /** \anchor cds_intrusive_EllenBinTree_rcu_erase_func
918 The function searches an item with key equal to \p key in the tree,
919 call \p f functor with item found, unlinks it from the tree, and returns \p true.
920 The \ref disposer specified in \p Traits class template parameter is called
921 by garbage collector \p GC asynchronously.
923 The \p Func interface is
926 void operator()( value_type const& item );
930 If the item with key equal to \p key is not found the function return \p false.
932 Note the hash functor should accept a parameter of type \p Q that can be not the same as \p value_type.
934 RCU \p synchronize method can be called. RCU should not be locked.
936 template <typename Q, typename Func>
937 bool erase( Q const& key, Func f )
939 return erase_( key, node_compare(),
940 []( Q const&, leaf_node const& ) -> bool { return true; },
944 /// Delete the item from the tree with comparing functor \p pred
946 The function is an analog of \ref cds_intrusive_EllenBinTree_rcu_erase_func "erase(Q const&, Func)"
947 but \p pred predicate is used for key comparing.
948 \p Less has the interface like \p std::less and should meet \ref cds_intrusive_EllenBinTree_rcu_less
949 "Predicate requirements".
950 \p pred must imply the same element order as the comparator used for building the tree.
952 template <typename Q, typename Less, typename Func>
953 bool erase_with( Q const& key, Less pred, Func f )
956 typedef ellen_bintree::details::compare<
959 opt::details::make_comparator_from_less<Less>,
963 return erase_( key, compare_functor(),
964 []( Q const&, leaf_node const& ) -> bool { return true; },
968 /// Extracts an item with minimal key from the tree
970 The function searches an item with minimal key, unlinks it, and returns
971 \ref cds::urcu::exempt_ptr "exempt_ptr" pointer to the leftmost item.
972 If the tree is empty the function returns empty \p exempt_ptr.
974 @note Due the concurrent nature of the tree, the function extracts <i>nearly</i> minimum key.
975 It means that the function gets leftmost leaf of the tree and tries to unlink it.
976 During unlinking, a concurrent thread may insert an item with key less than leftmost item's key.
977 So, the function returns the item with minimum key at the moment of tree traversing.
979 RCU \p synchronize method can be called. RCU should NOT be locked.
980 The function does not call the disposer for the item found.
981 The disposer will be implicitly invoked when the returned object is destroyed or when
982 its \p release() member function is called.
984 exempt_ptr extract_min()
986 return exempt_ptr( extract_min_() );
989 /// Extracts an item with maximal key from the tree
991 The function searches an item with maximal key, unlinks it, and returns
992 \ref cds::urcu::exempt_ptr "exempt_ptr" pointer to the rightmost item.
993 If the tree is empty the function returns empty \p exempt_ptr.
995 @note Due the concurrent nature of the tree, the function extracts <i>nearly</i> maximal key.
996 It means that the function gets rightmost leaf of the tree and tries to unlink it.
997 During unlinking, a concurrent thread may insert an item with key great than rightmost item's key.
998 So, the function returns the item with maximum key at the moment of tree traversing.
1000 RCU \p synchronize method can be called. RCU should NOT be locked.
1001 The function does not call the disposer for the item found.
1002 The disposer will be implicitly invoked when the returned object is destroyed or when
1003 its \p release() member function is called.
1005 exempt_ptr extract_max()
1007 return exempt_ptr( extract_max_() );
1010 /// Extracts an item from the tree
1011 /** \anchor cds_intrusive_EllenBinTree_rcu_extract
1012 The function searches an item with key equal to \p key in the tree,
1013 unlinks it, and returns \ref cds::urcu::exempt_ptr "exempt_ptr" pointer to an item found.
1014 If the item with the key equal to \p key is not found the function returns empty \p exempt_ptr.
1016 RCU \p synchronize method can be called. RCU should NOT be locked.
1017 The function does not call the disposer for the item found.
1018 The disposer will be implicitly invoked when the returned object is destroyed or when
1019 its \p release() member function is called.
1021 template <typename Q>
1022 exempt_ptr extract( Q const& key )
1024 return exempt_ptr( extract_( key, node_compare() ));
1027 /// Extracts an item from the set using \p pred for searching
1029 The function is an analog of \ref cds_intrusive_EllenBinTree_rcu_extract "extract(exempt_ptr&, Q const&)"
1030 but \p pred is used for key compare.
1031 \p Less has the interface like \p std::less and should meet \ref cds_intrusive_EllenBinTree_rcu_less
1032 "predicate requirements".
1033 \p pred must imply the same element order as the comparator used for building the tree.
1035 template <typename Q, typename Less>
1036 exempt_ptr extract_with( Q const& key, Less pred )
1038 return exempt_ptr( extract_with_( key, pred ));
1041 /// Finds the key \p key
1042 /** @anchor cds_intrusive_EllenBinTree_rcu_find_val
1043 The function searches the item with key equal to \p key
1044 and returns \p true if it is found, and \p false otherwise.
1046 Note the hash functor specified for class \p Traits template parameter
1047 should accept a parameter of type \p Q that can be not the same as \p value_type.
1049 The function applies RCU lock internally.
1051 template <typename Q>
1052 bool find( Q const& key ) const
1056 if ( search( res, key, node_compare() )) {
1057 m_Stat.onFindSuccess();
1061 m_Stat.onFindFailed();
1065 /// Finds the key \p key with comparing functor \p pred
1067 The function is an analog of \ref cds_intrusive_EllenBinTree_rcu_find_val "find(Q const&)"
1068 but \p pred is used for key compare.
1069 \p Less functor has the interface like \p std::less and should meet \ref cds_intrusive_EllenBinTree_rcu_less
1070 "Predicate requirements".
1071 \p pred must imply the same element order as the comparator used for building the tree.
1072 \p pred should accept arguments of type \p Q, \p key_type, \p value_type in any combination.
1074 template <typename Q, typename Less>
1075 bool find_with( Q const& key, Less pred ) const
1078 typedef ellen_bintree::details::compare<
1081 opt::details::make_comparator_from_less<Less>,
1087 if ( search( res, key, compare_functor() )) {
1088 m_Stat.onFindSuccess();
1091 m_Stat.onFindFailed();
1095 /// Finds the key \p key
1096 /** @anchor cds_intrusive_EllenBinTree_rcu_find_func
1097 The function searches the item with key equal to \p key and calls the functor \p f for item found.
1098 The interface of \p Func functor is:
1101 void operator()( value_type& item, Q& key );
1104 where \p item is the item found, \p key is the <tt>find</tt> function argument.
1106 The functor can change non-key fields of \p item. Note that the functor is only guarantee
1107 that \p item cannot be disposed during functor is executing.
1108 The functor does not serialize simultaneous access to the tree \p item. If such access is
1109 possible you must provide your own synchronization schema on item level to exclude unsafe item modifications.
1111 The function applies RCU lock internally.
1113 The function returns \p true if \p key is found, \p false otherwise.
1115 template <typename Q, typename Func>
1116 bool find( Q& key, Func f ) const
1118 return find_( key, f );
1121 template <typename Q, typename Func>
1122 bool find( Q const& key, Func f ) const
1124 return find_( key, f );
1128 /// Finds the key \p key with comparing functor \p pred
1130 The function is an analog of \ref cds_intrusive_EllenBinTree_rcu_find_func "find(Q&, Func)"
1131 but \p pred is used for key comparison.
1132 \p Less functor has the interface like \p std::less and should meet \ref cds_intrusive_EllenBinTree_rcu_less
1133 "Predicate requirements".
1134 \p pred must imply the same element order as the comparator used for building the tree.
1136 template <typename Q, typename Less, typename Func>
1137 bool find_with( Q& key, Less pred, Func f ) const
1139 return find_with_( key, pred, f );
1142 template <typename Q, typename Less, typename Func>
1143 bool find_with( Q const& key, Less pred, Func f ) const
1145 return find_with_( key, pred, f );
1149 /// Finds \p key and return the item found
1150 /** \anchor cds_intrusive_EllenBinTree_rcu_get
1151 The function searches the item with key equal to \p key and returns the pointer to item found.
1152 If \p key is not found it returns \p nullptr.
1154 RCU should be locked before call the function.
1155 Returned pointer is valid while RCU is locked.
1157 template <typename Q>
1158 value_type * get( Q const& key ) const
1160 return get_( key, node_compare() );
1163 /// Finds \p key with \p pred predicate and return the item found
1165 The function is an analog of \ref cds_intrusive_EllenBinTree_rcu_get "get(Q const&)"
1166 but \p pred is used for comparing the keys.
1168 \p Less functor has the semantics like \p std::less but should take arguments of type \ref value_type and \p Q
1170 \p pred must imply the same element order as the comparator used for building the tree.
1172 template <typename Q, typename Less>
1173 value_type * get_with( Q const& key, Less pred ) const
1176 typedef ellen_bintree::details::compare<
1179 opt::details::make_comparator_from_less<Less>,
1183 return get_( key, compare_functor());
1186 /// Checks if the tree is empty
1189 return m_Root.m_pLeft.load( memory_model::memory_order_relaxed )->is_leaf();
1192 /// Clears the tree (thread safe, not atomic)
1194 The function unlink all items from the tree.
1195 The function is thread safe but not atomic: in multi-threaded environment with parallel insertions
1199 assert( set.empty() );
1201 the assertion could be raised.
1203 For each leaf the \ref disposer will be called after unlinking.
1205 RCU \p synchronize method can be called. RCU should not be locked.
1209 for ( exempt_ptr ep = extract_min(); !ep.empty(); ep = extract_min() )
1213 /// Clears the tree (not thread safe)
1215 This function is not thread safe and may be called only when no other thread deals with the tree.
1216 The function is used in the tree destructor.
1223 internal_node * pParent = nullptr;
1224 internal_node * pGrandParent = nullptr;
1225 tree_node * pLeaf = const_cast<internal_node *>( &m_Root );
1227 // Get leftmost leaf
1228 while ( pLeaf->is_internal() ) {
1229 pGrandParent = pParent;
1230 pParent = static_cast<internal_node *>( pLeaf );
1231 pLeaf = pParent->m_pLeft.load( memory_model::memory_order_relaxed );
1234 if ( pLeaf->infinite_key()) {
1235 // The tree is empty
1239 // Remove leftmost leaf and its parent node
1240 assert( pGrandParent );
1242 assert( pLeaf->is_leaf() );
1244 pGrandParent->m_pLeft.store( pParent->m_pRight.load( memory_model::memory_order_relaxed ), memory_model::memory_order_relaxed );
1245 free_leaf_node( node_traits::to_value_ptr( static_cast<leaf_node *>( pLeaf ) ) );
1246 free_internal_node( pParent );
1250 /// Returns item count in the tree
1252 Only leaf nodes containing user data are counted.
1254 The value returned depends on item counter type provided by \p Traits template parameter.
1255 If it is \p atomicity::empty_item_counter this function always returns 0.
1257 The function is not suitable for checking the tree emptiness, use \p empty()
1258 member function for that.
1262 return m_ItemCounter;
1265 /// Returns const reference to internal statistics
1266 stat const& statistics() const
1271 /// Checks internal consistency (not atomic, not thread-safe)
1273 The debugging function to check internal consistency of the tree.
1275 bool check_consistency() const
1277 return check_consistency( &m_Root );
1283 bool check_consistency( internal_node const * pRoot ) const
1285 tree_node * pLeft = pRoot->m_pLeft.load( atomics::memory_order_relaxed );
1286 tree_node * pRight = pRoot->m_pRight.load( atomics::memory_order_relaxed );
1290 if ( node_compare()( *pLeft, *pRoot ) < 0
1291 && node_compare()( *pRoot, *pRight ) <= 0
1292 && node_compare()( *pLeft, *pRight ) < 0 )
1295 if ( pLeft->is_internal() )
1296 bRet = check_consistency( static_cast<internal_node *>( pLeft ) );
1299 if ( bRet && pRight->is_internal() )
1300 bRet = bRet && check_consistency( static_cast<internal_node *>( pRight ));
1308 void help( update_ptr pUpdate, retired_list& rl )
1311 switch ( pUpdate.bits() ) {
1312 case update_desc::IFlag:
1313 help_insert( pUpdate.ptr() );
1314 m_Stat.onHelpInsert();
1316 case update_desc::DFlag:
1317 //help_delete( pUpdate.ptr(), rl );
1318 //m_Stat.onHelpDelete();
1320 case update_desc::Mark:
1321 //help_marked( pUpdate.ptr() );
1322 //m_Stat.onHelpMark();
1328 void help_insert( update_desc * pOp )
1330 assert( gc::is_locked() );
1332 tree_node * pLeaf = static_cast<tree_node *>( pOp->iInfo.pLeaf );
1333 if ( pOp->iInfo.bRightLeaf ) {
1334 pOp->iInfo.pParent->m_pRight.compare_exchange_strong( pLeaf, static_cast<tree_node *>( pOp->iInfo.pNew ),
1335 memory_model::memory_order_release, atomics::memory_order_relaxed );
1338 pOp->iInfo.pParent->m_pLeft.compare_exchange_strong( pLeaf, static_cast<tree_node *>( pOp->iInfo.pNew ),
1339 memory_model::memory_order_release, atomics::memory_order_relaxed );
1342 update_ptr cur( pOp, update_desc::IFlag );
1343 pOp->iInfo.pParent->m_pUpdate.compare_exchange_strong( cur, pOp->iInfo.pParent->null_update_desc(),
1344 memory_model::memory_order_release, atomics::memory_order_relaxed );
1347 bool check_delete_precondition( search_result& res )
1349 assert( res.pGrandParent != nullptr );
1352 static_cast<internal_node *>( res.bRightParent
1353 ? res.pGrandParent->m_pRight.load(memory_model::memory_order_relaxed)
1354 : res.pGrandParent->m_pLeft.load(memory_model::memory_order_relaxed)
1357 static_cast<leaf_node *>( res.bRightLeaf
1358 ? res.pParent->m_pRight.load(memory_model::memory_order_relaxed)
1359 : res.pParent->m_pLeft.load(memory_model::memory_order_relaxed)
1363 bool help_delete( update_desc * pOp, retired_list& rl )
1365 assert( gc::is_locked() );
1367 update_ptr pUpdate( pOp->dInfo.pUpdateParent );
1368 update_ptr pMark( pOp, update_desc::Mark );
1369 if ( pOp->dInfo.pParent->m_pUpdate.compare_exchange_strong( pUpdate, pMark,
1370 memory_model::memory_order_acquire, atomics::memory_order_relaxed ))
1373 retire_node( pOp->dInfo.pParent, rl );
1374 // For extract operations the leaf should NOT be disposed
1375 if ( pOp->dInfo.bDisposeLeaf )
1376 retire_node( pOp->dInfo.pLeaf, rl );
1377 retire_update_desc( pOp, rl, false );
1381 else if ( pUpdate == pMark ) {
1382 // some other thread is processing help_marked()
1384 m_Stat.onHelpMark();
1388 // pUpdate has been changed by CAS
1389 help( pUpdate, rl );
1391 // Undo grandparent dInfo
1392 update_ptr pDel( pOp, update_desc::DFlag );
1393 if ( pOp->dInfo.pGrandParent->m_pUpdate.compare_exchange_strong( pDel, pOp->dInfo.pGrandParent->null_update_desc(),
1394 memory_model::memory_order_release, atomics::memory_order_relaxed ))
1396 retire_update_desc( pOp, rl, false );
1402 void help_marked( update_desc * pOp )
1404 assert( gc::is_locked() );
1406 tree_node * p = pOp->dInfo.pParent;
1407 if ( pOp->dInfo.bRightParent ) {
1408 pOp->dInfo.pGrandParent->m_pRight.compare_exchange_strong( p,
1409 pOp->dInfo.bRightLeaf
1410 ? pOp->dInfo.pParent->m_pLeft.load( memory_model::memory_order_acquire )
1411 : pOp->dInfo.pParent->m_pRight.load( memory_model::memory_order_acquire ),
1412 memory_model::memory_order_release, atomics::memory_order_relaxed );
1415 pOp->dInfo.pGrandParent->m_pLeft.compare_exchange_strong( p,
1416 pOp->dInfo.bRightLeaf
1417 ? pOp->dInfo.pParent->m_pLeft.load( memory_model::memory_order_acquire )
1418 : pOp->dInfo.pParent->m_pRight.load( memory_model::memory_order_acquire ),
1419 memory_model::memory_order_release, atomics::memory_order_relaxed );
1422 update_ptr upd( pOp, update_desc::DFlag );
1423 pOp->dInfo.pGrandParent->m_pUpdate.compare_exchange_strong( upd, pOp->dInfo.pGrandParent->null_update_desc(),
1424 memory_model::memory_order_release, atomics::memory_order_relaxed );
1427 template <typename KeyValue, typename Compare>
1428 bool search( search_result& res, KeyValue const& key, Compare cmp ) const
1430 assert( gc::is_locked() );
1432 internal_node * pParent;
1433 internal_node * pGrandParent = nullptr;
1435 update_ptr updParent;
1436 update_ptr updGrandParent;
1438 bool bRightParent = false;
1444 pLeaf = const_cast<internal_node *>( &m_Root );
1445 updParent = nullptr;
1447 while ( pLeaf->is_internal() ) {
1448 pGrandParent = pParent;
1449 pParent = static_cast<internal_node *>( pLeaf );
1450 bRightParent = bRightLeaf;
1451 updGrandParent = updParent;
1452 updParent = pParent->m_pUpdate.load( memory_model::memory_order_acquire );
1454 switch ( updParent.bits() ) {
1455 case update_desc::DFlag:
1456 case update_desc::Mark:
1457 m_Stat.onSearchRetry();
1461 nCmp = cmp( key, *pParent );
1462 bRightLeaf = nCmp >= 0;
1463 pLeaf = nCmp < 0 ? pParent->m_pLeft.load( memory_model::memory_order_acquire )
1464 : pParent->m_pRight.load( memory_model::memory_order_acquire );
1467 assert( pLeaf->is_leaf() );
1468 nCmp = cmp( key, *static_cast<leaf_node *>(pLeaf) );
1470 res.pGrandParent = pGrandParent;
1471 res.pParent = pParent;
1472 res.pLeaf = static_cast<leaf_node *>( pLeaf );
1473 res.updParent = updParent;
1474 res.updGrandParent = updGrandParent;
1475 res.bRightParent = bRightParent;
1476 res.bRightLeaf = bRightLeaf;
1481 bool search_min( search_result& res ) const
1483 assert( gc::is_locked() );
1485 internal_node * pParent;
1486 internal_node * pGrandParent = nullptr;
1488 update_ptr updParent;
1489 update_ptr updGrandParent;
1493 pLeaf = const_cast<internal_node *>( &m_Root );
1494 while ( pLeaf->is_internal() ) {
1495 pGrandParent = pParent;
1496 pParent = static_cast<internal_node *>( pLeaf );
1497 updGrandParent = updParent;
1498 updParent = pParent->m_pUpdate.load( memory_model::memory_order_acquire );
1500 switch ( updParent.bits() ) {
1501 case update_desc::DFlag:
1502 case update_desc::Mark:
1503 m_Stat.onSearchRetry();
1507 pLeaf = pParent->m_pLeft.load( memory_model::memory_order_acquire );
1510 if ( pLeaf->infinite_key())
1513 res.pGrandParent = pGrandParent;
1514 res.pParent = pParent;
1515 assert( pLeaf->is_leaf() );
1516 res.pLeaf = static_cast<leaf_node *>( pLeaf );
1517 res.updParent = updParent;
1518 res.updGrandParent = updGrandParent;
1519 res.bRightParent = false;
1520 res.bRightLeaf = false;
1525 bool search_max( search_result& res ) const
1527 assert( gc::is_locked() );
1529 internal_node * pParent;
1530 internal_node * pGrandParent = nullptr;
1532 update_ptr updParent;
1533 update_ptr updGrandParent;
1535 bool bRightParent = false;
1539 pLeaf = const_cast<internal_node *>( &m_Root );
1541 while ( pLeaf->is_internal() ) {
1542 pGrandParent = pParent;
1543 pParent = static_cast<internal_node *>( pLeaf );
1544 bRightParent = bRightLeaf;
1545 updGrandParent = updParent;
1546 updParent = pParent->m_pUpdate.load( memory_model::memory_order_acquire );
1548 switch ( updParent.bits() ) {
1549 case update_desc::DFlag:
1550 case update_desc::Mark:
1551 m_Stat.onSearchRetry();
1555 if ( pParent->infinite_key()) {
1556 pLeaf = pParent->m_pLeft.load( memory_model::memory_order_acquire );
1560 pLeaf = pParent->m_pRight.load( memory_model::memory_order_acquire );
1565 if ( pLeaf->infinite_key())
1568 res.pGrandParent = pGrandParent;
1569 res.pParent = pParent;
1570 assert( pLeaf->is_leaf() );
1571 res.pLeaf = static_cast<leaf_node *>( pLeaf );
1572 res.updParent = updParent;
1573 res.updGrandParent = updGrandParent;
1574 res.bRightParent = bRightParent;
1575 res.bRightLeaf = bRightLeaf;
1580 template <typename Q, typename Compare, typename Equal, typename Func>
1581 bool erase_( Q const& val, Compare cmp, Equal eq, Func f )
1583 check_deadlock_policy::check();
1585 retired_list updRetire;
1586 update_desc * pOp = nullptr;
1593 if ( !search( res, val, cmp ) || !eq( val, *res.pLeaf ) ) {
1595 retire_update_desc( pOp, updRetire, false );
1596 m_Stat.onEraseFailed();
1600 if ( res.updGrandParent.bits() != update_desc::Clean )
1601 help( res.updGrandParent, updRetire );
1602 else if ( res.updParent.bits() != update_desc::Clean )
1603 help( res.updParent, updRetire );
1606 pOp = alloc_update_desc();
1607 if ( check_delete_precondition( res ) ) {
1608 pOp->dInfo.pGrandParent = res.pGrandParent;
1609 pOp->dInfo.pParent = res.pParent;
1610 pOp->dInfo.pLeaf = res.pLeaf;
1611 pOp->dInfo.bDisposeLeaf = true;
1612 pOp->dInfo.pUpdateParent = res.updParent.ptr();
1613 pOp->dInfo.bRightParent = res.bRightParent;
1614 pOp->dInfo.bRightLeaf = res.bRightLeaf;
1616 update_ptr updGP( res.updGrandParent.ptr() );
1617 if ( res.pGrandParent->m_pUpdate.compare_exchange_strong( updGP, update_ptr( pOp, update_desc::DFlag ),
1618 memory_model::memory_order_acquire, atomics::memory_order_relaxed ))
1620 if ( help_delete( pOp, updRetire )) {
1621 // res.pLeaf is not deleted yet since RCU is blocked
1622 f( *node_traits::to_value_ptr( res.pLeaf ));
1628 // updGP has been changed by CAS
1629 help( updGP, updRetire );
1635 m_Stat.onEraseRetry();
1640 m_Stat.onEraseSuccess();
1644 template <typename Q, typename Less>
1645 value_type * extract_with_( Q const& val, Less pred )
1648 typedef ellen_bintree::details::compare<
1651 opt::details::make_comparator_from_less<Less>,
1655 return extract_( val, compare_functor() );
1658 template <typename Q, typename Compare>
1659 value_type * extract_( Q const& val, Compare cmp )
1661 check_deadlock_policy::check();
1663 retired_list updRetire;
1664 update_desc * pOp = nullptr;
1667 value_type * pResult;
1672 if ( !search( res, val, cmp ) ) {
1674 retire_update_desc( pOp, updRetire, false );
1675 m_Stat.onEraseFailed();
1679 if ( res.updGrandParent.bits() != update_desc::Clean )
1680 help( res.updGrandParent, updRetire );
1681 else if ( res.updParent.bits() != update_desc::Clean )
1682 help( res.updParent, updRetire );
1685 pOp = alloc_update_desc();
1686 if ( check_delete_precondition( res )) {
1687 pOp->dInfo.pGrandParent = res.pGrandParent;
1688 pOp->dInfo.pParent = res.pParent;
1689 pOp->dInfo.pLeaf = res.pLeaf;
1690 pOp->dInfo.bDisposeLeaf = false;
1691 pOp->dInfo.pUpdateParent = res.updParent.ptr();
1692 pOp->dInfo.bRightParent = res.bRightParent;
1693 pOp->dInfo.bRightLeaf = res.bRightLeaf;
1695 update_ptr updGP( res.updGrandParent.ptr() );
1696 if ( res.pGrandParent->m_pUpdate.compare_exchange_strong( updGP, update_ptr( pOp, update_desc::DFlag ),
1697 memory_model::memory_order_acquire, atomics::memory_order_relaxed ))
1699 if ( help_delete( pOp, updRetire )) {
1700 pResult = node_traits::to_value_ptr( res.pLeaf );
1706 // updGP has been changed by CAS
1707 help( updGP, updRetire );
1713 m_Stat.onEraseRetry();
1718 m_Stat.onEraseSuccess();
1723 value_type * extract_max_()
1725 check_deadlock_policy::check();
1727 retired_list updRetire;
1728 update_desc * pOp = nullptr;
1731 value_type * pResult;
1736 if ( !search_max( res )) {
1739 retire_update_desc( pOp, updRetire, false );
1740 m_Stat.onExtractMaxFailed();
1744 if ( res.updGrandParent.bits() != update_desc::Clean )
1745 help( res.updGrandParent, updRetire );
1746 else if ( res.updParent.bits() != update_desc::Clean )
1747 help( res.updParent, updRetire );
1750 pOp = alloc_update_desc();
1751 if ( check_delete_precondition( res ) ) {
1752 pOp->dInfo.pGrandParent = res.pGrandParent;
1753 pOp->dInfo.pParent = res.pParent;
1754 pOp->dInfo.pLeaf = res.pLeaf;
1755 pOp->dInfo.bDisposeLeaf = false;
1756 pOp->dInfo.pUpdateParent = res.updParent.ptr();
1757 pOp->dInfo.bRightParent = res.bRightParent;
1758 pOp->dInfo.bRightLeaf = res.bRightLeaf;
1760 update_ptr updGP( res.updGrandParent.ptr() );
1761 if ( res.pGrandParent->m_pUpdate.compare_exchange_strong( updGP, update_ptr( pOp, update_desc::DFlag ),
1762 memory_model::memory_order_acquire, atomics::memory_order_relaxed ))
1764 if ( help_delete( pOp, updRetire )) {
1765 pResult = node_traits::to_value_ptr( res.pLeaf );
1771 // updGP has been changed by CAS
1772 help( updGP, updRetire );
1778 m_Stat.onExtractMaxRetry();
1783 m_Stat.onExtractMaxSuccess();
1787 value_type * extract_min_()
1789 check_deadlock_policy::check();
1791 retired_list updRetire;
1792 update_desc * pOp = nullptr;
1795 value_type * pResult;
1800 if ( !search_min( res )) {
1803 retire_update_desc( pOp, updRetire, false );
1804 m_Stat.onExtractMinFailed();
1808 if ( res.updGrandParent.bits() != update_desc::Clean )
1809 help( res.updGrandParent, updRetire );
1810 else if ( res.updParent.bits() != update_desc::Clean )
1811 help( res.updParent, updRetire );
1814 pOp = alloc_update_desc();
1815 if ( check_delete_precondition( res ) ) {
1816 pOp->dInfo.pGrandParent = res.pGrandParent;
1817 pOp->dInfo.pParent = res.pParent;
1818 pOp->dInfo.pLeaf = res.pLeaf;
1819 pOp->dInfo.bDisposeLeaf = false;
1820 pOp->dInfo.pUpdateParent = res.updParent.ptr();
1821 pOp->dInfo.bRightParent = res.bRightParent;
1822 pOp->dInfo.bRightLeaf = res.bRightLeaf;
1824 update_ptr updGP( res.updGrandParent.ptr() );
1825 if ( res.pGrandParent->m_pUpdate.compare_exchange_strong( updGP, update_ptr( pOp, update_desc::DFlag ),
1826 memory_model::memory_order_acquire, atomics::memory_order_relaxed ))
1828 if ( help_delete( pOp, updRetire )) {
1829 pResult = node_traits::to_value_ptr( res.pLeaf );
1835 // updGP has been changed by CAS
1836 help( updGP, updRetire );
1842 m_Stat.onExtractMinRetry();
1847 m_Stat.onExtractMinSuccess();
1851 template <typename Q, typename Less, typename Func>
1852 bool find_with_( Q& val, Less pred, Func f ) const
1855 typedef ellen_bintree::details::compare<
1858 opt::details::make_comparator_from_less<Less>,
1864 if ( search( res, val, compare_functor() )) {
1865 assert( res.pLeaf );
1866 f( *node_traits::to_value_ptr( res.pLeaf ), val );
1868 m_Stat.onFindSuccess();
1872 m_Stat.onFindFailed();
1876 template <typename Q, typename Func>
1877 bool find_( Q& key, Func f ) const
1881 if ( search( res, key, node_compare() )) {
1882 assert( res.pLeaf );
1883 f( *node_traits::to_value_ptr( res.pLeaf ), key );
1885 m_Stat.onFindSuccess();
1889 m_Stat.onFindFailed();
1893 template <typename Q, typename Compare>
1894 value_type * get_( Q const& key, Compare cmp ) const
1896 assert( gc::is_locked());
1899 if ( search( res, key, cmp )) {
1900 m_Stat.onFindSuccess();
1901 return node_traits::to_value_ptr( res.pLeaf );
1904 m_Stat.onFindFailed();
1909 bool try_insert( value_type& val, internal_node * pNewInternal, search_result& res, retired_list& updRetire )
1911 assert( gc::is_locked() );
1912 assert( res.updParent.bits() == update_desc::Clean );
1914 // check search result
1915 if ( static_cast<leaf_node *>( res.bRightLeaf
1916 ? res.pParent->m_pRight.load( memory_model::memory_order_relaxed )
1917 : res.pParent->m_pLeft.load( memory_model::memory_order_relaxed ) ) == res.pLeaf )
1919 leaf_node * pNewLeaf = node_traits::to_node_ptr( val );
1921 int nCmp = node_compare()( val, *res.pLeaf );
1923 if ( res.pGrandParent ) {
1924 pNewInternal->infinite_key( 0 );
1925 key_extractor()( pNewInternal->m_Key, *node_traits::to_value_ptr( res.pLeaf ) );
1926 assert( !res.pLeaf->infinite_key() );
1929 assert( res.pLeaf->infinite_key() == tree_node::key_infinite1 );
1930 pNewInternal->infinite_key( 1 );
1932 pNewInternal->m_pLeft.store( static_cast<tree_node *>(pNewLeaf), memory_model::memory_order_relaxed );
1933 pNewInternal->m_pRight.store( static_cast<tree_node *>(res.pLeaf), memory_model::memory_order_release );
1936 assert( !res.pLeaf->is_internal() );
1937 pNewInternal->infinite_key( 0 );
1939 key_extractor()( pNewInternal->m_Key, val );
1940 pNewInternal->m_pLeft.store( static_cast<tree_node *>(res.pLeaf), memory_model::memory_order_relaxed );
1941 pNewInternal->m_pRight.store( static_cast<tree_node *>(pNewLeaf), memory_model::memory_order_release );
1942 assert( !res.pLeaf->infinite_key());
1945 update_desc * pOp = alloc_update_desc();
1947 pOp->iInfo.pParent = res.pParent;
1948 pOp->iInfo.pNew = pNewInternal;
1949 pOp->iInfo.pLeaf = res.pLeaf;
1950 pOp->iInfo.bRightLeaf = res.bRightLeaf;
1952 update_ptr updCur( res.updParent.ptr() );
1953 if ( res.pParent->m_pUpdate.compare_exchange_strong( updCur, update_ptr( pOp, update_desc::IFlag ),
1954 memory_model::memory_order_acquire, atomics::memory_order_relaxed ))
1958 retire_update_desc( pOp, updRetire, false );
1962 // updCur has been updated by CAS
1963 help( updCur, updRetire );
1964 retire_update_desc( pOp, updRetire, true );
1973 }} // namespace cds::intrusive
1975 #endif // #ifndef __CDS_INTRUSIVE_ELLEN_BINTREE_RCU_H