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 )
903 typedef ellen_bintree::details::compare<
906 opt::details::make_comparator_from_less<Less>,
910 return erase_( key, compare_functor(),
911 []( Q const&, leaf_node const& ) -> bool { return true; },
912 [](value_type const&) {} );
915 /// Deletes the item from the tree
916 /** \anchor cds_intrusive_EllenBinTree_rcu_erase_func
917 The function searches an item with key equal to \p key in the tree,
918 call \p f functor with item found, unlinks it from the tree, and returns \p true.
919 The \ref disposer specified in \p Traits class template parameter is called
920 by garbage collector \p GC asynchronously.
922 The \p Func interface is
925 void operator()( value_type const& item );
929 If the item with key equal to \p key is not found the function return \p false.
931 Note the hash functor should accept a parameter of type \p Q that can be not the same as \p value_type.
933 RCU \p synchronize method can be called. RCU should not be locked.
935 template <typename Q, typename Func>
936 bool erase( Q const& key, Func f )
938 return erase_( key, node_compare(),
939 []( Q const&, leaf_node const& ) -> bool { return true; },
943 /// Delete the item from the tree with comparing functor \p pred
945 The function is an analog of \ref cds_intrusive_EllenBinTree_rcu_erase_func "erase(Q const&, Func)"
946 but \p pred predicate is used for key comparing.
947 \p Less has the interface like \p std::less and should meet \ref cds_intrusive_EllenBinTree_rcu_less
948 "Predicate requirements".
949 \p pred must imply the same element order as the comparator used for building the tree.
951 template <typename Q, typename Less, typename Func>
952 bool erase_with( Q const& key, Less pred, Func f )
954 typedef ellen_bintree::details::compare<
957 opt::details::make_comparator_from_less<Less>,
961 return erase_( key, compare_functor(),
962 []( Q const&, leaf_node const& ) -> bool { return true; },
966 /// Extracts an item with minimal key from the tree
968 The function searches an item with minimal key, unlinks it, and returns
969 \ref cds::urcu::exempt_ptr "exempt_ptr" pointer to the leftmost item.
970 If the tree is empty the function returns empty \p exempt_ptr.
972 @note Due the concurrent nature of the tree, the function extracts <i>nearly</i> minimum key.
973 It means that the function gets leftmost leaf of the tree and tries to unlink it.
974 During unlinking, a concurrent thread may insert an item with key less than leftmost item's key.
975 So, the function returns the item with minimum key at the moment of tree traversing.
977 RCU \p synchronize method can be called. RCU should NOT be locked.
978 The function does not call the disposer for the item found.
979 The disposer will be implicitly invoked when the returned object is destroyed or when
980 its \p release() member function is called.
982 exempt_ptr extract_min()
984 return exempt_ptr( extract_min_() );
987 /// Extracts an item with maximal key from the tree
989 The function searches an item with maximal key, unlinks it, and returns
990 \ref cds::urcu::exempt_ptr "exempt_ptr" pointer to the rightmost item.
991 If the tree is empty the function returns empty \p exempt_ptr.
993 @note Due the concurrent nature of the tree, the function extracts <i>nearly</i> maximal key.
994 It means that the function gets rightmost leaf of the tree and tries to unlink it.
995 During unlinking, a concurrent thread may insert an item with key great than rightmost item's key.
996 So, the function returns the item with maximum key at the moment of tree traversing.
998 RCU \p synchronize method can be called. RCU should NOT be locked.
999 The function does not call the disposer for the item found.
1000 The disposer will be implicitly invoked when the returned object is destroyed or when
1001 its \p release() member function is called.
1003 exempt_ptr extract_max()
1005 return exempt_ptr( extract_max_() );
1008 /// Extracts an item from the tree
1009 /** \anchor cds_intrusive_EllenBinTree_rcu_extract
1010 The function searches an item with key equal to \p key in the tree,
1011 unlinks it, and returns \ref cds::urcu::exempt_ptr "exempt_ptr" pointer to an item found.
1012 If the item with the key equal to \p key is not found the function returns empty \p exempt_ptr.
1014 RCU \p synchronize method can be called. RCU should NOT be locked.
1015 The function does not call the disposer for the item found.
1016 The disposer will be implicitly invoked when the returned object is destroyed or when
1017 its \p release() member function is called.
1019 template <typename Q>
1020 exempt_ptr extract( Q const& key )
1022 return exempt_ptr( extract_( key, node_compare() ));
1025 /// Extracts an item from the set using \p pred for searching
1027 The function is an analog of \ref cds_intrusive_EllenBinTree_rcu_extract "extract(exempt_ptr&, Q const&)"
1028 but \p pred is used for key compare.
1029 \p Less has the interface like \p std::less and should meet \ref cds_intrusive_EllenBinTree_rcu_less
1030 "predicate requirements".
1031 \p pred must imply the same element order as the comparator used for building the tree.
1033 template <typename Q, typename Less>
1034 exempt_ptr extract_with( Q const& key, Less pred )
1036 return exempt_ptr( extract_with_( key, pred ));
1039 /// Finds the key \p key
1040 /** @anchor cds_intrusive_EllenBinTree_rcu_find_val
1041 The function searches the item with key equal to \p key
1042 and returns \p true if it is found, and \p false otherwise.
1044 Note the hash functor specified for class \p Traits template parameter
1045 should accept a parameter of type \p Q that can be not the same as \p value_type.
1047 The function applies RCU lock internally.
1049 template <typename Q>
1050 bool find( Q const& key ) const
1054 if ( search( res, key, node_compare() )) {
1055 m_Stat.onFindSuccess();
1059 m_Stat.onFindFailed();
1063 /// Finds the key \p key with comparing functor \p pred
1065 The function is an analog of \ref cds_intrusive_EllenBinTree_rcu_find_val "find(Q const&)"
1066 but \p pred is used for key compare.
1067 \p Less functor has the interface like \p std::less and should meet \ref cds_intrusive_EllenBinTree_rcu_less
1068 "Predicate requirements".
1069 \p pred must imply the same element order as the comparator used for building the tree.
1070 \p pred should accept arguments of type \p Q, \p key_type, \p value_type in any combination.
1072 template <typename Q, typename Less>
1073 bool find_with( Q const& key, Less pred ) const
1075 typedef ellen_bintree::details::compare<
1078 opt::details::make_comparator_from_less<Less>,
1084 if ( search( res, key, compare_functor() )) {
1085 m_Stat.onFindSuccess();
1088 m_Stat.onFindFailed();
1092 /// Finds the key \p key
1093 /** @anchor cds_intrusive_EllenBinTree_rcu_find_func
1094 The function searches the item with key equal to \p key and calls the functor \p f for item found.
1095 The interface of \p Func functor is:
1098 void operator()( value_type& item, Q& key );
1101 where \p item is the item found, \p key is the <tt>find</tt> function argument.
1103 The functor can change non-key fields of \p item. Note that the functor is only guarantee
1104 that \p item cannot be disposed during functor is executing.
1105 The functor does not serialize simultaneous access to the tree \p item. If such access is
1106 possible you must provide your own synchronization schema on item level to exclude unsafe item modifications.
1108 The function applies RCU lock internally.
1110 The function returns \p true if \p key is found, \p false otherwise.
1112 template <typename Q, typename Func>
1113 bool find( Q& key, Func f ) const
1115 return find_( key, f );
1118 template <typename Q, typename Func>
1119 bool find( Q const& key, Func f ) const
1121 return find_( key, f );
1125 /// Finds the key \p key with comparing functor \p pred
1127 The function is an analog of \ref cds_intrusive_EllenBinTree_rcu_find_func "find(Q&, Func)"
1128 but \p pred is used for key comparison.
1129 \p Less functor has the interface like \p std::less and should meet \ref cds_intrusive_EllenBinTree_rcu_less
1130 "Predicate requirements".
1131 \p pred must imply the same element order as the comparator used for building the tree.
1133 template <typename Q, typename Less, typename Func>
1134 bool find_with( Q& key, Less pred, Func f ) const
1136 return find_with_( key, pred, f );
1139 template <typename Q, typename Less, typename Func>
1140 bool find_with( Q const& key, Less pred, Func f ) const
1142 return find_with_( key, pred, f );
1146 /// Finds \p key and return the item found
1147 /** \anchor cds_intrusive_EllenBinTree_rcu_get
1148 The function searches the item with key equal to \p key and returns the pointer to item found.
1149 If \p key is not found it returns \p nullptr.
1151 RCU should be locked before call the function.
1152 Returned pointer is valid while RCU is locked.
1154 template <typename Q>
1155 value_type * get( Q const& key ) const
1157 return get_( key, node_compare() );
1160 /// Finds \p key with \p pred predicate and return the item found
1162 The function is an analog of \ref cds_intrusive_EllenBinTree_rcu_get "get(Q const&)"
1163 but \p pred is used for comparing the keys.
1165 \p Less functor has the semantics like \p std::less but should take arguments of type \ref value_type and \p Q
1167 \p pred must imply the same element order as the comparator used for building the tree.
1169 template <typename Q, typename Less>
1170 value_type * get_with( Q const& key, Less pred ) const
1172 typedef ellen_bintree::details::compare<
1175 opt::details::make_comparator_from_less<Less>,
1179 return get_( key, compare_functor());
1182 /// Checks if the tree is empty
1185 return m_Root.m_pLeft.load( memory_model::memory_order_relaxed )->is_leaf();
1188 /// Clears the tree (thread safe, not atomic)
1190 The function unlink all items from the tree.
1191 The function is thread safe but not atomic: in multi-threaded environment with parallel insertions
1195 assert( set.empty() );
1197 the assertion could be raised.
1199 For each leaf the \ref disposer will be called after unlinking.
1201 RCU \p synchronize method can be called. RCU should not be locked.
1205 for ( exempt_ptr ep = extract_min(); !ep.empty(); ep = extract_min() )
1209 /// Clears the tree (not thread safe)
1211 This function is not thread safe and may be called only when no other thread deals with the tree.
1212 The function is used in the tree destructor.
1219 internal_node * pParent = nullptr;
1220 internal_node * pGrandParent = nullptr;
1221 tree_node * pLeaf = const_cast<internal_node *>( &m_Root );
1223 // Get leftmost leaf
1224 while ( pLeaf->is_internal() ) {
1225 pGrandParent = pParent;
1226 pParent = static_cast<internal_node *>( pLeaf );
1227 pLeaf = pParent->m_pLeft.load( memory_model::memory_order_relaxed );
1230 if ( pLeaf->infinite_key()) {
1231 // The tree is empty
1235 // Remove leftmost leaf and its parent node
1236 assert( pGrandParent );
1238 assert( pLeaf->is_leaf() );
1240 pGrandParent->m_pLeft.store( pParent->m_pRight.load( memory_model::memory_order_relaxed ), memory_model::memory_order_relaxed );
1241 free_leaf_node( node_traits::to_value_ptr( static_cast<leaf_node *>( pLeaf ) ) );
1242 free_internal_node( pParent );
1246 /// Returns item count in the tree
1248 Only leaf nodes containing user data are counted.
1250 The value returned depends on item counter type provided by \p Traits template parameter.
1251 If it is \p atomicity::empty_item_counter this function always returns 0.
1253 The function is not suitable for checking the tree emptiness, use \p empty()
1254 member function for that.
1258 return m_ItemCounter;
1261 /// Returns const reference to internal statistics
1262 stat const& statistics() const
1267 /// Checks internal consistency (not atomic, not thread-safe)
1269 The debugging function to check internal consistency of the tree.
1271 bool check_consistency() const
1273 return check_consistency( &m_Root );
1279 bool check_consistency( internal_node const * pRoot ) const
1281 tree_node * pLeft = pRoot->m_pLeft.load( atomics::memory_order_relaxed );
1282 tree_node * pRight = pRoot->m_pRight.load( atomics::memory_order_relaxed );
1286 if ( node_compare()( *pLeft, *pRoot ) < 0
1287 && node_compare()( *pRoot, *pRight ) <= 0
1288 && node_compare()( *pLeft, *pRight ) < 0 )
1291 if ( pLeft->is_internal() )
1292 bRet = check_consistency( static_cast<internal_node *>( pLeft ) );
1295 if ( bRet && pRight->is_internal() )
1296 bRet = bRet && check_consistency( static_cast<internal_node *>( pRight ));
1304 void help( update_ptr pUpdate, retired_list& rl )
1307 switch ( pUpdate.bits() ) {
1308 case update_desc::IFlag:
1309 help_insert( pUpdate.ptr() );
1310 m_Stat.onHelpInsert();
1312 case update_desc::DFlag:
1313 //help_delete( pUpdate.ptr(), rl );
1314 //m_Stat.onHelpDelete();
1316 case update_desc::Mark:
1317 //help_marked( pUpdate.ptr() );
1318 //m_Stat.onHelpMark();
1324 void help_insert( update_desc * pOp )
1326 assert( gc::is_locked() );
1328 tree_node * pLeaf = static_cast<tree_node *>( pOp->iInfo.pLeaf );
1329 if ( pOp->iInfo.bRightLeaf ) {
1330 pOp->iInfo.pParent->m_pRight.compare_exchange_strong( pLeaf, static_cast<tree_node *>( pOp->iInfo.pNew ),
1331 memory_model::memory_order_release, atomics::memory_order_relaxed );
1334 pOp->iInfo.pParent->m_pLeft.compare_exchange_strong( pLeaf, static_cast<tree_node *>( pOp->iInfo.pNew ),
1335 memory_model::memory_order_release, atomics::memory_order_relaxed );
1338 update_ptr cur( pOp, update_desc::IFlag );
1339 pOp->iInfo.pParent->m_pUpdate.compare_exchange_strong( cur, pOp->iInfo.pParent->null_update_desc(),
1340 memory_model::memory_order_release, atomics::memory_order_relaxed );
1343 bool check_delete_precondition( search_result& res )
1345 assert( res.pGrandParent != nullptr );
1348 static_cast<internal_node *>( res.bRightParent
1349 ? res.pGrandParent->m_pRight.load(memory_model::memory_order_relaxed)
1350 : res.pGrandParent->m_pLeft.load(memory_model::memory_order_relaxed)
1353 static_cast<leaf_node *>( res.bRightLeaf
1354 ? res.pParent->m_pRight.load(memory_model::memory_order_relaxed)
1355 : res.pParent->m_pLeft.load(memory_model::memory_order_relaxed)
1359 bool help_delete( update_desc * pOp, retired_list& rl )
1361 assert( gc::is_locked() );
1363 update_ptr pUpdate( pOp->dInfo.pUpdateParent );
1364 update_ptr pMark( pOp, update_desc::Mark );
1365 if ( pOp->dInfo.pParent->m_pUpdate.compare_exchange_strong( pUpdate, pMark,
1366 memory_model::memory_order_acquire, atomics::memory_order_relaxed ))
1369 retire_node( pOp->dInfo.pParent, rl );
1370 // For extract operations the leaf should NOT be disposed
1371 if ( pOp->dInfo.bDisposeLeaf )
1372 retire_node( pOp->dInfo.pLeaf, rl );
1373 retire_update_desc( pOp, rl, false );
1377 else if ( pUpdate == pMark ) {
1378 // some other thread is processing help_marked()
1380 m_Stat.onHelpMark();
1384 // pUpdate has been changed by CAS
1385 help( pUpdate, rl );
1387 // Undo grandparent dInfo
1388 update_ptr pDel( pOp, update_desc::DFlag );
1389 if ( pOp->dInfo.pGrandParent->m_pUpdate.compare_exchange_strong( pDel, pOp->dInfo.pGrandParent->null_update_desc(),
1390 memory_model::memory_order_release, atomics::memory_order_relaxed ))
1392 retire_update_desc( pOp, rl, false );
1398 void help_marked( update_desc * pOp )
1400 assert( gc::is_locked() );
1402 tree_node * p = pOp->dInfo.pParent;
1403 if ( pOp->dInfo.bRightParent ) {
1404 pOp->dInfo.pGrandParent->m_pRight.compare_exchange_strong( p,
1405 pOp->dInfo.bRightLeaf
1406 ? pOp->dInfo.pParent->m_pLeft.load( memory_model::memory_order_acquire )
1407 : pOp->dInfo.pParent->m_pRight.load( memory_model::memory_order_acquire ),
1408 memory_model::memory_order_release, atomics::memory_order_relaxed );
1411 pOp->dInfo.pGrandParent->m_pLeft.compare_exchange_strong( p,
1412 pOp->dInfo.bRightLeaf
1413 ? pOp->dInfo.pParent->m_pLeft.load( memory_model::memory_order_acquire )
1414 : pOp->dInfo.pParent->m_pRight.load( memory_model::memory_order_acquire ),
1415 memory_model::memory_order_release, atomics::memory_order_relaxed );
1418 update_ptr upd( pOp, update_desc::DFlag );
1419 pOp->dInfo.pGrandParent->m_pUpdate.compare_exchange_strong( upd, pOp->dInfo.pGrandParent->null_update_desc(),
1420 memory_model::memory_order_release, atomics::memory_order_relaxed );
1423 template <typename KeyValue, typename Compare>
1424 bool search( search_result& res, KeyValue const& key, Compare cmp ) const
1426 assert( gc::is_locked() );
1428 internal_node * pParent;
1429 internal_node * pGrandParent = nullptr;
1431 update_ptr updParent;
1432 update_ptr updGrandParent;
1434 bool bRightParent = false;
1440 pLeaf = const_cast<internal_node *>( &m_Root );
1441 updParent = nullptr;
1443 while ( pLeaf->is_internal() ) {
1444 pGrandParent = pParent;
1445 pParent = static_cast<internal_node *>( pLeaf );
1446 bRightParent = bRightLeaf;
1447 updGrandParent = updParent;
1448 updParent = pParent->m_pUpdate.load( memory_model::memory_order_acquire );
1450 switch ( updParent.bits() ) {
1451 case update_desc::DFlag:
1452 case update_desc::Mark:
1453 m_Stat.onSearchRetry();
1457 nCmp = cmp( key, *pParent );
1458 bRightLeaf = nCmp >= 0;
1459 pLeaf = nCmp < 0 ? pParent->m_pLeft.load( memory_model::memory_order_acquire )
1460 : pParent->m_pRight.load( memory_model::memory_order_acquire );
1463 assert( pLeaf->is_leaf() );
1464 nCmp = cmp( key, *static_cast<leaf_node *>(pLeaf) );
1466 res.pGrandParent = pGrandParent;
1467 res.pParent = pParent;
1468 res.pLeaf = static_cast<leaf_node *>( pLeaf );
1469 res.updParent = updParent;
1470 res.updGrandParent = updGrandParent;
1471 res.bRightParent = bRightParent;
1472 res.bRightLeaf = bRightLeaf;
1477 bool search_min( search_result& res ) const
1479 assert( gc::is_locked() );
1481 internal_node * pParent;
1482 internal_node * pGrandParent = nullptr;
1484 update_ptr updParent;
1485 update_ptr updGrandParent;
1489 pLeaf = const_cast<internal_node *>( &m_Root );
1490 while ( pLeaf->is_internal() ) {
1491 pGrandParent = pParent;
1492 pParent = static_cast<internal_node *>( pLeaf );
1493 updGrandParent = updParent;
1494 updParent = pParent->m_pUpdate.load( memory_model::memory_order_acquire );
1496 switch ( updParent.bits() ) {
1497 case update_desc::DFlag:
1498 case update_desc::Mark:
1499 m_Stat.onSearchRetry();
1503 pLeaf = pParent->m_pLeft.load( memory_model::memory_order_acquire );
1506 if ( pLeaf->infinite_key())
1509 res.pGrandParent = pGrandParent;
1510 res.pParent = pParent;
1511 assert( pLeaf->is_leaf() );
1512 res.pLeaf = static_cast<leaf_node *>( pLeaf );
1513 res.updParent = updParent;
1514 res.updGrandParent = updGrandParent;
1515 res.bRightParent = false;
1516 res.bRightLeaf = false;
1521 bool search_max( search_result& res ) const
1523 assert( gc::is_locked() );
1525 internal_node * pParent;
1526 internal_node * pGrandParent = nullptr;
1528 update_ptr updParent;
1529 update_ptr updGrandParent;
1531 bool bRightParent = false;
1535 pLeaf = const_cast<internal_node *>( &m_Root );
1537 while ( pLeaf->is_internal() ) {
1538 pGrandParent = pParent;
1539 pParent = static_cast<internal_node *>( pLeaf );
1540 bRightParent = bRightLeaf;
1541 updGrandParent = updParent;
1542 updParent = pParent->m_pUpdate.load( memory_model::memory_order_acquire );
1544 switch ( updParent.bits() ) {
1545 case update_desc::DFlag:
1546 case update_desc::Mark:
1547 m_Stat.onSearchRetry();
1551 if ( pParent->infinite_key()) {
1552 pLeaf = pParent->m_pLeft.load( memory_model::memory_order_acquire );
1556 pLeaf = pParent->m_pRight.load( memory_model::memory_order_acquire );
1561 if ( pLeaf->infinite_key())
1564 res.pGrandParent = pGrandParent;
1565 res.pParent = pParent;
1566 assert( pLeaf->is_leaf() );
1567 res.pLeaf = static_cast<leaf_node *>( pLeaf );
1568 res.updParent = updParent;
1569 res.updGrandParent = updGrandParent;
1570 res.bRightParent = bRightParent;
1571 res.bRightLeaf = bRightLeaf;
1576 template <typename Q, typename Compare, typename Equal, typename Func>
1577 bool erase_( Q const& val, Compare cmp, Equal eq, Func f )
1579 check_deadlock_policy::check();
1581 retired_list updRetire;
1582 update_desc * pOp = nullptr;
1589 if ( !search( res, val, cmp ) || !eq( val, *res.pLeaf ) ) {
1591 retire_update_desc( pOp, updRetire, false );
1592 m_Stat.onEraseFailed();
1596 if ( res.updGrandParent.bits() != update_desc::Clean )
1597 help( res.updGrandParent, updRetire );
1598 else if ( res.updParent.bits() != update_desc::Clean )
1599 help( res.updParent, updRetire );
1602 pOp = alloc_update_desc();
1603 if ( check_delete_precondition( res ) ) {
1604 pOp->dInfo.pGrandParent = res.pGrandParent;
1605 pOp->dInfo.pParent = res.pParent;
1606 pOp->dInfo.pLeaf = res.pLeaf;
1607 pOp->dInfo.bDisposeLeaf = true;
1608 pOp->dInfo.pUpdateParent = res.updParent.ptr();
1609 pOp->dInfo.bRightParent = res.bRightParent;
1610 pOp->dInfo.bRightLeaf = res.bRightLeaf;
1612 update_ptr updGP( res.updGrandParent.ptr() );
1613 if ( res.pGrandParent->m_pUpdate.compare_exchange_strong( updGP, update_ptr( pOp, update_desc::DFlag ),
1614 memory_model::memory_order_acquire, atomics::memory_order_relaxed ))
1616 if ( help_delete( pOp, updRetire )) {
1617 // res.pLeaf is not deleted yet since RCU is blocked
1618 f( *node_traits::to_value_ptr( res.pLeaf ));
1624 // updGP has been changed by CAS
1625 help( updGP, updRetire );
1631 m_Stat.onEraseRetry();
1636 m_Stat.onEraseSuccess();
1640 template <typename Q, typename Less>
1641 value_type * extract_with_( Q const& val, Less pred )
1643 typedef ellen_bintree::details::compare<
1646 opt::details::make_comparator_from_less<Less>,
1650 return extract_( val, compare_functor() );
1653 template <typename Q, typename Compare>
1654 value_type * extract_( Q const& val, Compare cmp )
1656 check_deadlock_policy::check();
1658 retired_list updRetire;
1659 update_desc * pOp = nullptr;
1662 value_type * pResult;
1667 if ( !search( res, val, cmp ) ) {
1669 retire_update_desc( pOp, updRetire, false );
1670 m_Stat.onEraseFailed();
1674 if ( res.updGrandParent.bits() != update_desc::Clean )
1675 help( res.updGrandParent, updRetire );
1676 else if ( res.updParent.bits() != update_desc::Clean )
1677 help( res.updParent, updRetire );
1680 pOp = alloc_update_desc();
1681 if ( check_delete_precondition( res )) {
1682 pOp->dInfo.pGrandParent = res.pGrandParent;
1683 pOp->dInfo.pParent = res.pParent;
1684 pOp->dInfo.pLeaf = res.pLeaf;
1685 pOp->dInfo.bDisposeLeaf = false;
1686 pOp->dInfo.pUpdateParent = res.updParent.ptr();
1687 pOp->dInfo.bRightParent = res.bRightParent;
1688 pOp->dInfo.bRightLeaf = res.bRightLeaf;
1690 update_ptr updGP( res.updGrandParent.ptr() );
1691 if ( res.pGrandParent->m_pUpdate.compare_exchange_strong( updGP, update_ptr( pOp, update_desc::DFlag ),
1692 memory_model::memory_order_acquire, atomics::memory_order_relaxed ))
1694 if ( help_delete( pOp, updRetire )) {
1695 pResult = node_traits::to_value_ptr( res.pLeaf );
1701 // updGP has been changed by CAS
1702 help( updGP, updRetire );
1708 m_Stat.onEraseRetry();
1713 m_Stat.onEraseSuccess();
1718 value_type * extract_max_()
1720 check_deadlock_policy::check();
1722 retired_list updRetire;
1723 update_desc * pOp = nullptr;
1726 value_type * pResult;
1731 if ( !search_max( res )) {
1734 retire_update_desc( pOp, updRetire, false );
1735 m_Stat.onExtractMaxFailed();
1739 if ( res.updGrandParent.bits() != update_desc::Clean )
1740 help( res.updGrandParent, updRetire );
1741 else if ( res.updParent.bits() != update_desc::Clean )
1742 help( res.updParent, updRetire );
1745 pOp = alloc_update_desc();
1746 if ( check_delete_precondition( res ) ) {
1747 pOp->dInfo.pGrandParent = res.pGrandParent;
1748 pOp->dInfo.pParent = res.pParent;
1749 pOp->dInfo.pLeaf = res.pLeaf;
1750 pOp->dInfo.bDisposeLeaf = false;
1751 pOp->dInfo.pUpdateParent = res.updParent.ptr();
1752 pOp->dInfo.bRightParent = res.bRightParent;
1753 pOp->dInfo.bRightLeaf = res.bRightLeaf;
1755 update_ptr updGP( res.updGrandParent.ptr() );
1756 if ( res.pGrandParent->m_pUpdate.compare_exchange_strong( updGP, update_ptr( pOp, update_desc::DFlag ),
1757 memory_model::memory_order_acquire, atomics::memory_order_relaxed ))
1759 if ( help_delete( pOp, updRetire )) {
1760 pResult = node_traits::to_value_ptr( res.pLeaf );
1766 // updGP has been changed by CAS
1767 help( updGP, updRetire );
1773 m_Stat.onExtractMaxRetry();
1778 m_Stat.onExtractMaxSuccess();
1782 value_type * extract_min_()
1784 check_deadlock_policy::check();
1786 retired_list updRetire;
1787 update_desc * pOp = nullptr;
1790 value_type * pResult;
1795 if ( !search_min( res )) {
1798 retire_update_desc( pOp, updRetire, false );
1799 m_Stat.onExtractMinFailed();
1803 if ( res.updGrandParent.bits() != update_desc::Clean )
1804 help( res.updGrandParent, updRetire );
1805 else if ( res.updParent.bits() != update_desc::Clean )
1806 help( res.updParent, updRetire );
1809 pOp = alloc_update_desc();
1810 if ( check_delete_precondition( res ) ) {
1811 pOp->dInfo.pGrandParent = res.pGrandParent;
1812 pOp->dInfo.pParent = res.pParent;
1813 pOp->dInfo.pLeaf = res.pLeaf;
1814 pOp->dInfo.bDisposeLeaf = false;
1815 pOp->dInfo.pUpdateParent = res.updParent.ptr();
1816 pOp->dInfo.bRightParent = res.bRightParent;
1817 pOp->dInfo.bRightLeaf = res.bRightLeaf;
1819 update_ptr updGP( res.updGrandParent.ptr() );
1820 if ( res.pGrandParent->m_pUpdate.compare_exchange_strong( updGP, update_ptr( pOp, update_desc::DFlag ),
1821 memory_model::memory_order_acquire, atomics::memory_order_relaxed ))
1823 if ( help_delete( pOp, updRetire )) {
1824 pResult = node_traits::to_value_ptr( res.pLeaf );
1830 // updGP has been changed by CAS
1831 help( updGP, updRetire );
1837 m_Stat.onExtractMinRetry();
1842 m_Stat.onExtractMinSuccess();
1846 template <typename Q, typename Less, typename Func>
1847 bool find_with_( Q& val, Less pred, Func f ) const
1849 typedef ellen_bintree::details::compare<
1852 opt::details::make_comparator_from_less<Less>,
1858 if ( search( res, val, compare_functor() )) {
1859 assert( res.pLeaf );
1860 f( *node_traits::to_value_ptr( res.pLeaf ), val );
1862 m_Stat.onFindSuccess();
1866 m_Stat.onFindFailed();
1870 template <typename Q, typename Func>
1871 bool find_( Q& key, Func f ) const
1875 if ( search( res, key, node_compare() )) {
1876 assert( res.pLeaf );
1877 f( *node_traits::to_value_ptr( res.pLeaf ), key );
1879 m_Stat.onFindSuccess();
1883 m_Stat.onFindFailed();
1887 template <typename Q, typename Compare>
1888 value_type * get_( Q const& key, Compare cmp ) const
1890 assert( gc::is_locked());
1893 if ( search( res, key, cmp )) {
1894 m_Stat.onFindSuccess();
1895 return node_traits::to_value_ptr( res.pLeaf );
1898 m_Stat.onFindFailed();
1903 bool try_insert( value_type& val, internal_node * pNewInternal, search_result& res, retired_list& updRetire )
1905 assert( gc::is_locked() );
1906 assert( res.updParent.bits() == update_desc::Clean );
1908 // check search result
1909 if ( static_cast<leaf_node *>( res.bRightLeaf
1910 ? res.pParent->m_pRight.load( memory_model::memory_order_relaxed )
1911 : res.pParent->m_pLeft.load( memory_model::memory_order_relaxed ) ) == res.pLeaf )
1913 leaf_node * pNewLeaf = node_traits::to_node_ptr( val );
1915 int nCmp = node_compare()( val, *res.pLeaf );
1917 if ( res.pGrandParent ) {
1918 pNewInternal->infinite_key( 0 );
1919 key_extractor()( pNewInternal->m_Key, *node_traits::to_value_ptr( res.pLeaf ) );
1920 assert( !res.pLeaf->infinite_key() );
1923 assert( res.pLeaf->infinite_key() == tree_node::key_infinite1 );
1924 pNewInternal->infinite_key( 1 );
1926 pNewInternal->m_pLeft.store( static_cast<tree_node *>(pNewLeaf), memory_model::memory_order_relaxed );
1927 pNewInternal->m_pRight.store( static_cast<tree_node *>(res.pLeaf), memory_model::memory_order_release );
1930 assert( !res.pLeaf->is_internal() );
1931 pNewInternal->infinite_key( 0 );
1933 key_extractor()( pNewInternal->m_Key, val );
1934 pNewInternal->m_pLeft.store( static_cast<tree_node *>(res.pLeaf), memory_model::memory_order_relaxed );
1935 pNewInternal->m_pRight.store( static_cast<tree_node *>(pNewLeaf), memory_model::memory_order_release );
1936 assert( !res.pLeaf->infinite_key());
1939 update_desc * pOp = alloc_update_desc();
1941 pOp->iInfo.pParent = res.pParent;
1942 pOp->iInfo.pNew = pNewInternal;
1943 pOp->iInfo.pLeaf = res.pLeaf;
1944 pOp->iInfo.bRightLeaf = res.bRightLeaf;
1946 update_ptr updCur( res.updParent.ptr() );
1947 if ( res.pParent->m_pUpdate.compare_exchange_strong( updCur, update_ptr( pOp, update_desc::IFlag ),
1948 memory_model::memory_order_acquire, atomics::memory_order_relaxed ))
1952 retire_update_desc( pOp, updRetire, false );
1956 // updCur has been updated by CAS
1957 help( updCur, updRetire );
1958 retire_update_desc( pOp, updRetire, true );
1967 }} // namespace cds::intrusive
1969 #endif // #ifndef __CDS_INTRUSIVE_ELLEN_BINTREE_RCU_H