3 #ifndef CDSLIB_INTRUSIVE_ELLEN_BINTREE_RCU_H
4 #define CDSLIB_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 \p 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 \p 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 \p extract(Q const&) but \p pred is used for key compare.
1030 \p Less has the interface like \p std::less and should meet \ref cds_intrusive_EllenBinTree_rcu_less
1031 "predicate requirements".
1032 \p pred must imply the same element order as the comparator used for building the tree.
1034 template <typename Q, typename Less>
1035 exempt_ptr extract_with( Q const& key, Less pred )
1037 return exempt_ptr( extract_with_( key, pred ));
1040 /// Finds the key \p key
1041 /** @anchor cds_intrusive_EllenBinTree_rcu_find_val
1042 The function searches the item with key equal to \p key
1043 and returns \p true if it is found, and \p false otherwise.
1045 Note the hash functor specified for class \p Traits template parameter
1046 should accept a parameter of type \p Q that can be not the same as \p value_type.
1048 The function applies RCU lock internally.
1050 template <typename Q>
1051 bool find( Q const& key ) const
1055 if ( search( res, key, node_compare() )) {
1056 m_Stat.onFindSuccess();
1060 m_Stat.onFindFailed();
1064 /// Finds the key \p key with comparing functor \p pred
1066 The function is an analog of \ref cds_intrusive_EllenBinTree_rcu_find_val "find(Q const&)"
1067 but \p pred is used for key compare.
1068 \p Less functor has the interface like \p std::less and should meet \ref cds_intrusive_EllenBinTree_rcu_less
1069 "Predicate requirements".
1070 \p pred must imply the same element order as the comparator used for building the tree.
1071 \p pred should accept arguments of type \p Q, \p key_type, \p value_type in any combination.
1073 template <typename Q, typename Less>
1074 bool find_with( Q const& key, Less pred ) const
1077 typedef ellen_bintree::details::compare<
1080 opt::details::make_comparator_from_less<Less>,
1086 if ( search( res, key, compare_functor() )) {
1087 m_Stat.onFindSuccess();
1090 m_Stat.onFindFailed();
1094 /// Finds the key \p key
1095 /** @anchor cds_intrusive_EllenBinTree_rcu_find_func
1096 The function searches the item with key equal to \p key and calls the functor \p f for item found.
1097 The interface of \p Func functor is:
1100 void operator()( value_type& item, Q& key );
1103 where \p item is the item found, \p key is the <tt>find</tt> function argument.
1105 The functor can change non-key fields of \p item. Note that the functor is only guarantee
1106 that \p item cannot be disposed during functor is executing.
1107 The functor does not serialize simultaneous access to the tree \p item. If such access is
1108 possible you must provide your own synchronization schema on item level to exclude unsafe item modifications.
1110 The function applies RCU lock internally.
1112 The function returns \p true if \p key is found, \p false otherwise.
1114 template <typename Q, typename Func>
1115 bool find( Q& key, Func f ) const
1117 return find_( key, f );
1120 template <typename Q, typename Func>
1121 bool find( Q const& key, Func f ) const
1123 return find_( key, f );
1127 /// Finds the key \p key with comparing functor \p pred
1129 The function is an analog of \ref cds_intrusive_EllenBinTree_rcu_find_func "find(Q&, Func)"
1130 but \p pred is used for key comparison.
1131 \p Less functor has the interface like \p std::less and should meet \ref cds_intrusive_EllenBinTree_rcu_less
1132 "Predicate requirements".
1133 \p pred must imply the same element order as the comparator used for building the tree.
1135 template <typename Q, typename Less, typename Func>
1136 bool find_with( Q& key, Less pred, Func f ) const
1138 return find_with_( key, pred, f );
1141 template <typename Q, typename Less, typename Func>
1142 bool find_with( Q const& key, Less pred, Func f ) const
1144 return find_with_( key, pred, f );
1148 /// Finds \p key and return the item found
1149 /** \anchor cds_intrusive_EllenBinTree_rcu_get
1150 The function searches the item with key equal to \p key and returns the pointer to item found.
1151 If \p key is not found it returns \p nullptr.
1153 RCU should be locked before call the function.
1154 Returned pointer is valid while RCU is locked.
1156 template <typename Q>
1157 value_type * get( Q const& key ) const
1159 return get_( key, node_compare() );
1162 /// Finds \p key with \p pred predicate and return the item found
1164 The function is an analog of \ref cds_intrusive_EllenBinTree_rcu_get "get(Q const&)"
1165 but \p pred is used for comparing the keys.
1167 \p Less functor has the semantics like \p std::less but should take arguments of type \ref value_type and \p Q
1169 \p pred must imply the same element order as the comparator used for building the tree.
1171 template <typename Q, typename Less>
1172 value_type * get_with( Q const& key, Less pred ) const
1175 typedef ellen_bintree::details::compare<
1178 opt::details::make_comparator_from_less<Less>,
1182 return get_( key, compare_functor());
1185 /// Checks if the tree is empty
1188 return m_Root.m_pLeft.load( memory_model::memory_order_relaxed )->is_leaf();
1191 /// Clears the tree (thread safe, not atomic)
1193 The function unlink all items from the tree.
1194 The function is thread safe but not atomic: in multi-threaded environment with parallel insertions
1198 assert( set.empty() );
1200 the assertion could be raised.
1202 For each leaf the \ref disposer will be called after unlinking.
1204 RCU \p synchronize method can be called. RCU should not be locked.
1208 for ( exempt_ptr ep = extract_min(); !ep.empty(); ep = extract_min() )
1212 /// Clears the tree (not thread safe)
1214 This function is not thread safe and may be called only when no other thread deals with the tree.
1215 The function is used in the tree destructor.
1222 internal_node * pParent = nullptr;
1223 internal_node * pGrandParent = nullptr;
1224 tree_node * pLeaf = const_cast<internal_node *>( &m_Root );
1226 // Get leftmost leaf
1227 while ( pLeaf->is_internal() ) {
1228 pGrandParent = pParent;
1229 pParent = static_cast<internal_node *>( pLeaf );
1230 pLeaf = pParent->m_pLeft.load( memory_model::memory_order_relaxed );
1233 if ( pLeaf->infinite_key()) {
1234 // The tree is empty
1238 // Remove leftmost leaf and its parent node
1239 assert( pGrandParent );
1241 assert( pLeaf->is_leaf() );
1243 pGrandParent->m_pLeft.store( pParent->m_pRight.load( memory_model::memory_order_relaxed ), memory_model::memory_order_relaxed );
1244 free_leaf_node( node_traits::to_value_ptr( static_cast<leaf_node *>( pLeaf ) ) );
1245 free_internal_node( pParent );
1249 /// Returns item count in the tree
1251 Only leaf nodes containing user data are counted.
1253 The value returned depends on item counter type provided by \p Traits template parameter.
1254 If it is \p atomicity::empty_item_counter this function always returns 0.
1256 The function is not suitable for checking the tree emptiness, use \p empty()
1257 member function for that.
1261 return m_ItemCounter;
1264 /// Returns const reference to internal statistics
1265 stat const& statistics() const
1270 /// Checks internal consistency (not atomic, not thread-safe)
1272 The debugging function to check internal consistency of the tree.
1274 bool check_consistency() const
1276 return check_consistency( &m_Root );
1282 bool check_consistency( internal_node const * pRoot ) const
1284 tree_node * pLeft = pRoot->m_pLeft.load( atomics::memory_order_relaxed );
1285 tree_node * pRight = pRoot->m_pRight.load( atomics::memory_order_relaxed );
1289 if ( node_compare()( *pLeft, *pRoot ) < 0
1290 && node_compare()( *pRoot, *pRight ) <= 0
1291 && node_compare()( *pLeft, *pRight ) < 0 )
1294 if ( pLeft->is_internal() )
1295 bRet = check_consistency( static_cast<internal_node *>( pLeft ) );
1298 if ( bRet && pRight->is_internal() )
1299 bRet = bRet && check_consistency( static_cast<internal_node *>( pRight ));
1307 void help( update_ptr /*pUpdate*/, retired_list& /*rl*/ )
1310 switch ( pUpdate.bits() ) {
1311 case update_desc::IFlag:
1312 help_insert( pUpdate.ptr() );
1313 m_Stat.onHelpInsert();
1315 case update_desc::DFlag:
1316 //help_delete( pUpdate.ptr(), rl );
1317 //m_Stat.onHelpDelete();
1319 case update_desc::Mark:
1320 //help_marked( pUpdate.ptr() );
1321 //m_Stat.onHelpMark();
1327 void help_insert( update_desc * pOp )
1329 assert( gc::is_locked() );
1331 tree_node * pLeaf = static_cast<tree_node *>( pOp->iInfo.pLeaf );
1332 if ( pOp->iInfo.bRightLeaf ) {
1333 pOp->iInfo.pParent->m_pRight.compare_exchange_strong( pLeaf, static_cast<tree_node *>( pOp->iInfo.pNew ),
1334 memory_model::memory_order_release, atomics::memory_order_relaxed );
1337 pOp->iInfo.pParent->m_pLeft.compare_exchange_strong( pLeaf, static_cast<tree_node *>( pOp->iInfo.pNew ),
1338 memory_model::memory_order_release, atomics::memory_order_relaxed );
1341 update_ptr cur( pOp, update_desc::IFlag );
1342 pOp->iInfo.pParent->m_pUpdate.compare_exchange_strong( cur, pOp->iInfo.pParent->null_update_desc(),
1343 memory_model::memory_order_release, atomics::memory_order_relaxed );
1346 bool check_delete_precondition( search_result& res )
1348 assert( res.pGrandParent != nullptr );
1351 static_cast<internal_node *>( res.bRightParent
1352 ? res.pGrandParent->m_pRight.load(memory_model::memory_order_relaxed)
1353 : res.pGrandParent->m_pLeft.load(memory_model::memory_order_relaxed)
1356 static_cast<leaf_node *>( res.bRightLeaf
1357 ? res.pParent->m_pRight.load(memory_model::memory_order_relaxed)
1358 : res.pParent->m_pLeft.load(memory_model::memory_order_relaxed)
1362 bool help_delete( update_desc * pOp, retired_list& rl )
1364 assert( gc::is_locked() );
1366 update_ptr pUpdate( pOp->dInfo.pUpdateParent );
1367 update_ptr pMark( pOp, update_desc::Mark );
1368 if ( pOp->dInfo.pParent->m_pUpdate.compare_exchange_strong( pUpdate, pMark,
1369 memory_model::memory_order_acquire, atomics::memory_order_relaxed ))
1372 retire_node( pOp->dInfo.pParent, rl );
1373 // For extract operations the leaf should NOT be disposed
1374 if ( pOp->dInfo.bDisposeLeaf )
1375 retire_node( pOp->dInfo.pLeaf, rl );
1376 retire_update_desc( pOp, rl, false );
1380 else if ( pUpdate == pMark ) {
1381 // some other thread is processing help_marked()
1383 m_Stat.onHelpMark();
1387 // pUpdate has been changed by CAS
1388 help( pUpdate, rl );
1390 // Undo grandparent dInfo
1391 update_ptr pDel( pOp, update_desc::DFlag );
1392 if ( pOp->dInfo.pGrandParent->m_pUpdate.compare_exchange_strong( pDel, pOp->dInfo.pGrandParent->null_update_desc(),
1393 memory_model::memory_order_release, atomics::memory_order_relaxed ))
1395 retire_update_desc( pOp, rl, false );
1401 void help_marked( update_desc * pOp )
1403 assert( gc::is_locked() );
1405 tree_node * p = pOp->dInfo.pParent;
1406 if ( pOp->dInfo.bRightParent ) {
1407 pOp->dInfo.pGrandParent->m_pRight.compare_exchange_strong( p,
1408 pOp->dInfo.bRightLeaf
1409 ? pOp->dInfo.pParent->m_pLeft.load( memory_model::memory_order_acquire )
1410 : pOp->dInfo.pParent->m_pRight.load( memory_model::memory_order_acquire ),
1411 memory_model::memory_order_release, atomics::memory_order_relaxed );
1414 pOp->dInfo.pGrandParent->m_pLeft.compare_exchange_strong( p,
1415 pOp->dInfo.bRightLeaf
1416 ? pOp->dInfo.pParent->m_pLeft.load( memory_model::memory_order_acquire )
1417 : pOp->dInfo.pParent->m_pRight.load( memory_model::memory_order_acquire ),
1418 memory_model::memory_order_release, atomics::memory_order_relaxed );
1421 update_ptr upd( pOp, update_desc::DFlag );
1422 pOp->dInfo.pGrandParent->m_pUpdate.compare_exchange_strong( upd, pOp->dInfo.pGrandParent->null_update_desc(),
1423 memory_model::memory_order_release, atomics::memory_order_relaxed );
1426 template <typename KeyValue, typename Compare>
1427 bool search( search_result& res, KeyValue const& key, Compare cmp ) const
1429 assert( gc::is_locked() );
1431 internal_node * pParent;
1432 internal_node * pGrandParent = nullptr;
1434 update_ptr updParent;
1435 update_ptr updGrandParent;
1437 bool bRightParent = false;
1443 pLeaf = const_cast<internal_node *>( &m_Root );
1444 updParent = nullptr;
1446 while ( pLeaf->is_internal() ) {
1447 pGrandParent = pParent;
1448 pParent = static_cast<internal_node *>( pLeaf );
1449 bRightParent = bRightLeaf;
1450 updGrandParent = updParent;
1451 updParent = pParent->m_pUpdate.load( memory_model::memory_order_acquire );
1453 switch ( updParent.bits() ) {
1454 case update_desc::DFlag:
1455 case update_desc::Mark:
1456 m_Stat.onSearchRetry();
1460 nCmp = cmp( key, *pParent );
1461 bRightLeaf = nCmp >= 0;
1462 pLeaf = nCmp < 0 ? pParent->m_pLeft.load( memory_model::memory_order_acquire )
1463 : pParent->m_pRight.load( memory_model::memory_order_acquire );
1466 assert( pLeaf->is_leaf() );
1467 nCmp = cmp( key, *static_cast<leaf_node *>(pLeaf) );
1469 res.pGrandParent = pGrandParent;
1470 res.pParent = pParent;
1471 res.pLeaf = static_cast<leaf_node *>( pLeaf );
1472 res.updParent = updParent;
1473 res.updGrandParent = updGrandParent;
1474 res.bRightParent = bRightParent;
1475 res.bRightLeaf = bRightLeaf;
1480 bool search_min( search_result& res ) const
1482 assert( gc::is_locked() );
1484 internal_node * pParent;
1485 internal_node * pGrandParent = nullptr;
1487 update_ptr updParent;
1488 update_ptr updGrandParent;
1492 pLeaf = const_cast<internal_node *>( &m_Root );
1493 while ( pLeaf->is_internal() ) {
1494 pGrandParent = pParent;
1495 pParent = static_cast<internal_node *>( pLeaf );
1496 updGrandParent = updParent;
1497 updParent = pParent->m_pUpdate.load( memory_model::memory_order_acquire );
1499 switch ( updParent.bits() ) {
1500 case update_desc::DFlag:
1501 case update_desc::Mark:
1502 m_Stat.onSearchRetry();
1506 pLeaf = pParent->m_pLeft.load( memory_model::memory_order_acquire );
1509 if ( pLeaf->infinite_key())
1512 res.pGrandParent = pGrandParent;
1513 res.pParent = pParent;
1514 assert( pLeaf->is_leaf() );
1515 res.pLeaf = static_cast<leaf_node *>( pLeaf );
1516 res.updParent = updParent;
1517 res.updGrandParent = updGrandParent;
1518 res.bRightParent = false;
1519 res.bRightLeaf = false;
1524 bool search_max( search_result& res ) const
1526 assert( gc::is_locked() );
1528 internal_node * pParent;
1529 internal_node * pGrandParent = nullptr;
1531 update_ptr updParent;
1532 update_ptr updGrandParent;
1534 bool bRightParent = false;
1538 pLeaf = const_cast<internal_node *>( &m_Root );
1540 while ( pLeaf->is_internal() ) {
1541 pGrandParent = pParent;
1542 pParent = static_cast<internal_node *>( pLeaf );
1543 bRightParent = bRightLeaf;
1544 updGrandParent = updParent;
1545 updParent = pParent->m_pUpdate.load( memory_model::memory_order_acquire );
1547 switch ( updParent.bits() ) {
1548 case update_desc::DFlag:
1549 case update_desc::Mark:
1550 m_Stat.onSearchRetry();
1554 if ( pParent->infinite_key()) {
1555 pLeaf = pParent->m_pLeft.load( memory_model::memory_order_acquire );
1559 pLeaf = pParent->m_pRight.load( memory_model::memory_order_acquire );
1564 if ( pLeaf->infinite_key())
1567 res.pGrandParent = pGrandParent;
1568 res.pParent = pParent;
1569 assert( pLeaf->is_leaf() );
1570 res.pLeaf = static_cast<leaf_node *>( pLeaf );
1571 res.updParent = updParent;
1572 res.updGrandParent = updGrandParent;
1573 res.bRightParent = bRightParent;
1574 res.bRightLeaf = bRightLeaf;
1579 template <typename Q, typename Compare, typename Equal, typename Func>
1580 bool erase_( Q const& val, Compare cmp, Equal eq, Func f )
1582 check_deadlock_policy::check();
1584 retired_list updRetire;
1585 update_desc * pOp = nullptr;
1592 if ( !search( res, val, cmp ) || !eq( val, *res.pLeaf ) ) {
1594 retire_update_desc( pOp, updRetire, false );
1595 m_Stat.onEraseFailed();
1599 if ( res.updGrandParent.bits() != update_desc::Clean )
1600 help( res.updGrandParent, updRetire );
1601 else if ( res.updParent.bits() != update_desc::Clean )
1602 help( res.updParent, updRetire );
1605 pOp = alloc_update_desc();
1606 if ( check_delete_precondition( res ) ) {
1607 pOp->dInfo.pGrandParent = res.pGrandParent;
1608 pOp->dInfo.pParent = res.pParent;
1609 pOp->dInfo.pLeaf = res.pLeaf;
1610 pOp->dInfo.bDisposeLeaf = true;
1611 pOp->dInfo.pUpdateParent = res.updParent.ptr();
1612 pOp->dInfo.bRightParent = res.bRightParent;
1613 pOp->dInfo.bRightLeaf = res.bRightLeaf;
1615 update_ptr updGP( res.updGrandParent.ptr() );
1616 if ( res.pGrandParent->m_pUpdate.compare_exchange_strong( updGP, update_ptr( pOp, update_desc::DFlag ),
1617 memory_model::memory_order_acquire, atomics::memory_order_relaxed ))
1619 if ( help_delete( pOp, updRetire )) {
1620 // res.pLeaf is not deleted yet since RCU is blocked
1621 f( *node_traits::to_value_ptr( res.pLeaf ));
1627 // updGP has been changed by CAS
1628 help( updGP, updRetire );
1634 m_Stat.onEraseRetry();
1639 m_Stat.onEraseSuccess();
1643 template <typename Q, typename Less>
1644 value_type * extract_with_( Q const& val, Less /*pred*/ )
1646 typedef ellen_bintree::details::compare<
1649 opt::details::make_comparator_from_less<Less>,
1653 return extract_( val, compare_functor() );
1656 template <typename Q, typename Compare>
1657 value_type * extract_( Q const& val, Compare cmp )
1659 check_deadlock_policy::check();
1661 retired_list updRetire;
1662 update_desc * pOp = nullptr;
1665 value_type * pResult;
1670 if ( !search( res, val, cmp ) ) {
1672 retire_update_desc( pOp, updRetire, false );
1673 m_Stat.onEraseFailed();
1677 if ( res.updGrandParent.bits() != update_desc::Clean )
1678 help( res.updGrandParent, updRetire );
1679 else if ( res.updParent.bits() != update_desc::Clean )
1680 help( res.updParent, updRetire );
1683 pOp = alloc_update_desc();
1684 if ( check_delete_precondition( res )) {
1685 pOp->dInfo.pGrandParent = res.pGrandParent;
1686 pOp->dInfo.pParent = res.pParent;
1687 pOp->dInfo.pLeaf = res.pLeaf;
1688 pOp->dInfo.bDisposeLeaf = false;
1689 pOp->dInfo.pUpdateParent = res.updParent.ptr();
1690 pOp->dInfo.bRightParent = res.bRightParent;
1691 pOp->dInfo.bRightLeaf = res.bRightLeaf;
1693 update_ptr updGP( res.updGrandParent.ptr() );
1694 if ( res.pGrandParent->m_pUpdate.compare_exchange_strong( updGP, update_ptr( pOp, update_desc::DFlag ),
1695 memory_model::memory_order_acquire, atomics::memory_order_relaxed ))
1697 if ( help_delete( pOp, updRetire )) {
1698 pResult = node_traits::to_value_ptr( res.pLeaf );
1704 // updGP has been changed by CAS
1705 help( updGP, updRetire );
1711 m_Stat.onEraseRetry();
1716 m_Stat.onEraseSuccess();
1721 value_type * extract_max_()
1723 check_deadlock_policy::check();
1725 retired_list updRetire;
1726 update_desc * pOp = nullptr;
1729 value_type * pResult;
1734 if ( !search_max( res )) {
1737 retire_update_desc( pOp, updRetire, false );
1738 m_Stat.onExtractMaxFailed();
1742 if ( res.updGrandParent.bits() != update_desc::Clean )
1743 help( res.updGrandParent, updRetire );
1744 else if ( res.updParent.bits() != update_desc::Clean )
1745 help( res.updParent, updRetire );
1748 pOp = alloc_update_desc();
1749 if ( check_delete_precondition( res ) ) {
1750 pOp->dInfo.pGrandParent = res.pGrandParent;
1751 pOp->dInfo.pParent = res.pParent;
1752 pOp->dInfo.pLeaf = res.pLeaf;
1753 pOp->dInfo.bDisposeLeaf = false;
1754 pOp->dInfo.pUpdateParent = res.updParent.ptr();
1755 pOp->dInfo.bRightParent = res.bRightParent;
1756 pOp->dInfo.bRightLeaf = res.bRightLeaf;
1758 update_ptr updGP( res.updGrandParent.ptr() );
1759 if ( res.pGrandParent->m_pUpdate.compare_exchange_strong( updGP, update_ptr( pOp, update_desc::DFlag ),
1760 memory_model::memory_order_acquire, atomics::memory_order_relaxed ))
1762 if ( help_delete( pOp, updRetire )) {
1763 pResult = node_traits::to_value_ptr( res.pLeaf );
1769 // updGP has been changed by CAS
1770 help( updGP, updRetire );
1776 m_Stat.onExtractMaxRetry();
1781 m_Stat.onExtractMaxSuccess();
1785 value_type * extract_min_()
1787 check_deadlock_policy::check();
1789 retired_list updRetire;
1790 update_desc * pOp = nullptr;
1793 value_type * pResult;
1798 if ( !search_min( res )) {
1801 retire_update_desc( pOp, updRetire, false );
1802 m_Stat.onExtractMinFailed();
1806 if ( res.updGrandParent.bits() != update_desc::Clean )
1807 help( res.updGrandParent, updRetire );
1808 else if ( res.updParent.bits() != update_desc::Clean )
1809 help( res.updParent, updRetire );
1812 pOp = alloc_update_desc();
1813 if ( check_delete_precondition( res ) ) {
1814 pOp->dInfo.pGrandParent = res.pGrandParent;
1815 pOp->dInfo.pParent = res.pParent;
1816 pOp->dInfo.pLeaf = res.pLeaf;
1817 pOp->dInfo.bDisposeLeaf = false;
1818 pOp->dInfo.pUpdateParent = res.updParent.ptr();
1819 pOp->dInfo.bRightParent = res.bRightParent;
1820 pOp->dInfo.bRightLeaf = res.bRightLeaf;
1822 update_ptr updGP( res.updGrandParent.ptr() );
1823 if ( res.pGrandParent->m_pUpdate.compare_exchange_strong( updGP, update_ptr( pOp, update_desc::DFlag ),
1824 memory_model::memory_order_acquire, atomics::memory_order_relaxed ))
1826 if ( help_delete( pOp, updRetire )) {
1827 pResult = node_traits::to_value_ptr( res.pLeaf );
1833 // updGP has been changed by CAS
1834 help( updGP, updRetire );
1840 m_Stat.onExtractMinRetry();
1845 m_Stat.onExtractMinSuccess();
1849 template <typename Q, typename Less, typename Func>
1850 bool find_with_( Q& val, Less /*pred*/, Func f ) const
1852 typedef ellen_bintree::details::compare<
1855 opt::details::make_comparator_from_less<Less>,
1861 if ( search( res, val, compare_functor() )) {
1862 assert( res.pLeaf );
1863 f( *node_traits::to_value_ptr( res.pLeaf ), val );
1865 m_Stat.onFindSuccess();
1869 m_Stat.onFindFailed();
1873 template <typename Q, typename Func>
1874 bool find_( Q& key, Func f ) const
1878 if ( search( res, key, node_compare() )) {
1879 assert( res.pLeaf );
1880 f( *node_traits::to_value_ptr( res.pLeaf ), key );
1882 m_Stat.onFindSuccess();
1886 m_Stat.onFindFailed();
1890 template <typename Q, typename Compare>
1891 value_type * get_( Q const& key, Compare cmp ) const
1893 assert( gc::is_locked());
1896 if ( search( res, key, cmp )) {
1897 m_Stat.onFindSuccess();
1898 return node_traits::to_value_ptr( res.pLeaf );
1901 m_Stat.onFindFailed();
1906 bool try_insert( value_type& val, internal_node * pNewInternal, search_result& res, retired_list& updRetire )
1908 assert( gc::is_locked() );
1909 assert( res.updParent.bits() == update_desc::Clean );
1911 // check search result
1912 if ( static_cast<leaf_node *>( res.bRightLeaf
1913 ? res.pParent->m_pRight.load( memory_model::memory_order_relaxed )
1914 : res.pParent->m_pLeft.load( memory_model::memory_order_relaxed ) ) == res.pLeaf )
1916 leaf_node * pNewLeaf = node_traits::to_node_ptr( val );
1918 int nCmp = node_compare()( val, *res.pLeaf );
1920 if ( res.pGrandParent ) {
1921 pNewInternal->infinite_key( 0 );
1922 key_extractor()( pNewInternal->m_Key, *node_traits::to_value_ptr( res.pLeaf ) );
1923 assert( !res.pLeaf->infinite_key() );
1926 assert( res.pLeaf->infinite_key() == tree_node::key_infinite1 );
1927 pNewInternal->infinite_key( 1 );
1929 pNewInternal->m_pLeft.store( static_cast<tree_node *>(pNewLeaf), memory_model::memory_order_relaxed );
1930 pNewInternal->m_pRight.store( static_cast<tree_node *>(res.pLeaf), memory_model::memory_order_release );
1933 assert( !res.pLeaf->is_internal() );
1934 pNewInternal->infinite_key( 0 );
1936 key_extractor()( pNewInternal->m_Key, val );
1937 pNewInternal->m_pLeft.store( static_cast<tree_node *>(res.pLeaf), memory_model::memory_order_relaxed );
1938 pNewInternal->m_pRight.store( static_cast<tree_node *>(pNewLeaf), memory_model::memory_order_release );
1939 assert( !res.pLeaf->infinite_key());
1942 update_desc * pOp = alloc_update_desc();
1944 pOp->iInfo.pParent = res.pParent;
1945 pOp->iInfo.pNew = pNewInternal;
1946 pOp->iInfo.pLeaf = res.pLeaf;
1947 pOp->iInfo.bRightLeaf = res.bRightLeaf;
1949 update_ptr updCur( res.updParent.ptr() );
1950 if ( res.pParent->m_pUpdate.compare_exchange_strong( updCur, update_ptr( pOp, update_desc::IFlag ),
1951 memory_model::memory_order_acquire, atomics::memory_order_relaxed ))
1955 retire_update_desc( pOp, updRetire, false );
1959 // updCur has been updated by CAS
1960 help( updCur, updRetire );
1961 retire_update_desc( pOp, updRetire, true );
1970 }} // namespace cds::intrusive
1972 #endif // #ifndef CDSLIB_INTRUSIVE_ELLEN_BINTREE_RCU_H