--- /dev/null
+//$$CDS-header$$
+
+#ifndef __CDS_INTRUSIVE_IMPL_MICHAEL_LIST_H
+#define __CDS_INTRUSIVE_IMPL_MICHAEL_LIST_H
+
+#include <cds/intrusive/details/michael_list_base.h>
+#include <cds/gc/guarded_ptr.h>
+
+namespace cds { namespace intrusive {
+
+ /// Michael's lock-free ordered single-linked list
+ /** @ingroup cds_intrusive_list
+ \anchor cds_intrusive_MichaelList_hp
+
+ Usually, ordered single-linked list is used as a building block for the hash table implementation.
+ The complexity of searching is <tt>O(N)</tt>.
+
+ Source:
+ - [2002] Maged Michael "High performance dynamic lock-free hash tables and list-based sets"
+
+ Template arguments:
+ - \p GC - Garbage collector used. Note the \p GC must be the same as the GC used for item type \p T (see michael_list::node).
+ - \p T - type to be stored in the list. The type must be based on michael_list::node (for michael_list::base_hook)
+ or it must have a member of type michael_list::node (for michael_list::member_hook).
+ - \p Traits - type traits. See michael_list::type_traits for explanation.
+
+ It is possible to declare option-based list with cds::intrusive::michael_list::make_traits metafunction istead of \p Traits template
+ argument.
+
+ Template argument list \p Options of cds::intrusive::michael_list::make_traits metafunction are:
+ - opt::hook - hook used. Possible values are: michael_list::base_hook, michael_list::member_hook, michael_list::traits_hook.
+ If the option is not specified, <tt>michael_list::base_hook<></tt> and gc::HP is used.
+ - opt::compare - key comparison functor. No default functor is provided.
+ If the option is not specified, the opt::less is used.
+ - opt::less - specifies binary predicate used for key comparison. Default is \p std::less<T>.
+ - opt::back_off - back-off strategy used. If the option is not specified, the cds::backoff::Default is used.
+ - opt::disposer - the functor used for dispose removed items. Default is opt::v::empty_disposer. Due the nature
+ of GC schema the disposer may be called asynchronously.
+ - opt::link_checker - the type of node's link fields checking. Default is \ref opt::debug_check_link
+ - opt::item_counter - the type of item counting feature. Default is \ref atomicity::empty_item_counter that is no item counting.
+ - opt::memory_model - C++ memory ordering model. Can be opt::v::relaxed_ordering (relaxed memory model, the default)
+ or opt::v::sequential_consistent (sequentially consisnent memory model).
+
+ For example, the following traits-based declaration of gc::HP Michael's list
+ \code
+ #include <cds/intrusive/michael_list_hp.h>
+ // Declare item stored in your list
+ struct item: public cds::intrusive::michael_list::node< cds::gc::HP >
+ {
+ int nKey;
+ // .... other data
+ };
+
+ // Declare comparator for the item
+ struct my_compare {
+ int operator()( item const& i1, item const& i2 ) const
+ {
+ return i1.nKey - i2.nKey;
+ }
+ };
+
+ // Declare type_traits
+ struct my_traits: public cds::intrusive::michael_list::type_traits
+ {
+ typedef cds::intrusive::michael_list::base_hook< cds::opt::gc< cds::gc::HP > > hook;
+ typedef my_compare compare;
+ };
+
+ // Declare traits-based list
+ typedef cds::intrusive::MichaelList< cds::gc::HP, item, my_traits > traits_based_list;
+ \endcode
+
+ is equivalent for the following option-based list
+ \code
+ #include <cds/intrusive/michael_list_hp.h>
+
+ // item struct and my_compare are the same
+
+ // Declare option-based list
+ typedef cds::intrusive::MichaelList< cds::gc::HP, item,
+ typename cds::intrusive::michael_list::make_traits<
+ cds::intrusive::opt::hook< cds::intrusive::michael_list::base_hook< cds::opt::gc< cds::gc::HP > > > // hook option
+ ,cds::intrusive::opt::compare< my_compare > // item comparator option
+ >::type
+ > option_based_list;
+ \endcode
+
+ \par Usage
+ There are different specializations of this template for each garbage collecting schema used.
+ You should select GC needed and include appropriate .h-file:
+ - for gc::HP: \code #include <cds/intrusive/michael_list_hp.h> \endcode
+ - for gc::PTB: \code #include <cds/intrusive/michael_list_ptb.h> \endcode
+ - for gc::HRC: \code #include <cds/intrusive/michael_list_hrc.h> \endcode
+ - for \ref cds_urcu_gc "RCU type" - see \ref cds_intrusive_MichaelList_rcu "RCU-based MichaelList"
+ - for gc::nogc: \code #include <cds/intrusive/michael_list_nogc.h> \endcode
+ See \ref cds_intrusive_MichaelList_nogc "non-GC MichaelList"
+
+ Then, you should incorporate michael_list::node into your struct \p T and provide
+ appropriate michael_list::type_traits::hook in your \p Traits template parameters. Usually, for \p Traits you
+ define a struct based on michael_list::type_traits.
+
+ Example for gc::PTB and base hook:
+ \code
+ // Include GC-related Michael's list specialization
+ #include <cds/intrusive/michael_list_ptb.h>
+
+ // Data stored in Michael's list
+ struct my_data: public cds::intrusive::michael_list::node< cds::gc::PTB >
+ {
+ // key field
+ std::string strKey;
+
+ // other data
+ // ...
+ };
+
+ // my_data comparing functor
+ struct my_data_cmp {
+ int operator()( const my_data& d1, const my_data& d2 )
+ {
+ return d1.strKey.compare( d2.strKey );
+ }
+
+ int operator()( const my_data& d, const std::string& s )
+ {
+ return d.strKey.compare(s);
+ }
+
+ int operator()( const std::string& s, const my_data& d )
+ {
+ return s.compare( d.strKey );
+ }
+ };
+
+
+ // Declare type_traits
+ struct my_traits: public cds::intrusive::michael_list::type_traits
+ {
+ typedef cds::intrusive::michael_list::base_hook< cds::opt::gc< cds::gc::PTB > > hook;
+ typedef my_data_cmp compare;
+ };
+
+ // Declare list type
+ typedef cds::intrusive::MichaelList< cds::gc::PTB, my_data, my_traits > traits_based_list;
+ \endcode
+
+ Equivalent option-based code:
+ \code
+ // GC-related specialization
+ #include <cds/intrusive/michael_list_ptb.h>
+
+ struct my_data {
+ // see above
+ };
+ struct compare {
+ // see above
+ };
+
+ // Declare option-based list
+ typedef cds::intrusive::MichaelList< cds::gc::PTB
+ ,my_data
+ , typename cds::intrusive::michael_list::make_traits<
+ cds::intrusive::opt::hook< cds::intrusive::michael_list::base_hook< cds::opt::gc< cds::gc::PTB > > >
+ ,cds::intrusive::opt::compare< my_data_cmp >
+ >::type
+ > option_based_list;
+
+ \endcode
+ */
+ template <
+ class GC
+ ,typename T
+#ifdef CDS_DOXYGEN_INVOKED
+ ,class Traits = michael_list::type_traits
+#else
+ ,class Traits
+#endif
+ >
+ class MichaelList
+ {
+ public:
+ typedef T value_type ; ///< type of value stored in the list
+ typedef Traits options ; ///< Traits template parameter
+
+ typedef typename options::hook hook ; ///< hook type
+ typedef typename hook::node_type node_type ; ///< node type
+
+# ifdef CDS_DOXYGEN_INVOKED
+ typedef implementation_defined key_comparator ; ///< key comparison functor based on opt::compare and opt::less option setter.
+# else
+ typedef typename opt::details::make_comparator< value_type, options >::type key_comparator;
+# endif
+
+ typedef typename options::disposer disposer ; ///< disposer used
+ typedef typename get_node_traits< value_type, node_type, hook>::type node_traits ; ///< node traits
+ typedef typename michael_list::get_link_checker< node_type, options::link_checker >::type link_checker ; ///< link checker
+
+ typedef GC gc ; ///< Garbage collector
+ typedef typename options::back_off back_off ; ///< back-off strategy
+ typedef typename options::item_counter item_counter ; ///< Item counting policy used
+ typedef typename options::memory_model memory_model; ///< Memory ordering. See cds::opt::memory_model option
+
+ typedef cds::gc::guarded_ptr< gc, value_type > guarded_ptr; ///< Guarded pointer
+
+ //@cond
+ // Rebind options (split-list support)
+ template <typename... Options>
+ struct rebind_options {
+ typedef MichaelList<
+ gc
+ , value_type
+ , typename cds::opt::make_options< options, Options...>::type
+ > type;
+ };
+ //@endcond
+
+ protected:
+ typedef typename node_type::atomic_marked_ptr atomic_node_ptr ; ///< Atomic node pointer
+ typedef typename node_type::marked_ptr marked_node_ptr ; ///< Node marked pointer
+
+ typedef atomic_node_ptr auxiliary_head ; ///< Auxiliary head type (for split-list support)
+
+ atomic_node_ptr m_pHead ; ///< Head pointer
+ item_counter m_ItemCounter ; ///< Item counter
+
+ //@cond
+ /// Position pointer for item search
+ struct position {
+ atomic_node_ptr * pPrev ; ///< Previous node
+ node_type * pCur ; ///< Current node
+ node_type * pNext ; ///< Next node
+
+ typename gc::template GuardArray<3> guards ; ///< Guards array
+
+ enum {
+ guard_prev_item,
+ guard_current_item,
+ guard_next_item
+ };
+ };
+
+ struct clean_disposer {
+ void operator()( value_type * p )
+ {
+ michael_list::node_cleaner<gc, node_type, memory_model>()( node_traits::to_node_ptr( p ) );
+ disposer()( p );
+ }
+ };
+
+ //@endcond
+
+ protected:
+ //@cond
+ void retire_node( node_type * pNode )
+ {
+ assert( pNode != nullptr );
+ gc::template retire<clean_disposer>( node_traits::to_value_ptr( *pNode ) );
+ }
+
+ bool link_node( node_type * pNode, position& pos )
+ {
+ assert( pNode != nullptr );
+ link_checker::is_empty( pNode );
+
+ marked_node_ptr cur(pos.pCur);
+ pNode->m_pNext.store( cur, memory_model::memory_order_relaxed );
+ return pos.pPrev->compare_exchange_strong( cur, marked_node_ptr(pNode), memory_model::memory_order_release, atomics::memory_order_relaxed );
+ }
+
+ bool unlink_node( position& pos )
+ {
+ assert( pos.pPrev != nullptr );
+ assert( pos.pCur != nullptr );
+
+ // Mark the node (logical deleting)
+ marked_node_ptr next(pos.pNext, 0);
+ if ( pos.pCur->m_pNext.compare_exchange_strong( next, marked_node_ptr(pos.pNext, 1), memory_model::memory_order_release, atomics::memory_order_relaxed )) {
+ // physical deletion may be performed by search function if it detects that a node is logically deleted (marked)
+ // CAS may be successful here or in other thread that searching something
+ marked_node_ptr cur(pos.pCur);
+ if ( pos.pPrev->compare_exchange_strong( cur, marked_node_ptr( pos.pNext ), memory_model::memory_order_release, atomics::memory_order_relaxed ))
+ retire_node( pos.pCur );
+ return true;
+ }
+ return false;
+ }
+ //@endcond
+
+ protected:
+ //@cond
+ template <bool IsConst>
+ class iterator_type
+ {
+ friend class MichaelList;
+
+ protected:
+ value_type * m_pNode;
+ typename gc::Guard m_Guard;
+
+ void next()
+ {
+ if ( m_pNode ) {
+ typename gc::Guard g;
+ node_type * pCur = node_traits::to_node_ptr( *m_pNode );
+
+ marked_node_ptr pNext;
+ do {
+ pNext = pCur->m_pNext.load(memory_model::memory_order_relaxed);
+ g.assign( node_traits::to_value_ptr( pNext.ptr() ));
+ } while ( pNext != pCur->m_pNext.load(memory_model::memory_order_acquire) );
+
+ if ( pNext.ptr() ) {
+ m_pNode = m_Guard.assign( g.template get<value_type>() );
+ }
+ else {
+ m_pNode = nullptr;
+ m_Guard.clear();
+ }
+ }
+ }
+
+ iterator_type( atomic_node_ptr const& pNode )
+ {
+ for (;;) {
+ marked_node_ptr p = pNode.load(memory_model::memory_order_relaxed);
+ if ( p.ptr() ) {
+ m_pNode = m_Guard.assign( node_traits::to_value_ptr( p.ptr() ) );
+ }
+ else {
+ m_pNode = nullptr;
+ m_Guard.clear();
+ }
+ if ( p == pNode.load(memory_model::memory_order_acquire) )
+ break;
+ }
+ }
+
+ public:
+ typedef typename cds::details::make_const_type<value_type, IsConst>::pointer value_ptr;
+ typedef typename cds::details::make_const_type<value_type, IsConst>::reference value_ref;
+
+ iterator_type()
+ : m_pNode( nullptr )
+ {}
+
+ iterator_type( iterator_type const& src )
+ {
+ if ( src.m_pNode ) {
+ m_pNode = m_Guard.assign( src.m_pNode );
+ }
+ else
+ m_pNode = nullptr;
+ }
+
+ value_ptr operator ->() const
+ {
+ return m_pNode;
+ }
+
+ value_ref operator *() const
+ {
+ assert( m_pNode != nullptr );
+ return *m_pNode;
+ }
+
+ /// Pre-increment
+ iterator_type& operator ++()
+ {
+ next();
+ return *this;
+ }
+
+ iterator_type& operator = (iterator_type const& src)
+ {
+ m_pNode = src.m_pNode;
+ m_Guard.assign( m_pNode );
+ return *this;
+ }
+
+ /*
+ /// Post-increment
+ void operator ++(int)
+ {
+ next();
+ }
+ */
+
+ template <bool C>
+ bool operator ==(iterator_type<C> const& i ) const
+ {
+ return m_pNode == i.m_pNode;
+ }
+ template <bool C>
+ bool operator !=(iterator_type<C> const& i ) const
+ {
+ return m_pNode != i.m_pNode;
+ }
+ };
+ //@endcond
+
+ public:
+ /// Forward iterator
+ /**
+ The forward iterator for Michael's list has some features:
+ - it has no post-increment operator
+ - to protect the value, the iterator contains a GC-specific guard + another guard is required locally for increment operator.
+ For some GC (gc::HP, gc::HRC), a guard is limited resource per thread, so an exception (or assertion) "no free guard"
+ may be thrown if a limit of guard count per thread is exceeded.
+ - The iterator cannot be moved across thread boundary since it contains GC's guard that is thread-private GC data.
+ - Iterator ensures thread-safety even if you delete the item that iterator points to. However, in case of concurrent
+ deleting operations it is no guarantee that you iterate all item in the list.
+
+ Therefore, the use of iterators in concurrent environment is not good idea. Use the iterator on the concurrent container
+ for debug purpose only.
+
+ The iterator interface:
+ \code
+ class iterator {
+ public:
+ // Default constructor
+ iterator();
+
+ // Copy construtor
+ iterator( iterator const& src );
+
+ // Dereference operator
+ value_type * operator ->() const;
+
+ // Dereference operator
+ value_type& operator *() const;
+
+ // Preincrement operator
+ iterator& operator ++();
+
+ // Assignment operator
+ iterator& operator = (iterator const& src);
+
+ // Equality operators
+ bool operator ==(iterator const& i ) const;
+ bool operator !=(iterator const& i ) const;
+ };
+ \endcode
+ */
+ typedef iterator_type<false> iterator;
+ /// Const forward iterator
+ /**
+ For iterator's features and requirements see \ref iterator
+ */
+ typedef iterator_type<true> const_iterator;
+
+ /// Returns a forward iterator addressing the first element in a list
+ /**
+ For empty list \code begin() == end() \endcode
+ */
+ iterator begin()
+ {
+ return iterator( m_pHead );
+ }
+
+ /// Returns an iterator that addresses the location succeeding the last element in a list
+ /**
+ Do not use the value returned by <tt>end</tt> function to access any item.
+ Internally, <tt>end</tt> returning value equals to \p nullptr.
+
+ The returned value can be used only to control reaching the end of the list.
+ For empty list <tt>begin() == end()</tt>
+ */
+ iterator end()
+ {
+ return iterator();
+ }
+
+ /// Returns a forward const iterator addressing the first element in a list
+ const_iterator cbegin()
+ {
+ return const_iterator( m_pHead );
+ }
+
+ /// Returns a forward const iterator addressing the first element in a list
+ const_iterator begin() const
+ {
+ return const_iterator( m_pHead );
+ }
+
+ /// Returns an const iterator that addresses the location succeeding the last element in a list
+ const_iterator end() const
+ {
+ return const_iterator();
+ }
+
+ /// Returns an const iterator that addresses the location succeeding the last element in a list
+ const_iterator cend()
+ {
+ return const_iterator();
+ }
+
+ public:
+ /// Default constructor initializes empty list
+ MichaelList()
+ : m_pHead( nullptr )
+ {
+ static_assert( (std::is_same< gc, typename node_type::gc >::value), "GC and node_type::gc must be the same type" );
+ }
+
+ /// Destroys the list object
+ ~MichaelList()
+ {
+ clear();
+ }
+
+ /// Inserts new node
+ /**
+ The function inserts \p val in the list if the list does not contain
+ an item with key equal to \p val.
+
+ Returns \p true if \p val is linked into the list, \p false otherwise.
+ */
+ bool insert( value_type& val )
+ {
+ return insert_at( m_pHead, val );
+ }
+
+ /// Inserts new node
+ /**
+ This function is intended for derived non-intrusive containers.
+
+ The function allows to split new item creating into two part:
+ - create item with key only
+ - insert new item into the list
+ - if inserting is success, calls \p f functor to initialize value-field of \p val.
+
+ The functor signature is:
+ \code
+ void func( value_type& val );
+ \endcode
+ where \p val is the item inserted. User-defined functor \p f should guarantee that during changing
+ \p val no any other changes could be made on this list's item by concurrent threads.
+ The user-defined functor is called only if the inserting is success and may be passed by reference
+ using <tt>boost::ref</tt>.
+ */
+ template <typename Func>
+ bool insert( value_type& val, Func f )
+ {
+ return insert_at( m_pHead, val, f );
+ }
+
+ /// Ensures that the \p item exists in the list
+ /**
+ The operation performs inserting or changing data with lock-free manner.
+
+ If the item \p val not found in the list, then \p val is inserted into the list.
+ Otherwise, the functor \p func is called with item found.
+ The functor signature is:
+ \code
+ void func( bool bNew, value_type& item, value_type& val );
+ \endcode
+ with arguments:
+ - \p bNew - \p true if the item has been inserted, \p false otherwise
+ - \p item - item of the list
+ - \p val - argument \p val passed into the \p ensure function
+ If new item has been inserted (i.e. \p bNew is \p true) then \p item and \p val arguments
+ refers to the same thing.
+
+ The functor may change non-key fields of the \p item; however, \p func must guarantee
+ that during changing no any other modifications could be made on this item by concurrent threads.
+
+ You may pass \p func argument by reference using <tt>boost::ref</tt> or cds::ref.
+
+ Returns std::pair<bool, bool> where \p first is \p true if operation is successfull,
+ \p second is \p true if new item has been added or \p false if the item with \p key
+ already is in the list.
+ */
+ template <typename Func>
+ std::pair<bool, bool> ensure( value_type& val, Func func )
+ {
+ return ensure_at( m_pHead, val, func );
+ }
+
+ /// Unlinks the item \p val from the list
+ /**
+ The function searches the item \p val in the list and unlink it from the list
+ if it is found and it is equal to \p val.
+
+ Difference between \ref erase and \p unlink functions: \p erase finds <i>a key</i>
+ and deletes the item found. \p unlink finds an item by key and deletes it
+ only if \p val is an item of that list, i.e. the pointer to item found
+ is equal to <tt> &val </tt>.
+
+ The function returns \p true if success and \p false otherwise.
+ */
+ bool unlink( value_type& val )
+ {
+ return unlink_at( m_pHead, val );
+ }
+
+ /// Deletes the item from the list
+ /** \anchor cds_intrusive_MichaelList_hp_erase_val
+ The function searches an item with key equal to \p val in the list,
+ unlinks it from the list, and returns \p true.
+ If the item with the key equal to \p val is not found the function return \p false.
+ */
+ template <typename Q>
+ bool erase( Q const& val )
+ {
+ return erase_at( m_pHead, val, key_comparator() );
+ }
+
+ /// Deletes the item from the list using \p pred predicate for searching
+ /**
+ The function is an analog of \ref cds_intrusive_MichaelList_hp_erase_val "erase(Q const&)"
+ but \p pred is used for key comparing.
+ \p Less functor has the interface like \p std::less.
+ \p pred must imply the same element order as the comparator used for building the list.
+ */
+ template <typename Q, typename Less>
+ bool erase_with( Q const& val, Less pred )
+ {
+ return erase_at( m_pHead, val, cds::opt::details::make_comparator_from_less<Less>());
+ }
+
+ /// Deletes the item from the list
+ /** \anchor cds_intrusive_MichaelList_hp_erase_func
+ The function searches an item with key equal to \p val in the list,
+ call \p func functor with item found, unlinks it from the list, and returns \p true.
+ The \p Func interface is
+ \code
+ struct functor {
+ void operator()( value_type const& item );
+ };
+ \endcode
+ The functor may be passed by reference using <tt>boost:ref</tt>
+
+ If the item with the key equal to \p val is not found the function return \p false.
+ */
+ template <typename Q, typename Func>
+ bool erase( Q const& val, Func func )
+ {
+ return erase_at( m_pHead, val, key_comparator(), func );
+ }
+
+ /// Deletes the item from the list using \p pred predicate for searching
+ /**
+ The function is an analog of \ref cds_intrusive_MichaelList_hp_erase_func "erase(Q const&, Func)"
+ but \p pred is used for key comparing.
+ \p Less functor has the interface like \p std::less.
+ \p pred must imply the same element order as the comparator used for building the list.
+ */
+ template <typename Q, typename Less, typename Func>
+ bool erase_with( Q const& val, Less pred, Func f )
+ {
+ return erase_at( m_pHead, val, cds::opt::details::make_comparator_from_less<Less>(), f );
+ }
+
+ /// Extracts the item from the list with specified \p key
+ /** \anchor cds_intrusive_MichaelList_hp_extract
+ The function searches an item with key equal to \p key,
+ unlinks it from the list, and returns it in \p dest parameter.
+ If the item with key equal to \p key is not found the function returns \p false.
+
+ Note the compare functor should accept a parameter of type \p Q that can be not the same as \p value_type.
+
+ The \ref disposer specified in \p Traits class template parameter is called automatically
+ by garbage collector \p GC when returned \ref guarded_ptr object will be destroyed or released.
+ @note Each \p guarded_ptr object uses the GC's guard that can be limited resource.
+
+ Usage:
+ \code
+ typedef cds::intrusive::MichaelList< cds::gc::HP, foo, my_traits > ord_list;
+ ord_list theList;
+ // ...
+ {
+ ord_list::guarded_ptr gp;
+ theList.extract( gp, 5 );
+ // Deal with gp
+ // ...
+
+ // Destructor of gp releases internal HP guard
+ }
+ \endcode
+ */
+ template <typename Q>
+ bool extract( guarded_ptr& dest, Q const& key )
+ {
+ return extract_at( m_pHead, dest.guard(), key, key_comparator() );
+ }
+
+ /// Extracts the item using compare functor \p pred
+ /**
+ The function is an analog of \ref cds_intrusive_MichaelList_hp_extract "extract(guarded_ptr&, Q const&)"
+ but \p pred predicate is used for key comparing.
+
+ \p Less functor has the semantics like \p std::less but should take arguments of type \ref value_type and \p Q
+ in any order.
+ \p pred must imply the same element order as the comparator used for building the list.
+ */
+ template <typename Q, typename Less>
+ bool extract_with( guarded_ptr& dest, Q const& key, Less pred )
+ {
+ return extract_at( m_pHead, dest.guard(), key, cds::opt::details::make_comparator_from_less<Less>() );
+ }
+
+ /// Finds the key \p val
+ /** \anchor cds_intrusive_MichaelList_hp_find_func
+ The function searches the item with key equal to \p val and calls the functor \p f for item found.
+ The interface of \p Func functor is:
+ \code
+ struct functor {
+ void operator()( value_type& item, Q& val );
+ };
+ \endcode
+ where \p item is the item found, \p val is the <tt>find</tt> function argument.
+
+ You may pass \p f argument by reference using <tt>boost::ref</tt> or cds::ref.
+
+ The functor may change non-key fields of \p item. Note that the function is only guarantee
+ that \p item cannot be disposed during functor is executing.
+ The function does not serialize simultaneous access to the list \p item. If such access is
+ possible you must provide your own synchronization schema to exclude unsafe item modifications.
+
+ The \p val argument is non-const since it can be used as \p f functor destination i.e., the functor
+ may modify both arguments.
+
+ The function returns \p true if \p val is found, \p false otherwise.
+ */
+ template <typename Q, typename Func>
+ bool find( Q& val, Func f )
+ {
+ return find_at( m_pHead, val, key_comparator(), f );
+ }
+
+ /// Finds the key \p val using \p pred predicate for searching
+ /**
+ The function is an analog of \ref cds_intrusive_MichaelList_hp_find_func "find(Q&, Func)"
+ but \p pred is used for key comparing.
+ \p Less functor has the interface like \p std::less.
+ \p pred must imply the same element order as the comparator used for building the list.
+ */
+ template <typename Q, typename Less, typename Func>
+ bool find_with( Q& val, Less pred, Func f )
+ {
+ return find_at( m_pHead, val, cds::opt::details::make_comparator_from_less<Less>(), f );
+ }
+
+ /// Finds the key \p val
+ /** \anchor cds_intrusive_MichaelList_hp_find_cfunc
+ The function searches the item with key equal to \p val and calls the functor \p f for item found.
+ The interface of \p Func functor is:
+ \code
+ struct functor {
+ void operator()( value_type& item, Q const& val );
+ };
+ \endcode
+ where \p item is the item found, \p val is the <tt>find</tt> function argument.
+
+ You may pass \p f argument by reference using <tt>boost::ref</tt> or cds::ref.
+
+ The functor may change non-key fields of \p item. Note that the function is only guarantee
+ that \p item cannot be disposed during functor is executing.
+ The function does not serialize simultaneous access to the list \p item. If such access is
+ possible you must provide your own synchronization schema to exclude unsafe item modifications.
+
+ The function returns \p true if \p val is found, \p false otherwise.
+ */
+ template <typename Q, typename Func>
+ bool find( Q const& val, Func f )
+ {
+ return find_at( m_pHead, val, key_comparator(), f );
+ }
+
+ /// Finds the key \p val using \p pred predicate for searching
+ /**
+ The function is an analog of \ref cds_intrusive_MichaelList_hp_find_cfunc "find(Q const&, Func)"
+ but \p pred is used for key comparing.
+ \p Less functor has the interface like \p std::less.
+ \p pred must imply the same element order as the comparator used for building the list.
+ */
+ template <typename Q, typename Less, typename Func>
+ bool find_with( Q const& val, Less pred, Func f )
+ {
+ return find_at( m_pHead, val, cds::opt::details::make_comparator_from_less<Less>(), f );
+ }
+
+ /// Finds the key \p val
+ /** \anchor cds_intrusive_MichaelList_hp_find_val
+ The function searches the item with key equal to \p val
+ and returns \p true if it is found, and \p false otherwise
+ */
+ template <typename Q>
+ bool find( Q const & val )
+ {
+ return find_at( m_pHead, val, key_comparator() );
+ }
+
+ /// Finds the key \p val using \p pred predicate for searching
+ /**
+ The function is an analog of \ref cds_intrusive_MichaelList_hp_find_val "find(Q const&)"
+ but \p pred is used for key comparing.
+ \p Less functor has the interface like \p std::less.
+ \p pred must imply the same element order as the comparator used for building the list.
+ */
+ template <typename Q, typename Less>
+ bool find_with( Q const& val, Less pred )
+ {
+ return find_at( m_pHead, val, cds::opt::details::make_comparator_from_less<Less>() );
+ }
+
+ /// Finds the key \p val and return the item found
+ /** \anchor cds_intrusive_MichaelList_hp_get
+ The function searches the item with key equal to \p val
+ and assigns the item found to guarded pointer \p ptr.
+ The function returns \p true if \p val is found, and \p false otherwise.
+ If \p val is not found the \p ptr parameter is not changed.
+
+ The \ref disposer specified in \p Traits class template parameter is called
+ by garbage collector \p GC automatically when returned \ref guarded_ptr object
+ will be destroyed or released.
+ @note Each \p guarded_ptr object uses one GC's guard which can be limited resource.
+
+ Usage:
+ \code
+ typedef cds::intrusive::MichaelList< cds::gc::HP, foo, my_traits > ord_list;
+ ord_list theList;
+ // ...
+ {
+ ord_list::guarded_ptr gp;
+ if ( theList.get( gp, 5 )) {
+ // Deal with gp
+ //...
+ }
+ // Destructor of guarded_ptr releases internal HP guard
+ }
+ \endcode
+
+ Note the compare functor specified for \p Traits template parameter
+ should accept a parameter of type \p Q that can be not the same as \p value_type.
+ */
+ template <typename Q>
+ bool get( guarded_ptr& ptr, Q const& val )
+ {
+ return get_at( m_pHead, ptr.guard(), val, key_comparator() );
+ }
+
+ /// Finds the key \p val and return the item found
+ /**
+ The function is an analog of \ref cds_intrusive_MichaelList_hp_get "get( guarded_ptr& ptr, Q const&)"
+ but \p pred is used for comparing the keys.
+
+ \p Less functor has the semantics like \p std::less but should take arguments of type \ref value_type and \p Q
+ in any order.
+ \p pred must imply the same element order as the comparator used for building the list.
+ */
+ template <typename Q, typename Less>
+ bool get_with( guarded_ptr& ptr, Q const& val, Less pred )
+ {
+ return get_at( m_pHead, ptr.guard(), val, cds::opt::details::make_comparator_from_less<Less>() );
+ }
+
+ /// Clears the list
+ /**
+ The function unlink all items from the list.
+ */
+ void clear()
+ {
+ typename gc::Guard guard;
+ marked_node_ptr head;
+ while ( true ) {
+ head = m_pHead.load(memory_model::memory_order_relaxed);
+ if ( head.ptr() )
+ guard.assign( node_traits::to_value_ptr( *head.ptr() ));
+ if ( m_pHead.load(memory_model::memory_order_acquire) == head ) {
+ if ( head.ptr() == nullptr )
+ break;
+ value_type& val = *node_traits::to_value_ptr( *head.ptr() );
+ unlink( val );
+ }
+ }
+ }
+
+ /// Checks if the list is empty
+ bool empty() const
+ {
+ return m_pHead.load( memory_model::memory_order_relaxed ).all() == nullptr;
+ }
+
+ /// Returns list's item count
+ /**
+ The value returned depends on opt::item_counter option. For atomicity::empty_item_counter,
+ this function always returns 0.
+
+ <b>Warning</b>: even if you use real item counter and it returns 0, this fact is not mean that the list
+ is empty. To check list emptyness use \ref empty() method.
+ */
+ size_t size() const
+ {
+ return m_ItemCounter.value();
+ }
+
+ protected:
+ //@cond
+ // split-list support
+ bool insert_aux_node( node_type * pNode )
+ {
+ return insert_aux_node( m_pHead, pNode );
+ }
+
+ // split-list support
+ bool insert_aux_node( atomic_node_ptr& refHead, node_type * pNode )
+ {
+ assert( pNode != nullptr );
+
+ // Hack: convert node_type to value_type.
+ // In principle, auxiliary node can be non-reducible to value_type
+ // We assume that comparator can correctly distinguish aux and regular node.
+ return insert_at( refHead, *node_traits::to_value_ptr( pNode ) );
+ }
+
+ bool insert_at( atomic_node_ptr& refHead, value_type& val )
+ {
+ node_type * pNode = node_traits::to_node_ptr( val );
+ link_checker::is_empty( pNode );
+ position pos;
+
+ while ( true ) {
+ if ( search( refHead, val, pos, key_comparator() ) )
+ return false;
+
+ if ( link_node( pNode, pos ) ) {
+ ++m_ItemCounter;
+ return true;
+ }
+
+ // clear next field
+ pNode->m_pNext.store( marked_node_ptr(), memory_model::memory_order_relaxed );
+ }
+ }
+
+ template <typename Func>
+ bool insert_at( atomic_node_ptr& refHead, value_type& val, Func f )
+ {
+ node_type * pNode = node_traits::to_node_ptr( val );
+ link_checker::is_empty( pNode );
+ position pos;
+
+ while ( true ) {
+ if ( search( refHead, val, pos, key_comparator() ) )
+ return false;
+
+ typename gc::Guard guard;
+ guard.assign( &val );
+ if ( link_node( pNode, pos ) ) {
+ cds::unref(f)( val );
+ ++m_ItemCounter;
+ return true;
+ }
+
+ // clear next field
+ pNode->m_pNext.store( marked_node_ptr(), memory_model::memory_order_relaxed );
+ }
+ }
+
+ template <typename Func>
+ std::pair<bool, bool> ensure_at( atomic_node_ptr& refHead, value_type& val, Func func )
+ {
+ position pos;
+
+ node_type * pNode = node_traits::to_node_ptr( val );
+ while ( true ) {
+ if ( search( refHead, val, pos, key_comparator() ) ) {
+ if ( pos.pCur->m_pNext.load(memory_model::memory_order_acquire).bits() ) {
+ back_off()();
+ continue ; // the node found is marked as deleted
+ }
+ assert( key_comparator()( val, *node_traits::to_value_ptr( *pos.pCur ) ) == 0 );
+
+ unref(func)( false, *node_traits::to_value_ptr( *pos.pCur ) , val );
+ return std::make_pair( true, false );
+ }
+ else {
+ typename gc::Guard guard;
+ guard.assign( &val );
+ if ( link_node( pNode, pos ) ) {
+ ++m_ItemCounter;
+ unref(func)( true, val, val );
+ return std::make_pair( true, true );
+ }
+ // clear next field
+ pNode->m_pNext.store( marked_node_ptr(), memory_model::memory_order_relaxed );
+ }
+ }
+ }
+
+ bool unlink_at( atomic_node_ptr& refHead, value_type& val )
+ {
+ position pos;
+
+ back_off bkoff;
+ while ( search( refHead, val, pos, key_comparator() ) ) {
+ if ( node_traits::to_value_ptr( *pos.pCur ) == &val ) {
+ if ( unlink_node( pos ) ) {
+ --m_ItemCounter;
+ return true;
+ }
+ else
+ bkoff();
+ }
+ else
+ break;
+ }
+ return false;
+ }
+
+ template <typename Q, typename Compare, typename Func>
+ bool erase_at( atomic_node_ptr& refHead, const Q& val, Compare cmp, Func f, position& pos )
+ {
+ back_off bkoff;
+ while ( search( refHead, val, pos, cmp )) {
+ if ( unlink_node( pos ) ) {
+ cds::unref(f)( *node_traits::to_value_ptr( *pos.pCur ) );
+ --m_ItemCounter;
+ return true;
+ }
+ else
+ bkoff();
+ }
+ return false;
+ }
+
+ template <typename Q, typename Compare, typename Func>
+ bool erase_at( atomic_node_ptr& refHead, const Q& val, Compare cmp, Func f )
+ {
+ position pos;
+ return erase_at( refHead, val, cmp, f, pos );
+ }
+
+ template <typename Q, typename Compare>
+ bool erase_at( atomic_node_ptr& refHead, Q const& val, Compare cmp )
+ {
+ position pos;
+ return erase_at( refHead, val, cmp, [](value_type const&){}, pos );
+ }
+
+ template <typename Q, typename Compare>
+ bool extract_at( atomic_node_ptr& refHead, typename gc::Guard& dest, Q const& val, Compare cmp )
+ {
+ position pos;
+ back_off bkoff;
+ while ( search( refHead, val, pos, cmp )) {
+ if ( unlink_node( pos ) ) {
+ dest.assign( pos.guards.template get<value_type>( position::guard_current_item ) );
+ --m_ItemCounter;
+ return true;
+ }
+ else
+ bkoff();
+ }
+ return false;
+ }
+
+ template <typename Q, typename Compare>
+ bool find_at( atomic_node_ptr& refHead, Q const& val, Compare cmp )
+ {
+ position pos;
+ return search( refHead, val, pos, cmp );
+ }
+
+ template <typename Q, typename Compare, typename Func>
+ bool find_at( atomic_node_ptr& refHead, Q& val, Compare cmp, Func f )
+ {
+ position pos;
+ if ( search( refHead, val, pos, cmp )) {
+ cds::unref(f)( *node_traits::to_value_ptr( *pos.pCur ), val );
+ return true;
+ }
+ return false;
+ }
+
+ template <typename Q, typename Compare>
+ bool get_at( atomic_node_ptr& refHead, typename gc::Guard& guard, Q const& val, Compare cmp )
+ {
+ position pos;
+ if ( search( refHead, val, pos, cmp )) {
+ guard.assign( pos.guards.template get<value_type>( position::guard_current_item ));
+ return true;
+ }
+ return false;
+ }
+
+ //@endcond
+
+ protected:
+
+ //@cond
+ template <typename Q, typename Compare >
+ bool search( atomic_node_ptr& refHead, const Q& val, position& pos, Compare cmp )
+ {
+ atomic_node_ptr * pPrev;
+ marked_node_ptr pNext;
+ marked_node_ptr pCur;
+
+ back_off bkoff;
+
+try_again:
+ pPrev = &refHead;
+ pNext = nullptr;
+
+ pCur = pPrev->load(memory_model::memory_order_relaxed);
+ pos.guards.assign( position::guard_current_item, node_traits::to_value_ptr( pCur.ptr() ) );
+ if ( pPrev->load(memory_model::memory_order_acquire) != pCur.ptr() )
+ goto try_again;
+
+ while ( true ) {
+ if ( pCur.ptr() == nullptr ) {
+ pos.pPrev = pPrev;
+ pos.pCur = pCur.ptr();
+ pos.pNext = pNext.ptr();
+ return false;
+ }
+
+ pNext = pCur->m_pNext.load(memory_model::memory_order_relaxed);
+ pos.guards.assign( position::guard_next_item, node_traits::to_value_ptr( pNext.ptr() ));
+ if ( pCur->m_pNext.load(memory_model::memory_order_relaxed).all() != pNext.all() ) {
+ bkoff();
+ goto try_again;
+ }
+
+ if ( pPrev->load(memory_model::memory_order_relaxed).all() != pCur.ptr() ) {
+ bkoff();
+ goto try_again;
+ }
+
+ // pNext contains deletion mark for pCur
+ if ( pNext.bits() == 1 ) {
+ // pCur marked i.e. logically deleted. Help the erase/unlink function to unlink pCur node
+ marked_node_ptr cur( pCur.ptr());
+ if ( pPrev->compare_exchange_strong( cur, marked_node_ptr( pNext.ptr() ), memory_model::memory_order_release, atomics::memory_order_relaxed )) {
+ retire_node( pCur.ptr() );
+ }
+ else {
+ bkoff();
+ goto try_again;
+ }
+ }
+ else {
+ assert( pCur.ptr() != nullptr );
+ int nCmp = cmp( *node_traits::to_value_ptr( pCur.ptr() ), val );
+ if ( nCmp >= 0 ) {
+ pos.pPrev = pPrev;
+ pos.pCur = pCur.ptr();
+ pos.pNext = pNext.ptr();
+ return nCmp == 0;
+ }
+ pPrev = &( pCur->m_pNext );
+ pos.guards.assign( position::guard_prev_item, node_traits::to_value_ptr( pCur.ptr() ) );
+ }
+ pCur = pNext;
+ pos.guards.assign( position::guard_current_item, node_traits::to_value_ptr( pCur.ptr() ));
+ }
+ }
+ //@endcond
+ };
+}} // namespace cds::intrusive
+
+#endif // #ifndef __CDS_INTRUSIVE_IMPL_MICHAEL_LIST_H
#ifndef __CDS_INTRUSIVE_MICHAEL_LIST_HP_H
#define __CDS_INTRUSIVE_MICHAEL_LIST_HP_H
-#include <cds/intrusive/michael_list_impl.h>
+#include <cds/intrusive/impl/michael_list.h>
#include <cds/gc/hp.h>
#endif // #ifndef __CDS_INTRUSIVE_MICHAEL_LIST_HP_H
#ifndef __CDS_INTRUSIVE_MICHAEL_LIST_HRC_H
#define __CDS_INTRUSIVE_MICHAEL_LIST_HRC_H
-#include <cds/intrusive/michael_list_impl.h>
+#include <cds/intrusive/impl/michael_list.h>
#include <cds/gc/hrc.h>
namespace cds { namespace intrusive { namespace michael_list {
+++ /dev/null
-//$$CDS-header$$
-
-#ifndef __CDS_INTRUSIVE_MICHAEL_LIST_IMPL_H
-#define __CDS_INTRUSIVE_MICHAEL_LIST_IMPL_H
-
-#include <cds/intrusive/details/michael_list_base.h>
-#include <cds/gc/guarded_ptr.h>
-
-namespace cds { namespace intrusive {
-
- /// Michael's lock-free ordered single-linked list
- /** @ingroup cds_intrusive_list
- \anchor cds_intrusive_MichaelList_hp
-
- Usually, ordered single-linked list is used as a building block for the hash table implementation.
- The complexity of searching is <tt>O(N)</tt>.
-
- Source:
- - [2002] Maged Michael "High performance dynamic lock-free hash tables and list-based sets"
-
- Template arguments:
- - \p GC - Garbage collector used. Note the \p GC must be the same as the GC used for item type \p T (see michael_list::node).
- - \p T - type to be stored in the list. The type must be based on michael_list::node (for michael_list::base_hook)
- or it must have a member of type michael_list::node (for michael_list::member_hook).
- - \p Traits - type traits. See michael_list::type_traits for explanation.
-
- It is possible to declare option-based list with cds::intrusive::michael_list::make_traits metafunction istead of \p Traits template
- argument.
-
- Template argument list \p Options of cds::intrusive::michael_list::make_traits metafunction are:
- - opt::hook - hook used. Possible values are: michael_list::base_hook, michael_list::member_hook, michael_list::traits_hook.
- If the option is not specified, <tt>michael_list::base_hook<></tt> and gc::HP is used.
- - opt::compare - key comparison functor. No default functor is provided.
- If the option is not specified, the opt::less is used.
- - opt::less - specifies binary predicate used for key comparison. Default is \p std::less<T>.
- - opt::back_off - back-off strategy used. If the option is not specified, the cds::backoff::Default is used.
- - opt::disposer - the functor used for dispose removed items. Default is opt::v::empty_disposer. Due the nature
- of GC schema the disposer may be called asynchronously.
- - opt::link_checker - the type of node's link fields checking. Default is \ref opt::debug_check_link
- - opt::item_counter - the type of item counting feature. Default is \ref atomicity::empty_item_counter that is no item counting.
- - opt::memory_model - C++ memory ordering model. Can be opt::v::relaxed_ordering (relaxed memory model, the default)
- or opt::v::sequential_consistent (sequentially consisnent memory model).
-
- For example, the following traits-based declaration of gc::HP Michael's list
- \code
- #include <cds/intrusive/michael_list_hp.h>
- // Declare item stored in your list
- struct item: public cds::intrusive::michael_list::node< cds::gc::HP >
- {
- int nKey;
- // .... other data
- };
-
- // Declare comparator for the item
- struct my_compare {
- int operator()( item const& i1, item const& i2 ) const
- {
- return i1.nKey - i2.nKey;
- }
- };
-
- // Declare type_traits
- struct my_traits: public cds::intrusive::michael_list::type_traits
- {
- typedef cds::intrusive::michael_list::base_hook< cds::opt::gc< cds::gc::HP > > hook;
- typedef my_compare compare;
- };
-
- // Declare traits-based list
- typedef cds::intrusive::MichaelList< cds::gc::HP, item, my_traits > traits_based_list;
- \endcode
-
- is equivalent for the following option-based list
- \code
- #include <cds/intrusive/michael_list_hp.h>
-
- // item struct and my_compare are the same
-
- // Declare option-based list
- typedef cds::intrusive::MichaelList< cds::gc::HP, item,
- typename cds::intrusive::michael_list::make_traits<
- cds::intrusive::opt::hook< cds::intrusive::michael_list::base_hook< cds::opt::gc< cds::gc::HP > > > // hook option
- ,cds::intrusive::opt::compare< my_compare > // item comparator option
- >::type
- > option_based_list;
- \endcode
-
- \par Usage
- There are different specializations of this template for each garbage collecting schema used.
- You should select GC needed and include appropriate .h-file:
- - for gc::HP: \code #include <cds/intrusive/michael_list_hp.h> \endcode
- - for gc::PTB: \code #include <cds/intrusive/michael_list_ptb.h> \endcode
- - for gc::HRC: \code #include <cds/intrusive/michael_list_hrc.h> \endcode
- - for \ref cds_urcu_gc "RCU type" - see \ref cds_intrusive_MichaelList_rcu "RCU-based MichaelList"
- - for gc::nogc: \code #include <cds/intrusive/michael_list_nogc.h> \endcode
- See \ref cds_intrusive_MichaelList_nogc "non-GC MichaelList"
-
- Then, you should incorporate michael_list::node into your struct \p T and provide
- appropriate michael_list::type_traits::hook in your \p Traits template parameters. Usually, for \p Traits you
- define a struct based on michael_list::type_traits.
-
- Example for gc::PTB and base hook:
- \code
- // Include GC-related Michael's list specialization
- #include <cds/intrusive/michael_list_ptb.h>
-
- // Data stored in Michael's list
- struct my_data: public cds::intrusive::michael_list::node< cds::gc::PTB >
- {
- // key field
- std::string strKey;
-
- // other data
- // ...
- };
-
- // my_data comparing functor
- struct my_data_cmp {
- int operator()( const my_data& d1, const my_data& d2 )
- {
- return d1.strKey.compare( d2.strKey );
- }
-
- int operator()( const my_data& d, const std::string& s )
- {
- return d.strKey.compare(s);
- }
-
- int operator()( const std::string& s, const my_data& d )
- {
- return s.compare( d.strKey );
- }
- };
-
-
- // Declare type_traits
- struct my_traits: public cds::intrusive::michael_list::type_traits
- {
- typedef cds::intrusive::michael_list::base_hook< cds::opt::gc< cds::gc::PTB > > hook;
- typedef my_data_cmp compare;
- };
-
- // Declare list type
- typedef cds::intrusive::MichaelList< cds::gc::PTB, my_data, my_traits > traits_based_list;
- \endcode
-
- Equivalent option-based code:
- \code
- // GC-related specialization
- #include <cds/intrusive/michael_list_ptb.h>
-
- struct my_data {
- // see above
- };
- struct compare {
- // see above
- };
-
- // Declare option-based list
- typedef cds::intrusive::MichaelList< cds::gc::PTB
- ,my_data
- , typename cds::intrusive::michael_list::make_traits<
- cds::intrusive::opt::hook< cds::intrusive::michael_list::base_hook< cds::opt::gc< cds::gc::PTB > > >
- ,cds::intrusive::opt::compare< my_data_cmp >
- >::type
- > option_based_list;
-
- \endcode
- */
- template <
- class GC
- ,typename T
-#ifdef CDS_DOXYGEN_INVOKED
- ,class Traits = michael_list::type_traits
-#else
- ,class Traits
-#endif
- >
- class MichaelList
- {
- public:
- typedef T value_type ; ///< type of value stored in the list
- typedef Traits options ; ///< Traits template parameter
-
- typedef typename options::hook hook ; ///< hook type
- typedef typename hook::node_type node_type ; ///< node type
-
-# ifdef CDS_DOXYGEN_INVOKED
- typedef implementation_defined key_comparator ; ///< key comparison functor based on opt::compare and opt::less option setter.
-# else
- typedef typename opt::details::make_comparator< value_type, options >::type key_comparator;
-# endif
-
- typedef typename options::disposer disposer ; ///< disposer used
- typedef typename get_node_traits< value_type, node_type, hook>::type node_traits ; ///< node traits
- typedef typename michael_list::get_link_checker< node_type, options::link_checker >::type link_checker ; ///< link checker
-
- typedef GC gc ; ///< Garbage collector
- typedef typename options::back_off back_off ; ///< back-off strategy
- typedef typename options::item_counter item_counter ; ///< Item counting policy used
- typedef typename options::memory_model memory_model; ///< Memory ordering. See cds::opt::memory_model option
-
- typedef cds::gc::guarded_ptr< gc, value_type > guarded_ptr; ///< Guarded pointer
-
- //@cond
- // Rebind options (split-list support)
- template <typename... Options>
- struct rebind_options {
- typedef MichaelList<
- gc
- , value_type
- , typename cds::opt::make_options< options, Options...>::type
- > type;
- };
- //@endcond
-
- protected:
- typedef typename node_type::atomic_marked_ptr atomic_node_ptr ; ///< Atomic node pointer
- typedef typename node_type::marked_ptr marked_node_ptr ; ///< Node marked pointer
-
- typedef atomic_node_ptr auxiliary_head ; ///< Auxiliary head type (for split-list support)
-
- atomic_node_ptr m_pHead ; ///< Head pointer
- item_counter m_ItemCounter ; ///< Item counter
-
- //@cond
- /// Position pointer for item search
- struct position {
- atomic_node_ptr * pPrev ; ///< Previous node
- node_type * pCur ; ///< Current node
- node_type * pNext ; ///< Next node
-
- typename gc::template GuardArray<3> guards ; ///< Guards array
-
- enum {
- guard_prev_item,
- guard_current_item,
- guard_next_item
- };
- };
-
- struct clean_disposer {
- void operator()( value_type * p )
- {
- michael_list::node_cleaner<gc, node_type, memory_model>()( node_traits::to_node_ptr( p ) );
- disposer()( p );
- }
- };
-
- //@endcond
-
- protected:
- //@cond
- void retire_node( node_type * pNode )
- {
- assert( pNode != nullptr );
- gc::template retire<clean_disposer>( node_traits::to_value_ptr( *pNode ) );
- }
-
- bool link_node( node_type * pNode, position& pos )
- {
- assert( pNode != nullptr );
- link_checker::is_empty( pNode );
-
- marked_node_ptr cur(pos.pCur);
- pNode->m_pNext.store( cur, memory_model::memory_order_relaxed );
- return pos.pPrev->compare_exchange_strong( cur, marked_node_ptr(pNode), memory_model::memory_order_release, atomics::memory_order_relaxed );
- }
-
- bool unlink_node( position& pos )
- {
- assert( pos.pPrev != nullptr );
- assert( pos.pCur != nullptr );
-
- // Mark the node (logical deleting)
- marked_node_ptr next(pos.pNext, 0);
- if ( pos.pCur->m_pNext.compare_exchange_strong( next, marked_node_ptr(pos.pNext, 1), memory_model::memory_order_release, atomics::memory_order_relaxed )) {
- // physical deletion may be performed by search function if it detects that a node is logically deleted (marked)
- // CAS may be successful here or in other thread that searching something
- marked_node_ptr cur(pos.pCur);
- if ( pos.pPrev->compare_exchange_strong( cur, marked_node_ptr( pos.pNext ), memory_model::memory_order_release, atomics::memory_order_relaxed ))
- retire_node( pos.pCur );
- return true;
- }
- return false;
- }
- //@endcond
-
- protected:
- //@cond
- template <bool IsConst>
- class iterator_type
- {
- friend class MichaelList;
-
- protected:
- value_type * m_pNode;
- typename gc::Guard m_Guard;
-
- void next()
- {
- if ( m_pNode ) {
- typename gc::Guard g;
- node_type * pCur = node_traits::to_node_ptr( *m_pNode );
-
- marked_node_ptr pNext;
- do {
- pNext = pCur->m_pNext.load(memory_model::memory_order_relaxed);
- g.assign( node_traits::to_value_ptr( pNext.ptr() ));
- } while ( pNext != pCur->m_pNext.load(memory_model::memory_order_acquire) );
-
- if ( pNext.ptr() ) {
- m_pNode = m_Guard.assign( g.template get<value_type>() );
- }
- else {
- m_pNode = nullptr;
- m_Guard.clear();
- }
- }
- }
-
- iterator_type( atomic_node_ptr const& pNode )
- {
- for (;;) {
- marked_node_ptr p = pNode.load(memory_model::memory_order_relaxed);
- if ( p.ptr() ) {
- m_pNode = m_Guard.assign( node_traits::to_value_ptr( p.ptr() ) );
- }
- else {
- m_pNode = nullptr;
- m_Guard.clear();
- }
- if ( p == pNode.load(memory_model::memory_order_acquire) )
- break;
- }
- }
-
- public:
- typedef typename cds::details::make_const_type<value_type, IsConst>::pointer value_ptr;
- typedef typename cds::details::make_const_type<value_type, IsConst>::reference value_ref;
-
- iterator_type()
- : m_pNode( nullptr )
- {}
-
- iterator_type( iterator_type const& src )
- {
- if ( src.m_pNode ) {
- m_pNode = m_Guard.assign( src.m_pNode );
- }
- else
- m_pNode = nullptr;
- }
-
- value_ptr operator ->() const
- {
- return m_pNode;
- }
-
- value_ref operator *() const
- {
- assert( m_pNode != nullptr );
- return *m_pNode;
- }
-
- /// Pre-increment
- iterator_type& operator ++()
- {
- next();
- return *this;
- }
-
- iterator_type& operator = (iterator_type const& src)
- {
- m_pNode = src.m_pNode;
- m_Guard.assign( m_pNode );
- return *this;
- }
-
- /*
- /// Post-increment
- void operator ++(int)
- {
- next();
- }
- */
-
- template <bool C>
- bool operator ==(iterator_type<C> const& i ) const
- {
- return m_pNode == i.m_pNode;
- }
- template <bool C>
- bool operator !=(iterator_type<C> const& i ) const
- {
- return m_pNode != i.m_pNode;
- }
- };
- //@endcond
-
- public:
- /// Forward iterator
- /**
- The forward iterator for Michael's list has some features:
- - it has no post-increment operator
- - to protect the value, the iterator contains a GC-specific guard + another guard is required locally for increment operator.
- For some GC (gc::HP, gc::HRC), a guard is limited resource per thread, so an exception (or assertion) "no free guard"
- may be thrown if a limit of guard count per thread is exceeded.
- - The iterator cannot be moved across thread boundary since it contains GC's guard that is thread-private GC data.
- - Iterator ensures thread-safety even if you delete the item that iterator points to. However, in case of concurrent
- deleting operations it is no guarantee that you iterate all item in the list.
-
- Therefore, the use of iterators in concurrent environment is not good idea. Use the iterator on the concurrent container
- for debug purpose only.
-
- The iterator interface:
- \code
- class iterator {
- public:
- // Default constructor
- iterator();
-
- // Copy construtor
- iterator( iterator const& src );
-
- // Dereference operator
- value_type * operator ->() const;
-
- // Dereference operator
- value_type& operator *() const;
-
- // Preincrement operator
- iterator& operator ++();
-
- // Assignment operator
- iterator& operator = (iterator const& src);
-
- // Equality operators
- bool operator ==(iterator const& i ) const;
- bool operator !=(iterator const& i ) const;
- };
- \endcode
- */
- typedef iterator_type<false> iterator;
- /// Const forward iterator
- /**
- For iterator's features and requirements see \ref iterator
- */
- typedef iterator_type<true> const_iterator;
-
- /// Returns a forward iterator addressing the first element in a list
- /**
- For empty list \code begin() == end() \endcode
- */
- iterator begin()
- {
- return iterator( m_pHead );
- }
-
- /// Returns an iterator that addresses the location succeeding the last element in a list
- /**
- Do not use the value returned by <tt>end</tt> function to access any item.
- Internally, <tt>end</tt> returning value equals to \p nullptr.
-
- The returned value can be used only to control reaching the end of the list.
- For empty list <tt>begin() == end()</tt>
- */
- iterator end()
- {
- return iterator();
- }
-
- /// Returns a forward const iterator addressing the first element in a list
- const_iterator cbegin()
- {
- return const_iterator( m_pHead );
- }
-
- /// Returns a forward const iterator addressing the first element in a list
- const_iterator begin() const
- {
- return const_iterator( m_pHead );
- }
-
- /// Returns an const iterator that addresses the location succeeding the last element in a list
- const_iterator end() const
- {
- return const_iterator();
- }
-
- /// Returns an const iterator that addresses the location succeeding the last element in a list
- const_iterator cend()
- {
- return const_iterator();
- }
-
- public:
- /// Default constructor initializes empty list
- MichaelList()
- : m_pHead( nullptr )
- {
- static_assert( (std::is_same< gc, typename node_type::gc >::value), "GC and node_type::gc must be the same type" );
- }
-
- /// Destroys the list object
- ~MichaelList()
- {
- clear();
- }
-
- /// Inserts new node
- /**
- The function inserts \p val in the list if the list does not contain
- an item with key equal to \p val.
-
- Returns \p true if \p val is linked into the list, \p false otherwise.
- */
- bool insert( value_type& val )
- {
- return insert_at( m_pHead, val );
- }
-
- /// Inserts new node
- /**
- This function is intended for derived non-intrusive containers.
-
- The function allows to split new item creating into two part:
- - create item with key only
- - insert new item into the list
- - if inserting is success, calls \p f functor to initialize value-field of \p val.
-
- The functor signature is:
- \code
- void func( value_type& val );
- \endcode
- where \p val is the item inserted. User-defined functor \p f should guarantee that during changing
- \p val no any other changes could be made on this list's item by concurrent threads.
- The user-defined functor is called only if the inserting is success and may be passed by reference
- using <tt>boost::ref</tt>.
- */
- template <typename Func>
- bool insert( value_type& val, Func f )
- {
- return insert_at( m_pHead, val, f );
- }
-
- /// Ensures that the \p item exists in the list
- /**
- The operation performs inserting or changing data with lock-free manner.
-
- If the item \p val not found in the list, then \p val is inserted into the list.
- Otherwise, the functor \p func is called with item found.
- The functor signature is:
- \code
- void func( bool bNew, value_type& item, value_type& val );
- \endcode
- with arguments:
- - \p bNew - \p true if the item has been inserted, \p false otherwise
- - \p item - item of the list
- - \p val - argument \p val passed into the \p ensure function
- If new item has been inserted (i.e. \p bNew is \p true) then \p item and \p val arguments
- refers to the same thing.
-
- The functor may change non-key fields of the \p item; however, \p func must guarantee
- that during changing no any other modifications could be made on this item by concurrent threads.
-
- You may pass \p func argument by reference using <tt>boost::ref</tt> or cds::ref.
-
- Returns std::pair<bool, bool> where \p first is \p true if operation is successfull,
- \p second is \p true if new item has been added or \p false if the item with \p key
- already is in the list.
- */
- template <typename Func>
- std::pair<bool, bool> ensure( value_type& val, Func func )
- {
- return ensure_at( m_pHead, val, func );
- }
-
- /// Unlinks the item \p val from the list
- /**
- The function searches the item \p val in the list and unlink it from the list
- if it is found and it is equal to \p val.
-
- Difference between \ref erase and \p unlink functions: \p erase finds <i>a key</i>
- and deletes the item found. \p unlink finds an item by key and deletes it
- only if \p val is an item of that list, i.e. the pointer to item found
- is equal to <tt> &val </tt>.
-
- The function returns \p true if success and \p false otherwise.
- */
- bool unlink( value_type& val )
- {
- return unlink_at( m_pHead, val );
- }
-
- /// Deletes the item from the list
- /** \anchor cds_intrusive_MichaelList_hp_erase_val
- The function searches an item with key equal to \p val in the list,
- unlinks it from the list, and returns \p true.
- If the item with the key equal to \p val is not found the function return \p false.
- */
- template <typename Q>
- bool erase( Q const& val )
- {
- return erase_at( m_pHead, val, key_comparator() );
- }
-
- /// Deletes the item from the list using \p pred predicate for searching
- /**
- The function is an analog of \ref cds_intrusive_MichaelList_hp_erase_val "erase(Q const&)"
- but \p pred is used for key comparing.
- \p Less functor has the interface like \p std::less.
- \p pred must imply the same element order as the comparator used for building the list.
- */
- template <typename Q, typename Less>
- bool erase_with( Q const& val, Less pred )
- {
- return erase_at( m_pHead, val, cds::opt::details::make_comparator_from_less<Less>());
- }
-
- /// Deletes the item from the list
- /** \anchor cds_intrusive_MichaelList_hp_erase_func
- The function searches an item with key equal to \p val in the list,
- call \p func functor with item found, unlinks it from the list, and returns \p true.
- The \p Func interface is
- \code
- struct functor {
- void operator()( value_type const& item );
- };
- \endcode
- The functor may be passed by reference using <tt>boost:ref</tt>
-
- If the item with the key equal to \p val is not found the function return \p false.
- */
- template <typename Q, typename Func>
- bool erase( Q const& val, Func func )
- {
- return erase_at( m_pHead, val, key_comparator(), func );
- }
-
- /// Deletes the item from the list using \p pred predicate for searching
- /**
- The function is an analog of \ref cds_intrusive_MichaelList_hp_erase_func "erase(Q const&, Func)"
- but \p pred is used for key comparing.
- \p Less functor has the interface like \p std::less.
- \p pred must imply the same element order as the comparator used for building the list.
- */
- template <typename Q, typename Less, typename Func>
- bool erase_with( Q const& val, Less pred, Func f )
- {
- return erase_at( m_pHead, val, cds::opt::details::make_comparator_from_less<Less>(), f );
- }
-
- /// Extracts the item from the list with specified \p key
- /** \anchor cds_intrusive_MichaelList_hp_extract
- The function searches an item with key equal to \p key,
- unlinks it from the list, and returns it in \p dest parameter.
- If the item with key equal to \p key is not found the function returns \p false.
-
- Note the compare functor should accept a parameter of type \p Q that can be not the same as \p value_type.
-
- The \ref disposer specified in \p Traits class template parameter is called automatically
- by garbage collector \p GC when returned \ref guarded_ptr object will be destroyed or released.
- @note Each \p guarded_ptr object uses the GC's guard that can be limited resource.
-
- Usage:
- \code
- typedef cds::intrusive::MichaelList< cds::gc::HP, foo, my_traits > ord_list;
- ord_list theList;
- // ...
- {
- ord_list::guarded_ptr gp;
- theList.extract( gp, 5 );
- // Deal with gp
- // ...
-
- // Destructor of gp releases internal HP guard
- }
- \endcode
- */
- template <typename Q>
- bool extract( guarded_ptr& dest, Q const& key )
- {
- return extract_at( m_pHead, dest.guard(), key, key_comparator() );
- }
-
- /// Extracts the item using compare functor \p pred
- /**
- The function is an analog of \ref cds_intrusive_MichaelList_hp_extract "extract(guarded_ptr&, Q const&)"
- but \p pred predicate is used for key comparing.
-
- \p Less functor has the semantics like \p std::less but should take arguments of type \ref value_type and \p Q
- in any order.
- \p pred must imply the same element order as the comparator used for building the list.
- */
- template <typename Q, typename Less>
- bool extract_with( guarded_ptr& dest, Q const& key, Less pred )
- {
- return extract_at( m_pHead, dest.guard(), key, cds::opt::details::make_comparator_from_less<Less>() );
- }
-
- /// Finds the key \p val
- /** \anchor cds_intrusive_MichaelList_hp_find_func
- The function searches the item with key equal to \p val and calls the functor \p f for item found.
- The interface of \p Func functor is:
- \code
- struct functor {
- void operator()( value_type& item, Q& val );
- };
- \endcode
- where \p item is the item found, \p val is the <tt>find</tt> function argument.
-
- You may pass \p f argument by reference using <tt>boost::ref</tt> or cds::ref.
-
- The functor may change non-key fields of \p item. Note that the function is only guarantee
- that \p item cannot be disposed during functor is executing.
- The function does not serialize simultaneous access to the list \p item. If such access is
- possible you must provide your own synchronization schema to exclude unsafe item modifications.
-
- The \p val argument is non-const since it can be used as \p f functor destination i.e., the functor
- may modify both arguments.
-
- The function returns \p true if \p val is found, \p false otherwise.
- */
- template <typename Q, typename Func>
- bool find( Q& val, Func f )
- {
- return find_at( m_pHead, val, key_comparator(), f );
- }
-
- /// Finds the key \p val using \p pred predicate for searching
- /**
- The function is an analog of \ref cds_intrusive_MichaelList_hp_find_func "find(Q&, Func)"
- but \p pred is used for key comparing.
- \p Less functor has the interface like \p std::less.
- \p pred must imply the same element order as the comparator used for building the list.
- */
- template <typename Q, typename Less, typename Func>
- bool find_with( Q& val, Less pred, Func f )
- {
- return find_at( m_pHead, val, cds::opt::details::make_comparator_from_less<Less>(), f );
- }
-
- /// Finds the key \p val
- /** \anchor cds_intrusive_MichaelList_hp_find_cfunc
- The function searches the item with key equal to \p val and calls the functor \p f for item found.
- The interface of \p Func functor is:
- \code
- struct functor {
- void operator()( value_type& item, Q const& val );
- };
- \endcode
- where \p item is the item found, \p val is the <tt>find</tt> function argument.
-
- You may pass \p f argument by reference using <tt>boost::ref</tt> or cds::ref.
-
- The functor may change non-key fields of \p item. Note that the function is only guarantee
- that \p item cannot be disposed during functor is executing.
- The function does not serialize simultaneous access to the list \p item. If such access is
- possible you must provide your own synchronization schema to exclude unsafe item modifications.
-
- The function returns \p true if \p val is found, \p false otherwise.
- */
- template <typename Q, typename Func>
- bool find( Q const& val, Func f )
- {
- return find_at( m_pHead, val, key_comparator(), f );
- }
-
- /// Finds the key \p val using \p pred predicate for searching
- /**
- The function is an analog of \ref cds_intrusive_MichaelList_hp_find_cfunc "find(Q const&, Func)"
- but \p pred is used for key comparing.
- \p Less functor has the interface like \p std::less.
- \p pred must imply the same element order as the comparator used for building the list.
- */
- template <typename Q, typename Less, typename Func>
- bool find_with( Q const& val, Less pred, Func f )
- {
- return find_at( m_pHead, val, cds::opt::details::make_comparator_from_less<Less>(), f );
- }
-
- /// Finds the key \p val
- /** \anchor cds_intrusive_MichaelList_hp_find_val
- The function searches the item with key equal to \p val
- and returns \p true if it is found, and \p false otherwise
- */
- template <typename Q>
- bool find( Q const & val )
- {
- return find_at( m_pHead, val, key_comparator() );
- }
-
- /// Finds the key \p val using \p pred predicate for searching
- /**
- The function is an analog of \ref cds_intrusive_MichaelList_hp_find_val "find(Q const&)"
- but \p pred is used for key comparing.
- \p Less functor has the interface like \p std::less.
- \p pred must imply the same element order as the comparator used for building the list.
- */
- template <typename Q, typename Less>
- bool find_with( Q const& val, Less pred )
- {
- return find_at( m_pHead, val, cds::opt::details::make_comparator_from_less<Less>() );
- }
-
- /// Finds the key \p val and return the item found
- /** \anchor cds_intrusive_MichaelList_hp_get
- The function searches the item with key equal to \p val
- and assigns the item found to guarded pointer \p ptr.
- The function returns \p true if \p val is found, and \p false otherwise.
- If \p val is not found the \p ptr parameter is not changed.
-
- The \ref disposer specified in \p Traits class template parameter is called
- by garbage collector \p GC automatically when returned \ref guarded_ptr object
- will be destroyed or released.
- @note Each \p guarded_ptr object uses one GC's guard which can be limited resource.
-
- Usage:
- \code
- typedef cds::intrusive::MichaelList< cds::gc::HP, foo, my_traits > ord_list;
- ord_list theList;
- // ...
- {
- ord_list::guarded_ptr gp;
- if ( theList.get( gp, 5 )) {
- // Deal with gp
- //...
- }
- // Destructor of guarded_ptr releases internal HP guard
- }
- \endcode
-
- Note the compare functor specified for \p Traits template parameter
- should accept a parameter of type \p Q that can be not the same as \p value_type.
- */
- template <typename Q>
- bool get( guarded_ptr& ptr, Q const& val )
- {
- return get_at( m_pHead, ptr.guard(), val, key_comparator() );
- }
-
- /// Finds the key \p val and return the item found
- /**
- The function is an analog of \ref cds_intrusive_MichaelList_hp_get "get( guarded_ptr& ptr, Q const&)"
- but \p pred is used for comparing the keys.
-
- \p Less functor has the semantics like \p std::less but should take arguments of type \ref value_type and \p Q
- in any order.
- \p pred must imply the same element order as the comparator used for building the list.
- */
- template <typename Q, typename Less>
- bool get_with( guarded_ptr& ptr, Q const& val, Less pred )
- {
- return get_at( m_pHead, ptr.guard(), val, cds::opt::details::make_comparator_from_less<Less>() );
- }
-
- /// Clears the list
- /**
- The function unlink all items from the list.
- */
- void clear()
- {
- typename gc::Guard guard;
- marked_node_ptr head;
- while ( true ) {
- head = m_pHead.load(memory_model::memory_order_relaxed);
- if ( head.ptr() )
- guard.assign( node_traits::to_value_ptr( *head.ptr() ));
- if ( m_pHead.load(memory_model::memory_order_acquire) == head ) {
- if ( head.ptr() == nullptr )
- break;
- value_type& val = *node_traits::to_value_ptr( *head.ptr() );
- unlink( val );
- }
- }
- }
-
- /// Checks if the list is empty
- bool empty() const
- {
- return m_pHead.load( memory_model::memory_order_relaxed ).all() == nullptr;
- }
-
- /// Returns list's item count
- /**
- The value returned depends on opt::item_counter option. For atomicity::empty_item_counter,
- this function always returns 0.
-
- <b>Warning</b>: even if you use real item counter and it returns 0, this fact is not mean that the list
- is empty. To check list emptyness use \ref empty() method.
- */
- size_t size() const
- {
- return m_ItemCounter.value();
- }
-
- protected:
- //@cond
- // split-list support
- bool insert_aux_node( node_type * pNode )
- {
- return insert_aux_node( m_pHead, pNode );
- }
-
- // split-list support
- bool insert_aux_node( atomic_node_ptr& refHead, node_type * pNode )
- {
- assert( pNode != nullptr );
-
- // Hack: convert node_type to value_type.
- // In principle, auxiliary node can be non-reducible to value_type
- // We assume that comparator can correctly distinguish aux and regular node.
- return insert_at( refHead, *node_traits::to_value_ptr( pNode ) );
- }
-
- bool insert_at( atomic_node_ptr& refHead, value_type& val )
- {
- node_type * pNode = node_traits::to_node_ptr( val );
- link_checker::is_empty( pNode );
- position pos;
-
- while ( true ) {
- if ( search( refHead, val, pos, key_comparator() ) )
- return false;
-
- if ( link_node( pNode, pos ) ) {
- ++m_ItemCounter;
- return true;
- }
-
- // clear next field
- pNode->m_pNext.store( marked_node_ptr(), memory_model::memory_order_relaxed );
- }
- }
-
- template <typename Func>
- bool insert_at( atomic_node_ptr& refHead, value_type& val, Func f )
- {
- node_type * pNode = node_traits::to_node_ptr( val );
- link_checker::is_empty( pNode );
- position pos;
-
- while ( true ) {
- if ( search( refHead, val, pos, key_comparator() ) )
- return false;
-
- typename gc::Guard guard;
- guard.assign( &val );
- if ( link_node( pNode, pos ) ) {
- cds::unref(f)( val );
- ++m_ItemCounter;
- return true;
- }
-
- // clear next field
- pNode->m_pNext.store( marked_node_ptr(), memory_model::memory_order_relaxed );
- }
- }
-
- template <typename Func>
- std::pair<bool, bool> ensure_at( atomic_node_ptr& refHead, value_type& val, Func func )
- {
- position pos;
-
- node_type * pNode = node_traits::to_node_ptr( val );
- while ( true ) {
- if ( search( refHead, val, pos, key_comparator() ) ) {
- if ( pos.pCur->m_pNext.load(memory_model::memory_order_acquire).bits() ) {
- back_off()();
- continue ; // the node found is marked as deleted
- }
- assert( key_comparator()( val, *node_traits::to_value_ptr( *pos.pCur ) ) == 0 );
-
- unref(func)( false, *node_traits::to_value_ptr( *pos.pCur ) , val );
- return std::make_pair( true, false );
- }
- else {
- typename gc::Guard guard;
- guard.assign( &val );
- if ( link_node( pNode, pos ) ) {
- ++m_ItemCounter;
- unref(func)( true, val, val );
- return std::make_pair( true, true );
- }
- // clear next field
- pNode->m_pNext.store( marked_node_ptr(), memory_model::memory_order_relaxed );
- }
- }
- }
-
- bool unlink_at( atomic_node_ptr& refHead, value_type& val )
- {
- position pos;
-
- back_off bkoff;
- while ( search( refHead, val, pos, key_comparator() ) ) {
- if ( node_traits::to_value_ptr( *pos.pCur ) == &val ) {
- if ( unlink_node( pos ) ) {
- --m_ItemCounter;
- return true;
- }
- else
- bkoff();
- }
- else
- break;
- }
- return false;
- }
-
- template <typename Q, typename Compare, typename Func>
- bool erase_at( atomic_node_ptr& refHead, const Q& val, Compare cmp, Func f, position& pos )
- {
- back_off bkoff;
- while ( search( refHead, val, pos, cmp )) {
- if ( unlink_node( pos ) ) {
- cds::unref(f)( *node_traits::to_value_ptr( *pos.pCur ) );
- --m_ItemCounter;
- return true;
- }
- else
- bkoff();
- }
- return false;
- }
-
- template <typename Q, typename Compare, typename Func>
- bool erase_at( atomic_node_ptr& refHead, const Q& val, Compare cmp, Func f )
- {
- position pos;
- return erase_at( refHead, val, cmp, f, pos );
- }
-
- template <typename Q, typename Compare>
- bool erase_at( atomic_node_ptr& refHead, Q const& val, Compare cmp )
- {
- position pos;
- return erase_at( refHead, val, cmp, [](value_type const&){}, pos );
- }
-
- template <typename Q, typename Compare>
- bool extract_at( atomic_node_ptr& refHead, typename gc::Guard& dest, Q const& val, Compare cmp )
- {
- position pos;
- back_off bkoff;
- while ( search( refHead, val, pos, cmp )) {
- if ( unlink_node( pos ) ) {
- dest.assign( pos.guards.template get<value_type>( position::guard_current_item ) );
- --m_ItemCounter;
- return true;
- }
- else
- bkoff();
- }
- return false;
- }
-
- template <typename Q, typename Compare>
- bool find_at( atomic_node_ptr& refHead, Q const& val, Compare cmp )
- {
- position pos;
- return search( refHead, val, pos, cmp );
- }
-
- template <typename Q, typename Compare, typename Func>
- bool find_at( atomic_node_ptr& refHead, Q& val, Compare cmp, Func f )
- {
- position pos;
- if ( search( refHead, val, pos, cmp )) {
- cds::unref(f)( *node_traits::to_value_ptr( *pos.pCur ), val );
- return true;
- }
- return false;
- }
-
- template <typename Q, typename Compare>
- bool get_at( atomic_node_ptr& refHead, typename gc::Guard& guard, Q const& val, Compare cmp )
- {
- position pos;
- if ( search( refHead, val, pos, cmp )) {
- guard.assign( pos.guards.template get<value_type>( position::guard_current_item ));
- return true;
- }
- return false;
- }
-
- //@endcond
-
- protected:
-
- //@cond
- template <typename Q, typename Compare >
- bool search( atomic_node_ptr& refHead, const Q& val, position& pos, Compare cmp )
- {
- atomic_node_ptr * pPrev;
- marked_node_ptr pNext;
- marked_node_ptr pCur;
-
- back_off bkoff;
-
-try_again:
- pPrev = &refHead;
- pNext = nullptr;
-
- pCur = pPrev->load(memory_model::memory_order_relaxed);
- pos.guards.assign( position::guard_current_item, node_traits::to_value_ptr( pCur.ptr() ) );
- if ( pPrev->load(memory_model::memory_order_acquire) != pCur.ptr() )
- goto try_again;
-
- while ( true ) {
- if ( pCur.ptr() == nullptr ) {
- pos.pPrev = pPrev;
- pos.pCur = pCur.ptr();
- pos.pNext = pNext.ptr();
- return false;
- }
-
- pNext = pCur->m_pNext.load(memory_model::memory_order_relaxed);
- pos.guards.assign( position::guard_next_item, node_traits::to_value_ptr( pNext.ptr() ));
- if ( pCur->m_pNext.load(memory_model::memory_order_relaxed).all() != pNext.all() ) {
- bkoff();
- goto try_again;
- }
-
- if ( pPrev->load(memory_model::memory_order_relaxed).all() != pCur.ptr() ) {
- bkoff();
- goto try_again;
- }
-
- // pNext contains deletion mark for pCur
- if ( pNext.bits() == 1 ) {
- // pCur marked i.e. logically deleted. Help the erase/unlink function to unlink pCur node
- marked_node_ptr cur( pCur.ptr());
- if ( pPrev->compare_exchange_strong( cur, marked_node_ptr( pNext.ptr() ), memory_model::memory_order_release, atomics::memory_order_relaxed )) {
- retire_node( pCur.ptr() );
- }
- else {
- bkoff();
- goto try_again;
- }
- }
- else {
- assert( pCur.ptr() != nullptr );
- int nCmp = cmp( *node_traits::to_value_ptr( pCur.ptr() ), val );
- if ( nCmp >= 0 ) {
- pos.pPrev = pPrev;
- pos.pCur = pCur.ptr();
- pos.pNext = pNext.ptr();
- return nCmp == 0;
- }
- pPrev = &( pCur->m_pNext );
- pos.guards.assign( position::guard_prev_item, node_traits::to_value_ptr( pCur.ptr() ) );
- }
- pCur = pNext;
- pos.guards.assign( position::guard_current_item, node_traits::to_value_ptr( pCur.ptr() ));
- }
- }
- //@endcond
- };
-}} // namespace cds::intrusive
-
-#endif // #ifndef __CDS_INTRUSIVE_MICHAEL_LIST_IMPL_H
#ifndef __CDS_INTRUSIVE_MICHAEL_LIST_PTB_H
#define __CDS_INTRUSIVE_MICHAEL_LIST_PTB_H
-#include <cds/intrusive/michael_list_impl.h>
+#include <cds/intrusive/impl/michael_list.h>
#include <cds/gc/ptb.h>
#endif // #ifndef __CDS_INTRUSIVE_MICHAEL_LIST_PTB_H
<ClInclude Include="..\..\..\cds\intrusive\ellen_bintree_rcu.h" />\r
<ClInclude Include="..\..\..\cds\intrusive\impl\ellen_bintree.h" />\r
<ClInclude Include="..\..\..\cds\intrusive\impl\lazy_list.h" />\r
+ <ClInclude Include="..\..\..\cds\intrusive\impl\michael_list.h" />\r
<ClInclude Include="..\..\..\cds\intrusive\lazy_list_rcu.h" />\r
<ClInclude Include="..\..\..\cds\intrusive\michael_list_rcu.h" />\r
<ClInclude Include="..\..\..\cds\intrusive\michael_set_rcu.h" />\r
<ClInclude Include="..\..\..\cds\intrusive\lazy_list_ptb.h" />\r
<ClInclude Include="..\..\..\cds\intrusive\michael_list_hp.h" />\r
<ClInclude Include="..\..\..\cds\intrusive\michael_list_hrc.h" />\r
- <ClInclude Include="..\..\..\cds\intrusive\michael_list_impl.h" />\r
<ClInclude Include="..\..\..\cds\intrusive\michael_list_nogc.h" />\r
<ClInclude Include="..\..\..\cds\intrusive\michael_list_ptb.h" />\r
<ClInclude Include="..\..\..\cds\intrusive\michael_set.h" />\r
<ClInclude Include="..\..\..\cds\intrusive\michael_list_hrc.h">\r
<Filter>Header Files\cds\intrusive</Filter>\r
</ClInclude>\r
- <ClInclude Include="..\..\..\cds\intrusive\michael_list_impl.h">\r
- <Filter>Header Files\cds\intrusive</Filter>\r
- </ClInclude>\r
<ClInclude Include="..\..\..\cds\intrusive\michael_list_nogc.h">\r
<Filter>Header Files\cds\intrusive</Filter>\r
</ClInclude>\r
<ClInclude Include="..\..\..\cds\intrusive\details\michael_list_base.h">\r
<Filter>Header Files\cds\intrusive\details</Filter>\r
</ClInclude>\r
+ <ClInclude Include="..\..\..\cds\intrusive\impl\michael_list.h">\r
+ <Filter>Header Files\cds\intrusive\impl</Filter>\r
+ </ClInclude>\r
</ItemGroup>\r
</Project>
\ No newline at end of file
projects / libcds.git / commitdiff