--- /dev/null
+/*
+ This file is a part of libcds - Concurrent Data Structures library
+
+ (C) Copyright Maxim Khizhinsky (libcds.dev@gmail.com) 2006-2017
+
+ Source code repo: http://github.com/khizmax/libcds/
+ Download: http://sourceforge.net/projects/libcds/files/
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are met:
+
+ * Redistributions of source code must retain the above copyright notice, this
+ list of conditions and the following disclaimer.
+
+ * Redistributions in binary form must reproduce the above copyright notice,
+ this list of conditions and the following disclaimer in the documentation
+ and/or other materials provided with the distribution.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#ifndef CDSLIB_INTRUSIVE_MICHAEL_LIST_NOGC_H
+#define CDSLIB_INTRUSIVE_MICHAEL_LIST_NOGC_H
+
+#include <cds/intrusive/details/michael_list_base.h>
+#include <cds/gc/nogc.h>
+#include <cds/details/make_const_type.h>
+
+namespace cds { namespace intrusive {
+
+ namespace michael_list {
+ /// Michael list node
+ /**
+ Template parameters:
+ - Tag - a tag used to distinguish between different implementation
+ */
+ template <typename Tag>
+ struct node<gc::nogc, Tag>
+ {
+ typedef gc::nogc gc ; ///< Garbage collector
+ typedef Tag tag ; ///< tag
+
+ typedef atomics::atomic< node * > atomic_ptr ; ///< atomic marked pointer
+
+ atomic_ptr m_pNext ; ///< pointer to the next node in the container
+
+ node()
+ : m_pNext( nullptr )
+ {}
+ };
+ } // namespace michael_list
+
+ /// Michael's lock-free ordered single-linked list (template specialization for gc::nogc)
+ /** @ingroup cds_intrusive_list
+ \anchor cds_intrusive_MichaelList_nogc
+
+ This specialization is intended for so-called append-only usage when no item
+ reclamation may be performed. The class does not support item removal.
+
+ See \ref cds_intrusive_MichaelList_hp "MichaelList" for description of template parameters.
+ */
+ template < typename T,
+#ifdef CDS_DOXYGEN_INVOKED
+ class Traits = michael_list::traits
+#else
+ class Traits
+#endif
+ >
+ class MichaelList<gc::nogc, T, Traits>
+ {
+ public:
+ typedef gc::nogc gc; ///< Garbage collector
+ typedef T value_type; ///< type of value to be stored in the queue
+ typedef Traits traits; ///< List traits
+
+ typedef typename traits::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, traits >::type key_comparator;
+# endif
+
+ typedef typename traits::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, traits::link_checker >::type link_checker; ///< link checker
+
+ typedef typename traits::back_off back_off; ///< back-off strategy
+ typedef typename traits::item_counter item_counter; ///< Item counting policy used
+ typedef typename traits::memory_model memory_model; ///< Memory ordering. See cds::opt::memory_model option
+ typedef typename traits::stat stat; ///< Internal statistics
+
+ //@cond
+ static_assert((std::is_same< gc, typename node_type::gc >::value), "GC and node_type::gc must be the same type");
+
+ // Rebind traits (split-list support)
+ template <typename... Options>
+ struct rebind_traits {
+ typedef MichaelList<
+ gc
+ , value_type
+ , typename cds::opt::make_options< traits, Options...>::type
+ > type;
+ };
+
+ // Stat selector
+ template <typename Stat>
+ using select_stat_wrapper = michael_list::select_stat_wrapper< Stat >;
+ //@endcond
+
+ protected:
+ typedef typename node_type::atomic_ptr atomic_node_ptr ; ///< Atomic node 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
+ stat m_Stat; ///< Internal statistics
+
+ //@cond
+ /// Position pointer for item search
+ struct position {
+ atomic_node_ptr * pPrev ; ///< Previous node
+ node_type * pCur ; ///< Current node
+ node_type * pNext ; ///< Next node
+ };
+ //@endcond
+
+ protected:
+ //@cond
+ static void clear_links( node_type * pNode )
+ {
+ pNode->m_pNext.store( nullptr, memory_model::memory_order_release );
+ }
+
+ template <class Disposer>
+ static void dispose_node( node_type * pNode, Disposer disp )
+ {
+ clear_links( pNode );
+ disp( node_traits::to_value_ptr( *pNode ));
+ }
+
+ template <class Disposer>
+ static void dispose_value( value_type& val, Disposer disp )
+ {
+ dispose_node( node_traits::to_node_ptr( val ), disp );
+ }
+
+ static bool link_node( node_type * pNode, position& pos )
+ {
+ assert( pNode != nullptr );
+ link_checker::is_empty( pNode );
+
+ pNode->m_pNext.store( pos.pCur, memory_model::memory_order_relaxed );
+ if ( cds_likely( pos.pPrev->compare_exchange_strong( pos.pCur, pNode, memory_model::memory_order_release, atomics::memory_order_relaxed )))
+ return true;
+
+ pNode->m_pNext.store( nullptr, memory_model::memory_order_relaxed );
+ return false;
+ }
+ //@endcond
+
+ protected:
+ //@cond
+ template <bool IsConst>
+ class iterator_type
+ {
+ friend class MichaelList;
+ value_type * m_pNode;
+
+ void next()
+ {
+ if ( m_pNode ) {
+ node_type * pNode = node_traits::to_node_ptr( *m_pNode )->m_pNext.load(memory_model::memory_order_acquire);
+ if ( pNode )
+ m_pNode = node_traits::to_value_ptr( *pNode );
+ else
+ m_pNode = nullptr;
+ }
+ }
+
+ protected:
+ explicit iterator_type( node_type * pNode)
+ {
+ if ( pNode )
+ m_pNode = node_traits::to_value_ptr( *pNode );
+ else
+ m_pNode = nullptr;
+ }
+ explicit iterator_type( atomic_node_ptr const& refNode)
+ {
+ node_type * pNode = refNode.load(memory_model::memory_order_relaxed);
+ if ( pNode )
+ m_pNode = node_traits::to_value_ptr( *pNode );
+ else
+ m_pNode = nullptr;
+ }
+
+ 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( const iterator_type& src )
+ : m_pNode( src.m_pNode )
+ {}
+
+ 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;
+ }
+
+ /// Post-increment
+ iterator_type operator ++(int)
+ {
+ iterator_type i(*this);
+ next();
+ return i;
+ }
+
+ iterator_type& operator = (const iterator_type& src)
+ {
+ m_pNode = src.m_pNode;
+ return *this;
+ }
+
+ 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
+ typedef iterator_type<false> iterator;
+ /// Const forward 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.load(memory_model::memory_order_relaxed));
+ }
+
+ /// 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 \code begin() == end() \endcode
+ */
+ iterator end()
+ {
+ return iterator();
+ }
+
+ /// Returns a forward const iterator addressing the first element in a list
+ const_iterator begin() const
+ {
+ return const_iterator(m_pHead.load(memory_model::memory_order_relaxed));
+ }
+ /// Returns a forward const iterator addressing the first element in a list
+ const_iterator cbegin() const
+ {
+ return const_iterator(m_pHead.load(memory_model::memory_order_relaxed));
+ }
+
+ /// 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() const
+ {
+ return const_iterator();
+ }
+
+ public:
+ /// Default constructor initializes empty list
+ MichaelList()
+ : m_pHead( nullptr )
+ {}
+
+ //@cond
+ template <typename Stat, typename = std::enable_if<std::is_same<stat, michael_list::wrapped_stat<Stat>>::value >>
+ explicit MichaelList( Stat& st )
+ : m_pHead( nullptr )
+ , m_Stat( st )
+ {}
+ //@endcond
+
+ /// Destroys the list objects
+ ~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 );
+ }
+
+ /// Updates the item
+ /**
+ 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
+ iff \p bAllowInsert is \p true.
+ Otherwise, the functor \p func is called with item found.
+ The functor signature is:
+ \code
+ struct functor {
+ void operator()( 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 update() function
+ If new item has been inserted (i.e. \p bNew is \p true) then \p item and \p val arguments
+ refer 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.
+
+ Returns <tt> std::pair<bool, bool> </tt> where \p first is \p true if operation is successful,
+ \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> update( value_type& val, Func func, bool bAllowInsert = true )
+ {
+ return update_at( m_pHead, val, func, bAllowInsert );
+ }
+ //@cond
+ template <typename Func>
+ CDS_DEPRECATED("ensure() is deprecated, use update()")
+ std::pair<bool, bool> ensure( value_type& val, Func func )
+ {
+ return update( val, func );
+ }
+ //@endcond
+
+ /// Finds the key \p val
+ /** \anchor cds_intrusive_MichaelList_nogc_find_func
+ The function searches the item with key equal to \p key
+ 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& key );
+ };
+ \endcode
+ where \p item is the item found, \p key is the <tt>find</tt> function argument.
+
+ The functor can change non-key fields of \p item.
+ The function \p find 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& key, Func f )
+ {
+ return find_at( m_pHead, key, key_comparator(), f );
+ }
+ //@cond
+ template <typename Q, typename Func>
+ bool find( Q const& key, Func f )
+ {
+ return find_at( m_pHead, key, key_comparator(), f );
+ }
+ //@endcond
+
+ /// Finds the key \p key using \p pred predicate for searching
+ /**
+ The function is an analog of \ref cds_intrusive_MichaelList_nogc_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& key, Less pred, Func f )
+ {
+ CDS_UNUSED( pred );
+ return find_at( m_pHead, key, cds::opt::details::make_comparator_from_less<Less>(), f );
+ }
+ //@cond
+ template <typename Q, typename Less, typename Func>
+ bool find_with( Q const& key, Less pred, Func f )
+ {
+ CDS_UNUSED( pred );
+ return find_at( m_pHead, key, cds::opt::details::make_comparator_from_less<Less>(), f );
+ }
+ //@endcond
+
+ /// Checks whether the list contains \p key
+ /**
+ The function searches the item with key equal to \p key
+ and returns \p true if it is found, and \p false otherwise.
+ */
+ template <typename Q>
+ value_type * contains( Q const& key )
+ {
+ return find_at( m_pHead, key, key_comparator());
+ }
+ //@cond
+ template <typename Q>
+ CDS_DEPRECATED("deprecated, use contains()")
+ value_type * find( Q const& key )
+ {
+ return contains( key );
+ }
+ //@endcond
+
+ /// Checks whether the map contains \p key using \p pred predicate for searching
+ /**
+ The function is an analog of <tt>contains( key )</tt> but \p pred is used for key comparing.
+ \p Less functor has the interface like \p std::less.
+ \p Less must imply the same element order as the comparator used for building the list.
+ */
+ template <typename Q, typename Less>
+ value_type * contains( Q const& key, Less pred )
+ {
+ CDS_UNUSED( pred );
+ return find_at( m_pHead, key, cds::opt::details::make_comparator_from_less<Less>());
+ }
+ //@cond
+ template <typename Q, typename Less>
+ CDS_DEPRECATED("deprecated, use contains()")
+ value_type * find_with( Q const& key, Less pred )
+ {
+ return contains( key, pred );
+ }
+ //@endcond
+
+ /// Clears the list
+ /**
+ The function unlink all items from the list.
+
+ For each unlinked item the item disposer \p disp is called after unlinking.
+ */
+ template <typename Disposer>
+ void clear( Disposer disp )
+ {
+ node_type * pHead = m_pHead.load(memory_model::memory_order_relaxed);
+ do {} while ( cds_unlikely( !m_pHead.compare_exchange_weak( pHead, nullptr, memory_model::memory_order_relaxed )));
+
+ while ( pHead ) {
+ node_type * p = pHead->m_pNext.load(memory_model::memory_order_relaxed);
+ dispose_node( pHead, disp );
+ pHead = p;
+ --m_ItemCounter;
+ }
+ }
+
+ /// Clears the list using default disposer
+ /**
+ The function clears the list using default (provided in class template) disposer functor.
+ */
+ void clear()
+ {
+ clear( disposer());
+ }
+
+ /// Checks if the list is empty
+ bool empty() const
+ {
+ return m_pHead.load( memory_model::memory_order_relaxed ) == nullptr;
+ }
+
+ /// Returns list's item count
+ /**
+ The value returned depends on item counter provided by \p Traits. For \p atomicity::empty_item_counter,
+ this function always returns 0.
+
+ @note Even if you use real item counter and it returns 0, this fact does not mean that the list
+ is empty. To check list emptyness use \p empty() method.
+ */
+ size_t size() const
+ {
+ return m_ItemCounter.value();
+ }
+
+ /// Returns const reference to internal statistics
+ stat const& statistics() const
+ {
+ return m_Stat;
+ }
+
+ 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 )
+ {
+ position pos;
+
+ while ( true ) {
+ if ( search( refHead, val, key_comparator(), pos )) {
+ m_Stat.onInsertFailed();
+ return false;
+ }
+
+ if ( link_node( node_traits::to_node_ptr( val ), pos )) {
+ ++m_ItemCounter;
+ m_Stat.onInsertSuccess();
+ return true;
+ }
+
+ m_Stat.onInsertRetry();
+ }
+ }
+
+ iterator insert_at_( atomic_node_ptr& refHead, value_type& val )
+ {
+ if ( insert_at( refHead, val ))
+ return iterator( node_traits::to_node_ptr( val ));
+ return end();
+ }
+
+ template <typename Func>
+ std::pair<iterator, bool> update_at_( atomic_node_ptr& refHead, value_type& val, Func func, bool bAllowInsert )
+ {
+ position pos;
+
+ while ( true ) {
+ if ( search( refHead, val, key_comparator(), pos )) {
+ assert( key_comparator()( val, *node_traits::to_value_ptr( *pos.pCur )) == 0 );
+
+ func( false, *node_traits::to_value_ptr( *pos.pCur ) , val );
+ m_Stat.onUpdateExisting();
+ return std::make_pair( iterator( pos.pCur ), false );
+ }
+ else {
+ if ( !bAllowInsert ) {
+ m_Stat.onUpdateFailed();
+ return std::make_pair( end(), false );
+ }
+
+ if ( link_node( node_traits::to_node_ptr( val ), pos )) {
+ ++m_ItemCounter;
+ func( true, val , val );
+ m_Stat.onUpdateNew();
+ return std::make_pair( iterator( node_traits::to_node_ptr( val )), true );
+ }
+ }
+
+ m_Stat.onUpdateRetry();
+ }
+ }
+
+ template <typename Func>
+ std::pair<bool, bool> update_at( atomic_node_ptr& refHead, value_type& val, Func func, bool bAllowInsert )
+ {
+ std::pair<iterator, bool> ret = update_at_( refHead, val, func, bAllowInsert );
+ return std::make_pair( ret.first != end(), ret.second );
+ }
+
+ 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, cmp, pos )) {
+ assert( pos.pCur != nullptr );
+ f( *node_traits::to_value_ptr( *pos.pCur ), val );
+ m_Stat.onFindSuccess();
+ return true;
+ }
+
+ m_Stat.onFindFailed();
+ return false;
+ }
+
+ template <typename Q, typename Compare>
+ value_type * find_at( atomic_node_ptr& refHead, Q const& val, Compare cmp )
+ {
+ iterator it = find_at_( refHead, val, cmp );
+ if ( it != end()) {
+ m_Stat.onFindSuccess();
+ return &*it;
+ }
+
+ m_Stat.onFindFailed();
+ return nullptr;
+ }
+
+ template <typename Q, typename Compare>
+ iterator find_at_( atomic_node_ptr& refHead, Q const& val, Compare cmp )
+ {
+ position pos;
+
+ if ( search( refHead, val, cmp, pos )) {
+ assert( pos.pCur != nullptr );
+ m_Stat.onFindSuccess();
+ return iterator( pos.pCur );
+ }
+
+ m_Stat.onFindFailed();
+ return end();
+ }
+
+ //@endcond
+
+ protected:
+
+ //@cond
+ template <typename Q, typename Compare >
+ bool search( atomic_node_ptr& refHead, const Q& val, Compare cmp, position& pos )
+ {
+ atomic_node_ptr * pPrev;
+ node_type * pNext;
+ node_type * pCur;
+
+ back_off bkoff;
+
+ try_again:
+ pPrev = &refHead;
+ pCur = pPrev->load(memory_model::memory_order_acquire);
+ pNext = nullptr;
+
+ while ( true ) {
+ if ( !pCur ) {
+ pos.pPrev = pPrev;
+ pos.pCur = pCur;
+ pos.pNext = pNext;
+ return false;
+ }
+
+ pNext = pCur->m_pNext.load(memory_model::memory_order_relaxed);
+ if ( cds_unlikely( pCur->m_pNext.load(memory_model::memory_order_acquire) != pNext )) {
+ bkoff();
+ goto try_again;
+ }
+
+ if ( cds_unlikely( pPrev->load(memory_model::memory_order_acquire) != pCur )) {
+ bkoff();
+ goto try_again;
+ }
+
+ assert( pCur != nullptr );
+ int nCmp = cmp( *node_traits::to_value_ptr( *pCur ), val );
+ if ( nCmp >= 0 ) {
+ pos.pPrev = pPrev;
+ pos.pCur = pCur;
+ pos.pNext = pNext;
+ return nCmp == 0;
+ }
+ pPrev = &( pCur->m_pNext );
+ pCur = pNext;
+ }
+ }
+
+ // for split-list
+ template <typename Predicate>
+ void erase_for( Predicate pred )
+ {
+ node_type * pPred = nullptr;
+ node_type * pHead = m_pHead.load( memory_model::memory_order_relaxed );
+ while ( pHead ) {
+ node_type * p = pHead->m_pNext.load( memory_model::memory_order_relaxed );
+ if ( pred( *node_traits::to_value_ptr( pHead ))) {
+ assert( pPred != nullptr );
+ pPred->m_pNext.store( p, memory_model::memory_order_relaxed );
+ dispose_node( pHead, disposer());
+ }
+ else
+ pPred = pHead;
+ pHead = p;
+ }
+ }
+ //@endcond
+ };
+
+}} // namespace cds::intrusive
+
+#endif // #ifndef CDSLIB_INTRUSIVE_MICHAEL_LIST_NOGC_H
projects / c11concurrency-benchmarks.git / blobdiff