-//$$CDS-header$$
-
-#ifndef __CDS_INTRUSIVE_IMPL_MICHAEL_LIST_H
-#define __CDS_INTRUSIVE_IMPL_MICHAEL_LIST_H
+/*
+ This file is a part of libcds - Concurrent Data Structures library
+
+ (C) Copyright Maxim Khizhinsky (libcds.dev@gmail.com) 2006-2016
+
+ 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_IMPL_MICHAEL_LIST_H
+#define CDSLIB_INTRUSIVE_IMPL_MICHAEL_LIST_H
#include <cds/intrusive/details/michael_list_base.h>
-#include <cds/gc/guarded_ptr.h>
+#include <cds/details/make_const_type.h>
namespace cds { namespace intrusive {
- [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
+ - \p GC - Garbage collector used. Note the \p GC must be the same as the GC used for item type \p T (see \p michael_list::node).
+ - \p T - type to be stored in the list. The type must be based on \p michael_list::node (for \p michael_list::base_hook)
+ or it must have a member of type \p michael_list::node (for \p michael_list::member_hook).
+ - \p Traits - type traits, default is \p michael_list::traits. It is possible to declare option-based
+ list with \p cds::intrusive::michael_list::make_traits metafunction:
+ For example, the following traits-based declaration of \p 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 >
{
- return i1.nKey - i2.nKey;
- }
- };
+ int nKey;
+ // .... other data
+ };
- // 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 comparator for the item
+ struct my_compare {
+ int operator()( item const& i1, item const& i2 ) const
+ {
+ return i1.nKey - i2.nKey;
+ }
+ };
- // Declare traits-based list
- typedef cds::intrusive::MichaelList< cds::gc::HP, item, my_traits > traits_based_list;
- \endcode
+ // Declare traits
+ struct my_traits: public cds::intrusive::michael_list::traits
+ {
+ typedef cds::intrusive::michael_list::base_hook< cds::opt::gc< cds::gc::HP > > hook;
+ typedef my_compare compare;
+ };
- is equivalent for the following option-based list
- \code
- #include <cds/intrusive/michael_list_hp.h>
+ // 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
+ // 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
+ // 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.
+ There are different specializations of this template for each garbage collecting schema.
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 \p gc::HP: <tt> <cds/intrusive/michael_list_hp.h> </tt>
+ - for \p gc::DHP: <tt> <cds/intrusive/michael_list_dhp.h> </tt>
- 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
+ - for \p gc::nogc: <tt> <cds/intrusive/michael_list_nogc.h> </tt>
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.
+ Then, you should incorporate \p michael_list::node into your struct \p T and provide
+ appropriate \p michael_list::traits::hook in your \p Traits template parameters. Usually, for \p Traits you
+ define a struct based on \p michael_list::traits.
- Example for gc::PTB and base hook:
+ Example for \p gc::DHP and base hook:
\code
// Include GC-related Michael's list specialization
- #include <cds/intrusive/michael_list_ptb.h>
+ #include <cds/intrusive/michael_list_dhp.h>
// Data stored in Michael's list
- struct my_data: public cds::intrusive::michael_list::node< cds::gc::PTB >
+ struct my_data: public cds::intrusive::michael_list::node< cds::gc::DHP >
{
// key field
std::string strKey;
};
- // Declare type_traits
- struct my_traits: public cds::intrusive::michael_list::type_traits
+ // Declare traits
+ struct my_traits: public cds::intrusive::michael_list::traits
{
- typedef cds::intrusive::michael_list::base_hook< cds::opt::gc< cds::gc::PTB > > hook;
+ typedef cds::intrusive::michael_list::base_hook< cds::opt::gc< cds::gc::DHP > > hook;
typedef my_data_cmp compare;
};
// Declare list type
- typedef cds::intrusive::MichaelList< cds::gc::PTB, my_data, my_traits > traits_based_list;
+ typedef cds::intrusive::MichaelList< cds::gc::DHP, my_data, my_traits > traits_based_list;
\endcode
Equivalent option-based code:
\code
// GC-related specialization
- #include <cds/intrusive/michael_list_ptb.h>
+ #include <cds/intrusive/michael_list_dhp.h>
struct my_data {
// see above
};
// Declare option-based list
- typedef cds::intrusive::MichaelList< cds::gc::PTB
+ typedef cds::intrusive::MichaelList< cds::gc::DHP
,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::hook< cds::intrusive::michael_list::base_hook< cds::opt::gc< cds::gc::DHP > > >
,cds::intrusive::opt::compare< my_data_cmp >
>::type
> option_based_list;
class GC
,typename T
#ifdef CDS_DOXYGEN_INVOKED
- ,class Traits = michael_list::type_traits
+ ,class Traits = michael_list::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 T value_type; ///< type of value stored in the list
+ typedef Traits traits; ///< Traits template parameter
- typedef typename options::hook hook ; ///< hook type
- typedef typename hook::node_type node_type ; ///< node type
+ 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, options >::type key_comparator;
+ typedef typename opt::details::make_comparator< value_type, traits >::type key_comparator;
# endif
- typedef typename options::disposer disposer ; ///< disposer used
+ 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, options::link_checker >::type link_checker ; ///< link checker
+ typedef typename michael_list::get_link_checker< node_type, traits::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 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 cds::gc::guarded_ptr< gc, value_type > guarded_ptr; ///< Guarded pointer
+ typedef typename gc::template guarded_ptr< value_type > guarded_ptr; ///< Guarded pointer
+
+ static CDS_CONSTEXPR const size_t c_nHazardPtrCount = 4; ///< Count of hazard pointer required for the algorithm
//@cond
- // Rebind options (split-list support)
+ // Rebind traits (split-list support)
template <typename... Options>
- struct rebind_options {
+ struct rebind_traits {
typedef MichaelList<
gc
, value_type
- , typename cds::opt::make_options< options, Options...>::type
+ , typename cds::opt::make_options< traits, 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 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)
+ 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
+ atomic_node_ptr m_pHead; ///< Head pointer
+ item_counter m_ItemCounter; ///< Item counter
//@cond
/// Position pointer for item search
struct clean_disposer {
void operator()( value_type * p )
{
- michael_list::node_cleaner<gc, node_type, memory_model>()( node_traits::to_node_ptr( 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 )
+ static void retire_node( node_type * pNode )
{
assert( pNode != nullptr );
- gc::template retire<clean_disposer>( node_traits::to_value_ptr( *pNode ) );
+ gc::template retire<clean_disposer>( node_traits::to_value_ptr( *pNode ));
}
- bool link_node( node_type * pNode, position& pos )
+ static 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 );
+ pNode->m_pNext.store( cur, memory_model::memory_order_release );
+ if ( pos.pPrev->compare_exchange_strong( cur, marked_node_ptr(pNode), memory_model::memory_order_release, atomics::memory_order_relaxed ))
+ return true;
+
+ pNode->m_pNext.store( marked_node_ptr(), memory_model::memory_order_relaxed );
+ return false;
}
- bool unlink_node( position& pos )
+ static bool unlink_node( position& pos )
{
assert( pos.pPrev != nullptr );
assert( pos.pCur != nullptr );
// 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 ))
+ if ( pos.pPrev->compare_exchange_strong( cur, marked_node_ptr( pos.pNext ), memory_model::memory_order_acquire, atomics::memory_order_relaxed ))
retire_node( pos.pCur );
return true;
}
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) );
+ 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>() );
- }
+ if ( pNext.ptr())
+ m_pNode = m_Guard.assign( g.template get<value_type>());
else {
m_pNode = nullptr;
m_Guard.clear();
{
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() ) );
+ 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) )
+ if ( p == pNode.load(memory_model::memory_order_acquire))
break;
}
}
//@endcond
public:
+ ///@name Forward iterators (only for debugging purpose)
+ //@{
/// 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.
+ For some GC (like as \p gc::HP), a guard is a limited resource per thread, so an exception (or assertion) "no free guard"
+ may be thrown if the limit of guard count per thread is exceeded.
+ - The iterator cannot be moved across thread boundary since it contains thread-private GC's guard.
+ - Iterator ensures thread-safety even if you delete the item the iterator points to. However, in case of concurrent
+ deleting operations there is no guarantee that you iterate all item in the list.
+ Moreover, a crash is possible when you try to iterate the next element that has been deleted by concurrent thread.
- Therefore, the use of iterators in concurrent environment is not good idea. Use the iterator on the concurrent container
- for debug purpose only.
+ @warning Use this iterator on the concurrent container for debugging purpose only.
The iterator interface:
\code
}
/// Returns a forward const iterator addressing the first element in a list
- const_iterator cbegin()
+ const_iterator cbegin() const
{
return const_iterator( m_pHead );
}
}
/// Returns an const iterator that addresses the location succeeding the last element in a list
- const_iterator cend()
+ const_iterator cend() const
{
return const_iterator();
}
+ //@}
public:
/// Default constructor initializes empty list
/// Inserts new node
/**
- The function inserts \p val in the list if the list does not contain
+ The function inserts \p val into 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.
+ Returns \p true if \p val has been linked to the list, \p false otherwise.
*/
bool insert( 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 \p std::ref
+ The user-defined functor is called only if the inserting is success.
+
+ @warning See \ref cds_intrusive_item_creating "insert item troubleshooting"
*/
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
+ /// Updates the node
/**
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.
+ If the item \p val is not found in the list, then \p val is inserted
+ iff \p bInsert is \p true.
Otherwise, the functor \p func is called with item found.
The functor signature is:
\code
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
+ - \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
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 \p std::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.
+
+ @warning See \ref cds_intrusive_item_creating "insert item troubleshooting"
*/
template <typename Func>
+ std::pair<bool, bool> update( value_type& val, Func func, bool bInsert = true )
+ {
+ return update_at( m_pHead, val, func, bInsert );
+ }
+
+ //@cond
+ template <typename Func>
+ CDS_DEPRECATED("ensure() is deprecated, use update()")
std::pair<bool, bool> ensure( value_type& val, Func func )
{
- return ensure_at( m_pHead, val, func );
+ return update( val, func, true );
}
+ //@endcond
/// Unlinks the item \p val from the list
/**
- The function searches the item \p val in the list and unlink it from the list
+ The function searches the item \p val in the list and unlinks 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
+ Difference between \p erase() and \p %unlink(): \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 the list, i.e. the pointer to item found
is equal to <tt> &val </tt>.
+ \p disposer specified in \p Traits is called for deleted item.
+
The function returns \p true if success and \p false otherwise.
*/
bool unlink( value_type& 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,
+ The function searches an item with key equal to \p key 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.
+ If \p key is not found the function return \p false.
+
+ \p disposer specified in \p Traits is called for deleted item.
*/
template <typename Q>
- bool erase( Q const& val )
+ bool erase( Q const& key )
{
- return erase_at( m_pHead, val, key_comparator() );
+ return erase_at( m_pHead, key, key_comparator());
}
/// Deletes the item from the list using \p pred predicate for searching
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.
+
+ \p disposer specified in \p Traits is called for deleted item.
*/
template <typename Q, typename Less>
- bool erase_with( Q const& val, Less pred )
+ bool erase_with( Q const& key, Less pred )
{
- return erase_at( m_pHead, val, cds::opt::details::make_comparator_from_less<Less>());
+ CDS_UNUSED( pred );
+ return erase_at( m_pHead, key, 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,
+ The function searches an item with key equal to \p key 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
void operator()( value_type const& item );
};
\endcode
- The functor may be passed by reference using <tt>boost:ref</tt>
+ If \p key is not found the function return \p false, \p func is not called.
- If the item with the key equal to \p val is not found the function return \p false.
+ \p disposer specified in \p Traits is called for deleted item.
*/
template <typename Q, typename Func>
- bool erase( Q const& val, Func func )
+ bool erase( Q const& key, Func func )
{
- return erase_at( m_pHead, val, key_comparator(), func );
+ return erase_at( m_pHead, key, key_comparator(), func );
}
/// Deletes the item from the list using \p pred predicate for searching
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.
+
+ \p disposer specified in \p Traits is called for deleted item.
*/
template <typename Q, typename Less, typename Func>
- bool erase_with( Q const& val, Less pred, Func f )
+ bool erase_with( Q const& key, Less pred, Func f )
{
- return erase_at( m_pHead, val, cds::opt::details::make_comparator_from_less<Less>(), f );
+ CDS_UNUSED( pred );
+ return erase_at( m_pHead, key, 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.
+ unlinks it from the list, and returns it as \p guarded_ptr.
+ If \p key is not found returns an empty guarded pointer.
Note the compare functor should accept a parameter of type \p Q that can be not the same as \p value_type.
ord_list theList;
// ...
{
- ord_list::guarded_ptr gp;
- theList.extract( gp, 5 );
- // Deal with gp
- // ...
-
+ ord_list::guarded_ptr gp(theList.extract( 5 ));
+ if ( gp ) {
+ // Deal with gp
+ // ...
+ }
// Destructor of gp releases internal HP guard
}
\endcode
*/
template <typename Q>
- bool extract( guarded_ptr& dest, Q const& key )
+ guarded_ptr extract( Q const& key )
{
- return extract_at( m_pHead, dest.guard(), key, key_comparator() );
+ guarded_ptr gp;
+ extract_at( m_pHead, gp.guard(), key, key_comparator());
+ return gp;
}
/// 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&)"
+ The function is an analog of \ref cds_intrusive_MichaelList_hp_extract "extract(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
\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 )
+ guarded_ptr extract_with( Q const& key, Less pred )
{
- return extract_at( m_pHead, dest.guard(), key, cds::opt::details::make_comparator_from_less<Less>() );
+ CDS_UNUSED( pred );
+ guarded_ptr gp;
+ extract_at( m_pHead, gp.guard(), key, cds::opt::details::make_comparator_from_less<Less>());
+ return gp;
}
- /// Finds the key \p val
+ /// Finds \p key in the list
/** \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 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& val );
+ void operator()( value_type& item, Q& key );
};
\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 \p std::ref.
+ where \p item is the item found, \p key is the <tt>find</tt> function argument.
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 does not serialize simultaneous access to the \p item. If such access is
+ possible you must provide your own synchronization schema to keep out unsafe item modifications.
- The \p val argument is non-const since it can be used as \p f functor destination i.e., the functor
+ The \p key 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 )
+ bool find( Q& key, Func f )
{
- return find_at( m_pHead, val, key_comparator(), 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 val using \p pred predicate for searching
+ /// Finds the \p key 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 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 )
+ bool find_with( Q& key, Less pred, Func f )
{
- return find_at( m_pHead, val, cds::opt::details::make_comparator_from_less<Less>(), f );
+ CDS_UNUSED( pred );
+ return find_at( m_pHead, key, 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 \p std::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 )
+ //@cond
+ template <typename Q, typename Less, typename Func>
+ bool find_with( Q const& key, Less pred, Func f )
{
- return find_at( m_pHead, val, key_comparator(), f );
+ CDS_UNUSED( pred );
+ return find_at( m_pHead, key, cds::opt::details::make_comparator_from_less<Less>(), f );
}
+ //@endcond
- /// Finds the key \p val using \p pred predicate for searching
+ /// Checks whether the list contains \p key
/**
- 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.
+ 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, typename Less, typename Func>
- bool find_with( Q const& val, Less pred, Func f )
+ template <typename Q>
+ bool contains( Q const& key )
{
- return find_at( m_pHead, val, cds::opt::details::make_comparator_from_less<Less>(), f );
+ return find_at( m_pHead, key, key_comparator());
}
-
- /// 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
- */
+ //@cond
template <typename Q>
- bool find( Q const & val )
+ CDS_DEPRECATED("deprecated, use contains()")
+ bool find( Q const& key )
{
- return find_at( m_pHead, val, key_comparator() );
+ return contains( key );
}
+ //@endcond
- /// Finds the key \p val using \p pred predicate for searching
+ /// Checks whether the list contains \p key 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.
+ 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 pred must imply the same element order as the comparator used for building the list.
+ \p Less 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 )
+ bool 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()")
+ bool find_with( Q const& key, Less pred )
{
- return find_at( m_pHead, val, cds::opt::details::make_comparator_from_less<Less>() );
+ return contains( key, pred );
}
+ //@endcond
- /// Finds the key \p val and return the item found
+ /// Finds the \p key 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 function searches the item with key equal to \p key
+ and returns it as \p guarded_ptr.
+ If \p key is not found the function returns an empty guarded pointer.
The \ref disposer specified in \p Traits class template parameter is called
by garbage collector \p GC automatically when returned \ref guarded_ptr object
ord_list theList;
// ...
{
- ord_list::guarded_ptr gp;
- if ( theList.get( gp, 5 )) {
+ ord_list::guarded_ptr gp(theList.get( 5 ));
+ if ( gp ) {
// Deal with gp
//...
}
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 )
+ guarded_ptr get( Q const& key )
{
- return get_at( m_pHead, ptr.guard(), val, key_comparator() );
+ guarded_ptr gp;
+ get_at( m_pHead, gp.guard(), key, key_comparator());
+ return gp;
}
- /// Finds the key \p val and return the item found
+ /// Finds the \p key and return the item found
/**
- The function is an analog of \ref cds_intrusive_MichaelList_hp_get "get( guarded_ptr& ptr, Q const&)"
+ The function is an analog of \ref cds_intrusive_MichaelList_hp_get "get( 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
\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 )
+ guarded_ptr get_with( Q const& key, Less pred )
{
- return get_at( m_pHead, ptr.guard(), val, cds::opt::details::make_comparator_from_less<Less>() );
+ CDS_UNUSED( pred );
+ guarded_ptr gp;
+ get_at( m_pHead, gp.guard(), key, cds::opt::details::make_comparator_from_less<Less>());
+ return gp;
}
/// Clears the list
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 ( 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() );
+ value_type& val = *node_traits::to_value_ptr( *head.ptr());
unlink( val );
}
}
}
- /// Checks if the list is empty
+ /// Checks whether 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,
+ The value returned depends on item counter provided by \p Traits. For \p 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.
+ @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
{
// 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 ) );
+ 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() ) )
+ if ( search( refHead, val, pos, key_comparator()))
return false;
- if ( link_node( pNode, pos ) ) {
+ if ( link_node( pNode, pos )) {
++m_ItemCounter;
return true;
}
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() ) )
+ if ( search( refHead, val, pos, key_comparator()))
return false;
typename gc::Guard guard;
guard.assign( &val );
- if ( link_node( pNode, pos ) ) {
+ if ( link_node( pNode, pos )) {
f( val );
++m_ItemCounter;
return true;
}
template <typename Func>
- std::pair<bool, bool> ensure_at( atomic_node_ptr& refHead, value_type& val, Func func )
+ std::pair<bool, bool> update_at( atomic_node_ptr& refHead, value_type& val, Func func, bool bInsert )
{
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() ) {
+ 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
+ continue; // the node found is marked as deleted
}
- assert( key_comparator()( val, *node_traits::to_value_ptr( *pos.pCur ) ) == 0 );
+ assert( key_comparator()( val, *node_traits::to_value_ptr( *pos.pCur )) == 0 );
func( false, *node_traits::to_value_ptr( *pos.pCur ) , val );
return std::make_pair( true, false );
}
else {
+ if ( !bInsert )
+ return std::make_pair( false, false );
+
typename gc::Guard guard;
guard.assign( &val );
- if ( link_node( pNode, pos ) ) {
+ if ( link_node( pNode, pos )) {
++m_ItemCounter;
func( true, val, val );
return std::make_pair( true, true );
position pos;
back_off bkoff;
- while ( search( refHead, val, pos, key_comparator() ) ) {
+ while ( search( refHead, val, pos, key_comparator())) {
if ( node_traits::to_value_ptr( *pos.pCur ) == &val ) {
- if ( unlink_node( pos ) ) {
+ if ( unlink_node( pos )) {
--m_ItemCounter;
return true;
}
{
back_off bkoff;
while ( search( refHead, val, pos, cmp )) {
- if ( unlink_node( pos ) ) {
- f( *node_traits::to_value_ptr( *pos.pCur ) );
+ if ( unlink_node( pos )) {
+ f( *node_traits::to_value_ptr( *pos.pCur ));
--m_ItemCounter;
return true;
}
}
template <typename Q, typename Compare>
- bool extract_at( atomic_node_ptr& refHead, typename gc::Guard& dest, Q const& val, Compare cmp )
+ bool extract_at( atomic_node_ptr& refHead, typename guarded_ptr::native_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 ) );
+ if ( unlink_node( pos )) {
+ dest.set( pos.guards.template get<value_type>( position::guard_current_item ));
--m_ItemCounter;
return true;
}
}
template <typename Q, typename Compare>
- bool get_at( atomic_node_ptr& refHead, typename gc::Guard& guard, Q const& val, Compare cmp )
+ bool get_at( atomic_node_ptr& refHead, typename guarded_ptr::native_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 ));
+ guard.set( pos.guards.template get<value_type>( position::guard_current_item ));
return true;
}
return false;
back_off bkoff;
-try_again:
+ 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;
+ pCur = pos.guards.protect( position::guard_current_item, *pPrev,
+ [](marked_node_ptr p) -> value_type *
+ {
+ return node_traits::to_value_ptr( p.ptr());
+ });
while ( true ) {
if ( pCur.ptr() == nullptr ) {
pos.pPrev = pPrev;
- pos.pCur = pCur.ptr();
- pos.pNext = pNext.ptr();
+ pos.pCur = nullptr;
+ pos.pNext = nullptr;
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() ) {
+ pNext = pos.guards.protect( position::guard_next_item, pCur->m_pNext,
+ [](marked_node_ptr p ) -> value_type *
+ {
+ return node_traits::to_value_ptr( p.ptr());
+ });
+ if ( pPrev->load(memory_model::memory_order_acquire).all() != pCur.ptr()) {
bkoff();
goto try_again;
}
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() );
+ if ( pPrev->compare_exchange_strong( cur, marked_node_ptr( pNext.ptr()), memory_model::memory_order_acquire, atomics::memory_order_relaxed )) {
+ retire_node( pCur.ptr());
}
else {
bkoff();
}
else {
assert( pCur.ptr() != nullptr );
- int nCmp = cmp( *node_traits::to_value_ptr( pCur.ptr() ), val );
+ int nCmp = cmp( *node_traits::to_value_ptr( pCur.ptr()), val );
if ( nCmp >= 0 ) {
pos.pPrev = pPrev;
pos.pCur = pCur.ptr();
return nCmp == 0;
}
pPrev = &( pCur->m_pNext );
- pos.guards.assign( position::guard_prev_item, node_traits::to_value_ptr( pCur.ptr() ) );
+ pos.guards.copy( position::guard_prev_item, position::guard_current_item );
}
pCur = pNext;
- pos.guards.assign( position::guard_current_item, node_traits::to_value_ptr( pCur.ptr() ));
+ pos.guards.copy( position::guard_current_item, position::guard_next_item );
}
}
//@endcond
};
}} // namespace cds::intrusive
-#endif // #ifndef __CDS_INTRUSIVE_IMPL_MICHAEL_LIST_H
+#endif // #ifndef CDSLIB_INTRUSIVE_IMPL_MICHAEL_LIST_H
projects / libcds.git / blobdiff