cds::intrusive::MichaelList< gc::nogc, T, Traits > Class Template Reference

Michael's lock-free ordered single-linked list (template specialization for gc::nogc) More...

#include <cds/intrusive/michael_list_nogc.h>

Inheritance diagram for cds::intrusive::MichaelList< gc::nogc, T, Traits >:

Public Types
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 traits::hook	hook
	hook type
typedef hook::node_type	node_type
	node type
typedef implementation_defined	key_comparator
	key comparison functor based on opt::compare and opt::less option setter.
typedef traits::disposer	disposer
	disposer used
typedef get_node_traits< value_type, node_type, hook >::type	node_traits
	node traits
typedef michael_list::get_link_checker< node_type, traits::link_checker >::type	link_checker
	link checker
typedef traits::back_off	back_off
	back-off strategy
typedef traits::item_counter	item_counter
	Item counting policy used.
typedef traits::memory_model	memory_model
	Memory ordering. See cds::opt::memory_model option.
typedef traits::stat	stat
	Internal statistics.
typedef iterator_type< false >	iterator
	Forward iterator.
typedef iterator_type< true >	const_iterator
	Const forward iterator.

Public Member Functions
iterator	begin ()
	Returns a forward iterator addressing the first element in a list. More...
iterator	end ()
	Returns an iterator that addresses the location succeeding the last element in a list. More...
const_iterator	begin () const
	Returns a forward const iterator addressing the first element in a list.
const_iterator	cbegin () const
	Returns a forward const iterator addressing the first element in a list.
const_iterator	end () const
	Returns an const iterator that addresses the location succeeding the last element in a list.
const_iterator	cend () const
	Returns an const iterator that addresses the location succeeding the last element in a list.
	MichaelList ()
	Default constructor initializes empty list.
	~MichaelList ()
	Destroys the list objects.
bool	insert (value_type &val)
	Inserts new node. More...
template<typename Func >
std::pair< bool, bool >	update (value_type &val, Func func, bool bAllowInsert=true)
	Updates the item. More...
template<typename Q , typename Func >
bool	find (Q &key, Func f)
	Finds the key val. More...
template<typename Q , typename Less , typename Func >
bool	find_with (Q &key, Less pred, Func f)
	Finds the key key using pred predicate for searching. More...
template<typename Q >
value_type *	contains (Q const &key)
	Checks whether the list contains key. More...
template<typename Q , typename Less >
value_type *	contains (Q const &key, Less pred)
	Checks whether the map contains key using pred predicate for searching. More...
template<typename Disposer >
void	clear (Disposer disp)
	Clears the list. More...
void	clear ()
	Clears the list using default disposer. More...
bool	empty () const
	Checks if the list is empty.
size_t	size () const
	Returns list's item count. More...
stat const &	statistics () const
	Returns const reference to internal statistics.

Protected Types
typedef node_type::atomic_ptr	atomic_node_ptr
	Atomic node pointer.
typedef atomic_node_ptr	auxiliary_head
	Auxiliary head type (for split-list support)

Protected Attributes
atomic_node_ptr	m_pHead
	Head pointer.
item_counter	m_ItemCounter
	Item counter.
stat	m_Stat
	Internal statistics.

Detailed Description

template<typename T, class Traits = michael_list::traits>
class cds::intrusive::MichaelList< gc::nogc, T, Traits >

Michael's lock-free ordered single-linked list (template specialization for gc::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 MichaelList for description of template parameters.

Member Function Documentation

template<typename T , class Traits = michael_list::traits>

iterator cds::intrusive::MichaelList< gc::nogc, T, Traits >::begin ( )

inline

Returns a forward iterator addressing the first element in a list.

For empty list

begin() == end() 

template<typename T , class Traits = michael_list::traits>

template<typename Disposer >

void cds::intrusive::MichaelList< gc::nogc, T, Traits >::clear ( Disposer  disp )

inline

Clears the list.

The function unlink all items from the list.

For each unlinked item the item disposer disp is called after unlinking.

template<typename T , class Traits = michael_list::traits>

void cds::intrusive::MichaelList< gc::nogc, T, Traits >::clear ( )

inline

Clears the list using default disposer.

The function clears the list using default (provided in class template) disposer functor.

template<typename T , class Traits = michael_list::traits>

template<typename Q >

value_type* cds::intrusive::MichaelList< gc::nogc, T, Traits >::contains ( Q const &  key )

inline

Checks whether the list contains key.

The function searches the item with key equal to key and returns true if it is found, and false otherwise.

template<typename T , class Traits = michael_list::traits>

template<typename Q , typename Less >

value_type* cds::intrusive::MichaelList< gc::nogc, T, Traits >::contains ( Q const &  key, Less  pred  )

inline

Checks whether the map contains key using pred predicate for searching.

The function is an analog of contains( key ) but pred is used for key comparing. Less functor has the interface like std::less. Less must imply the same element order as the comparator used for building the list.

template<typename T , class Traits = michael_list::traits>

iterator cds::intrusive::MichaelList< gc::nogc, T, Traits >::end ( )

inline

Returns an iterator that addresses the location succeeding the last element in a list.

Do not use the value returned by end function to access any item. Internally, end returning value equals to nullptr.

The returned value can be used only to control reaching the end of the list. For empty list

begin() == end() 

template<typename T , class Traits = michael_list::traits>

template<typename Q , typename Func >

bool cds::intrusive::MichaelList< gc::nogc, T, Traits >::find ( Q &  key, Func  f  )

inline

Finds the key val.

The function searches the item with key equal to key and calls the functor f for item found. The interface of Func functor is:

struct functor {
    void operator()( value_type& item, Q& key );
};

where item is the item found, key is the find function argument.

The functor can change non-key fields of item. The function find does not serialize simultaneous access to the list item. If such access is possible you must provide your own synchronization schema to exclude unsafe item modifications.

The function returns true if val is found, false otherwise.

template<typename T , class Traits = michael_list::traits>

template<typename Q , typename Less , typename Func >

bool cds::intrusive::MichaelList< gc::nogc, T, Traits >::find_with ( Q &  key, Less  pred, Func  f  )

inline

Finds the key key using pred predicate for searching.

The function is an analog of find(Q&, Func) but pred is used for key comparing. Less functor has the interface like std::less. pred must imply the same element order as the comparator used for building the list.

template<typename T , class Traits = michael_list::traits>

bool cds::intrusive::MichaelList< gc::nogc, T, Traits >::insert ( value_type &  val )

inline

Inserts new node.

The function inserts val in the list if the list does not contain an item with key equal to val.

Returns true if val is linked into the list, false otherwise.

template<typename T , class Traits = michael_list::traits>

size_t cds::intrusive::MichaelList< gc::nogc, T, Traits >::size ( ) const

inline

Returns list's item count.

The value returned depends on item counter provided by Traits. For 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 empty() method.

template<typename T , class Traits = michael_list::traits>

template<typename Func >

std::pair<bool, bool> cds::intrusive::MichaelList< gc::nogc, T, Traits >::update ( value_type &  val, Func  func, bool  bAllowInsert = true  )

inline

Updates the item.

The operation performs inserting or changing data with lock-free manner.

If the item val not found in the list, then val is inserted into the list iff bAllowInsert is true. Otherwise, the functor func is called with item found. The functor signature is:

struct functor {
    void operator()( bool bNew, value_type& item, value_type& val );
};

with arguments:

• bNew - true if the item has been inserted, false otherwise
• item - item of the list
• val - argument val passed into the update() function If new item has been inserted (i.e. bNew is true) then item and val arguments refer to the same thing.

The functor may change non-key fields of the item; however, func must guarantee that during changing no any other modifications could be made on this item by concurrent threads.

Returns std::pair<bool, bool> where first is true if operation is successful, second is true if new item has been added or false if the item with key already is in the list.

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The documentation for this class was generated from the following file:

• cds/intrusive/michael_list_nogc.h