Lock-free skip-list map (template specialization for gc::nogc) More...

#include <cds/container/skip_list_map_nogc.h>

Inheritance diagram for cds::container::SkipListMap< cds::gc::nogc, Key, T, Traits >:

Public Types
typedef cds::gc::nogc	gc
	Garbage collector.

typedef Key	key_type
	Key type.

typedef T	mapped_type
	Mapped type.

typedef std::pair< key_type const, mapped_type >	value_type
	Key-value pair stored in the map.

typedef Traits	traits
	Options specified.

typedef base_class::back_off	back_off
	Back-off strategy.

typedef base_class::allocator_type	allocator_type
	Allocator type used for allocate/deallocate the skip-list nodes.

typedef base_class::item_counter	item_counter
	Item counting policy.

typedef base_class::key_comparator	key_comparator
	key compare functor

typedef base_class::memory_model	memory_model
	Memory ordering, see `cds::opt::memory_model` option.

typedef base_class::stat	stat
	internal statistics type

typedef base_class::random_level_generator	random_level_generator
	random level generator

Public Member Functions
	SkipListMap ()
	Default constructor.

	~SkipListMap ()
	Destructor clears the map.

template<typename K >
iterator	insert (K const &key)
	Inserts new node with key and default value. More...

template<typename K , typename V >
iterator	insert (K const &key, V const &val)
	Inserts new node. More...

template<typename K , typename Func >
iterator	insert_with (K const &key, Func func)
	Inserts new node and initialize it by a functor. More...

template<typename K , typename... Args>
iterator	emplace (K &&key, Args &&...args)
	For key `key` inserts data of type `mapped_type` created in-place from `args`. More...

template<typename K >
std::pair< iterator, bool >	update (K const &key, bool bInsert=true)
	UPdates data by `key`. More...

template<typename K >
iterator	contains (K const &key)
	Checks whether the map contains `key`. More...

template<typename K , typename Less >
iterator	contains (K const &key, Less pred) const
	Checks whether the map contains `key` using `pred` predicate for searching. More...

value_type *	get_min () const
	Gets minimum key from the map. More...

value_type *	get_max () const
	Gets maximum key from the map. More...

void	clear ()
	Clears the map (not atomic) More...

bool	empty () const
	Checks if the map is empty. More...

size_t	size () const
	Returns item count in the map.

stat const &	statistics () const
	Returns const reference to internal statistics.

Static Public Member Functions
static constexpr unsigned int	max_height () noexcept
	Returns maximum height of skip-list. The max height is a constant for each object and does not exceed 32.

Forward ordered iterators
typedef base_class::iterator	iterator
	Forward iterator. More...

typedef base_class::const_iterator	const_iterator
	Const forward iterator.

iterator	begin ()
	Returns a forward iterator addressing the first element in a map. More...

iterator	end ()
	Returns an iterator that addresses the location succeeding the last element in a map. More...

const_iterator	begin () const
	Returns a forward const iterator addressing the first element in a map.

const_iterator	cbegin () const
	Returns a forward const iterator addressing the first element in a map.

const_iterator	end () const
	Returns an const iterator that addresses the location succeeding the last element in a map.

const_iterator	cend () const
	Returns an const iterator that addresses the location succeeding the last element in a map.

Additional Inherited Members
Protected Types inherited from cds::container::SkipListSet< cds::gc::nogc, std::pair< Key const, T >, Traits >
typedef cds::gc::nogc	gc
	Garbage collector used.

typedef std::pair< Key const, T >	value_type

typedef Traits	traits
	Options specified.

typedef base_class::back_off	back_off
	Back-off strategy.

typedef traits::allocator	allocator_type
	Allocator type used for allocate/deallocate the skip-list nodes.

typedef base_class::item_counter	item_counter
	Item counting policy used.

typedef maker::key_comparator	key_comparator
	key comparison functor

typedef base_class::memory_model	memory_model
	Memory ordering. See cds::opt::memory_model option.

typedef traits::random_level_generator	random_level_generator
	random level generator

typedef traits::stat	stat
	internal statistics type

typedef gc::template guarded_ptr< node_type, value_type, details::guarded_ptr_cast_set< node_type, value_type > >	guarded_ptr
	Guarded pointer.

typedef skip_list::details::iterator< typename base_class::iterator >	iterator
	Iterator type. More...

typedef skip_list::details::iterator< typename base_class::const_iterator >	const_iterator
	Const iterator type.

Protected Types inherited from cds::intrusive::SkipListSet< cds::gc::nogc, std::pair< Key const, T >, Traits >
typedef node_type::atomic_marked_ptr	atomic_node_ptr
	Atomic marked node pointer.

typedef node_type::marked_ptr	marked_node_ptr
	Node marked pointer.

typedef cds::gc::nogc	gc
	Garbage collector.

typedef std::pair< Key const, T >	value_type
	type of value stored in the skip-list

typedef Traits	traits
	Traits template parameter.

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
	item disposer

typedef get_node_traits< value_type, node_type, hook >::type	node_traits
	node traits

typedef traits::item_counter	item_counter
	Item counting policy.

typedef traits::memory_model	memory_model
	Memory ordering, see `cds::opt::memory_model` option.

typedef traits::random_level_generator	random_level_generator
	random level generator

typedef traits::allocator	allocator_type
	allocator for maintaining array of next pointers of the node

typedef traits::back_off	back_off
	Back-off strategy.

typedef traits::stat	stat
	internal statistics type

typedef gc::template guarded_ptr< value_type >	guarded_ptr
	Guarded pointer.

typedef skip_list::details::iterator< gc, node_traits, back_off, false >	iterator
	Iterator type. More...

typedef skip_list::details::iterator< gc, node_traits, back_off, true >	const_iterator
	Const iterator type.

Protected Member Functions inherited from cds::container::SkipListSet< cds::gc::nogc, std::pair< Key const, T >, Traits >
	SkipListSet ()
	Default ctor.

	~SkipListSet ()
	Destructor destroys the set object.

bool	insert (Q const &val)
	Inserts new node. More...

bool	insert (Q const &val, Func f)
	Inserts new node. More...

std::pair< bool, bool >	update (const Q &val, Func func, bool bInsert=true)
	Updates the item. More...

bool	emplace (Args &&...args)
	Inserts data of type `value_type` created in-place from `std::forward<Args>(args)...` More...

bool	erase (Q const &key)
	Delete `key` from the set. More...

bool	erase (Q const &key, Func f)
	Delete `key` from the set. More...

bool	erase_with (Q const &key, Less pred)
	Deletes the item from the set using `pred` predicate for searching. More...

bool	erase_with (Q const &key, Less pred, Func f)
	Deletes the item from the set using `pred` predicate for searching. More...

guarded_ptr	extract (Q const &key)
	Extracts the item from the set with specified `key`. More...

guarded_ptr	extract_with (Q const &key, Less pred)
	Extracts the item from the set with comparing functor `pred`. More...

guarded_ptr	extract_min ()
	Extracts an item with minimal key from the set. More...

guarded_ptr	extract_max ()
	Extracts an item with maximal key from the set. More...

bool	find (Q &key, Func f)
	Find the `key`. More...

bool	find_with (Q &key, Less pred, Func f)
	Finds `key` using `pred` predicate for searching. More...

bool	contains (Q const &key)
	Checks whether the set contains `key`. More...

bool	contains (Q const &key, Less pred)
	Checks whether the set contains `key` using `pred` predicate for searching. More...

guarded_ptr	get (Q const &key)
	Finds `key` and return the item found. More...

guarded_ptr	get_with (Q const &key, Less pred)
	Finds `key` and return the item found. More...

void	clear ()
	Clears the set (not atomic). More...

bool	empty () const
	Checks if the set is empty.

size_t	size () const
	Returns item count in the set. More...

stat const &	statistics () const
	Returns const reference to internal statistics.

iterator	begin ()
	Returns a forward iterator addressing the first element in a set.

const_iterator	begin () const
	Returns a forward const iterator addressing the first element in a set.

const_iterator	cbegin () const
	Returns a forward const iterator addressing the first element in a set.

iterator	end ()
	Returns a forward iterator that addresses the location succeeding the last element in a set.

const_iterator	end () const
	Returns a forward const iterator that addresses the location succeeding the last element in a set.

const_iterator	cend () const
	Returns a forward const iterator that addresses the location succeeding the last element in a set.

Protected Member Functions inherited from cds::intrusive::SkipListSet< cds::gc::nogc, std::pair< Key const, T >, Traits >
	SkipListSet ()
	Default constructor. More...

	~SkipListSet ()
	Clears and destructs the skip-list.

bool	insert (value_type &val)
	Inserts new node. More...

bool	insert (value_type &val, Func f)
	Inserts new node. More...

std::pair< bool, bool >	update (value_type &val, Func func, bool bInsert=true)
	Updates the node. More...

bool	unlink (value_type &val)
	Unlinks the item `val` from the set. More...

guarded_ptr	extract (Q const &key)
	Extracts the item from the set with specified `key`. More...

guarded_ptr	extract_with (Q const &key, Less pred)
	Extracts the item from the set with comparing functor `pred`. More...

guarded_ptr	extract_min ()
	Extracts an item with minimal key from the list. More...

guarded_ptr	extract_max ()
	Extracts an item with maximal key from the list. More...

bool	erase (Q const &key)
	Deletes the item from the set. More...

bool	erase (Q const &key, Func f)
	Deletes the item from the set. More...

bool	erase_with (Q const &key, Less pred)
	Deletes the item from the set with comparing functor `pred`. More...

bool	erase_with (Q const &key, Less pred, Func f)
	Deletes the item from the set with comparing functor `pred`. More...

bool	find (Q &key, Func f)
	Finds `key`. More...

bool	find_with (Q &key, Less pred, Func f)
	Finds the key `key` with `pred` predicate for comparing. More...

bool	contains (Q const &key)
	Checks whether the set contains `key`. More...

bool	contains (Q const &key, Less pred)
	Checks whether the set contains `key` using `pred` predicate for searching. More...

guarded_ptr	get (Q const &key)
	Finds `key` and return the item found. More...

guarded_ptr	get_with (Q const &key, Less pred)
	Finds `key` and return the item found. More...

size_t	size () const
	Returns item count in the set. More...

bool	empty () const
	Checks if the set is empty.

void	clear ()
	Clears the set (not atomic) More...

stat const &	statistics () const
	Returns const reference to internal statistics.

iterator	begin ()
	Returns a forward iterator addressing the first element in a set.

const_iterator	begin () const
	Returns a forward const iterator addressing the first element in a set.

const_iterator	cbegin () const
	Returns a forward const iterator addressing the first element in a set.

iterator	end ()
	Returns a forward iterator that addresses the location succeeding the last element in a set.

const_iterator	end () const
	Returns a forward const iterator that addresses the location succeeding the last element in a set.

const_iterator	cend () const
	Returns a forward const iterator that addresses the location succeeding the last element in a set.

Static Protected Member Functions inherited from cds::intrusive::SkipListSet< cds::gc::nogc, std::pair< Key const, T >, Traits >
static constexpr unsigned int	max_height () noexcept
	Returns maximum height of skip-list. The max height is a constant for each object and does not exceed 32.

Static Protected Attributes inherited from cds::container::SkipListSet< cds::gc::nogc, std::pair< Key const, T >, Traits >
static size_t const	c_nHazardPtrCount
	Count of hazard pointer required for the skip-list.

Static Protected Attributes inherited from cds::intrusive::SkipListSet< cds::gc::nogc, std::pair< Key const, T >, Traits >
static unsigned int const	c_nMaxHeight
	Max node height. The actual node height should be in range `[0 .. c_nMaxHeight)` More...

static size_t const	c_nHazardPtrCount
	Count of hazard pointer required for the skip-list.

Detailed Description

template<typename Key, typename T, typename Traits = skip_list::traits>
class cds::container::SkipListMap< cds::gc::nogc, Key, T, Traits >

Lock-free skip-list map (template specialization for gc::nogc)

This specialization is intended for so-called persistent usage when no item reclamation may be performed. The class does not support deleting of map item. See SkipListMap for detailed description.

Template arguments:

K - type of a key to be stored in the map.
T - type of a value to be stored in the map.
Traits - map traits, default is skip_list::traits It is possible to declare option-based list with cds::container::skip_list::make_traits metafunction istead of Traits template argument.

Member Typedef Documentation

template<typename Key , typename T , typename Traits = skip_list::traits>

typedef base_class::iterator cds::container::SkipListMap< cds::gc::nogc, Key, T, Traits >::iterator

Forward iterator.

The forward iterator for a split-list has some features:

it has no post-increment operator
it depends on iterator of underlying OrderedList

Member Function Documentation

template<typename Key , typename T , typename Traits = skip_list::traits>

iterator cds::container::SkipListMap< cds::gc::nogc, Key, T, Traits >::begin ( )

inline

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

For empty set

begin() == end()

template<typename Key , typename T , typename Traits = skip_list::traits>

void cds::container::SkipListMap< cds::gc::nogc, Key, T, Traits >::clear ( )

inline

Clears the map (not atomic)

Finding and/or inserting is prohibited while clearing. Otherwise an unpredictable result may be encountered. Thus, clear() may be used only for debugging purposes.

template<typename Key , typename T , typename Traits = skip_list::traits>

template<typename K >

iterator cds::container::SkipListMap< cds::gc::nogc, Key, T, Traits >::contains ( K const & key )

inline

Checks whether the map contains key.

The function searches the item with key equal to key and returns an iterator pointed to item found if the key is found, and end() otherwise

template<typename Key , typename T , typename Traits = skip_list::traits>

template<typename K , typename Less >

iterator cds::container::SkipListMap< cds::gc::nogc, Key, T, Traits >::contains	(	K const &	key,
		Less	pred
	)		const

inline

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

The function is similar to 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 map.

template<typename Key , typename T , typename Traits = skip_list::traits>

template<typename K , typename... Args>

iterator cds::container::SkipListMap< cds::gc::nogc, Key, T, Traits >::emplace	(	K &&	key,
		Args &&...	args
	)

inline

For key key inserts data of type mapped_type created in-place from args.

key_type should be constructible from type K

Returns true if inserting successful, false otherwise.

template<typename Key , typename T , typename Traits = skip_list::traits>

bool cds::container::SkipListMap< cds::gc::nogc, Key, T, Traits >::empty ( ) const

inline

Checks if the map is empty.

Emptiness is checked by item counting: if item count is zero then the map is empty. Thus, the correct item counting feature is an important part of Michael's map implementation.

template<typename Key , typename T , typename Traits = skip_list::traits>

iterator cds::container::SkipListMap< cds::gc::nogc, Key, T, Traits >::end ( )

inline

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

Do not use the value returned by end function to access any item. The returned value can be used only to control reaching the end of the set. For empty set

begin() == end()

template<typename Key , typename T , typename Traits = skip_list::traits>

value_type* cds::container::SkipListMap< cds::gc::nogc, Key, T, Traits >::get_max ( ) const

inline

Gets maximum key from the map.

The function returns nullptr if the map is empty

template<typename Key , typename T , typename Traits = skip_list::traits>

value_type* cds::container::SkipListMap< cds::gc::nogc, Key, T, Traits >::get_min ( ) const

inline

Gets minimum key from the map.

If the map is empty the function returns nullptr

template<typename Key , typename T , typename Traits = skip_list::traits>

template<typename K >

iterator cds::container::SkipListMap< cds::gc::nogc, Key, T, Traits >::insert ( K const & key )

inline

Inserts new node with key and default value.

The function creates a node with key and default value, and then inserts the node created into the map.

Preconditions:

The key_type should be constructible from value of type K. In trivial case, K is equal to key_type.
The mapped_type should be default-constructible.

Returns an iterator pointed to inserted value, or end() if inserting is failed

template<typename Key , typename T , typename Traits = skip_list::traits>

template<typename K , typename V >

iterator cds::container::SkipListMap< cds::gc::nogc, Key, T, Traits >::insert	(	K const &	key,
		V const &	val
	)

inline

Inserts new node.

The function creates a node with copy of val value and then inserts the node created into the map.

Preconditions:

The key_type should be constructible from key of type K.
The mapped_type should be constructible from val of type V.

Returns an iterator pointed to inserted value, or end() if inserting is failed

template<typename Key , typename T , typename Traits = skip_list::traits>

template<typename K , typename Func >

iterator cds::container::SkipListMap< cds::gc::nogc, Key, T, Traits >::insert_with	(	K const &	key,
		Func	func
	)

inline

Inserts new node and initialize it by a functor.

This function inserts new node with key key and if inserting is successful then it calls func functor with signature

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

The argument item of user-defined functor func is the reference to the map's item inserted. item.second is a reference to item's value that may be changed. User-defined functor func should guarantee that during changing item's value no any other changes could be made on this map's item by concurrent threads.

The key_type should be constructible from value of type K.

The function allows to split creating of new item into three part:

create item from key;
insert new item into the map;
if inserting is successful, initialize the value of item by calling f functor

This can be useful if complete initialization of object of mapped_type is heavyweight and it is preferable that the initialization should be completed only if inserting is successful.

Returns an iterator pointed to inserted value, or end() if inserting is failed

template<typename Key , typename T , typename Traits = skip_list::traits>

template<typename K >

std::pair<iterator, bool> cds::container::SkipListMap< cds::gc::nogc, Key, T, Traits >::update	(	K const &	key,
		bool	bInsert = `true`
	)

inline

UPdates data by key.

The operation inserts new item if key is not found in the map and bInsert is true. Otherwise, if key is found, the function returns an iterator that points to item found.

Returns std::pair<iterator, bool> where first is an iterator pointing to item found or inserted or end() if key is not found and insertion is not allowed (bInsert is false), second is true if new item has been added or false if the item already exists.

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

cds/container/skip_list_map_nogc.h

Public Types

Public Member Functions

Static Public Member Functions

Forward ordered iterators

Additional Inherited Members

Detailed Description

template<typename Key, typename T, typename Traits = skip_list::traits> class cds::container::SkipListMap< cds::gc::nogc, Key, T, Traits >

Member Typedef Documentation

Member Function Documentation

template<typename Key, typename T, typename Traits = skip_list::traits>
class cds::container::SkipListMap< cds::gc::nogc, Key, T, Traits >