Michael's ordered list (key-value pair) More...

#include <cds/container/michael_kvlist_impl.h>

Inheritance diagram for cds::container::MichaelKVList< GC, Key, Value, Traits >:

Public Types
typedef Key	key_type
	Key type.

typedef Value	mapped_type
	Type of value stored in the list.

typedef std::pair< key_type const, mapped_type >	value_type
	key/value pair stored in the list

typedef base_class::gc	gc
	Garbage collector used.

typedef base_class::back_off	back_off
	Back-off strategy used.

typedef options::allocator_type	allocator_type
	Allocator type used for allocate/deallocate the nodes.

typedef base_class::item_counter	item_counter
	Item counting policy used.

typedef options::key_comparator	key_comparator
	key comparision functor

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

typedef iterator_type< false >	iterator
	Forward iterator. More...

typedef iterator_type< true >	const_iterator
	Const forward iterator. More...

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...

	MichaelKVList ()
	Default constructor. More...

	~MichaelKVList ()
	List desctructor. More...

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

template<typename K , typename V >
bool	insert (const K &key, const V &val)
	Inserts new node with a key and a value. More...

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

template<typename K , typename Func >
std::pair< bool, bool >	ensure (const K &key, Func f)
	Ensures that the `key` exists in the list. More...

template<typename K , typename... Args>
bool	emplace (K &&key, Args &&...args)
	Inserts data of type mapped_type constructed with `std::forward<Args>(args)...` More...

template<typename K >
bool	erase (K const &key)
	Deletes `key` from the list. More...

template<typename K , typename Less >
bool	erase_with (K const &key, Less pred)
	Deletes the item from the list using `pred` predicate for searching. More...

template<typename K , typename Func >
bool	erase (K const &key, Func f)
	Deletes `key` from the list. More...

template<typename K , typename Less , typename Func >
bool	erase_with (K const &key, Less pred, Func f)
	Deletes the item from the list using `pred` predicate for searching. More...

template<typename Q >
bool	find (Q const &key)
	Finds the key `key`. More...

template<typename Q , typename Less >
bool	find_with (Q const &key, Less pred)
	Finds the key `val` using `pred` predicate for searching. More...

template<typename Q , typename Func >
bool	find (Q const &key, Func f)
	Finds the key `key` and performs an action with it. More...

template<typename Q , typename Less , typename Func >
bool	find_with (Q const &key, Less pred, Func f)
	Finds the key `val` using `pred` predicate for searching. More...

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

size_t	size () const
	Returns list's item count. More...

void	clear ()
	Clears the list. More...


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

const_iterator	cbegin ()


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

const_iterator	cend ()

Additional Inherited Members
Protected Types inherited from cds::intrusive::MichaelList< GC, implementation_defined, Traits >
typedef implementation_defined	value_type
	type of value stored in the list

typedef Traits	options
	Traits template parameter.

typedef options::hook	hook
	hook type

typedef hook::node_type	node_type
	node type

typedef implementation_defined	key_comparator
	key comparision functor based on opt::compare and opt::less option setter.

typedef options::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, options::link_checker >::type	link_checker
	link checker

typedef GC	gc
	Garbage collector.

typedef options::back_off	back_off
	back-off strategy

typedef options::item_counter	item_counter
	Item counting policy used.

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

typedef iterator_type< false >	iterator
	Forward iterator. More...

typedef iterator_type< true >	const_iterator
	Const forward iterator. More...

typedef node_type::atomic_marked_ptr	atomic_node_ptr
	Atomic node pointer.

typedef node_type::marked_ptr	marked_node_ptr
	Node marked pointer.

typedef atomic_node_ptr	auxiliary_head
	Auxiliary head type (for split-list support)

Protected Member Functions inherited from cds::intrusive::MichaelList< GC, implementation_defined, Traits >
iterator	begin ()
	Returns a forward iterator addressing the first element in a list. More...

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

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

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

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

const_iterator	cend ()
	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 object.

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

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

std::pair< bool, bool >	ensure (value_type &val, Func func)
	Ensures that the `item` exists in the list. More...

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

bool	erase (Q const &val)
	Deletes the item from the list. More...

bool	erase (Q const &val, Func func)
	Deletes the item from the list. More...

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

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

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

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

bool	find (Q const &val)
	Finds the key `val`. More...

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

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

bool	find_with (Q const &val, Less pred)
	Finds the key `val` using `pred` predicate for searching. More...

void	clear ()
	Clears the list. More...

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

size_t	size () const
	Returns list's item count. More...

Detailed Description

template<typename GC, typename Key, typename Value, typename Traits = michael_list::type_traits>
class cds::container::MichaelKVList< GC, Key, Value, Traits >

Michael's ordered list (key-value pair)

This is key-value variation of non-intrusive MichaelList. Like standard container, this implementation split a value stored into two part - constant key and alterable value.

Template arguments:

GC - garbage collector used
Key - key type of an item stored in the list. It should be copy-constructible
Value - value type stored in a list
Traits - type traits, default is michael_list::type_traits

It is possible to declare option-based list with cds::container::michael_list::make_traits metafunction istead of Traits template argument. For example, the following traits-based declaration of gc::HP Michael's list

#include <cds/container/michael_kvlist_hp.h>
// Declare comparator for the item
struct my_compare {
    int operator ()( int i1, int i2 )
    {
        return i1 - i2  ;
    }
};
// Declare type_traits
struct my_traits: public cds::container::michael_list::type_traits
{
    typedef my_compare compare ;
};
// Declare traits-based list
typedef cds::container::MichaelKVList< cds::gc::HP, int, int, my_traits >     traits_based_list   ;

is equivalent for the following option-based list

#include <cds/container/michael_kvlist_hp.h>
// my_compare is the same
// Declare option-based list
typedef cds::container::MichaelKVList< cds::gc::HP, int, int,
    typename cds::container::michael_list::make_traits<
        cds::container::opt::compare< my_compare >     // item comparator option
    >::type
>     option_based_list   ;

Template argument list Options of cds::container::michael_list::make_traits metafunction are:

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 comparision. Default is std::less<T>.
opt::back_off - back-off strategy used. If the option is not specified, the cds::backoff::empty is used.
opt::item_counter - the type of item counting feature. Default is atomicity::empty_item_counter that is no item counting.
opt::allocator - the allocator used for creating and freeing list's item. Default is CDS_DEFAULT_ALLOCATOR macro.
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).

Usage

There are different specializations of this template for each garbage collecting schema used. You should include appropriate .h-file depending on GC you are using:

for gc::HP:
#include <cds/container/michael_kvlist_hp.h>
for gc::PTB:
#include <cds/container/michael_kvlist_ptb.h>
for gc::HRC:
#include <cds/container/michael_kvlist_hrc.h>
for RCU:
#include <cds/container/michael_kvlist_rcu.h>
for gc::nogc:
#include <cds/container/michael_kvlist_nogc.h>

Member Typedef Documentation

template<typename GC , typename Key , typename Value , typename Traits = michael_list::type_traits>

typedef iterator_type<true> cds::container::MichaelKVList< GC, Key, Value, Traits >::const_iterator

Const forward iterator.

For iterator's features and requirements see iterator

template<typename GC , typename Key , typename Value , typename Traits = michael_list::type_traits>

typedef iterator_type<false> cds::container::MichaelKVList< GC, Key, Value, Traits >::iterator

Forward iterator.

The forward iterator for Michael's list has some features:

it has no post-increment operator
to protect the value, the iterator contains a GC-specific guard + another guard is required locally for increment operator. For some GC (gc::HP, gc::HRC), a guard is limited resource per thread, so an exception (or assertion) "no free guard" may be thrown if a limit of guard count per thread is exceeded.
The iterator cannot be moved across thread boundary since it contains GC's guard that is thread-private GC data.
Iterator ensures thread-safety even if you delete the item that iterator points to. However, in case of concurrent deleting operations it is no guarantee that you iterate all item in the list.

Therefore, the use of iterators in concurrent environment is not good idea. Use the iterator on the concurrent container for debug purpose only.

The iterator interface to access item data:

operator -> - returns a pointer to value_type for iterator
operator * - returns a reference (a const reference for const_iterator) to value_type for iterator
const key_type& key() - returns a key reference for iterator
mapped_type& val() - retuns a value reference for iterator (const reference for const_iterator)

For both functions the iterator should not be equal to end()

Constructor & Destructor Documentation

template<typename GC , typename Key , typename Value , typename Traits = michael_list::type_traits>

cds::container::MichaelKVList< GC, Key, Value, Traits >::MichaelKVList ( )

inline

Default constructor.

Initializes empty list

template<typename GC , typename Key , typename Value , typename Traits = michael_list::type_traits>

cds::container::MichaelKVList< GC, Key, Value, Traits >::~MichaelKVList ( )

inline

List desctructor.

Clears the list

Member Function Documentation

template<typename GC , typename Key , typename Value , typename Traits = michael_list::type_traits>

iterator cds::container::MichaelKVList< GC, Key, Value, Traits >::begin ( )

inline

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

For empty list

begin() == end()

template<typename GC , typename Key , typename Value , typename Traits = michael_list::type_traits>

void cds::container::MichaelKVList< GC, Key, Value, Traits >::clear ( )

inline

Clears the list.

Post-condition: the list is empty

template<typename GC , typename Key , typename Value , typename Traits = michael_list::type_traits>

template<typename K , typename... Args>

bool cds::container::MichaelKVList< GC, Key, Value, Traits >::emplace	(	K &&	key,
		Args &&...	args
	)

inline

Inserts data of type mapped_type constructed with std::forward<Args>(args)...

Returns true if inserting successful, false otherwise.

Note: This function is available only for compiler that supports variadic template and move semantics

template<typename GC , typename Key , typename Value , typename Traits = michael_list::type_traits>

iterator cds::container::MichaelKVList< GC, Key, Value, 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 NULL.

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

begin() == end()

template<typename GC , typename Key , typename Value , typename Traits = michael_list::type_traits>

template<typename K , typename Func >

std::pair<bool, bool> cds::container::MichaelKVList< GC, Key, Value, Traits >::ensure	(	const K &	key,
		Func	f
	)

inline

Ensures that the key exists in the list.

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

If the key not found in the list, then the new item created from key is inserted into the list (note that in this case the key_type should be copy-constructible from type K). Otherwise, the functor func is called with item found. The functor Func may be a function with signature:

void func( bool bNew, value_type& item ) ;

or a functor:

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

with arguments:

bNew - true if the item has been inserted, false otherwise
item - item of the list

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

You may pass func argument by reference using boost::ref.

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

template<typename GC , typename Key , typename Value , typename Traits = michael_list::type_traits>

template<typename K >

bool cds::container::MichaelKVList< GC, Key, Value, Traits >::erase ( K const & key )

inline

Deletes key from the list.

Returns true if key is found and has been deleted, false otherwise

template<typename GC , typename Key , typename Value , typename Traits = michael_list::type_traits>

template<typename K , typename Func >

bool cds::container::MichaelKVList< GC, Key, Value, Traits >::erase	(	K const &	key,
		Func	f
	)

inline

Deletes key from the list.

The function searches an item with key key, calls f functor and deletes the item. If key is not found, the functor is not called.

The functor Func interface:

struct extractor {
    void operator()(value_type& val) { ... }
};

The functor may be passed by reference with boost:ref

Return true if key is found and deleted, false otherwise

See also: erase

template<typename GC , typename Key , typename Value , typename Traits = michael_list::type_traits>

template<typename K , typename Less >

bool cds::container::MichaelKVList< GC, Key, Value, Traits >::erase_with	(	K const &	key,
		Less	pred
	)

inline

Deletes the item from the list using pred predicate for searching.

The function is an analog of erase(K const&) 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 GC , typename Key , typename Value , typename Traits = michael_list::type_traits>

template<typename K , typename Less , typename Func >

bool cds::container::MichaelKVList< GC, Key, Value, Traits >::erase_with	(	K const &	key,
		Less	pred,
		Func	f
	)

inline

Deletes the item from the list using pred predicate for searching.

The function is an analog of erase(K const&, 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 GC , typename Key , typename Value , typename Traits = michael_list::type_traits>

template<typename Q >

bool cds::container::MichaelKVList< GC, Key, Value, Traits >::find ( Q const & key )

inline

Finds the key key.

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

template<typename GC , typename Key , typename Value , typename Traits = michael_list::type_traits>

template<typename Q , typename Func >

bool cds::container::MichaelKVList< GC, Key, Value, Traits >::find	(	Q const &	key,
		Func	f
	)

inline

Finds the key key and performs an action with it.

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

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

where item is the item found.

You may pass f argument by reference using boost::ref or cds::ref.

The functor may change item.second that is reference to value of node. Note that the function is only guarantee that item cannot be deleted during functor is executing. The function 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 key is found, false otherwise.

template<typename GC , typename Key , typename Value , typename Traits = michael_list::type_traits>

template<typename Q , typename Less >

bool cds::container::MichaelKVList< GC, Key, Value, Traits >::find_with	(	Q const &	key,
		Less	pred
	)

inline

Finds the key val using pred predicate for searching.

The function is an analog of find(Q const&) 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 GC , typename Key , typename Value , typename Traits = michael_list::type_traits>

template<typename Q , typename Less , typename Func >

bool cds::container::MichaelKVList< GC, Key, Value, Traits >::find_with	(	Q const &	key,
		Less	pred,
		Func	f
	)

inline

Finds the key val 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 GC , typename Key , typename Value , typename Traits = michael_list::type_traits>

template<typename K >

bool cds::container::MichaelKVList< GC, Key, Value, Traits >::insert ( const K & 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 list.

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 true if inserting successful, false otherwise.

template<typename GC , typename Key , typename Value , typename Traits = michael_list::type_traits>

template<typename K , typename V >

bool cds::container::MichaelKVList< GC, Key, Value, Traits >::insert	(	const K &	key,
		const V &	val
	)

inline

Inserts new node with a key and a value.

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

Preconditions:

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

Returns true if inserting successful, false otherwise.

template<typename GC , typename Key , typename Value , typename Traits = michael_list::type_traits>

template<typename K , typename Func >

bool cds::container::MichaelKVList< GC, Key, Value, Traits >::insert_key	(	const K &	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 list'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 list's item by concurrent threads. The user-defined functor can be passed by reference using boost::ref and it is called only if inserting is successful.

The key_type should be constructible from value of type K.

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

create item from key;
insert new item into the list;
if inserting is successful, initialize the value of item by calling func 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.

template<typename GC , typename Key , typename Value , typename Traits = michael_list::type_traits>

size_t cds::container::MichaelKVList< GC, Key, Value, Traits >::size ( ) const

inline

Returns list's item count.

The value returned depends on opt::item_counter option. For atomicity::empty_item_counter, this function always returns 0.

Warning: 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 empty() method.

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

cds/container/michael_kvlist_impl.h

Public Types

Public Member Functions

Additional Inherited Members

Detailed Description

template<typename GC, typename Key, typename Value, typename Traits = michael_list::type_traits> class cds::container::MichaelKVList< GC, Key, Value, Traits >

Member Typedef Documentation

Constructor & Destructor Documentation

Member Function Documentation

template<typename GC, typename Key, typename Value, typename Traits = michael_list::type_traits>
class cds::container::MichaelKVList< GC, Key, Value, Traits >