Split-ordered list map (template specialization for RCU) More...

#include <cds/container/split_list_map_rcu.h>

Inheritance diagram for cds::container::SplitListMap< cds::urcu::gc< RCU >, Key, Value, Traits >:

Public Types
typedef cds::urcu::gc< RCU >	gc
	Garbage collector.

typedef Key	key_type
	key type

typedef Value	mapped_type
	type of value to be stored in the map

typedef Traits	traits
	Map traits.

typedef std::pair< key_type const, mapped_type >	value_type
	key-value pair type

typedef base_class::ordered_list	ordered_list
	Underlying ordered list class.

typedef base_class::key_comparator	key_comparator
	key comparison functor

typedef base_class::hash	hash
	Hash functor for key_type.

typedef base_class::item_counter	item_counter
	Item counter type.

typedef base_class::stat	stat
	Internal statistics.

typedef base_class::rcu_lock	rcu_lock
	RCU scoped lock.

typedef base_class::exempt_ptr	exempt_ptr

typedef base_class::raw_ptr	raw_ptr
	type of `get()` return value

typedef base_class::iterator	iterator
	Forward iterator.

typedef base_class::const_iterator	const_iterator
	Const forward iterator.

Public Member Functions
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...

	SplitListMap ()
	Initializes split-ordered map of default capacity. More...

	SplitListMap (size_t nItemCount, size_t nLoadFactor=1)
	Initializes split-ordered map. More...

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

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

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

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

template<typename K , typename Func >
std::pair< bool, bool >	update (K const &key, Func func, bool bAllowInsert=true)
	Updates data by `key`. More...

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

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

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

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

template<typename K >
exempt_ptr	extract (K const &key)
	Extracts an item from the map. More...

template<typename K , typename Less >
exempt_ptr	extract_with (K const &key, Less pred)
	Extracts an item from the map using `pred` predicate for searching. More...

template<typename K , typename Func >
bool	find (K const &key, Func f)
	Finds the key `key`. More...

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

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

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

template<typename K >
raw_ptr	get (K const &key)
	Finds `key` and return the item found. More...

template<typename K , typename Less >
raw_ptr	get_with (K const &key, Less pred)
	Finds `key` with predicate specified and return the item found. More...

void	clear ()
	Clears the map (not atomic)

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 internal statistics.

ordered_list::stat const &	list_statistics () const
	Returns internal statistics for `ordered_list`.


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

const_iterator	cbegin () const


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

const_iterator	cend () const

Static Public Attributes
static constexpr const bool	c_bExtractLockExternal = base_class::c_bExtractLockExternal
	Group of `extract_xxx` functions require external locking if underlying ordered list requires that.

Additional Inherited Members
Protected Types inherited from cds::container::SplitListSet< cds::urcu::gc< RCU >, std::pair< Key const, Value >, split_list::details::wrap_map_traits< Key, Value, Traits > >
typedef cds::urcu::gc< RCU >	gc
	Garbage collector.

typedef std::pair< Key const, Value >	value_type
	Type of vlue to be stored in split-list.

typedef split_list::details::wrap_map_traits< Key, Value, Traits >	traits
	`Traits` template argument

typedef maker::ordered_list	ordered_list
	Underlying ordered list class.

typedef base_class::key_comparator	key_comparator
	key compare functor

typedef base_class::hash	hash
	Hash functor for `value_type` and all its derivatives that you use.

typedef base_class::item_counter	item_counter
	Item counter type.

typedef base_class::stat	stat
	Internal statistics.

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

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

typedef iterator_type< true >	const_iterator
	Const forward iterator.

Protected Types inherited from cds::intrusive::SplitListSet< cds::urcu::gc< RCU >, split_list::details::wrap_map_traits< Key, Value, Traits >::ordered_list, split_list::details::wrap_map_traits< Key, Value, Traits > >
typedef cds::urcu::gc< RCU >	gc
	Garbage collector.

typedef split_list::details::wrap_map_traits< Key, Value, Traits >	traits
	Set traits.

typedef split_list::details::wrap_map_traits< Key, Value, Traits >::ordered_list	ordered_list
	type of ordered list used as a base for split-list

typedef ordered_list::value_type	value_type
	type of value stored in the split-list

typedef ordered_list::key_comparator	key_comparator
	key comparison functor

typedef ordered_list::disposer	disposer
	Node disposer functor.

typedef cds::opt::v::hash_selector< typename traits::hash >::type	hash
	Hash functor for `value_type` and all its derivatives you use.

typedef traits::bit_reversal	bit_reversal
	Bit reversal algorithm, see `split_list::traits::bit_reversal`.

typedef traits::item_counter	item_counter
	Item counter type.

typedef traits::back_off	back_off
	back-off strategy for spinning

typedef traits::memory_model	memory_model
	Memory ordering. See `cds::opt::memory_model` option.

typedef traits::stat	stat
	Internal statistics, see `spit_list::stat`.

typedef ordered_list::guarded_ptr	guarded_ptr
	Guarded pointer.

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

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

Protected Member Functions inherited from cds::container::SplitListSet< cds::urcu::gc< RCU >, std::pair< Key const, Value >, split_list::details::wrap_map_traits< Key, Value, Traits > >
	SplitListSet ()
	Initializes split-ordered list of default capacity. More...

	SplitListSet (size_t nItemCount, size_t nLoadFactor=1)
	Initializes split-ordered list. More...

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

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

bool	emplace (Args &&...args)
	Inserts data of type `value_type` created from `args`. More...

std::pair< bool, bool >	upsert (Q &&val, bool bAllowInsert=true)
	Inserts or updates the node (only for `IterableList` -based set) More...

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

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

bool	erase (Q const &key, Func f)
	Deletes `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...

bool	erase_at (iterator const &iter)
	Deletes the item pointed by iterator `iter` (only for `IterableList` based set) More...

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

guarded_ptr	extract_with (Q const &key, Less pred)
	Extracts the item using compare functor `pred`. More...

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

iterator	find (Q &key)
	Finds `key` and returns iterator pointed to the item found (only for `IterableList` -based set) More...

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

iterator	find_with (Q &key, Less pred)
	Finds `key` using `pred` predicate and returns iterator pointed to the item found (only for `IterableList` -based set) More...

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

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

guarded_ptr	get (Q const &key)
	Finds the key `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)

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

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

stat const &	statistics () const
	Returns internal statistics.

ordered_list::stat const &	list_statistics () const
	Returns internal statistics for `ordered_list`.

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

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

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

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

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

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

Protected Member Functions inherited from cds::intrusive::SplitListSet< cds::urcu::gc< RCU >, split_list::details::wrap_map_traits< Key, Value, Traits >::ordered_list, split_list::details::wrap_map_traits< Key, Value, Traits > >
	SplitListSet ()
	Initialize split-ordered list of default capacity. More...

	SplitListSet (size_t nItemCount, size_t nLoadFactor=1)
	Initialize split-ordered list. More...

	~SplitListSet ()
	Destroys split-list set.

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 bAllowInsert=true)
	Updates the node. More...

std::pair< bool, bool >	upsert (value_type &val, bool bAllowInsert=true)
	Inserts or updates the node (only for `IterableList`) More...

bool	unlink (value_type &val)
	Unlinks the item `val` from the set. 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 (const Q &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	erase_at (iterator const &iter)
	Deletes the item pointed by iterator `iter` (only for `IterableList` based set) More...

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

guarded_ptr	extract_with (Q const &key, Less pred)
	Extracts the item using compare functor `pred`. More...

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

iterator	find (Q &key)
	Finds `key` and returns iterator pointed to the item found (only for `IterableList`) More...

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

iterator	find_with (Q &key, Less pred)
	Finds `key` using `pred` predicate and returns iterator pointed to the item found (only for `IterableList`) 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 the key `key` and return the item found. More...

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

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

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

void	clear ()
	Clears the set (non-atomic) More...

stat const &	statistics () const
	Returns internal statistics.

split_list::details::wrap_map_traits< Key, Value, Traits >::ordered_list::stat const &	list_statistics () const
	Returns internal statistics for `OrderedList`.

iterator	begin ()
	Returns a forward iterator addressing the first element in a split-list. More...

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

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

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

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

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

Static Protected Attributes inherited from cds::container::SplitListSet< cds::urcu::gc< RCU >, std::pair< Key const, Value >, split_list::details::wrap_map_traits< Key, Value, Traits > >
static constexpr const size_t	c_nHazardPtrCount
	Count of hazard pointer required.

Static Protected Attributes inherited from cds::intrusive::SplitListSet< cds::urcu::gc< RCU >, split_list::details::wrap_map_traits< Key, Value, Traits >::ordered_list, split_list::details::wrap_map_traits< Key, Value, Traits > >
static constexpr const size_t	c_nHazardPtrCount
	Count of hazard pointer required.

Detailed Description

template<class RCU, typename Key, typename Value, class Traits = split_list::traits>
class cds::container::SplitListMap< cds::urcu::gc< RCU >, Key, Value, Traits >

Split-ordered list map (template specialization for RCU)

Hash table implementation based on split-ordered list algorithm discovered by Ori Shalev and Nir Shavit, see

[2003] Ori Shalev, Nir Shavit "Split-Ordered Lists - Lock-free Resizable Hash Tables"
[2008] Nir Shavit "The Art of Multiprocessor Programming"

See intrusive::SplitListSet for a brief description of the split-list algorithm.

Template parameters:

RCU - one of RCU type
Key - key type to be stored in the map
Value - value type to be stored in the map
Traits - type traits, default is split_list::traits. Instead of declaring split_list::traits -based struct you may apply option-based notation with split_list::make_traits metafunction.

Iterators

The class supports a forward unordered iterator (iterator and const_iterator). You may iterate over split-list map items only under RCU lock. Only in this case the iterator is thread-safe since while RCU is locked any map's item cannot be reclaimed. The requirement of RCU lock during iterating means that deletion of the elements is not possible.

Warning: The iterator object cannot be passed between threads. Due to concurrent nature of split-list map it is not guarantee that you can iterate all elements in the map: any concurrent deletion can exclude the element pointed by the iterator from the map, and your iteration can be terminated before end of the map. Therefore, such iteration is more suitable for debugging purposes

The iterator class supports the following minimalistic interface:

struct iterator {
    // Default ctor
    iterator();
    // Copy ctor
    iterator( iterator const& s);
    value_type * operator ->() const;
    value_type& operator *() const;
    // Pre-increment
    iterator& operator ++();
    // Copy assignment
    iterator& operator = (const iterator& src);
    bool operator ==(iterator const& i ) const;
    bool operator !=(iterator const& i ) const;
};

Note, the iterator object returned by end, cend member functions points to nullptr and should not be dereferenced.

Usage

You should decide what garbage collector you want, and what ordered list you want to use. Split-ordered list is original data structure based on an ordered list. Suppose, you want construct split-list map based on cds::urcu::general_buffered<> GC and MichaelList as ordered list implementation. Your map should map int key to std::string value. So, you beginning your program with following include:

#include <cds/urcu/general_buffered.h>
#include <cds/container/michael_list_rcu.h>
#include <cds/container/split_list_map_rcu.h>
namespace cc = cds::container;

The inclusion order is important:

first, include one of RCU implementation (cds/urcu/general_buffered.h in our case)
second, include the header of ordered-list implementation (for this example, cds/container/michael_list_rcu.h),
then, the header for RCU-based split-list map cds/container/split_list_map_rcu.h.

Now, you should declare traits for split-list map. The main parts of traits are a hash functor for the map key and a comparing functor for ordered list. We use std::hash<int> and std::less<int>.

The second attention: instead of using MichaelList in SplitListMap traits we use a tag ds::contaner::michael_list_tag for the Michael's list. The split-list requires significant support from underlying ordered list class and it is not good idea to dive you into deep implementation details of split-list and ordered list interrelations. The tag paradigm simplifies split-list interface.

// SplitListMap traits
struct foo_set_traits: public cc::split_list::traits
{
    typedef cc::michael_list_tag   ordered_list    ;   // what type of ordered list we want to use
    typedef std::hash<int>         hash            ;   // hash functor for the key stored in split-list map
    // Type traits for our MichaelList class
    struct ordered_list_traits: public cc::michael_list::traits
    {
        typedef std::less<int> less   ;   // use our std::less predicate as comparator to order list nodes
    };
};

Now you are ready to declare our map class based on SplitListMap:

typedef cc::SplitListMap< cds::urcu::gc<cds::urcu::general_buffered<> >, int, std::string, foo_set_traits > int_string_map;

You may use the modern option-based declaration instead of classic traits-based one:

typedef cc::SplitListMap<
    cds::urcu::gc<cds::urcu::general_buffered<> >  // RCU type
    ,int                    // key type
    ,std::string            // value type
    ,cc::split_list::make_traits<      // metafunction to build split-list traits
        cc::split_list::ordered_list<cc::michael_list_tag>     // tag for underlying ordered list implementation
        ,cc::opt::hash< std::hash<int> >        // hash functor
        ,cc::split_list::ordered_list_traits<    // ordered list traits desired
            cc::michael_list::make_traits<    // metafunction to build lazy list traits
                cc::opt::less< std::less<int> >         // less-based compare functor
            >::type
        >
    >::type
>  int_string_map;

In case of option-based declaration using split_list::make_traits metafunction the struct foo_set_traits is not required.

Now, the map of type int_string_map is ready to use in your program.

Note that in this example we show only mandatory traits parts, optional ones is the default and they are inherited from cds::container::split_list::traits. There are many other useful options for deep tuning the split-list and ordered-list containers.

Member Typedef Documentation

template<class RCU , typename Key , typename Value , class Traits = split_list::traits>

typedef base_class::exempt_ptr cds::container::SplitListMap< cds::urcu::gc< RCU >, Key, Value, Traits >::exempt_ptr

pointer to extracted node

Constructor & Destructor Documentation

template<class RCU , typename Key , typename Value , class Traits = split_list::traits>

cds::container::SplitListMap< cds::urcu::gc< RCU >, Key, Value, Traits >::SplitListMap ( )

inline

Initializes split-ordered map of default capacity.

The default capacity is defined in bucket table constructor. See intrusive::split_list::expandable_bucket_table, intrusive::split_list::static_bucket_table which selects by split_list::dynamic_bucket_table option.

template<class RCU , typename Key , typename Value , class Traits = split_list::traits>

cds::container::SplitListMap< cds::urcu::gc< RCU >, Key, Value, Traits >::SplitListMap	(	size_t	nItemCount,
		size_t	nLoadFactor = `1`
	)

inline

Initializes split-ordered map.

Parameters

nItemCount	estimated average item count
nLoadFactor	load factor - average item count per bucket. Small integer up to 10, default is 1.

Member Function Documentation

template<class RCU , typename Key , typename Value , class Traits = split_list::traits>

iterator cds::container::SplitListMap< cds::urcu::gc< RCU >, Key, Value, Traits >::begin ( )

inline

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

For empty map

begin() == end()

template<class RCU , typename Key , typename Value , class Traits = split_list::traits>

template<typename K >

bool cds::container::SplitListMap< cds::urcu::gc< RCU >, Key, Value, Traits >::contains ( K const & key )

inline

Checks whether the map contains key.

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

The function applies RCU lock internally.

template<class RCU , typename Key , typename Value , class Traits = split_list::traits>

template<typename K , typename Less >

bool cds::container::SplitListMap< cds::urcu::gc< RCU >, Key, Value, Traits >::contains	(	K 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 map.

template<class RCU , typename Key , typename Value , class Traits = split_list::traits>

template<typename K , typename... Args>

bool cds::container::SplitListMap< cds::urcu::gc< RCU >, Key, Value, 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

The function applies RCU lock internally.

Returns true if inserting successful, false otherwise.

template<class RCU , typename Key , typename Value , class Traits = split_list::traits>

bool cds::container::SplitListMap< cds::urcu::gc< RCU >, Key, Value, 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 is an important part of the map implementation.

template<class RCU , typename Key , typename Value , class Traits = split_list::traits>

iterator cds::container::SplitListMap< cds::urcu::gc< RCU >, Key, Value, 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 map. For empty map

begin() == end()

template<class RCU , typename Key , typename Value , class Traits = split_list::traits>

template<typename K >

bool cds::container::SplitListMap< cds::urcu::gc< RCU >, Key, Value, Traits >::erase ( K const & key )

inline

Deletes key from the map.

RCU synchronize method can be called. RCU should not be locked.

Return true if key is found and deleted, false otherwise

template<class RCU , typename Key , typename Value , class Traits = split_list::traits>

template<typename K , typename Func >

bool cds::container::SplitListMap< cds::urcu::gc< RCU >, Key, Value, Traits >::erase	(	K const &	key,
		Func	f
	)

inline

Deletes key from the map.

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 is:

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

RCU synchronize method can be called. RCU should not be locked.

Return true if key is found and deleted, false otherwise

template<class RCU , typename Key , typename Value , class Traits = split_list::traits>

template<typename K , typename Less >

bool cds::container::SplitListMap< cds::urcu::gc< RCU >, Key, Value, Traits >::erase_with	(	K const &	key,
		Less	pred
	)

inline

Deletes the item from the map 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. Less must imply the same element order as the comparator used for building the map.

template<class RCU , typename Key , typename Value , class Traits = split_list::traits>

template<typename K , typename Less , typename Func >

bool cds::container::SplitListMap< cds::urcu::gc< RCU >, Key, Value, Traits >::erase_with	(	K const &	key,
		Less	pred,
		Func	f
	)

inline

Deletes the item from the map 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. Less must imply the same element order as the comparator used for building the map.

template<class RCU , typename Key , typename Value , class Traits = split_list::traits>

template<typename K >

exempt_ptr cds::container::SplitListMap< cds::urcu::gc< RCU >, Key, Value, Traits >::extract ( K const & key )

inline

Extracts an item from the map.

The function searches an item with key equal to key in the map, unlinks it from the map, and returns exempt_ptr pointer to the item found. If the item with the key equal to key is not found the function returns an empty exempt_ptr.

Depends on ordered list you should or should not lock RCU before calling of this function:

for the set based on MichaelList RCU should not be locked
for the set based on LazyList RCU should be locked See ordered list implementation for details.

typedef cds::urcu::gc< general_buffered<> > rcu;
// Split-list set based on MichaelList by default
typedef cds::container::SplitListMap< rcu, int, Foo > splitlist_map;
splitlist_map theMap;
// ...
typename splitlist_map::exempt_ptr p;
// For MichaelList we should not lock RCU
// Now, you can apply extract function
p = theMap.extract( 10 )
if ( p ) {
    // do something with p
    ...
}
// We may safely release p here
// release() passes the pointer to RCU reclamation cycle
p.release();

template<class RCU , typename Key , typename Value , class Traits = split_list::traits>

template<typename K , typename Less >

exempt_ptr cds::container::SplitListMap< cds::urcu::gc< RCU >, Key, Value, Traits >::extract_with	(	K const &	key,
		Less	pred
	)

inline

Extracts an item from the map using pred predicate for searching.

The function is an analog of extract(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 map.

template<class RCU , typename Key , typename Value , class Traits = split_list::traits>

template<typename K , typename Func >

bool cds::container::SplitListMap< cds::urcu::gc< RCU >, Key, Value, Traits >::find	(	K const &	key,
		Func	f
	)

inline

Finds the key key.

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 );
};

where item is the item found.

The functor may change item.second. Note that the functor is only guarantee that item cannot be disposed during functor is executing. The functor does not serialize simultaneous access to the map's item. If such access is possible you must provide your own synchronization schema on item level to exclude unsafe item modifications.

The function applies RCU lock internally.

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

template<class RCU , typename Key , typename Value , class Traits = split_list::traits>

template<typename K , typename Less , typename Func >

bool cds::container::SplitListMap< cds::urcu::gc< RCU >, Key, Value, Traits >::find_with	(	K const &	key,
		Less	pred,
		Func	f
	)

inline

Finds the key key using pred predicate for searching.

The function is an analog of find(K const&, Func) 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<class RCU , typename Key , typename Value , class Traits = split_list::traits>

template<typename K >

raw_ptr cds::container::SplitListMap< cds::urcu::gc< RCU >, Key, Value, Traits >::get ( K const & key )

inline

Finds key and return the item found.

The function searches the item with key equal to key and returns the pointer to item found. If key is not found it returns empty raw_ptr.

Note the compare functor should accept a parameter of type K that can be not the same as value_type.

RCU should be locked before call of this function. Returned item is valid only while RCU is locked:

typedef cds::urcu::gc< general_buffered<> > rcu;
typedef cds::container::SplitListMap< rcu, int, Foo > splitlist_map;
splitlist_map theMap;
// ...
{
    // Lock RCU
    typename splitlist_map::rcu_lock lock;
    typename splitlist_map::raw_ptr pVal = theMap.get( 5 );
    if ( pVal ) {
        // Deal with pVal
        //...
    }
    // Unlock RCU by rcu_lock destructor
    // pVal can be retired by disposer at any time after RCU has been unlocked
}

template<class RCU , typename Key , typename Value , class Traits = split_list::traits>

template<typename K , typename Less >

raw_ptr cds::container::SplitListMap< cds::urcu::gc< RCU >, Key, Value, Traits >::get_with	(	K const &	key,
		Less	pred
	)

inline

Finds key with predicate specified and return the item found.

The function is an analog of get(K const&) but pred is used for comparing the keys.

Less functor has the semantics like std::less but should take arguments of type value_type and K in any order. pred must imply the same element order as the comparator used for building the map.

template<class RCU , typename Key , typename Value , class Traits = split_list::traits>

template<typename K >

bool cds::container::SplitListMap< cds::urcu::gc< RCU >, Key, Value, Traits >::insert ( K const & key )

inline

Inserts new node with key and default value.

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

Preconditions:

The key_type should be constructible from value of type K.
The mapped_type should be default-constructible.

The function applies RCU lock internally.

Returns true if inserting successful, false otherwise.

template<class RCU , typename Key , typename Value , class Traits = split_list::traits>

template<typename K , typename V >

bool cds::container::SplitListMap< cds::urcu::gc< RCU >, Key, Value, 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 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.

The function applies RCU lock internally.

Returns true if val is inserted into the map, false otherwise.

template<class RCU , typename Key , typename Value , class Traits = split_list::traits>

template<typename K , typename Func >

bool cds::container::SplitListMap< cds::urcu::gc< RCU >, Key, Value, 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.first is a const reference to item's key that cannot be changed.
item.second is a reference to item's value that may be changed.

It should be keep in mind that concurrent modifications of item.second in func body should be careful. You shouldf guarantee that during changing item's value in func no any other changes could be made on this item by concurrent threads.

func is called only if inserting is successful.

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

create item from key;
insert new item into the map;
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.

The function applies RCU lock internally.

template<class RCU , typename Key , typename Value , class Traits = split_list::traits>

template<typename K , typename Func >

std::pair<bool, bool> cds::container::SplitListMap< cds::urcu::gc< RCU >, Key, Value, Traits >::update	(	K const &	key,
		Func	func,
		bool	bAllowInsert = `true`
	)

inline

Updates data by key.

The operation performs inserting or replacing the element with lock-free manner.

If the key not found in the map, then the new item created from key will be inserted into the map iff bAllowInsert is true. (note that in this case the key_type should be constructible from type K). Otherwise, if key is found, the functor func is called with item found.

The functor Func signature is:

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

with arguments:

bNew - true if the item has been inserted, false otherwise
item - the item found or inserted

The functor may change any fields of the item.second that is mapped_type.

The function applies RCU lock internally.

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 exists.

Warning: For MichaelKVList as the ordered list see insert item troubleshooting. LazyKVList provides exclusive access to inserted item and does not require any node-level synchronization.

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

cds/container/split_list_map_rcu.h

Public Types

Public Member Functions

Static Public Attributes

Additional Inherited Members

Detailed Description

template<class RCU, typename Key, typename Value, class Traits = split_list::traits> class cds::container::SplitListMap< cds::urcu::gc< RCU >, Key, Value, Traits >

Member Typedef Documentation

Constructor & Destructor Documentation

Member Function Documentation

template<class RCU, typename Key, typename Value, class Traits = split_list::traits>
class cds::container::SplitListMap< cds::urcu::gc< RCU >, Key, Value, Traits >