Bronson et al AVL-tree (RCU specialization for pointers) More...

#include <cds/container/bronson_avltree_map_rcu.h>

Inheritance diagram for cds::container::BronsonAVLTreeMap< cds::urcu::gc< RCU >, Key, T *, Traits >:

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

typedef Key	key_type
	type of a key stored in the map

typedef T *	mapped_type
	type of value stored in the map

typedef Traits	traits
	Traits template parameter.

typedef implementation_defined	key_comparator
	key compare functor based on `Traits::compare` and `Traits::less`

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::node_allocator	node_allocator_type
	allocator for maintaining internal nodes

typedef traits::stat	stat
	internal statistics

typedef traits::rcu_check_deadlock	rcu_check_deadlock
	Deadlock checking policy.

typedef traits::back_off	back_off
	Back-off strategy.

typedef traits::disposer	disposer
	Value disposer.

typedef traits::sync_monitor	sync_monitor
	Synchronization monitor type for node-level locking

typedef cds::urcu::exempt_ptr< gc, T, T, disposer, void >	exempt_ptr
	Returned pointer to `mapped_type` of extracted node.

typedef gc::scoped_lock	rcu_lock
	RCU scoped lock.

Public Member Functions
	BronsonAVLTreeMap ()
	Creates empty map.

	~BronsonAVLTreeMap ()
	Destroys the map.

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

template<typename K >
std::pair< bool, bool >	update (K const &key, mapped_type pVal, bool bInsert=true)
	Updates the value for `key`. More...

template<typename K >
bool	erase (K const &key)
	Delete `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)
	Delete `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...

exempt_ptr	extract_min ()
	Extracts a value with minimal key from the map. More...

template<typename Func >
exempt_ptr	extract_min (Func f)
	Extracts minimal key and corresponding value. More...

std::enable_if< std::is_copy_assignable< key_type >::value, exempt_ptr >::type	extract_min_key (key_type &min_key)
	Extracts minimal key and corresponding value. More...

exempt_ptr	extract_max ()
	Extracts a value with maximal key from the tree. More...

template<typename Func >
exempt_ptr	extract_max (Func f)
	Extracts the maximal key and corresponding value. More...

std::enable_if< std::is_copy_assignable< key_type >::value, exempt_ptr >::type	extract_max_key (key_type &max_key)
	Extracts the maximal key and corresponding value. More...

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

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

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

template<typename K , typename Less , typename Func >
bool	find_with (K const &key, Less pred, Func f)
	Finds the key `val` 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...

void	clear ()
	Clears the tree (thread safe, not atomic) More...

void	unsafe_clear ()
	Clears the tree (not thread safe) More...

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

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

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

sync_monitor &	monitor ()
	Returns reference to `sync_monitor` object.

bool	check_consistency () const
	Checks internal consistency (not atomic, not thread-safe) More...

template<typename Func >
bool	check_consistency (Func f) const
	Checks internal consistency (not atomic, not thread-safe) More...

Static Public Attributes
static constexpr bool const	c_bRelaxedInsert = traits::relaxed_insert
	Enabled or disabled relaxed insertion.

static constexpr const bool	c_bExtractLockExternal = false
	Group of `extract_xxx` functions does not require external locking.

Detailed Description

template<typename RCU, typename Key, typename T, typename Traits = bronson_avltree::traits>
class cds::container::BronsonAVLTreeMap< cds::urcu::gc< RCU >, Key, T *, Traits >

Bronson et al AVL-tree (RCU specialization for pointers)

This is the specialization of RCU-based Bronson et al AVL-tree for "key -> value pointer" map. This specialization stores the pointer to user-allocated values instead of the copy of the value. When a tree node is removed, the algorithm does not free the value pointer directly, instead, it call the disposer functor provided by Traits template parameter.

Template arguments:

RCU - one of RCU type
Key - key type
T - value type to be stored in tree's nodes. Note, the specialization stores the pointer to user-allocated value, not the copy.
Traits - tree traits, default is bronson_avltree::traits It is possible to declare option-based tree with bronson_avltree::make_traits metafunction instead of Traits template argument.

Note: Before including <cds/container/bronson_avltree_map_rcu.h> you should include appropriate RCU header file, see RCU type for list of existing RCU class and corresponding header files.

Member Function Documentation

template<typename RCU , typename Key , typename T , typename Traits = bronson_avltree::traits>

bool cds::container::BronsonAVLTreeMap< cds::urcu::gc< RCU >, Key, T *, Traits >::check_consistency ( ) const

inline

Checks internal consistency (not atomic, not thread-safe)

The debugging function to check internal consistency of the tree.

template<typename RCU , typename Key , typename T , typename Traits = bronson_avltree::traits>

template<typename Func >

bool cds::container::BronsonAVLTreeMap< cds::urcu::gc< RCU >, Key, T *, Traits >::check_consistency ( Func f ) const

inline

Checks internal consistency (not atomic, not thread-safe)

The debugging function to check internal consistency of the tree. The functor Func is called if a violation of internal tree structure is found:

struct functor {
    void operator()( size_t nLevel, size_t hLeft, size_t hRight );
};

where

nLevel - the level where the violation is found
hLeft - the height of left subtree
hRight - the height of right subtree

The functor is called for each violation found.

template<typename RCU , typename Key , typename T , typename Traits = bronson_avltree::traits>

void cds::container::BronsonAVLTreeMap< cds::urcu::gc< RCU >, Key, T *, Traits >::clear ( )

inline

Clears the tree (thread safe, not atomic)

The function unlink all items from the tree. The function is thread safe but not atomic: in multi-threaded environment with parallel insertions this sequence

set.clear();

assert( set.empty());

the assertion could be raised.

For each node the disposer will be called after unlinking.

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

template<typename RCU , typename Key , typename T , typename Traits = bronson_avltree::traits>

template<typename K >

bool cds::container::BronsonAVLTreeMap< cds::urcu::gc< RCU >, 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 true if it is found, and false otherwise.

The function applies RCU lock internally.

template<typename RCU , typename Key , typename T , typename Traits = bronson_avltree::traits>

template<typename K , typename Less >

bool cds::container::BronsonAVLTreeMap< cds::urcu::gc< RCU >, Key, T *, Traits >::contains	(	K const &	key,
		Less	pred
	)

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 set.

template<typename RCU , typename Key , typename T , typename Traits = bronson_avltree::traits>

template<typename K >

bool cds::container::BronsonAVLTreeMap< cds::urcu::gc< RCU >, Key, T *, Traits >::erase ( K const & key )

inline

Delete 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<typename RCU , typename Key , typename T , typename Traits = bronson_avltree::traits>

template<typename K , typename Func >

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

inline

Delete 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:

struct functor {
    void operator()( key_type const& key, std::remove_pointer<mapped_type>::type& val) { ... }
};

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

Return true if key is found and deleted, false otherwise

template<typename RCU , typename Key , typename T , typename Traits = bronson_avltree::traits>

template<typename K , typename Less >

bool cds::container::BronsonAVLTreeMap< cds::urcu::gc< RCU >, Key, T *, 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<typename RCU , typename Key , typename T , typename Traits = bronson_avltree::traits>

template<typename K , typename Less , typename Func >

bool cds::container::BronsonAVLTreeMap< cds::urcu::gc< RCU >, Key, T *, 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<typename RCU , typename Key , typename T , typename Traits = bronson_avltree::traits>

template<typename Q >

exempt_ptr cds::container::BronsonAVLTreeMap< cds::urcu::gc< RCU >, Key, T *, Traits >::extract ( Q const & key )

inline

Extracts an item from the map.

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

RCU synchronize method can be called. RCU should NOT be locked. The function does not destroy the value found. The disposer will be implicitly invoked when the returned object is destroyed or when its release() member function is called.

template<typename RCU , typename Key , typename T , typename Traits = bronson_avltree::traits>

exempt_ptr cds::container::BronsonAVLTreeMap< cds::urcu::gc< RCU >, Key, T *, Traits >::extract_max ( )

inline

Extracts a value with maximal key from the tree.

Returns exempt_ptr pointer to the rightmost item. If the set is empty, returns empty exempt_ptr.

Note that the function returns only the value for maximal key. To retrieve its key use extract_max( Func ) member function.

Note: Due the concurrent nature of the map, the function extracts nearly maximal key. It means that the function gets rightmost leaf of the tree and tries to unlink it. During unlinking, a concurrent thread may insert an item with key greater than rightmost item's key. So, the function returns the item with maximum key at the moment of tree traversing.

RCU synchronize method can be called. RCU should NOT be locked. The function does not free the item. The deallocator will be implicitly invoked when the returned object is destroyed or when its release() is called.

template<typename RCU , typename Key , typename T , typename Traits = bronson_avltree::traits>

template<typename Func >

exempt_ptr cds::container::BronsonAVLTreeMap< cds::urcu::gc< RCU >, Key, T *, Traits >::extract_max ( Func f )

inline

Extracts the maximal key and corresponding value.

Returns exempt_ptr pointer to the rightmost item. If the set is empty, returns empty exempt_ptr.

Func functor is used to store maximal key. Func has the following signature:

struct functor {
    void operator()( key_type const& key );
};

If the tree is empty, f is not called. Otherwise, it is called with maximal key, the pointer to corresponding value is returned as exempt_ptr.

Note: Due the concurrent nature of the map, the function extracts nearly maximal key. It means that the function gets rightmost leaf of the tree and tries to unlink it. During unlinking, a concurrent thread may insert an item with key greater than rightmost item's key. So, the function returns the item with maximum key at the moment of tree traversing.

RCU synchronize method can be called. RCU should NOT be locked. The function does not free the item. The deallocator will be implicitly invoked when the returned object is destroyed or when its release() is called.

template<typename RCU , typename Key , typename T , typename Traits = bronson_avltree::traits>

std::enable_if< std::is_copy_assignable<key_type>::value, exempt_ptr >::type cds::container::BronsonAVLTreeMap< cds::urcu::gc< RCU >, Key, T *, Traits >::extract_max_key ( key_type & max_key )

inline

Extracts the maximal key and corresponding value.

This function is a shortcut for the following call:

key_type key;

exempt_ptr xp = theTree.extract_max( [&key]( key_type const& k ) { key = k; } );

key_type should be copy-assignable. The copy of maximal key is returned in max_key argument.

template<typename RCU , typename Key , typename T , typename Traits = bronson_avltree::traits>

exempt_ptr cds::container::BronsonAVLTreeMap< cds::urcu::gc< RCU >, Key, T *, Traits >::extract_min ( )

inline

Extracts a value with minimal key from the map.

Returns exempt_ptr to the leftmost item. If the tree is empty, returns empty exempt_ptr.

Note that the function returns only the value for minimal key. To retrieve its key use extract_min( Func ) member function.

Note: Due the concurrent nature of the map, the function extracts nearly minimum key. It means that the function gets leftmost leaf of the tree and tries to unlink it. During unlinking, a concurrent thread may insert an item with key less than leftmost item's key. So, the function returns the item with minimum key at the moment of tree traversing.

RCU synchronize method can be called. RCU should NOT be locked. The function does not free the item. The deallocator will be implicitly invoked when the returned object is destroyed or when its release() member function is called.

template<typename RCU , typename Key , typename T , typename Traits = bronson_avltree::traits>

template<typename Func >

exempt_ptr cds::container::BronsonAVLTreeMap< cds::urcu::gc< RCU >, Key, T *, Traits >::extract_min ( Func f )

inline

Extracts minimal key and corresponding value.

Returns exempt_ptr to the leftmost item. If the tree is empty, returns empty exempt_ptr.

Func functor is used to store minimal key. Func has the following signature:

struct functor {
    void operator()( key_type const& key );
};

If the tree is empty, f is not called. Otherwise, it is called with minimal key, the pointer to corresponding value is returned as exempt_ptr.

Note: Due the concurrent nature of the map, the function extracts nearly minimum key. It means that the function gets leftmost leaf of the tree and tries to unlink it. During unlinking, a concurrent thread may insert an item with key less than leftmost item's key. So, the function returns the item with minimum key at the moment of tree traversing.

RCU synchronize method can be called. RCU should NOT be locked. The function does not free the item. The deallocator will be implicitly invoked when the returned object is destroyed or when its release() member function is called.

template<typename RCU , typename Key , typename T , typename Traits = bronson_avltree::traits>

std::enable_if< std::is_copy_assignable<key_type>::value, exempt_ptr >::type cds::container::BronsonAVLTreeMap< cds::urcu::gc< RCU >, Key, T *, Traits >::extract_min_key ( key_type & min_key )

inline

Extracts minimal key and corresponding value.

This function is a shortcut for the following call:

key_type key;

exempt_ptr xp = theTree.extract_min( [&key]( key_type const& k ) { key = k; } );

key_type should be copy-assignable. The copy of minimal key is returned in min_key argument.

template<typename RCU , typename Key , typename T , typename Traits = bronson_avltree::traits>

template<typename Q , typename Less >

exempt_ptr cds::container::BronsonAVLTreeMap< cds::urcu::gc< RCU >, Key, T *, Traits >::extract_with	(	Q const &	key,
		Less	pred
	)

inline

Extracts an item from the map using pred for searching.

The function is an analog of extract(Q const&) but pred is used for key compare. Less has the interface like std::less. pred must imply the same element order as the comparator used for building the tree.

template<typename RCU , typename Key , typename T , typename Traits = bronson_avltree::traits>

template<typename K , typename Func >

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

inline

Find 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()( key_type const& key, std::remove_pointer< mapped_type )::type& item );
};

where item is the item found. The functor is called under node-level lock.

The function applies RCU lock internally.

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

template<typename RCU , typename Key , typename T , typename Traits = bronson_avltree::traits>

template<typename K , typename Less , typename Func >

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

inline

Finds the key val 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<typename RCU , typename Key , typename T , typename Traits = bronson_avltree::traits>

template<typename K >

bool cds::container::BronsonAVLTreeMap< cds::urcu::gc< RCU >, Key, T *, Traits >::insert	(	K const &	key,
		mapped_type	pVal
	)

inline

Inserts new node.

The key_type should be constructible from a value of type K.

RCU synchronize() can be called. RCU should not be locked.

Returns true if inserting successful, false otherwise.

template<typename RCU , typename Key , typename T , typename Traits = bronson_avltree::traits>

size_t cds::container::BronsonAVLTreeMap< cds::urcu::gc< RCU >, Key, T *, Traits >::size ( ) const

inline

Returns item count in the map.

Only leaf nodes containing user data are counted.

The value returned depends on item counter type provided by Traits template parameter. If it is atomicity::empty_item_counter this function always returns 0.

The function is not suitable for checking the tree emptiness, use empty() member function for this purpose.

template<typename RCU , typename Key , typename T , typename Traits = bronson_avltree::traits>

void cds::container::BronsonAVLTreeMap< cds::urcu::gc< RCU >, Key, T *, Traits >::unsafe_clear ( )

inline

Clears the tree (not thread safe)

This function is not thread safe and may be called only when no other thread deals with the tree. The function is used in the tree destructor.

template<typename RCU , typename Key , typename T , typename Traits = bronson_avltree::traits>

template<typename K >

std::pair<bool, bool> cds::container::BronsonAVLTreeMap< cds::urcu::gc< RCU >, Key, T *, Traits >::update	(	K const &	key,
		mapped_type	pVal,
		bool	bInsert = `true`
	)

inline

Updates the value for key.

The operation performs inserting or updating the value for key with lock-free manner. If bInsert is false, only updating of existing node is possible.

If key is not found and inserting is allowed (i.e. bInsert is true), then the new node created from key will be inserted into the map; note that in this case the key_type should be constructible from type K. Otherwise, the value for key will be changed to pVal.

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

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

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

cds/container/impl/bronson_avltree_map_rcu.h

Public Types

Public Member Functions

Static Public Attributes

Detailed Description

template<typename RCU, typename Key, typename T, typename Traits = bronson_avltree::traits> class cds::container::BronsonAVLTreeMap< cds::urcu::gc< RCU >, Key, T *, Traits >

Member Function Documentation

template<typename RCU, typename Key, typename T, typename Traits = bronson_avltree::traits>
class cds::container::BronsonAVLTreeMap< cds::urcu::gc< RCU >, Key, T *, Traits >