cds  2.2.0
cds::container::BronsonAVLTreeMap< cds::urcu::gc< RCU >, Key, T, Traits > Class Template Reference

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

#include <cds/container/bronson_avltree_map_rcu.h>

Inheritance diagram for cds::container::BronsonAVLTreeMap< cds::urcu::gc< RCU >, Key, T, Traits >:
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 base_class::key_comparator 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::allocator allocator_type
 allocator for value
 
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::sync_monitor sync_monitor
 Synchronization monitor type for node-level locking
 
typedef base_class::rcu_lock rcu_lock
 RCU scoped lock.
 
typedef base_class::exempt_ptr exempt_ptr
 Returned pointer to mapped_type of extracted node.
 

Public Member Functions

 BronsonAVLTreeMap ()
 Creates empty map.
 
 ~BronsonAVLTreeMap ()
 Destroys the map.
 
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 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 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 an item with maximal key from the map. 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 map.
 
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_monitormonitor ()
 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 bool const c_bRelaxedInsert = traits::relaxed_insert
 Enabled or disabled relaxed insertion.
 
static constexpr const bool c_bExtractLockExternal = base_class::c_bExtractLockExternal
 Group of extract_xxx functions does not require external locking.
 

Additional Inherited Members

- Private Types inherited from cds::container::BronsonAVLTreeMap< cds::urcu::gc< RCU >, Key, T *, Traits >
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.
 
- Private Member Functions inherited from cds::container::BronsonAVLTreeMap< cds::urcu::gc< RCU >, Key, T *, Traits >
 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_monitormonitor ()
 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 Private Attributes inherited from cds::container::BronsonAVLTreeMap< cds::urcu::gc< RCU >, Key, T *, Traits >
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)

Source:

  • [2010] N.Bronson, J.Casper, H.Chafi, K.Olukotun "A Practical Concurrent Binary Search Tree"
  • Java implementation

This is a concurrent AVL tree algorithm that uses hand-over-hand optimistic validation, a concurrency control mechanism for searching and navigating a binary search tree. This mechanism minimizes spurious retries when concurrent structural changes cannot affect the correctness of the search or navigation result. The algorithm is based on partially external trees, a simple scheme that simplifies deletions by leaving a routing node in the tree when deleting a node that has two children, then opportunistically unlinking routing nodes during rebalancing. As in external trees, which store values only in leaf nodes, deletions can be performed locally while holding a fixed number of locks. Partially external trees, however, require far fewer routing nodes than an external tree for most sequences of insertions and deletions. The algorithm uses optimistic concurrency control, but carefully manage the tree in such a way that all atomic regions have fixed read and write sets that are known ahead of time. This allows to reduce practical overheads by embedding the concurrency control directly. To perform tree operations using only fixed sized atomic regions the algo uses the following mechanisms: search operations overlap atomic blocks as in the hand-over-hand locking technique; mutations perform rebalancing separately; and deletions occasionally leave a routing node in the tree.

Template arguments:

There is a specialization for "key -> value pointer" map.

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

§ check_consistency() [1/2]

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.

§ check_consistency() [2/2]

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.

§ contains() [1/2]

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.

§ contains() [2/2]

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.

§ emplace()

template<typename RCU , typename Key , typename T , typename Traits = bronson_avltree::traits>
template<typename K , typename... Args>
bool cds::container::BronsonAVLTreeMap< cds::urcu::gc< RCU >, Key, T, Traits >::emplace ( K &&  key,
Args &&...  args 
)
inline

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

Returns true if inserting successful, false otherwise.

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

§ erase() [1/2]

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

§ erase() [2/2]

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 extractor {
void operator()(key_type const& key, mapped_type& item) { ... }
};

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

Return true if key is found and deleted, false otherwise

§ erase_with() [1/2]

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.

§ erase_with() [2/2]

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.

§ extract()

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 dealloctor will be implicitly invoked when the returned object is destroyed or when its release() member function is called.

§ extract_max() [1/2]

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 an item with maximal key from the map.

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 ) or extract_max_key(key_type&) 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 great than leftmost 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.

§ extract_max() [2/2]

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, is it 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 great than leftmost 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.

§ extract_max_key()

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:

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.

§ extract_min() [1/2]

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 pointer to the leftmost item. If the set 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.

§ extract_min() [2/2]

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, is it 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.

§ extract_min_key()

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:

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.

§ extract_with()

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 map.

§ find()

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, mapped_type& val );
};

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

The function applies RCU lock internally.

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

§ find_with()

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.

§ insert() [1/2]

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)
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 a value of type K.
  • The mapped_type should be default-constructible.

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

Returns true if inserting successful, false otherwise.

§ insert() [2/2]

template<typename RCU , typename Key , typename T , typename Traits = bronson_avltree::traits>
template<typename K , typename V >
bool cds::container::BronsonAVLTreeMap< cds::urcu::gc< RCU >, 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.

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

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

§ insert_with()

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 >::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()( key_type const& key, mapped_type& item );
};

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 map;
  • if inserting is successful, initialize the value of item by calling func functor

This can be useful if complete initialization of object of value_type is heavyweight and it is preferable that the initialization should be completed only if inserting is successful. The functor is called under the node lock.

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

§ size()

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.

§ update()

template<typename RCU , typename Key , typename T , typename Traits = bronson_avltree::traits>
template<typename K , typename Func >
std::pair<bool, bool> cds::container::BronsonAVLTreeMap< cds::urcu::gc< RCU >, Key, T, Traits >::update ( K const &  key,
Func  func,
bool  bAllowInsert = true 
)
inline

Updates the value for key.

The operation performs inserting or changing data 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, the functor func is called with item found. The functor Func signature is:

struct my_functor {
void operator()( bool bNew, key_type const& key, mapped_type& item );
};

with arguments:

  • bNew - true if the item has been inserted, false otherwise
  • item - value

The functor may change any fields of the item. The functor is called under the node lock, the caller can change any field of item.

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 item has been added or false if the item with key already exists.


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

cds 2.2.0 Developed by Maxim Khizhinsky aka khizmax 2007 - 2017
Autogenerated Wed Jan 4 2017 08:49:33 by Doxygen 1.8.12