The split-ordered list is a lock-free implementation of an extensible unbounded hash table. It uses original
recursive split-ordering algorithm discovered by Ori Shalev and Nir Shavit that allows to split buckets
- without items moving on resizing.
+ without item moving on resizing.
\anchor cds_SplitList_algo_desc
<b>Short description</b>
<b>Implementation</b>
Template parameters are:
- - \p GC - Garbage collector used. Note the \p GC must be the same as the GC used for \p OrderedList
- - \p OrderedList - ordered list implementation used as bucket for hash set, for example, MichaelList, LazyList.
+ - \p GC - Garbage collector. Note the \p GC must be the same as the \p GC used for \p OrderedList
+ - \p OrderedList - ordered list implementation used as a bucket for hash set, for example, \p MichaelList, \p LazyList.
The intrusive ordered list implementation specifies the type \p T stored in the hash-set, the reclamation
schema \p GC used by hash-set, the comparison functor for the type \p T and other features specific for
the ordered list.
- - \p Traits - type traits. See split_list::type_traits for explanation.
- Instead of defining \p Traits struct you may use option-based syntax with split_list::make_traits metafunction.
+ - \p Traits - split-list traits, default is \p split_list::traits.
+ Instead of defining \p Traits struct you may use option-based syntax with \p split_list::make_traits metafunction.
There are several specialization of the split-list class for different \p GC:
- for \ref cds_urcu_gc "RCU type" include <tt><cds/intrusive/split_list_rcu.h></tt> - see
Some member functions of split-ordered list accept the key parameter of type \p Q which differs from \p value_type.
It is expected that type \p Q contains full key of \p value_type, and for equal keys of type \p Q and \p value_type
the hash values of these keys must be equal too.
- The hash functor <tt>Traits::hash</tt> should accept parameters of both type:
+ The hash functor \p Traits::hash should accept parameters of both type:
\code
// Our node type
struct Foo {
};
// Declare base ordered-list type for split-list
- // It may be any ordered list type like MichaelList, LazyList
typedef cds::intrusive::MichaelList< cds::gc::HP, Foo,
typename cds::intrusive::michael_list::make_traits<
// hook option
// and so on ...
\endcode
-
*/
template <
class GC,
class OrderedList,
# ifdef CDS_DOXYGEN_INVOKED
- class Traits = split_list::type_traits
+ class Traits = split_list::traits
# else
class Traits
# endif
class SplitListSet
{
public:
- typedef Traits options ; ///< Traits template parameters
- typedef GC gc ; ///< Garbage collector
+ typedef GC gc; ///< Garbage collector
+ typedef Traits traits; ///< Set traits
protected:
//@cond
- typedef split_list::details::rebind_list_options<OrderedList, options> wrapped_ordered_list;
+ typedef split_list::details::rebind_list_options<OrderedList, traits> wrapped_ordered_list;
//@endcond
public:
# ifdef CDS_DOXYGEN_INVOKED
- typedef OrderedList ordered_list ; ///< type of ordered list used as base for split-list
+ typedef OrderedList ordered_list; ///< type of ordered list used as a base for split-list
# else
typedef typename wrapped_ordered_list::result ordered_list;
# endif
- typedef typename ordered_list::value_type value_type ; ///< type of value stored in the split-list
- typedef typename ordered_list::key_comparator key_comparator ; ///< key comparison functor
- typedef typename ordered_list::disposer disposer ; ///< Node disposer functor
+ typedef typename ordered_list::value_type value_type; ///< type of value stored in the split-list
+ typedef typename ordered_list::key_comparator key_comparator; ///< key comparison functor
+ typedef typename ordered_list::disposer disposer; ///< Node disposer functor
/// Hash functor for \p %value_type and all its derivatives that you use
- typedef typename cds::opt::v::hash_selector< typename options::hash >::type hash;
+ typedef typename cds::opt::v::hash_selector< typename traits::hash >::type hash;
- typedef typename options::item_counter item_counter ; ///< Item counter type
- typedef typename options::back_off back_off ; ///< back-off strategy for spinning
- typedef typename options::memory_model memory_model ; ///< Memory ordering. See cds::opt::memory_model option
- typedef typename ordered_list::guarded_ptr guarded_ptr; ///< Guarded pointer
+ typedef typename traits::item_counter item_counter; ///< Item counter type
+ typedef typename traits::back_off back_off; ///< back-off strategy for spinning
+ typedef typename traits::memory_model memory_model; ///< Memory ordering. See cds::opt::memory_model option
+ typedef typename traits::stat stat; ///< Internal statistics, see \p spit_list::stat
+ typedef typename ordered_list::guarded_ptr guarded_ptr; ///< Guarded pointer
protected:
- typedef typename ordered_list::node_type list_node_type ; ///< Node type as declared in ordered list
- typedef split_list::node<list_node_type> node_type ; ///< split-list node type
- typedef node_type dummy_node_type ; ///< dummy node type
+ typedef typename ordered_list::node_type list_node_type; ///< Node type as declared in ordered list
+ typedef split_list::node<list_node_type> node_type; ///< split-list node type
+ typedef node_type dummy_node_type; ///< dummy node type
/// Split-list node traits
/**
- This traits is intended for converting between underlying ordered list node type \ref list_node_type
- and split-list node type \ref node_type
+ This traits is intended for converting between underlying ordered list node type \p list_node_type
+ and split-list node type \p node_type
*/
typedef split_list::node_traits<typename ordered_list::node_traits> node_traits;
//@cond
/// Bucket table implementation
typedef typename split_list::details::bucket_table_selector<
- options::dynamic_bucket_table
+ traits::dynamic_bucket_table
, gc
, dummy_node_type
- , opt::allocator< typename options::allocator >
+ , opt::allocator< typename traits::allocator >
, opt::memory_model< memory_model >
>::type bucket_table;
-
//@endcond
protected:
//@endcond
protected:
- ordered_list_wrapper m_List ; ///< Ordered list containing split-list items
- bucket_table m_Buckets ; ///< bucket table
- atomics::atomic<size_t> m_nBucketCountLog2 ; ///< log2( current bucket count )
- item_counter m_ItemCounter ; ///< Item counter
- hash m_HashFunctor ; ///< Hash functor
+ ordered_list_wrapper m_List; ///< Ordered list containing split-list items
+ bucket_table m_Buckets; ///< bucket table
+ atomics::atomic<size_t> m_nBucketCountLog2; ///< log2( current bucket count )
+ item_counter m_ItemCounter; ///< Item counter
+ hash m_HashFunctor; ///< Hash functor
+ stat m_Stat; ///< Internal statistics
protected:
//@cond
- typedef cds::details::Allocator< dummy_node_type, typename options::allocator > dummy_node_allocator;
- static dummy_node_type * alloc_dummy_node( size_t nHash )
+ typedef cds::details::Allocator< dummy_node_type, typename traits::allocator > dummy_node_allocator;
+
+ dummy_node_type * alloc_dummy_node( size_t nHash )
{
+ m_Stat.onHeadNodeAllocated();
return dummy_node_allocator().New( nHash );
}
- static void free_dummy_node( dummy_node_type * p )
+ void free_dummy_node( dummy_node_type * p )
{
dummy_node_allocator().Delete( p );
+ m_Stat.onHeadNodeFreed();
}
/// Calculates hash value of \p key
dummy_node_type * pParentBucket = m_Buckets.bucket( nParent );
if ( pParentBucket == nullptr ) {
pParentBucket = init_bucket( nParent );
+ m_Stat.onRecursiveInitBucket();
}
assert( pParentBucket != nullptr );
dummy_node_type * pBucket = alloc_dummy_node( split_list::dummy_hash( nBucket ) );
if ( m_List.insert_aux_node( pParentBucket, pBucket ) ) {
m_Buckets.bucket( nBucket, pBucket );
+ m_Stat.onNewBucket();
return pBucket;
}
free_dummy_node( pBucket );
// The compiler can decide that waiting loop can be "optimized" (stripped)
// To prevent this situation, we use waiting on volatile bucket_head_ptr pointer.
//
+ m_Stat.onBucketInitContenton();
back_off bkoff;
while ( true ) {
dummy_node_type volatile * p = m_Buckets.bucket( nBucket );
if ( p != nullptr )
return const_cast<dummy_node_type *>( p );
bkoff();
+ m_Stat.onBusyWaitBucketInit();
}
}
dummy_node_type * pHead = get_bucket( nHash );
assert( pHead != nullptr );
- return m_List.find_at( pHead, sv, cmp,
- [&f](value_type& item, split_list::details::search_value_type<Q>& val){ f(item, val.val ); });
+ return m_Stat.onFind(
+ m_List.find_at( pHead, sv, cmp,
+ [&f](value_type& item, split_list::details::search_value_type<Q>& val){ f(item, val.val ); })
+ );
}
template <typename Q, typename Compare>
dummy_node_type * pHead = get_bucket( nHash );
assert( pHead != nullptr );
- return m_List.find_at( pHead, sv, cmp );
+ return m_Stat.onFind( m_List.find_at( pHead, sv, cmp ));
}
template <typename Q, typename Compare>
dummy_node_type * pHead = get_bucket( nHash );
assert( pHead != nullptr );
- return m_List.get_at( pHead, guard, sv, cmp );
+ return m_Stat.onFind( m_List.get_at( pHead, guard, sv, cmp ));
}
template <typename Q>
if ( m_List.erase_at( pHead, sv, cmp, f )) {
--m_ItemCounter;
+ m_Stat.onEraseSuccess();
return true;
}
+ m_Stat.onEraseFailed();
return false;
}
if ( m_List.erase_at( pHead, sv, cmp ) ) {
--m_ItemCounter;
+ m_Stat.onEraseSuccess();
return true;
}
+ m_Stat.onEraseFailed();
return false;
}
if ( m_List.extract_at( pHead, guard, sv, cmp ) ) {
--m_ItemCounter;
+ m_Stat.onExtractSuccess();
return true;
}
+ m_Stat.onExtractFailed();
return false;
}
/// Initialize split-ordered list of default capacity
/**
The default capacity is defined in bucket table constructor.
- See split_list::expandable_bucket_table, split_list::static_ducket_table
- which selects by split_list::dynamic_bucket_table option.
+ See \p split_list::expandable_bucket_table, \p split_list::static_ducket_table
+ which selects by \p split_list::dynamic_bucket_table option.
*/
SplitListSet()
: m_nBucketCountLog2(1)
if ( m_List.insert_at( pHead, val )) {
inc_item_count();
+ m_Stat.onInsertSuccess();
return true;
}
+ m_Stat.onInsertFailed();
return false;
}
\code
void func( value_type& val );
\endcode
- where \p val is the item inserted. User-defined functor \p f should guarantee that during changing
- \p val no any other changes could be made on this set's item by concurrent threads.
- The user-defined functor is called only if the inserting is success and may be passed by reference
- using \p std::ref.
+ where \p val is the item inserted.
+ The user-defined functor is called only if the inserting is success.
+
+ @warning For \ref cds_intrusive_MichaelList_hp "MichaelList" as the bucket see \ref cds_intrusive_item_creating "insert item troubleshooting".
+ \ref cds_intrusive_LazyList_hp "LazyList" provides exclusive access to inserted item and does not require any node-level
+ synchronization.
*/
template <typename Func>
bool insert( value_type& val, Func f )
if ( m_List.insert_at( pHead, val, f )) {
inc_item_count();
+ m_Stat.onInsertSuccess();
return true;
}
+ m_Stat.onInsertFailed();
return false;
}
If new item has been inserted (i.e. \p bNew is \p true) then \p item and \p val arguments
refers to the same thing.
- The functor can change non-key fields of the \p item; however, \p func must guarantee
- that during changing no any other modifications could be made on this item by concurrent threads.
-
- You can pass \p func argument by value or by reference using \p std::ref.
+ The functor can change non-key fields of the \p item.
Returns std::pair<bool, bool> where \p first is \p true if operation is successfull,
\p second is \p true if new item has been added or \p false if the item with \p key
already is in the set.
+
+ @warning For \ref cds_intrusive_MichaelList_hp "MichaelList" as the bucket see \ref cds_intrusive_item_creating "insert item troubleshooting".
+ \ref cds_intrusive_LazyList_hp "LazyList" provides exclusive access to inserted item and does not require any node-level
+ synchronization.
*/
template <typename Func>
std::pair<bool, bool> ensure( value_type& val, Func func )
node_traits::to_node_ptr( val )->m_nHash = split_list::regular_hash( nHash );
std::pair<bool, bool> bRet = m_List.ensure_at( pHead, val, func );
- if ( bRet.first && bRet.second )
+ if ( bRet.first && bRet.second ) {
inc_item_count();
+ m_Stat.onEnsureNew();
+ }
+ else
+ m_Stat.onEnsureExist();
return bRet;
}
if ( m_List.unlink_at( pHead, val ) ) {
--m_ItemCounter;
+ m_Stat.onEraseSuccess();
return true;
}
+ m_Stat.onEraseFailed();
return false;
}
/// Deletes the item from the set
/** \anchor cds_intrusive_SplitListSet_hp_erase
- The function searches an item with key equal to \p val in the set,
+ The function searches an item with key equal to \p key in the set,
unlinks it from the set, and returns \p true.
- If the item with key equal to \p val is not found the function return \p false.
+ If the item with key equal to \p key is not found the function return \p false.
Difference between \ref erase and \p unlink functions: \p erase finds <i>a key</i>
and deletes the item found. \p unlink finds an item by key and deletes it
- only if \p val is an item of that set, i.e. the pointer to item found
- is equal to <tt> &val </tt>.
+ only if \p key is an item of that set, i.e. the pointer to item found
+ is equal to <tt> &key </tt>.
Note the hash functor should accept a parameter of type \p Q that can be not the same as \p value_type.
*/
template <typename Q>
- bool erase( Q const& val )
+ bool erase( Q const& key )
{
- return erase_( val, key_comparator() );
+ return erase_( key, key_comparator() );
}
/// Deletes the item from the set with comparing functor \p pred
/**
+
The function is an analog of \ref cds_intrusive_SplitListSet_hp_erase "erase(Q const&)"
but \p pred predicate is used for key comparing.
\p Less has the interface like \p std::less.
\p pred must imply the same element order as the comparator used for building the set.
*/
template <typename Q, typename Less>
- bool erase_with( const Q& val, Less pred )
+ bool erase_with( const Q& key, Less pred )
{
- return erase_( val, typename wrapped_ordered_list::template make_compare_from_less<Less>() );
+ return erase_( key, typename wrapped_ordered_list::template make_compare_from_less<Less>() );
}
/// Deletes the item from the set
/** \anchor cds_intrusive_SplitListSet_hp_erase_func
- The function searches an item with key equal to \p val in the set,
+ The function searches an item with key equal to \p key in the set,
call \p f functor with item found, unlinks it from the set, and returns \p true.
The \ref disposer specified by \p OrderedList class template parameter is called
by garbage collector \p GC asynchronously.
\endcode
The functor can be passed by reference with <tt>boost:ref</tt>
- If the item with key equal to \p val is not found the function return \p false.
+ If the item with key equal to \p key is not found the function return \p false.
Note the hash functor should accept a parameter of type \p Q that can be not the same as \p value_type.
*/
template <typename Q, typename Func>
- bool erase( Q const& val, Func f )
+ bool erase( Q const& key, Func f )
{
- return erase_( val, key_comparator(), f );
+ return erase_( key, key_comparator(), f );
}
/// Deletes the item from the set with comparing functor \p pred
\p pred must imply the same element order as the comparator used for building the set.
*/
template <typename Q, typename Less, typename Func>
- bool erase_with( Q const& val, Less pred, Func f )
+ bool erase_with( Q const& key, Less pred, Func f )
{
- return erase_( val, typename wrapped_ordered_list::template make_compare_from_less<Less>(), f );
+ return erase_( key, typename wrapped_ordered_list::template make_compare_from_less<Less>(), f );
}
/// Extracts the item with specified \p key
return extract_with_( dest.guard(), key, pred );
}
-
- /// Finds the key \p val
+ /// Finds the key \p key
/** \anchor cds_intrusive_SplitListSet_hp_find_func
- The function searches the item with key equal to \p val and calls the functor \p f for item found.
+ The function searches the item with key equal to \p key and calls the functor \p f for item found.
The interface of \p Func functor is:
\code
struct functor {
- void operator()( value_type& item, Q& val );
+ void operator()( value_type& item, Q& key );
};
\endcode
- where \p item is the item found, \p val is the <tt>find</tt> function argument.
+ where \p item is the item found, \p key is the <tt>find</tt> function argument.
You can pass \p f argument by value or by reference using \p std::ref.
The functor does not serialize simultaneous access to the set \p item. If such access is
possible you must provide your own synchronization schema on item level to exclude unsafe item modifications.
- The \p val argument is non-const since it can be used as \p f functor destination i.e., the functor
- can modify both arguments.
-
Note the hash functor specified for class \p Traits template parameter
should accept a parameter of type \p Q that can be not the same as \p value_type.
- The function returns \p true if \p val is found, \p false otherwise.
+ The function returns \p true if \p key is found, \p false otherwise.
*/
template <typename Q, typename Func>
- bool find( Q& val, Func f )
+ bool find( Q& key, Func f )
{
- return find_( val, key_comparator(), f );
+ return find_( key, key_comparator(), f );
}
- /// Finds the key \p val with \p pred predicate for comparing
+ /// Finds the key \p key with \p pred predicate for comparing
/**
The function is an analog of \ref cds_intrusive_SplitListSet_hp_find_func "find(Q&, Func)"
but \p cmp is used for key compare.
\p cmp must imply the same element order as the comparator used for building the set.
*/
template <typename Q, typename Less, typename Func>
- bool find_with( Q& val, Less pred, Func f )
- {
- return find_( val, typename wrapped_ordered_list::template make_compare_from_less<Less>(), f );
- }
-
- /// Finds the key \p val
- /** \anchor cds_intrusive_SplitListSet_hp_find_cfunc
- The function searches the item with key equal to \p val and calls the functor \p f for item found.
- The interface of \p Func functor is:
- \code
- struct functor {
- void operator()( value_type& item, Q const& val );
- };
- \endcode
- where \p item is the item found, \p val is the <tt>find</tt> function argument.
-
- You can pass \p f argument by value or by reference using \p std::ref.
-
- The functor can change non-key fields of \p item. Note that the functor is only guarantee
- that \p item cannot be disposed during functor is executing.
- The functor does not serialize simultaneous access to the set \p item. If such access is
- possible you must provide your own synchronization schema on item level to exclude unsafe item modifications.
-
- Note the hash functor specified for class \p Traits template parameter
- should accept a parameter of type \p Q that can be not the same as \p value_type.
-
- The function returns \p true if \p val is found, \p false otherwise.
- */
- template <typename Q, typename Func>
- bool find( Q const& val, Func f )
- {
- return find_( val, key_comparator(), f );
- }
-
- /// Finds the key \p val with \p pred predicate for comparing
- /**
- The function is an analog of \ref cds_intrusive_SplitListSet_hp_find_cfunc "find(Q const&, Func)"
- but \p cmp is used for key compare.
- \p Less has the interface like \p std::less.
- \p cmp must imply the same element order as the comparator used for building the set.
- */
- template <typename Q, typename Less, typename Func>
- bool find_with( Q const& val, Less pred, Func f )
+ bool find_with( Q& key, Less pred, Func f )
{
- return find_( val, typename wrapped_ordered_list::template make_compare_from_less<Less>(), f );
+ return find_( key, typename wrapped_ordered_list::template make_compare_from_less<Less>(), f );
}
- /// Finds the key \p val
+ /// Finds the key \p key
/** \anchor cds_intrusive_SplitListSet_hp_find_val
- The function searches the item with key equal to \p val
+ The function searches the item with key equal to \p key
and returns \p true if it is found, and \p false otherwise.
Note the hash functor specified for class \p Traits template parameter
Otherwise, you may use \p find_with functions with explicit predicate for key comparing.
*/
template <typename Q>
- bool find( Q const& val )
+ bool find( Q const& key )
{
- return find_( val, key_comparator() );
+ return find_( key, key_comparator() );
}
- /// Finds the key \p val with \p pred predicate for comparing
+ /// Finds the key \p key with \p pred predicate for comparing
/**
The function is an analog of \ref cds_intrusive_SplitListSet_hp_find_val "find(Q const&)"
but \p cmp is used for key compare.
\p cmp must imply the same element order as the comparator used for building the set.
*/
template <typename Q, typename Less>
- bool find_with( Q const& val, Less pred )
+ bool find_with( Q const& key, Less pred )
{
- return find_( val, typename wrapped_ordered_list::template make_compare_from_less<Less>() );
+ return find_( key, typename wrapped_ordered_list::template make_compare_from_less<Less>() );
}
- /// Finds the key \p val and return the item found
+ /// Finds the key \p key and return the item found
/** \anchor cds_intrusive_SplitListSet_hp_get
- The function searches the item with key equal to \p val
+ The function searches the item with key equal to \p key
and assigns the item found to guarded pointer \p ptr.
- The function returns \p true if \p val is found, and \p false otherwise.
- If \p val is not found the \p ptr parameter is not changed.
+ The function returns \p true if \p key is found, and \p false otherwise.
+ If \p key is not found the \p ptr parameter is not changed.
The \ref disposer specified in \p OrderedList class' template parameter is called
by garbage collector \p GC automatically when returned \ref guarded_ptr object
should accept a parameter of type \p Q that can be not the same as \p value_type.
*/
template <typename Q>
- bool get( guarded_ptr& ptr, Q const& val )
+ bool get( guarded_ptr& ptr, Q const& key )
{
- return get_( ptr.guard(), val );
+ return get_( ptr.guard(), key );
}
- /// Finds the key \p val and return the item found
+ /// Finds the key \p key and return the item found
/**
The function is an analog of \ref cds_intrusive_SplitListSet_hp_get "get( guarded_ptr& ptr, Q const&)"
but \p pred is used for comparing the keys.
\p pred must imply the same element order as the comparator used for building the set.
*/
template <typename Q, typename Less>
- bool get_with( guarded_ptr& ptr, Q const& val, Less pred )
+ bool get_with( guarded_ptr& ptr, Q const& key, Less pred )
{
- return get_with_( ptr.guard(), val, pred );
+ return get_with_( ptr.guard(), key, pred );
}
/// Returns item count in the set