-//$$CDS-header$$
+/*
+ This file is a part of libcds - Concurrent Data Structures library
-#ifndef __CDS_INTRUSIVE_SPLIT_LIST_H
-#define __CDS_INTRUSIVE_SPLIT_LIST_H
+ (C) Copyright Maxim Khizhinsky (libcds.dev@gmail.com) 2006-2016
+ Source code repo: http://github.com/khizmax/libcds/
+ Download: http://sourceforge.net/projects/libcds/files/
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are met:
+
+ * Redistributions of source code must retain the above copyright notice, this
+ list of conditions and the following disclaimer.
+
+ * Redistributions in binary form must reproduce the above copyright notice,
+ this list of conditions and the following disclaimer in the documentation
+ and/or other materials provided with the distribution.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#ifndef CDSLIB_INTRUSIVE_SPLIT_LIST_H
+#define CDSLIB_INTRUSIVE_SPLIT_LIST_H
+
+#include <limits>
#include <cds/intrusive/details/split_list_base.h>
+#include <cds/details/type_padding.h>
namespace cds { namespace intrusive {
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 moving an item on resizing.
+ without item moving on resizing.
\anchor cds_SplitList_algo_desc
<b>Short description</b>
[from [2003] Ori Shalev, Nir Shavit "Split-Ordered Lists - Lock-free Resizable Hash Tables"]
The algorithm keeps all the items in one lock-free linked list, and gradually assigns the bucket pointers to
- the places in the list where a sublist of \93correct\94 items can be found. A bucket is initialized upon first
- access by assigning it to a new \93dummy\94 node (dashed contour) in the list, preceding all items that should be
- in that bucket. A newly created bucket splits an older bucket\92s chain, reducing the access cost to its items. The
- table uses a modulo 2**i hash (there are known techniques for \93pre-hashing\94 before a modulo 2**i hash
+ the places in the list where a sublist of 'correct' items can be found. A bucket is initialized upon first
+ access by assigning it to a new 'dummy' node (dashed contour) in the list, preceding all items that should be
+ in that bucket. A newly created bucket splits an older bucket's chain, reducing the access cost to its items. The
+ table uses a modulo 2**i hash (there are known techniques for 'pre-hashing' before a modulo 2**i hash
to overcome possible binary correlations among values). The table starts at size 2 and repeatedly doubles in size.
Unlike moving an item, the operation of directing a bucket pointer can be done
- in a single CAS operation, and since items are not moved, they are never \93lost\94.
+ in a single CAS operation, and since items are not moved, they are never 'lost'.
However, to make this approach work, one must be able to keep the items in the
- list sorted in such a way that any bucket\92s sublist can be \93split\94 by directing a new
+ list sorted in such a way that any bucket's sublist can be 'split' by directing a new
bucket pointer within it. This operation must be recursively repeatable, as every
split bucket may be split again and again as the hash table grows. To achieve this
goal the authors introduced recursive split-ordering, a new ordering on keys that keeps items
in a given bucket adjacent in the list throughout the repeated splitting process.
Magically, yet perhaps not surprisingly, recursive split-ordering is achieved by
- simple binary reversal: reversing the bits of the hash key so that the new key\92s
+ simple binary reversal: reversing the bits of the hash key so that the new key's
most significant bits (MSB) are those that were originally its least significant.
The split-order keys of regular nodes are exactly the bit-reverse image of the original
keys after turning on their MSB. For example, items 9 and 13 are in the <tt>1 mod
To insert (respectively delete or search for) an item in the hash table, hash its
key to the appropriate bucket using recursive split-ordering, follow the pointer to
- the appropriate location in the sorted items list, and traverse the list until the key\92s
+ the appropriate location in the sorted items list, and traverse the list until the key's
proper location in the split-ordering (respectively until the key or a key indicating
the item is not in the list is found). Because of the combinatorial structure induced
by the split-ordering, this will require traversal of no more than an expected constant number of items.
<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.
- 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 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 split-list set, the comparison
+ functor for the type \p T and other features specific for the ordered list.
+ - \p Traits - split-list traits, default is \p split_list::traits.
+ Instead of defining \p Traits struct you can use option-based syntax provided by \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 {
<b>How to use</b>
+ Split-list based on \p IterableList differs from split-list based on \p MichaelList or \p LazyList
+ because \p %IterableList stores data "as is" - it cannot use any hook.
+
+ Suppose, your split-list contains values of type \p Foo.
+ For \p %MichaelList and \p %LazyList, \p Foo declaration should be based on ordered-list node:
+ - \p %MichaelList:
+ \code
+ struct Foo: public cds::intrusive::split_list::node< cds::intrusive::michael_list::node< cds::gc::HP > >
+ {
+ // ... field declarations
+ };
+ \endcode
+ - \p %LazyList:
+ \code
+ struct Foo: public cds::intrusive::split_list::node< cds::intrusive::lazy_list::node< cds::gc::HP > >
+ {
+ // ... field declarations
+ };
+ \endcode
+
+ For \p %IterableList, \p Foo should be based on \p void:
+ \code
+ struct Foo: public cds::intrusive::split_list::node<void>
+ {
+ // ... field declarations
+ };
+ \endcode
+
+ Everything else is the same.
+ Consider split-list based on \p MichaelList.
+
First, you should choose ordered list type to use in your split-list set:
\code
// For gc::HP-based MichaelList implementation
};
// 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_traits<OrderedList, traits> ordered_list_adapter;
//@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;
+ typedef typename ordered_list_adapter::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;
+ /// Hash functor for \p %value_type and all its derivatives you use
+ 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 \p 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
-
- /// 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
- */
- typedef split_list::node_traits<typename ordered_list::node_traits> node_traits;
+ /// Count of hazard pointer required
+ static CDS_CONSTEXPR const size_t c_nHazardPtrCount = ordered_list::c_nHazardPtrCount + 4; // +4 - for iterators
+ protected:
//@cond
+ typedef split_list::node<typename ordered_list_adapter::ordered_list_node_type> node_type; ///< split-list node type
+ typedef typename ordered_list_adapter::node_traits node_traits;
+
/// 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 >
+ , typename ordered_list_adapter::aux_node
+ , opt::allocator< typename traits::allocator >
, opt::memory_model< memory_model >
+ , opt::free_list< typename traits::free_list >
>::type bucket_table;
+ typedef typename bucket_table::aux_node_type aux_node_type; ///< auxiliary node type
//@endcond
protected:
class ordered_list_wrapper: public ordered_list
{
typedef ordered_list base_class;
- typedef typename base_class::auxiliary_head bucket_head_type;
+ typedef typename base_class::auxiliary_head bucket_head_type;
public:
- bool insert_at( dummy_node_type * pHead, value_type& val )
+ bool insert_at( aux_node_type* pHead, value_type& val )
{
assert( pHead != nullptr );
bucket_head_type h(pHead);
}
template <typename Func>
- bool insert_at( dummy_node_type * pHead, value_type& val, Func f )
+ bool insert_at( aux_node_type * pHead, value_type& val, Func f )
{
assert( pHead != nullptr );
bucket_head_type h(pHead);
}
template <typename Func>
- std::pair<bool, bool> ensure_at( dummy_node_type * pHead, value_type& val, Func func )
+ std::pair<bool, bool> update_at( aux_node_type * pHead, value_type& val, Func func, bool bAllowInsert )
{
assert( pHead != nullptr );
bucket_head_type h(pHead);
- return base_class::ensure_at( h, val, func );
+ return base_class::update_at( h, val, func, bAllowInsert );
+ }
+
+ template <typename Q>
+ typename std::enable_if<
+ std::is_same< Q, value_type>::value && is_iterable_list< ordered_list >::value,
+ std::pair<bool, bool>
+ >::type
+ upsert_at( aux_node_type * pHead, Q& val, bool bAllowInsert )
+ {
+ assert( pHead != nullptr );
+ bucket_head_type h( pHead );
+ return base_class::upsert_at( h, val, bAllowInsert );
}
- bool unlink_at( dummy_node_type * pHead, value_type& val )
+ bool unlink_at( aux_node_type * pHead, value_type& val )
{
assert( pHead != nullptr );
bucket_head_type h(pHead);
}
template <typename Q, typename Compare, typename Func>
- bool erase_at( dummy_node_type * pHead, split_list::details::search_value_type<Q> const& val, Compare cmp, Func f )
+ bool erase_at( aux_node_type * pHead, split_list::details::search_value_type<Q> const& val, Compare cmp, Func f )
{
assert( pHead != nullptr );
bucket_head_type h(pHead);
}
template <typename Q, typename Compare>
- bool erase_at( dummy_node_type * pHead, split_list::details::search_value_type<Q> const& val, Compare cmp )
+ bool erase_at( aux_node_type * pHead, split_list::details::search_value_type<Q> const& val, Compare cmp )
{
assert( pHead != nullptr );
bucket_head_type h(pHead);
}
template <typename Q, typename Compare>
- bool extract_at( dummy_node_type * pHead, typename gc::Guard& guard, split_list::details::search_value_type<Q> const& val, Compare cmp )
+ guarded_ptr extract_at( aux_node_type * pHead, split_list::details::search_value_type<Q> const& val, Compare cmp )
{
assert( pHead != nullptr );
bucket_head_type h(pHead);
- return base_class::extract_at( h, guard, val, cmp );
+ return base_class::extract_at( h, val, cmp );
}
template <typename Q, typename Compare, typename Func>
- bool find_at( dummy_node_type * pHead, split_list::details::search_value_type<Q>& val, Compare cmp, Func f )
+ bool find_at( aux_node_type * pHead, split_list::details::search_value_type<Q>& val, Compare cmp, Func f )
{
assert( pHead != nullptr );
bucket_head_type h(pHead);
}
template <typename Q, typename Compare>
- bool find_at( dummy_node_type * pHead, split_list::details::search_value_type<Q> const& val, Compare cmp )
+ bool find_at( aux_node_type * pHead, split_list::details::search_value_type<Q> const& val, Compare cmp )
{
assert( pHead != nullptr );
bucket_head_type h(pHead);
}
template <typename Q, typename Compare>
- bool get_at( dummy_node_type * pHead, typename gc::Guard& guard, split_list::details::search_value_type<Q> const& val, Compare cmp )
+ typename std::enable_if<
+ std::is_same<Q, Q>::value && is_iterable_list< ordered_list >::value,
+ typename base_class::iterator
+ >::type
+ find_iterator_at( aux_node_type * pHead, split_list::details::search_value_type<Q> const& val, Compare cmp )
+ {
+ assert( pHead != nullptr );
+ bucket_head_type h( pHead );
+ return base_class::find_iterator_at( h, val, cmp );
+ }
+
+ template <typename Q, typename Compare>
+ guarded_ptr get_at( aux_node_type * pHead, split_list::details::search_value_type<Q> const& val, Compare cmp )
{
assert( pHead != nullptr );
bucket_head_type h(pHead);
- return base_class::get_at( h, guard, val, cmp );
+ return base_class::get_at( h, val, cmp );
}
- bool insert_aux_node( dummy_node_type * pNode )
+ bool insert_aux_node( aux_node_type * pNode )
{
return base_class::insert_aux_node( pNode );
}
- bool insert_aux_node( dummy_node_type * pHead, dummy_node_type * pNode )
+ bool insert_aux_node( aux_node_type * pHead, aux_node_type * pNode )
{
bucket_head_type h(pHead);
return base_class::insert_aux_node( h, pNode );
}
+
+ template <typename Predicate>
+ void destroy( Predicate pred )
+ {
+ base_class::destroy( pred );
+ }
};
//@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
-
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 )
- {
- return dummy_node_allocator().New( nHash );
- }
- static void free_dummy_node( dummy_node_type * p )
- {
- dummy_node_allocator().Delete( p );
- }
-
- /// Calculates hash value of \p key
- template <typename Q>
- size_t hash_value( Q const& key ) const
- {
- return m_HashFunctor( key );
- }
-
- size_t bucket_no( size_t nHash ) const
- {
- return nHash & ( (1 << m_nBucketCountLog2.load(atomics::memory_order_relaxed)) - 1 );
- }
-
- static size_t parent_bucket( size_t nBucket )
- {
- assert( nBucket > 0 );
- return nBucket & ~( 1 << bitop::MSBnz( nBucket ) );
- }
-
- dummy_node_type * init_bucket( size_t nBucket )
- {
- assert( nBucket > 0 );
- size_t nParent = parent_bucket( nBucket );
-
- dummy_node_type * pParentBucket = m_Buckets.bucket( nParent );
- if ( pParentBucket == nullptr ) {
- pParentBucket = init_bucket( nParent );
- }
-
- assert( pParentBucket != nullptr );
-
- // Allocate a dummy node for new bucket
- {
- 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 );
- return pBucket;
- }
- free_dummy_node( pBucket );
- }
-
- // Another thread set the bucket. Wait while it done
-
- // In this point, we must wait while nBucket is empty.
- // The compiler can decide that waiting loop can be "optimized" (stripped)
- // To prevent this situation, we use waiting on volatile bucket_head_ptr pointer.
- //
- 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();
- }
- }
-
- dummy_node_type * get_bucket( size_t nHash )
- {
- size_t nBucket = bucket_no( nHash );
-
- dummy_node_type * pHead = m_Buckets.bucket( nBucket );
- if ( pHead == nullptr )
- pHead = init_bucket( nBucket );
-
- assert( pHead->is_dummy() );
-
- return pHead;
- }
-
- void init()
- {
- // GC and OrderedList::gc must be the same
- static_assert(( std::is_same<gc, typename ordered_list::gc>::value ), "GC and OrderedList::gc must be the same");
-
- // atomicity::empty_item_counter is not allowed as a item counter
- static_assert(( !std::is_same<item_counter, atomicity::empty_item_counter>::value ), "atomicity::empty_item_counter is not allowed as a item counter");
-
- // Initialize bucket 0
- dummy_node_type * pNode = alloc_dummy_node( 0 /*split_list::dummy_hash(0)*/ );
-
- // insert_aux_node cannot return false for empty list
- CDS_VERIFY( m_List.insert_aux_node( pNode ));
-
- m_Buckets.bucket( 0, pNode );
- }
-
- void inc_item_count()
- {
- size_t sz = m_nBucketCountLog2.load(atomics::memory_order_relaxed);
- if ( ( ++m_ItemCounter >> sz ) > m_Buckets.load_factor() && ((size_t)(1 << sz )) < m_Buckets.capacity() )
- {
- m_nBucketCountLog2.compare_exchange_strong( sz, sz + 1, atomics::memory_order_seq_cst, atomics::memory_order_relaxed );
- }
- }
-
- template <typename Q, typename Compare, typename Func>
- bool find_( Q& val, Compare cmp, Func f )
+ template <bool IsConst>
+ class iterator_type
+ :public split_list::details::iterator_type<node_traits, ordered_list, IsConst>
{
- size_t nHash = hash_value( val );
- split_list::details::search_value_type<Q> sv( val, split_list::regular_hash( nHash ));
- 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){ cds::unref(f)(item, val.val ); });
- }
+ typedef split_list::details::iterator_type<node_traits, ordered_list, IsConst> iterator_base_class;
+ typedef typename iterator_base_class::list_iterator list_iterator;
+ public:
+ iterator_type()
+ : iterator_base_class()
+ {}
- template <typename Q, typename Compare>
- bool find_( Q const& val, Compare cmp )
- {
- size_t nHash = hash_value( val );
- split_list::details::search_value_type<Q const> sv( val, split_list::regular_hash( nHash ));
- dummy_node_type * pHead = get_bucket( nHash );
- assert( pHead != nullptr );
+ iterator_type( iterator_type const& src )
+ : iterator_base_class( src )
+ {}
- return m_List.find_at( pHead, sv, cmp );
- }
+ // This ctor should be protected...
+ iterator_type( list_iterator itCur, list_iterator itEnd )
+ : iterator_base_class( itCur, itEnd )
+ {}
+ };
+ //@endcond
- template <typename Q, typename Compare>
- bool get_( typename gc::Guard& guard, Q const& val, Compare cmp )
- {
- size_t nHash = hash_value( val );
- split_list::details::search_value_type<Q const> sv( val, split_list::regular_hash( nHash ));
- dummy_node_type * pHead = get_bucket( nHash );
- assert( pHead != nullptr );
+ public:
+ ///@name Forward iterators
+ //@{
+ /// Forward iterator
+ /**
+ The forward iterator is based on \p OrderedList forward iterator and has some features:
+ - it has no post-increment operator
+ - it iterates items in unordered fashion
+ - iterator cannot be moved across thread boundary because it may contain GC's guard that is thread-private GC data.
+
+ Iterator thread safety depends on type of \p OrderedList:
+ - for \p MichaelList and \p LazyList: iterator guarantees safety even if you delete the item that iterator points to
+ because that item is guarded by hazard pointer.
+ However, in case of concurrent deleting operations it is no guarantee that you iterate all item in the set.
+ Moreover, a crash is possible when you try to iterate the next element that has been deleted by concurrent thread.
+ Use this iterator on the concurrent container for debugging purpose only.
+ - for \p IterableList: iterator is thread-safe. You may use it freely in concurrent environment.
+ */
+ typedef iterator_type<false> iterator;
- return m_List.get_at( pHead, guard, sv, cmp );
- }
+ /// Const forward iterator
+ /**
+ For iterator's features and requirements see \ref iterator
+ */
+ typedef iterator_type<true> const_iterator;
- template <typename Q>
- bool get_( typename gc::Guard& guard, Q const& key)
+ /// Returns a forward iterator addressing the first element in a split-list
+ /**
+ For empty list \code begin() == end() \endcode
+ */
+ iterator begin()
{
- return get_( guard, key, key_comparator());
+ return iterator( m_List.begin(), m_List.end());
}
- template <typename Q, typename Less>
- bool get_with_( typename gc::Guard& guard, Q const& key, Less )
- {
- return get_( guard, key, typename wrapped_ordered_list::template make_compare_from_less<Less>());
- }
+ /// Returns an iterator that addresses the location succeeding the last element in a split-list
+ /**
+ Do not use the value returned by <tt>end</tt> function to access any item.
- template <typename Q, typename Compare, typename Func>
- bool erase_( Q const& val, Compare cmp, Func f )
+ The returned value can be used only to control reaching the end of the split-list.
+ For empty list \code begin() == end() \endcode
+ */
+ iterator end()
{
- size_t nHash = hash_value( val );
- split_list::details::search_value_type<Q const> sv( val, split_list::regular_hash( nHash ));
- dummy_node_type * pHead = get_bucket( nHash );
- assert( pHead != nullptr );
-
- if ( m_List.erase_at( pHead, sv, cmp, f )) {
- --m_ItemCounter;
- return true;
- }
- return false;
+ return iterator( m_List.end(), m_List.end());
}
- template <typename Q, typename Compare>
- bool erase_( Q const& val, Compare cmp )
+ /// Returns a forward const iterator addressing the first element in a split-list
+ const_iterator begin() const
{
- size_t nHash = hash_value( val );
- split_list::details::search_value_type<Q const> sv( val, split_list::regular_hash( nHash ));
- dummy_node_type * pHead = get_bucket( nHash );
- assert( pHead != nullptr );
-
- if ( m_List.erase_at( pHead, sv, cmp ) ) {
- --m_ItemCounter;
- return true;
- }
- return false;
+ return cbegin();
}
-
- template <typename Q, typename Compare>
- bool extract_( typename gc::Guard& guard, Q const& val, Compare cmp )
+ /// Returns a forward const iterator addressing the first element in a split-list
+ const_iterator cbegin() const
{
- size_t nHash = hash_value( val );
- split_list::details::search_value_type<Q const> sv( val, split_list::regular_hash( nHash ));
- dummy_node_type * pHead = get_bucket( nHash );
- assert( pHead != nullptr );
-
- if ( m_List.extract_at( pHead, guard, sv, cmp ) ) {
- --m_ItemCounter;
- return true;
- }
- return false;
+ return const_iterator( m_List.cbegin(), m_List.cend());
}
- template <typename Q>
- bool extract_( typename gc::Guard& guard, Q const& key)
+ /// Returns an const iterator that addresses the location succeeding the last element in a split-list
+ const_iterator end() const
{
- return extract_( guard, key, key_comparator());
+ return cend();
}
-
- template <typename Q, typename Less>
- bool extract_with_( typename gc::Guard& guard, Q const& key, Less )
+ /// Returns an const iterator that addresses the location succeeding the last element in a split-list
+ const_iterator cend() const
{
- return extract_( guard, key, typename wrapped_ordered_list::template make_compare_from_less<Less>() );
+ return const_iterator( m_List.cend(), m_List.cend());
}
-
- //@endcond
+ //@}
public:
/// 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_bucket_table
+ which selects by \p split_list::dynamic_bucket_table option.
*/
SplitListSet()
: m_nBucketCountLog2(1)
+ , m_nMaxItemCount( max_item_count(2, m_Buckets.load_factor()))
{
init();
}
)
: m_Buckets( nItemCount, nLoadFactor )
, m_nBucketCountLog2(1)
+ , m_nMaxItemCount( max_item_count(2, m_Buckets.load_factor()))
{
init();
}
+ /// Destroys split-list set
+ ~SplitListSet()
+ {
+ // list contains aux node that cannot be retired
+ // all aux nodes will be destroyed by bucket table dtor
+ m_List.destroy(
+ []( node_type * pNode ) -> bool {
+ return !pNode->is_dummy();
+ }
+ );
+ gc::force_dispose();
+ }
+
public:
/// Inserts new node
/**
bool insert( value_type& val )
{
size_t nHash = hash_value( val );
- dummy_node_type * pHead = get_bucket( nHash );
+ aux_node_type * pHead = get_bucket( nHash );
assert( pHead != nullptr );
node_traits::to_node_ptr( val )->m_nHash = split_list::regular_hash( nHash );
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 <tt>boost::ref</tt>
+ 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 )
{
size_t nHash = hash_value( val );
- dummy_node_type * pHead = get_bucket( nHash );
+ aux_node_type * pHead = get_bucket( nHash );
assert( pHead != nullptr );
node_traits::to_node_ptr( val )->m_nHash = split_list::regular_hash( nHash );
if ( m_List.insert_at( pHead, val, f )) {
inc_item_count();
+ m_Stat.onInsertSuccess();
return true;
}
+ m_Stat.onInsertFailed();
return false;
}
- /// Ensures that the \p val exists in the set
+ /// Updates the node
/**
The operation performs inserting or changing data with lock-free manner.
- If the item \p val is not found in the set, then \p val is inserted into the set.
+ If the item \p val is not found in the set, then \p val is inserted
+ iff \p bAllowInsert is \p true.
Otherwise, the functor \p func is called with item found.
- The functor signature is:
- \code
- void func( bool bNew, value_type& item, value_type& val );
- \endcode
- with arguments:
- - \p bNew - \p true if the item has been inserted, \p false otherwise
- - \p item - item of the set
- - \p val - argument \p val passed into the \p ensure function
- 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.
+ The functor signature depends of the type of \p OrderedList:
+
+ <b>for \p MichaelList, \p LazyList</b>
+ \code
+ struct functor {
+ void operator()( bool bNew, value_type& item, value_type& val );
+ };
+ \endcode
+ with arguments:
+ - \p bNew - \p true if the item has been inserted, \p false otherwise
+ - \p item - item of the set
+ - \p val - argument \p val passed into the \p %update() function
+ 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 may change non-key fields of the \p item.
+ @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.
+
+ <b>for \p IterableList</b>
+ \code
+ void func( value_type& val, value_type * old );
+ \endcode
+ where
+ - \p val - argument \p val passed into the \p %update() function
+ - \p old - old value that will be retired. If new item has been inserted then \p old is \p nullptr.
+
+ Returns std::pair<bool, bool> where \p first is \p true if operation is successful,
+ \p second is \p true if new item has been added or \p false if the item with \p val
+ already is in the list.
+ */
+ template <typename Func>
+ std::pair<bool, bool> update( value_type& val, Func func, bool bAllowInsert = true )
+ {
+ size_t nHash = hash_value( val );
+ aux_node_type * pHead = get_bucket( nHash );
+ assert( pHead != nullptr );
- You can pass \p func argument by value or by reference using <tt>boost::ref</tt> or cds::ref.
+ node_traits::to_node_ptr( val )->m_nHash = split_list::regular_hash( nHash );
- 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.
- */
+ std::pair<bool, bool> bRet = m_List.update_at( pHead, val, func, bAllowInsert );
+ if ( bRet.first && bRet.second ) {
+ inc_item_count();
+ m_Stat.onUpdateNew();
+ }
+ else
+ m_Stat.onUpdateExist();
+ return bRet;
+ }
+ //@cond
template <typename Func>
+ CDS_DEPRECATED("ensure() is deprecated, use update()")
std::pair<bool, bool> ensure( value_type& val, Func func )
+ {
+ return update( val, func, true );
+ }
+ //@endcond
+
+ /// Inserts or updates the node (only for \p IterableList)
+ /**
+ The operation performs inserting or changing data with lock-free manner.
+
+ If the item \p val is not found in the set, then \p val is inserted iff \p bAllowInsert is \p true.
+ Otherwise, the current element is changed to \p val, the old element will be retired later
+ by call \p Traits::disposer.
+
+ Returns std::pair<bool, bool> where \p first is \p true if operation is successful,
+ \p second is \p true if \p val has been added or \p false if the item with that key
+ already in the set.
+ */
+#ifdef CDS_DOXYGEN_INVOKED
+ std::pair<bool, bool> upsert( value_type& val, bool bAllowInsert = true )
+#else
+ template <typename Q>
+ typename std::enable_if<
+ std::is_same< Q, value_type>::value && is_iterable_list< ordered_list >::value,
+ std::pair<bool, bool>
+ >::type
+ upsert( Q& val, bool bAllowInsert = true )
+#endif
{
size_t nHash = hash_value( val );
- dummy_node_type * pHead = get_bucket( nHash );
+ aux_node_type * pHead = get_bucket( nHash );
assert( pHead != nullptr );
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 )
+ std::pair<bool, bool> bRet = m_List.upsert_at( pHead, val, bAllowInsert );
+ if ( bRet.first && bRet.second ) {
inc_item_count();
+ m_Stat.onUpdateNew();
+ }
+ else
+ m_Stat.onUpdateExist();
return bRet;
}
bool unlink( value_type& val )
{
size_t nHash = hash_value( val );
- dummy_node_type * pHead = get_bucket( nHash );
+ aux_node_type * pHead = get_bucket( nHash );
assert( pHead != nullptr );
- if ( m_List.unlink_at( pHead, val ) ) {
+ 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>() );
+ CDS_UNUSED( pred );
+ return erase_( key, typename ordered_list_adapter::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.
void operator()( value_type const& item );
};
\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 );
+ CDS_UNUSED( pred );
+ return erase_( key, typename ordered_list_adapter::template make_compare_from_less<Less>(), f );
}
/// Extracts the item with specified \p key
/** \anchor cds_intrusive_SplitListSet_hp_extract
The function searches an item with key equal to \p key,
- unlinks it from the set, and returns it in \p dest parameter.
- If the item with key equal to \p key is not found the function returns \p false.
+ unlinks it from the set, and returns it as \p guarded_ptr.
+ If \p key is not found the function returns an empty guarded pointer.
Note the compare functor should accept a parameter of type \p Q that may be not the same as \p value_type.
- The \ref disposer specified in \p OrderedList class' template parameter is called automatically
- by garbage collector \p GC when returned \ref guarded_ptr object will be destroyed or released.
+ The \p disposer specified in \p OrderedList class' template parameter is called automatically
+ by garbage collector \p GC when returned \p guarded_ptr object will be destroyed or released.
@note Each \p guarded_ptr object uses the GC's guard that can be limited resource.
Usage:
splitlist_set theSet;
// ...
{
- splitlist_set::guarded_ptr gp;
- theSet.extract( gp, 5 );
- // Deal with gp
- // ...
-
+ splitlist_set::guarded_ptr gp( theSet.extract( 5 ));
+ if ( gp) {
+ // Deal with gp
+ // ...
+ }
// Destructor of gp releases internal HP guard
}
\endcode
*/
template <typename Q>
- bool extract( guarded_ptr& dest, Q const& key )
+ guarded_ptr extract( Q const& key )
{
- return extract_( dest.guard(), key );
+ return extract_( key );
}
/// Extracts the item using compare functor \p pred
/**
- The function is an analog of \ref cds_intrusive_SplitListSet_hp_extract "extract(guarded_ptr&, Q const&)"
+ The function is an analog of \ref cds_intrusive_SplitListSet_hp_extract "extract(Q const&)"
but \p pred predicate is used for key comparing.
\p Less functor has the semantics like \p std::less but should take arguments of type \ref value_type and \p Q
\p pred must imply the same element order as the comparator used for building the set.
*/
template <typename Q, typename Less>
- bool extract_with( guarded_ptr& dest, Q const& key, Less pred )
+ guarded_ptr extract_with( Q const& key, Less pred )
{
- return extract_with_( dest.guard(), key, pred );
+ return extract_with_( 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.
-
- You can pass \p f argument by value or by reference using <tt>boost::ref</tt> or cds::ref.
+ where \p item is the item found, \p key is the <tt>find</tt> function argument.
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.
- 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_( key, key_comparator(), f );
+ }
+ //@cond
+ template <typename Q, typename Func>
+ bool find( Q const& key, Func f )
+ {
+ return find_( key, key_comparator(), f );
+ }
+ //@endcond
+
+ /// Finds \p key and returns iterator pointed to the item found (only for \p IterableList)
+ /**
+ If \p key is not found the function returns \p end().
+
+ @note This function is supported only for the set based on \p IterableList
+ */
+ template <typename Q>
+#ifdef CDS_DOXYGEN_INVOKED
+ iterator
+#else
+ typename std::enable_if< std::is_same<Q, Q>::value && is_iterable_list< ordered_list >::value, iterator >::type
+#endif
+ find( Q& key )
{
- return find_( val, key_comparator(), f );
+ return find_iterator_( key, key_comparator());
}
+ //@cond
+ template <typename Q>
+ typename std::enable_if< std::is_same<Q, Q>::value && is_iterable_list< ordered_list >::value, iterator >::type
+ find( Q const& key )
+ {
+ return find_iterator_( key, key_comparator());
+ }
+ //@endcond
- /// 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 )
+ bool find_with( Q& key, Less pred, Func f )
{
- return find_( val, typename wrapped_ordered_list::template make_compare_from_less<Less>(), f );
+ CDS_UNUSED( pred );
+ return find_( key, typename ordered_list_adapter::template make_compare_from_less<Less>(), f );
}
+ //@cond
+ template <typename Q, typename Less, typename Func>
+ bool find_with( Q const& key, Less pred, Func f )
+ {
+ CDS_UNUSED( pred );
+ return find_( key, typename ordered_list_adapter::template make_compare_from_less<Less>(), f );
+ }
+ //@endcond
- /// 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 <tt>boost::ref</tt> or cds::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.
+ /// Finds \p key using \p pred predicate and returns iterator pointed to the item found (only for \p IterableList)
+ /**
+ The function is an analog of \p find(Q&) but \p pred is used for key comparing.
+ \p Less functor has the interface like \p std::less.
+ \p pred must imply the same element order as the comparator used for building the set.
- 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.
+ If \p key is not found the function returns \p end().
- The function returns \p true if \p val is found, \p false otherwise.
+ @note This function is supported only for the set based on \p IterableList
*/
- template <typename Q, typename Func>
- bool find( Q const& val, Func f )
+ template <typename Q, typename Less>
+#ifdef CDS_DOXYGEN_INVOKED
+ iterator
+#else
+ typename std::enable_if< std::is_same<Q, Q>::value && is_iterable_list< ordered_list >::value, iterator >::type
+#endif
+ find_with( Q& key, Less pred )
{
- return find_( val, key_comparator(), f );
+ CDS_UNUSED( pred );
+ return find_iterator_( key, typename ordered_list_adapter::template make_compare_from_less<Less>());
}
-
- /// 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 )
+ //@cond
+ template <typename Q, typename Less>
+ typename std::enable_if< std::is_same<Q, Q>::value && is_iterable_list< ordered_list >::value, iterator >::type
+ find_with( Q const& key, Less pred )
{
- return find_( val, typename wrapped_ordered_list::template make_compare_from_less<Less>(), f );
+ CDS_UNUSED( pred );
+ return find_iterator_( key, typename ordered_list_adapter::template make_compare_from_less<Less>());
}
+ //@endcond
- /// Finds the key \p val
- /** \anchor cds_intrusive_SplitListSet_hp_find_val
- The function searches the item with key equal to \p val
+
+ /// Checks whether the set contains \p key
+ /**
+ 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
should accept a parameter of type \p Q that can be not the same as \p value_type.
- Otherwise, you may use \p find_with functions with explicit predicate for key comparing.
+ Otherwise, you may use \p contains( Q const&, Less pred ) functions with explicit predicate for key comparing.
*/
template <typename Q>
- bool find( Q const& val )
+ bool contains( Q const& key )
{
- return find_( val, key_comparator() );
+ return find_( key, key_comparator());
}
- /// Finds the key \p val with \p pred predicate for comparing
+ /// Checks whether the set contains \p key using \p pred predicate for searching
/**
- 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 Less has the interface like \p std::less.
- \p cmp must imply the same element order as the comparator used for building the set.
+ The function is an analog of <tt>contains( key )</tt> but \p pred is used for key comparing.
+ \p Less functor has the interface like \p std::less.
+ \p Less 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 contains( Q const& key, Less pred )
{
- return find_( val, typename wrapped_ordered_list::template make_compare_from_less<Less>() );
+ CDS_UNUSED( pred );
+ return find_( key, typename ordered_list_adapter::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
- 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 searches the item with key equal to \p key
+ and returns the item found as \p guarded_ptr.
+ If \p key is not found the function returns an empty guarded pointer.
- The \ref disposer specified in \p OrderedList class' template parameter is called
- by garbage collector \p GC automatically when returned \ref guarded_ptr object
+ The \p disposer specified in \p OrderedList class' template parameter is called
+ by garbage collector \p GC automatically when returned \p guarded_ptr object
will be destroyed or released.
@note Each \p guarded_ptr object uses one GC's guard which can be limited resource.
splitlist_set theSet;
// ...
{
- splitlist_set::guarded_ptr gp;
- if ( theSet.get( gp, 5 )) {
+ splitlist_set::guarded_ptr gp = theSet.get( 5 );
+ if ( gp ) {
// Deal with gp
//...
}
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 )
+ guarded_ptr get( Q const& key )
{
- return get_( ptr.guard(), val );
+ return get_( 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&)"
+ The function is an analog of \ref cds_intrusive_SplitListSet_hp_get "get( Q const&)"
but \p pred is used for comparing the keys.
\p Less functor has the semantics like \p std::less but should take arguments of type \ref value_type and \p Q
\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 )
+ guarded_ptr get_with( Q const& key, Less pred )
{
- return get_with_( ptr.guard(), val, pred );
+ return get_with_( key, pred );
}
/// Returns item count in the set
/// Clears the set (non-atomic)
/**
The function unlink all items from the set.
- The function is not atomic. Therefore, \p clear may be used only for debugging purposes.
+ The function is not atomic. After call the split-list can be non-empty.
For each item the \p disposer is called after unlinking.
*/
void clear()
{
iterator it = begin();
- while ( it != end() ) {
+ while ( it != end()) {
iterator i(it);
++i;
unlink( *it );
}
}
+ /// Returns internal statistics
+ stat const& statistics() const
+ {
+ return m_Stat;
+ }
+
+ /// Returns internal statistics for \p OrderedList
+ typename OrderedList::stat const& list_statistics() const
+ {
+ return m_List.statistics();
+ }
+
protected:
//@cond
- template <bool IsConst>
- class iterator_type
- :public split_list::details::iterator_type<node_traits, ordered_list, IsConst>
+ aux_node_type * alloc_aux_node( size_t nHash )
{
- typedef split_list::details::iterator_type<node_traits, ordered_list, IsConst> iterator_base_class;
- typedef typename iterator_base_class::list_iterator list_iterator;
- public:
- iterator_type()
- : iterator_base_class()
- {}
+ m_Stat.onHeadNodeAllocated();
+ aux_node_type* p = m_Buckets.alloc_aux_node();
+ if ( p )
+ p->m_nHash = nHash;
+ return p;
+ }
- iterator_type( iterator_type const& src )
- : iterator_base_class( src )
- {}
+ void free_aux_node( aux_node_type * p )
+ {
+ m_Buckets.free_aux_node( p );
+ m_Stat.onHeadNodeFreed();
+ }
- // This ctor should be protected...
- iterator_type( list_iterator itCur, list_iterator itEnd )
- : iterator_base_class( itCur, itEnd )
- {}
- };
- //@endcond
- public:
- /// Forward iterator
- /**
- The forward iterator for a split-list has some features:
- - it has no post-increment operator
- - it depends on iterator of underlying \p OrderedList
- - The iterator cannot be moved across thread boundary since it may contain GC's guard that is thread-private GC data.
- - Iterator ensures thread-safety even if you delete the item that iterator points to. However, in case of concurrent
- deleting operations it is no guarantee that you iterate all item in the split-list.
+ /// Calculates hash value of \p key
+ template <typename Q>
+ size_t hash_value( Q const& key ) const
+ {
+ return m_HashFunctor( key );
+ }
- Therefore, the use of iterators in concurrent environment is not good idea. Use the iterator on the concurrent container
- for debug purpose only.
- */
- typedef iterator_type<false> iterator;
- /// Const forward iterator
- /**
- For iterator's features and requirements see \ref iterator
- */
- typedef iterator_type<true> const_iterator;
+ size_t bucket_no( size_t nHash ) const
+ {
+ return nHash & ((1 << m_nBucketCountLog2.load( memory_model::memory_order_relaxed )) - 1);
+ }
- /// Returns a forward iterator addressing the first element in a split-list
- /**
- For empty list \code begin() == end() \endcode
- */
- iterator begin()
+ static size_t parent_bucket( size_t nBucket )
{
- return iterator( m_List.begin(), m_List.end() );
+ assert( nBucket > 0 );
+ return nBucket & ~(1 << bitop::MSBnz( nBucket ));
}
- /// Returns an iterator that addresses the location succeeding the last element in a split-list
- /**
- Do not use the value returned by <tt>end</tt> function to access any item.
+ aux_node_type * init_bucket( size_t const nBucket )
+ {
+ assert( nBucket > 0 );
+ size_t nParent = parent_bucket( nBucket );
- The returned value can be used only to control reaching the end of the split-list.
- For empty list \code begin() == end() \endcode
- */
- iterator end()
+ aux_node_type * pParentBucket = m_Buckets.bucket( nParent );
+ if ( pParentBucket == nullptr ) {
+ pParentBucket = init_bucket( nParent );
+ m_Stat.onRecursiveInitBucket();
+ }
+
+ assert( pParentBucket != nullptr );
+
+ // Allocate an aux node for new bucket
+ aux_node_type * pBucket = m_Buckets.bucket( nBucket );
+
+ back_off bkoff;
+ for ( ;; pBucket = m_Buckets.bucket( nBucket )) {
+ if ( pBucket )
+ return pBucket;
+
+ pBucket = alloc_aux_node( split_list::dummy_hash( nBucket ));
+ if ( pBucket ) {
+ if ( m_List.insert_aux_node( pParentBucket, pBucket )) {
+ m_Buckets.bucket( nBucket, pBucket );
+ m_Stat.onNewBucket();
+ return pBucket;
+ }
+
+ // Another thread set the bucket. Wait while it done
+ free_aux_node( pBucket );
+ m_Stat.onBucketInitContenton();
+ break;
+ }
+
+ // There are no free buckets. It means that the bucket table is full
+ // Wait while another thread set the bucket or a free bucket will be available
+ m_Stat.onBucketsExhausted();
+ bkoff();
+ }
+
+ // Another thread set the bucket. Wait while it done
+ for ( pBucket = m_Buckets.bucket( nBucket ); pBucket == nullptr; pBucket = m_Buckets.bucket( nBucket )) {
+ bkoff();
+ m_Stat.onBusyWaitBucketInit();
+ }
+
+ return pBucket;
+ }
+
+ aux_node_type * get_bucket( size_t nHash )
{
- return iterator( m_List.end(), m_List.end() );
+ size_t nBucket = bucket_no( nHash );
+
+ aux_node_type * pHead = m_Buckets.bucket( nBucket );
+ if ( pHead == nullptr )
+ pHead = init_bucket( nBucket );
+
+ assert( pHead->is_dummy());
+
+ return pHead;
}
- /// Returns a forward const iterator addressing the first element in a split-list
- const_iterator begin() const
+ void init()
{
- return const_iterator( m_List.begin(), m_List.end() );
+ // GC and OrderedList::gc must be the same
+ static_assert(std::is_same<gc, typename ordered_list::gc>::value, "GC and OrderedList::gc must be the same");
+
+ // atomicity::empty_item_counter is not allowed as a item counter
+ static_assert(!std::is_same<item_counter, cds::atomicity::empty_item_counter>::value,
+ "cds::atomicity::empty_item_counter is not allowed as a item counter");
+
+ // Initialize bucket 0
+ aux_node_type * pNode = alloc_aux_node( 0 /*split_list::dummy_hash(0)*/ );
+ assert( pNode != nullptr );
+
+ // insert_aux_node cannot return false for empty list
+ CDS_VERIFY( m_List.insert_aux_node( pNode ));
+
+ m_Buckets.bucket( 0, pNode );
}
- /// Returns an const iterator that addresses the location succeeding the last element in a split-list
- const_iterator end() const
+ static size_t max_item_count( size_t nBucketCount, size_t nLoadFactor )
+ {
+ return nBucketCount * nLoadFactor;
+ }
+
+ void inc_item_count()
+ {
+ size_t nMaxCount = m_nMaxItemCount.load( memory_model::memory_order_relaxed );
+ if ( ++m_ItemCounter <= nMaxCount )
+ return;
+
+ size_t sz = m_nBucketCountLog2.load( memory_model::memory_order_relaxed );
+ const size_t nBucketCount = static_cast<size_t>(1) << sz;
+ if ( nBucketCount < m_Buckets.capacity()) {
+ // we may grow the bucket table
+ const size_t nLoadFactor = m_Buckets.load_factor();
+ if ( nMaxCount < max_item_count( nBucketCount, nLoadFactor ))
+ return; // someone already have updated m_nBucketCountLog2, so stop here
+
+ m_nMaxItemCount.compare_exchange_strong( nMaxCount, max_item_count( nBucketCount << 1, nLoadFactor ),
+ memory_model::memory_order_relaxed, atomics::memory_order_relaxed );
+ m_nBucketCountLog2.compare_exchange_strong( sz, sz + 1, memory_model::memory_order_relaxed, atomics::memory_order_relaxed );
+ }
+ else
+ m_nMaxItemCount.store( std::numeric_limits<size_t>::max(), memory_model::memory_order_relaxed );
+ }
+
+ template <typename Q, typename Compare, typename Func>
+ bool find_( Q& val, Compare cmp, Func f )
+ {
+ size_t nHash = hash_value( val );
+ split_list::details::search_value_type<Q> sv( val, split_list::regular_hash( nHash ));
+ aux_node_type * pHead = get_bucket( nHash );
+ assert( pHead != nullptr );
+
+ 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>
+ bool find_( Q const& val, Compare cmp )
+ {
+ size_t nHash = hash_value( val );
+ split_list::details::search_value_type<Q const> sv( val, split_list::regular_hash( nHash ));
+ aux_node_type * pHead = get_bucket( nHash );
+ assert( pHead != nullptr );
+
+ return m_Stat.onFind( m_List.find_at( pHead, sv, cmp ));
+ }
+
+ template <typename Q, typename Compare>
+ iterator find_iterator_( Q const& val, Compare cmp )
+ {
+ size_t nHash = hash_value( val );
+ split_list::details::search_value_type<Q const> sv( val, split_list::regular_hash( nHash ));
+ aux_node_type * pHead = get_bucket( nHash );
+ assert( pHead != nullptr );
+
+ return iterator( m_List.find_iterator_at( pHead, sv, cmp ), m_List.end());
+ }
+
+ template <typename Q, typename Compare>
+ guarded_ptr get_( Q const& val, Compare cmp )
+ {
+ size_t nHash = hash_value( val );
+ split_list::details::search_value_type<Q const> sv( val, split_list::regular_hash( nHash ));
+ aux_node_type * pHead = get_bucket( nHash );
+ assert( pHead != nullptr );
+
+ guarded_ptr gp = m_List.get_at( pHead, sv, cmp );
+ m_Stat.onFind( !gp.empty());
+ return gp;
+ }
+
+ template <typename Q>
+ guarded_ptr get_( Q const& key )
+ {
+ return get_( key, key_comparator());
+ }
+
+ template <typename Q, typename Less>
+ guarded_ptr get_with_( Q const& key, Less )
+ {
+ return get_( key, typename ordered_list_adapter::template make_compare_from_less<Less>());
+ }
+
+ template <typename Q, typename Compare, typename Func>
+ bool erase_( Q const& val, Compare cmp, Func f )
{
- return const_iterator( m_List.end(), m_List.end() );
+ size_t nHash = hash_value( val );
+ split_list::details::search_value_type<Q const> sv( val, split_list::regular_hash( nHash ));
+ aux_node_type * pHead = get_bucket( nHash );
+ assert( pHead != nullptr );
+
+ if ( m_List.erase_at( pHead, sv, cmp, f )) {
+ --m_ItemCounter;
+ m_Stat.onEraseSuccess();
+ return true;
+ }
+ m_Stat.onEraseFailed();
+ return false;
}
+ template <typename Q, typename Compare>
+ bool erase_( Q const& val, Compare cmp )
+ {
+ size_t nHash = hash_value( val );
+ split_list::details::search_value_type<Q const> sv( val, split_list::regular_hash( nHash ));
+ aux_node_type * pHead = get_bucket( nHash );
+ assert( pHead != nullptr );
+
+ if ( m_List.erase_at( pHead, sv, cmp )) {
+ --m_ItemCounter;
+ m_Stat.onEraseSuccess();
+ return true;
+ }
+ m_Stat.onEraseFailed();
+ return false;
+ }
+
+ template <typename Q, typename Compare>
+ guarded_ptr extract_( Q const& val, Compare cmp )
+ {
+ size_t nHash = hash_value( val );
+ split_list::details::search_value_type<Q const> sv( val, split_list::regular_hash( nHash ));
+ aux_node_type * pHead = get_bucket( nHash );
+ assert( pHead != nullptr );
+
+ guarded_ptr gp = m_List.extract_at( pHead, sv, cmp );
+ if ( gp ) {
+ --m_ItemCounter;
+ m_Stat.onExtractSuccess();
+ }
+ else
+ m_Stat.onExtractFailed();
+ return gp;
+ }
+
+ template <typename Q>
+ guarded_ptr extract_( Q const& key )
+ {
+ return extract_( key, key_comparator());
+ }
+
+ template <typename Q, typename Less>
+ guarded_ptr extract_with_( Q const& key, Less )
+ {
+ return extract_( key, typename ordered_list_adapter::template make_compare_from_less<Less>());
+ }
+ //@endcond
+
+ protected:
+ //@cond
+ static unsigned const c_padding = cds::opt::actual_padding< traits::padding >::value;
+
+ typedef typename cds::details::type_padding< bucket_table, c_padding >::type padded_bucket_table;
+ padded_bucket_table m_Buckets; ///< bucket table
+
+ typedef typename cds::details::type_padding< ordered_list_wrapper, c_padding >::type padded_ordered_list;
+ padded_ordered_list m_List; ///< Ordered list containing split-list items
+
+ atomics::atomic<size_t> m_nBucketCountLog2; ///< log2( current bucket count )
+ atomics::atomic<size_t> m_nMaxItemCount; ///< number of items container can hold, before we have to resize
+ item_counter m_ItemCounter; ///< Item counter
+ hash m_HashFunctor; ///< Hash functor
+ stat m_Stat; ///< Internal statistics
+ //@endcond
};
}} // namespace cds::intrusive
-#endif // #ifndef __CDS_INTRUSIVE_SPLIT_LIST_H
+#endif // #ifndef CDSLIB_INTRUSIVE_SPLIT_LIST_H
projects / libcds.git / blobdiff