-//$$CDS-header$$
+/*
+ This file is a part of libcds - Concurrent Data Structures library
+
+ (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 {
Template parameters are:
- \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.
+ The intrusive ordered list implementation specifies the type \p T stored in the split-list set, the reclamation
+ schema \p GC used by 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 may use option-based syntax with \p split_list::make_traits metafunction.
+ @warning \p IterableList is not supported as \p OrderedList template parameter.
+
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
\ref cds_intrusive_SplitListSet_rcu "RCU-based split-list"
typedef typename traits::stat stat; ///< Internal statistics, see \p spit_list::stat
typedef typename ordered_list::guarded_ptr guarded_ptr; ///< Guarded pointer
+ /// Count of hazard pointer required
+ static CDS_CONSTEXPR const size_t c_nHazardPtrCount = ordered_list::c_nHazardPtrCount + 4; // +4 - for iterators
+
protected:
+ //@cond
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 node_type aux_node_type; ///< dummy node type
/// Split-list node traits
/**
*/
typedef split_list::node_traits<typename ordered_list::node_traits> node_traits;
- //@cond
/// Bucket table implementation
typedef typename split_list::details::bucket_table_selector<
traits::dynamic_bucket_table
, gc
- , dummy_node_type
+ , aux_node_type
, opt::allocator< typename traits::allocator >
, opt::memory_model< memory_model >
+ , opt::free_list< typename traits::free_list >
>::type bucket_table;
//@endcond
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> update_at( dummy_node_type * pHead, value_type& val, Func func, bool bAllowInsert )
+ 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::update_at( h, val, func, 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 guarded_ptr::native_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 guarded_ptr::native_guard& guard, split_list::details::search_value_type<Q> const& val, Compare cmp )
+ 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 );
};
//@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 )
- 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
-
- protected:
- //@cond
- 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 );
- }
- void free_dummy_node( dummy_node_type * p )
- {
- dummy_node_allocator().Delete( p );
- m_Stat.onHeadNodeFreed();
- }
-
- /// 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(memory_model::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 );
- m_Stat.onRecursiveInitBucket();
- }
-
- 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 );
- m_Stat.onNewBucket();
- 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.
- 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 * 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, cds::atomicity::empty_item_counter>::value,
- "cds::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 );
- }
-
- 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 ));
- dummy_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 ));
- dummy_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>
- bool get_( typename guarded_ptr::native_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 );
-
- return m_Stat.onFind( m_List.get_at( pHead, guard, sv, cmp ));
- }
-
- template <typename Q>
- bool get_( typename guarded_ptr::native_guard& guard, Q const& key )
- {
- return get_( guard, key, key_comparator());
- }
-
- template <typename Q, typename Less>
- bool get_with_( typename guarded_ptr::native_guard& guard, Q const& key, Less )
- {
- return get_( guard, key, typename wrapped_ordered_list::template make_compare_from_less<Less>());
- }
-
- template <typename Q, typename Compare, typename Func>
- bool erase_( Q const& val, Compare cmp, Func f )
- {
- 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;
- 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 ));
- dummy_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>
- bool extract_( typename guarded_ptr::native_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 );
-
- if ( m_List.extract_at( pHead, guard, sv, cmp )) {
- --m_ItemCounter;
- m_Stat.onExtractSuccess();
- return true;
- }
- m_Stat.onExtractFailed();
- return false;
- }
-
- template <typename Q>
- bool extract_( typename guarded_ptr::native_guard& guard, Q const& key )
- {
- return extract_( guard, key, key_comparator());
- }
-
- template <typename Q, typename Less>
- bool extract_with_( typename guarded_ptr::native_guard& guard, Q const& key, Less )
- {
- return extract_( guard, key, typename wrapped_ordered_list::template make_compare_from_less<Less>());
- }
- //@endcond
-
public:
/// Initialize split-ordered list of default capacity
/**
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 );
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 );
The functor may change non-key fields of the \p item.
- Returns std::pair<bool, bool> where \p first is \p true if operation is successfull,
+ 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.
std::pair<bool, bool> update( value_type& val, Func func, bool bAllowInsert = true )
{
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.update_at( pHead, val, func, bAllowInsert );
if ( bRet.first && bRet.second ) {
inc_item_count();
- m_Stat.onEnsureNew();
+ m_Stat.onUpdateNew();
}
else
- m_Stat.onEnsureExist();
+ m_Stat.onUpdateExist();
return bRet;
}
//@cond
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 )) {
template <typename Q>
guarded_ptr extract( Q const& key )
{
- guarded_ptr gp;
- extract_( gp.guard(), key );
- return gp;
+ return extract_( key );
}
/// Extracts the item using compare functor \p pred
template <typename Q, typename Less>
guarded_ptr extract_with( Q const& key, Less pred )
{
- guarded_ptr gp;
- extract_with_( gp.guard(), key, pred );
- return gp;
+ return extract_with_( key, pred );
}
/// Finds the key \p key
template <typename Q>
guarded_ptr get( Q const& key )
{
- guarded_ptr gp;
- get_( gp.guard(), key );
- return gp;
+ return get_( key );
}
/// Finds the key \p key and return the item found
template <typename Q, typename Less>
guarded_ptr get_with( Q const& key, Less pred )
{
- guarded_ptr gp;
- get_with_( gp.guard(), key, pred );
- return gp;
+ return get_with_( key, pred );
}
/// Returns item count in the set
};
//@endcond
public:
+ ///@name Forward iterators (only for debugging purpose)
+ //@{
/// Forward iterator
/**
The forward iterator for a split-list has some features:
- 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.
+ 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.
- Therefore, the use of iterators in concurrent environment is not good idea. Use the iterator on the concurrent container
- for debug purpose only.
+ @warning Use this iterator on the concurrent container for debugging purpose only.
*/
typedef iterator_type<false> iterator;
+
/// Const forward iterator
/**
For iterator's features and requirements see \ref iterator
{
return const_iterator( m_List.cend(), m_List.cend());
}
+ //@}
+
+ protected:
+ //@cond
+ aux_node_type * alloc_aux_node( size_t nHash )
+ {
+ m_Stat.onHeadNodeAllocated();
+ aux_node_type* p = m_Buckets.alloc_aux_node();
+ if ( p )
+ p->m_nHash = nHash;
+ return p;
+ }
+
+ void free_aux_node( aux_node_type * p )
+ {
+ m_Buckets.free_aux_node( p );
+ m_Stat.onHeadNodeFreed();
+ }
+
+ /// 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( memory_model::memory_order_relaxed )) - 1);
+ }
+
+ static size_t parent_bucket( size_t nBucket )
+ {
+ assert( nBucket > 0 );
+ return nBucket & ~(1 << bitop::MSBnz( nBucket ));
+ }
+
+ aux_node_type * init_bucket( size_t nBucket )
+ {
+ assert( nBucket > 0 );
+ size_t nParent = parent_bucket( nBucket );
+
+ aux_node_type * pParentBucket = m_Buckets.bucket( nParent );
+ if ( pParentBucket == nullptr ) {
+ pParentBucket = init_bucket( nParent );
+ m_Stat.onRecursiveInitBucket();
+ }
+
+ assert( pParentBucket != nullptr );
+
+ // Allocate a dummy node for new bucket
+ aux_node_type * pBucket;
+ if ( ( pBucket = m_Buckets.bucket( nBucket )) == nullptr ) {
+ 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;
+ }
+ else {
+ // Another thread set the bucket. Wait while it done
+ free_aux_node( pBucket );
+ }
+ }
+ else {
+ // There are no free buckets. It means that the bucket table is full
+ // Wait while another thread set th bucket
+ m_Stat.onBucketsExhausted();
+ }
+ }
+ else
+ return 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.
+
+ m_Stat.onBucketInitContenton();
+ back_off bkoff;
+ while ( true ) {
+ aux_node_type volatile * p = m_Buckets.bucket( nBucket );
+ if ( p != nullptr )
+ return const_cast<aux_node_type *>(p);
+ bkoff();
+ m_Stat.onBusyWaitBucketInit();
+ }
+ }
+
+ aux_node_type * get_bucket( size_t nHash )
+ {
+ 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;
+ }
+
+ 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, 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 );
+ }
+
+ 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>
+ 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 wrapped_ordered_list::template make_compare_from_less<Less>() );
+ }
+
+ template <typename Q, typename Compare, typename Func>
+ bool erase_( Q const& val, Compare cmp, Func f )
+ {
+ 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 wrapped_ordered_list::template make_compare_from_less<Less>() );
+ }
+ //@endcond
+
+ protected:
+ //@cond
+ typedef typename cds::details::type_padding< bucket_table, traits::padding >::type padded_bucket_table;
+ padded_bucket_table m_Buckets; ///< bucket table
+
+ typedef typename cds::details::type_padding< ordered_list_wrapper, traits::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
projects / libcds.git / blobdiff