/*
This file is a part of libcds - Concurrent Data Structures library
- (C) Copyright Maxim Khizhinsky (libcds.dev@gmail.com) 2006-2016
+ (C) Copyright Maxim Khizhinsky (libcds.dev@gmail.com) 2006-2017
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:
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.
+ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef CDSLIB_INTRUSIVE_STRIPED_SET_H
Note that the choose of resizing policy depends of \p Container type:
for sequential containers like \p boost::intrusive::list the right policy can significantly improve performance.
For other, non-sequential types of \p Container (like a \p boost::intrusive::set) the resizing policy is not so important.
- - \p cds::opt::buffer - a buffer type used only for \p boost::intrusive::unordered_set.
- Default is <tt>cds::opt::v::static_buffer< cds::any_type, 256 > </tt>.
+ - \p cds::opt::buffer - an initialized buffer type used only for \p boost::intrusive::unordered_set.
+ Default is <tt>cds::opt::v::initialized_static_buffer< cds::any_type, 256 > </tt>.
\p opt::compare or \p opt::less options are used in some \p Container class for ordering.
\p %opt::compare option has the highest priority: if \p %opt::compare is specified, \p %opt::less is not used.
You should provide two different hash function \p h1 and \p h2 - one for \p boost::intrusive::unordered_set
and other for \p %StripedSet. For the best result, \p h1 and \p h2 must be orthogonal i.e. <tt>h1(X) != h2(X)</tt> for any value \p X
- The option \p opt::buffer is used for \p boost::intrusive::bucket_traits. Default is <tt> cds::opt::v::static_buffer< cds::any_type, 256 > </tt>.
+ The option \p opt::buffer is used for \p boost::intrusive::bucket_traits.
+ Default is <tt> cds::opt::v::initialized_static_buffer< cds::any_type, 256 > </tt>.
The resizing policy should correlate with the buffer capacity.
The default resizing policy is <tt>cds::container::striped_set::load_factor_resizing<256> </tt> what gives load factor 1 for
default bucket buffer that is the best for \p boost::intrusive::unordered_set.
typedef cds::details::Allocator< bucket_type, allocator_type > bucket_allocator; ///< bucket allocator type based on allocator_type
protected:
- bucket_type * m_Buckets ; ///< Bucket table
- size_t m_nBucketMask ; ///< Bucket table size - 1. m_nBucketMask + 1 should be power of two.
- item_counter m_ItemCounter ; ///< Item counter
- hash m_Hash ; ///< Hash functor
+ bucket_type * m_Buckets; ///< Bucket table
+ atomics::atomic<size_t> m_nBucketMask; ///< Bucket table size - 1. m_nBucketMask + 1 should be power of two.
+ item_counter m_ItemCounter; ///< Item counter
+ hash m_Hash; ///< Hash functor
mutex_policy m_MutexPolicy ; ///< Mutex policy
resizing_policy m_ResizingPolicy; ///< Resizing policy
void alloc_bucket_table( size_t nSize )
{
assert( cds::beans::is_power2( nSize ));
- m_nBucketMask = nSize - 1;
+ m_nBucketMask.store( nSize - 1, atomics::memory_order_release );
m_Buckets = bucket_allocator().NewArray( nSize );
}
bucket_type * bucket( size_t nHash ) const CDS_NOEXCEPT
{
- return m_Buckets + (nHash & m_nBucketMask);
+ return m_Buckets + (nHash & m_nBucketMask.load( atomics::memory_order_relaxed ));
}
template <typename Q, typename Func>
for ( bucket_iterator it = pCur->begin(); it != itEnd; it = itNext ) {
itNext = it;
++itNext;
- bucket( m_Hash( *it ) )->move_item( *pCur, it );
+ bucket( m_Hash( *it ))->move_item( *pCur, it );
}
pCur->clear();
}
void resize()
{
- size_t nOldCapacity = bucket_count();
- size_t volatile& refBucketMask = m_nBucketMask;
+ size_t nOldCapacity = bucket_count( atomics::memory_order_acquire );
scoped_resize_lock al( m_MutexPolicy );
- if ( al.success() ) {
- if ( nOldCapacity != refBucketMask + 1 ) {
+ if ( al.success()) {
+ if ( nOldCapacity != bucket_count( atomics::memory_order_acquire )) {
// someone resized already
return;
}
/// Default ctor. The initial capacity is 16.
StripedSet()
: m_Buckets( nullptr )
- , m_nBucketMask( c_nMinimalCapacity - 1 )
- , m_MutexPolicy( c_nMinimalCapacity )
+ , m_nBucketMask( c_nMinimalCapacity - 1 )
+ , m_MutexPolicy( c_nMinimalCapacity )
{
- alloc_bucket_table( m_nBucketMask + 1 );
+ alloc_bucket_table( bucket_count());
}
/// Ctor with initial capacity specified
StripedSet(
size_t nCapacity ///< Initial size of bucket table and lock array. Must be power of two, the minimum is 16.
)
- : m_Buckets( nullptr )
- , m_nBucketMask( calc_init_capacity(nCapacity) - 1 )
- , m_MutexPolicy( m_nBucketMask + 1 )
+ : m_Buckets( nullptr )
+ , m_nBucketMask( calc_init_capacity(nCapacity) - 1 )
+ , m_MutexPolicy( bucket_count())
{
- alloc_bucket_table( m_nBucketMask + 1 );
+ alloc_bucket_table( bucket_count());
}
/// Ctor with resizing policy (copy semantics)
)
: m_Buckets( nullptr )
, m_nBucketMask( ( nCapacity ? calc_init_capacity(nCapacity) : c_nMinimalCapacity ) - 1 )
- , m_MutexPolicy( m_nBucketMask + 1 )
+ , m_MutexPolicy( bucket_count())
, m_ResizingPolicy( resizingPolicy )
{
- alloc_bucket_table( m_nBucketMask + 1 );
+ alloc_bucket_table( bucket_count());
}
/// Ctor with resizing policy (move semantics)
)
: m_Buckets( nullptr )
, m_nBucketMask( ( nCapacity ? calc_init_capacity(nCapacity) : c_nMinimalCapacity ) - 1 )
- , m_MutexPolicy( m_nBucketMask + 1 )
- , m_ResizingPolicy( std::forward<resizing_policy>( resizingPolicy ) )
+ , m_MutexPolicy( bucket_count())
+ , m_ResizingPolicy( std::forward<resizing_policy>( resizingPolicy ))
{
- alloc_bucket_table( m_nBucketMask + 1 );
+ alloc_bucket_table( bucket_count());
}
/// Destructor destroys internal data
~StripedSet()
{
- free_bucket_table( m_Buckets, m_nBucketMask + 1 );
+ free_bucket_table( m_Buckets, bucket_count());
}
public:
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 set.
*/
*/
size_t bucket_count() const
{
- return m_nBucketMask + 1;
+ return m_nBucketMask.load( atomics::memory_order_relaxed ) + 1;
}
+ //@cond
+ size_t bucket_count( atomics::memory_order load_mo ) const
+ {
+ return m_nBucketMask.load( load_mo ) + 1;
+ }
+ //@endcond
/// Returns lock array size
size_t lock_count() const