-//$$CDS-header$$
+/*
+ This file is a part of libcds - Concurrent Data Structures library
-#ifndef __CDS_INTRUSIVE_MICHAEL_SET_RCU_H
-#define __CDS_INTRUSIVE_MICHAEL_SET_RCU_H
+ (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:
+
+ * 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_MICHAEL_SET_RCU_H
+#define CDSLIB_INTRUSIVE_MICHAEL_SET_RCU_H
#include <cds/intrusive/details/michael_set_base.h>
-#include <cds/details/allocator.h>
namespace cds { namespace intrusive {
class MichaelHashSet< cds::urcu::gc< RCU >, OrderedList, Traits >
{
public:
- typedef cds::urcu::gc< RCU > gc; ///< RCU schema
- typedef OrderedList bucket_type; ///< type of ordered list used as a bucket implementation
- typedef Traits traits; ///< Set traits
+ typedef cds::urcu::gc< RCU > gc; ///< RCU schema
+ typedef OrderedList ordered_list; ///< type of ordered list used as a bucket implementation
+ typedef Traits traits; ///< Set traits
- typedef typename bucket_type::value_type value_type ; ///< type of value stored in the list
- typedef typename bucket_type::key_comparator key_comparator ; ///< key comparing functor
- typedef typename bucket_type::disposer disposer ; ///< Node disposer functor
+ typedef typename ordered_list::value_type value_type; ///< type of value stored in the list
+ typedef typename ordered_list::key_comparator key_comparator; ///< key comparing functor
+ typedef typename ordered_list::disposer disposer; ///< Node disposer functor
+#ifdef CDS_DOXYGEN_INVOKED
+ typedef typename ordered_list::stat stat; ///< Internal statistics
+#endif
/// Hash functor for \ref value_type and all its derivatives that you use
typedef typename cds::opt::v::hash_selector< typename traits::hash >::type hash;
typedef typename traits::item_counter item_counter; ///< Item counter type
+ typedef typename traits::allocator allocator; ///< Bucket table allocator
- /// Bucket table allocator
- typedef cds::details::Allocator< bucket_type, typename traits::allocator > bucket_table_allocator;
-
- typedef typename bucket_type::rcu_lock rcu_lock; ///< RCU scoped lock
- typedef typename bucket_type::exempt_ptr exempt_ptr; ///< pointer to extracted node
+ typedef typename ordered_list::rcu_lock rcu_lock; ///< RCU scoped lock
/// Group of \p extract_xxx functions require external locking if underlying ordered list requires that
- static CDS_CONSTEXPR const bool c_bExtractLockExternal = bucket_type::c_bExtractLockExternal;
+ static CDS_CONSTEXPR const bool c_bExtractLockExternal = ordered_list::c_bExtractLockExternal;
- protected:
- item_counter m_ItemCounter; ///< Item counter
- hash m_HashFunctor; ///< Hash functor
- bucket_type * m_Buckets; ///< bucket table
+ // 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");
- private:
+ // 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");
+
+ protected:
//@cond
- const size_t m_nHashBitmask;
+ typedef typename ordered_list::template select_stat_wrapper< typename ordered_list::stat > bucket_stat;
+
+ typedef typename ordered_list::template rebind_traits<
+ cds::opt::item_counter< cds::atomicity::empty_item_counter >
+ , cds::opt::stat< typename bucket_stat::wrapped_stat >
+ >::type internal_bucket_type;
+
+ typedef typename allocator::template rebind< internal_bucket_type >::other bucket_table_allocator;
//@endcond
- protected:
+ public:
+ typedef typename internal_bucket_type::exempt_ptr exempt_ptr; ///< pointer to extracted node
+ typedef typename internal_bucket_type::raw_ptr raw_ptr; ///< Return type of \p get() member function and its derivatives
+
//@cond
- /// Calculates hash value of \p key
- template <typename Q>
- size_t hash_value( Q const& key ) const
- {
- return m_HashFunctor( key ) & m_nHashBitmask;
- }
+ typedef typename bucket_stat::stat stat;
+ //@endcond
- /// Returns the bucket (ordered list) for \p key
- template <typename Q>
- bucket_type& bucket( Q const& key )
- {
- return m_Buckets[ hash_value( key ) ];
- }
- template <typename Q>
- bucket_type const& bucket( Q const& key ) const
- {
- return m_Buckets[ hash_value( key ) ];
- }
+ private:
+ //@cond
+ hash m_HashFunctor; ///< Hash functor
+ size_t const m_nHashBitmask;
+ internal_bucket_type* m_Buckets; ///< bucket table
+ item_counter m_ItemCounter; ///< Item counter
+ stat m_Stat; ///< Internal statistics
//@endcond
public:
+ ///@name Forward iterators (thread-safe under RCU lock)
+ //@{
/// Forward iterator
/**
The forward iterator for Michael's set is based on \p OrderedList forward iterator and has some features:
- it has no post-increment operator
- it iterates items in unordered fashion
+
+ You may safely use iterators in multi-threaded environment only under RCU lock.
+ Otherwise, a crash is possible if another thread deletes the element the iterator points to.
+
+ The iterator interface:
+ \code
+ class iterator {
+ public:
+ // Default constructor
+ iterator();
+
+ // Copy construtor
+ iterator( iterator const& src );
+
+ // Dereference operator
+ value_type * operator ->() const;
+
+ // Dereference operator
+ value_type& operator *() const;
+
+ // Preincrement operator
+ iterator& operator ++();
+
+ // Assignment operator
+ iterator& operator = (iterator const& src);
+
+ // Equality operators
+ bool operator ==(iterator const& i ) const;
+ bool operator !=(iterator const& i ) const;
+ };
+ \endcode
*/
- typedef michael_set::details::iterator< bucket_type, false > iterator;
+ typedef michael_set::details::iterator< internal_bucket_type, false > iterator;
/// Const forward iterator
/**
For iterator's features and requirements see \ref iterator
*/
- typedef michael_set::details::iterator< bucket_type, true > const_iterator;
+ typedef michael_set::details::iterator< internal_bucket_type, true > const_iterator;
/// Returns a forward iterator addressing the first element in a set
/**
*/
iterator begin()
{
- return iterator( m_Buckets[0].begin(), m_Buckets, m_Buckets + bucket_count() );
+ return iterator( m_Buckets[0].begin(), m_Buckets, m_Buckets + bucket_count());
}
/// Returns an iterator that addresses the location succeeding the last element in a set
*/
iterator end()
{
- return iterator( m_Buckets[bucket_count() - 1].end(), m_Buckets + bucket_count() - 1, m_Buckets + bucket_count() );
+ return iterator( m_Buckets[bucket_count() - 1].end(), m_Buckets + bucket_count() - 1, m_Buckets + bucket_count());
}
/// Returns a forward const iterator addressing the first element in a set
- //@{
const_iterator begin() const
{
return cbegin();
}
+
+ /// Returns a forward const iterator addressing the first element in a set
const_iterator cbegin() const
{
- return const_iterator( m_Buckets[0].cbegin(), m_Buckets, m_Buckets + bucket_count() );
+ return const_iterator( m_Buckets[0].cbegin(), m_Buckets, m_Buckets + bucket_count());
}
- //@}
/// Returns an const iterator that addresses the location succeeding the last element in a set
- //@{
const_iterator end() const
{
return cend();
}
+
+ /// Returns an const iterator that addresses the location succeeding the last element in a set
const_iterator cend() const
{
- return const_iterator( m_Buckets[bucket_count() - 1].cend(), m_Buckets + bucket_count() - 1, m_Buckets + bucket_count() );
+ return const_iterator( m_Buckets[bucket_count() - 1].cend(), m_Buckets + bucket_count() - 1, m_Buckets + bucket_count());
}
- //@}
+ //@}
public:
/// Initialize hash set
size_t nMaxItemCount, ///< estimation of max item count in the hash set
size_t nLoadFactor ///< load factor: average size of the bucket
) : m_nHashBitmask( michael_set::details::init_hash_bitmask( nMaxItemCount, nLoadFactor ))
+ , m_Buckets( bucket_table_allocator().allocate( bucket_count()))
{
- // GC and OrderedList::gc must be the same
- static_assert( std::is_same<gc, typename bucket_type::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");
-
- m_Buckets = bucket_table_allocator().NewArray( bucket_count() );
+ for ( auto it = m_Buckets, itEnd = m_Buckets + bucket_count(); it != itEnd; ++it )
+ construct_bucket<bucket_stat>( it );
}
/// Clear hash set and destroy it
~MichaelHashSet()
{
clear();
- bucket_table_allocator().Delete( m_Buckets, bucket_count() );
+
+ for ( auto it = m_Buckets, itEnd = m_Buckets + bucket_count(); it != itEnd; ++it )
+ it->~internal_bucket_type();
+ bucket_table_allocator().deallocate( m_Buckets, bucket_count());
}
/// Inserts new node
return bRet;
}
- /// Ensures that the \p item exists in the set
+ /// Updates the element
/**
The operation performs inserting or changing data with lock-free manner.
- If the item \p val not found in the set, then \p val is inserted into the set.
+ If the item \p val 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 );
+ 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 ensure function
+ - \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 can change non-key fields of the \p item.
+ 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 <tt> std::pair<bool, bool> </tt> 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 key
already is in the set.
- @warning For \ref cds_intrusive_MichaelList_rcu "MichaelList" as the bucket see \ref cds_intrusive_item_creating "insert item troubleshooting".
- \ref cds_intrusive_LazyList_rcu "LazyList" provides exclusive access to inserted item and does not require any node-level
+ @warning For \ref cds_intrusive_MichaelList_hp "MichaelList" as the bucket see \ref cds_intrusive_item_creating "insert item troubleshooting".
+ \ref cds_intrusive_LazyList_hp "LazyList" provides exclusive access to inserted item and does not require any node-level
synchronization.
- */
+ */
template <typename Func>
- std::pair<bool, bool> ensure( value_type& val, Func func )
+ std::pair<bool, bool> update( value_type& val, Func func, bool bAllowInsert = true )
{
- std::pair<bool, bool> bRet = bucket( val ).ensure( val, func );
- if ( bRet.first && bRet.second )
+ std::pair<bool, bool> bRet = bucket( val ).update( val, func, bAllowInsert );
+ if ( bRet.second )
++m_ItemCounter;
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
/// Unlinks the item \p val from the set
/**
void operator()( value_type const& item );
};
\endcode
- The functor may be passed by reference with <tt>boost:ref</tt>
If the item with key equal to \p key is not found the function return \p false.
/// Extracts an item from the set
/** \anchor cds_intrusive_MichaelHashSet_rcu_extract
The function searches an item with key equal to \p key in the set,
- unlinks it from the set, places item pointer into \p dest argument, and returns \p true.
- If the item with the key equal to \p key is not found the function return \p false.
+ unlinks it from the set, and returns \ref cds::urcu::exempt_ptr "exempt_ptr" pointer to the item found.
+ If the item with the key equal to \p key is not found the function returns an empty \p exempt_ptr.
- @note The function does NOT call RCU read-side lock or synchronization,
- and does NOT dispose the item found. It just excludes the item from the set
- and returns a pointer to item found.
- You should lock RCU before calling of the function, and you should synchronize RCU
- outside the RCU lock before reusing returned pointer.
+ Depends on \p ordered_list you should or should not lock RCU before calling of this function:
+ - for the set based on \ref cds_intrusive_MichaelList_rcu "MichaelList" RCU should not be locked
+ - for the set based on \ref cds_intrusive_LazyList_rcu "LazyList" RCU should be locked
+
+ See ordered list implementation for details.
\code
#include <cds/urcu/general_buffered.h>
rcu_michael_set theSet;
// ...
- rcu_michael_set::exempt_ptr p;
- {
- // first, we should lock RCU
- rcu_michael_set::rcu_lock lock;
-
- // Now, you can apply extract function
- // Note that you must not delete the item found inside the RCU lock
- if ( theSet.extract( p, 10 )) {
- // do something with p
- ...
- }
+ typename rcu_michael_set::exempt_ptr p;
+
+ // For MichaelList we should not lock RCU
+
+ // Now, you can apply extract function
+ // Note that you must not delete the item found inside the RCU lock
+ p = theSet.extract( 10 )
+ if ( p ) {
+ // do something with p
+ ...
}
// We may safely release p here
\endcode
*/
template <typename Q>
- bool extract( exempt_ptr& dest, Q const& key )
+ exempt_ptr extract( Q const& key )
{
- if ( bucket( key ).extract( dest, key )) {
+ exempt_ptr p( bucket( key ).extract( key ));
+ if ( p )
--m_ItemCounter;
- return true;
- }
- return false;
+ return p;
}
/// Extracts an item from the set using \p pred predicate for searching
/**
- The function is an analog of \ref cds_intrusive_MichaelHashSet_rcu_extract "extract(exempt_ptr&, Q const&)"
- but \p pred is used for key comparing.
+ The function is an analog of \p extract(Q const&) 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.
*/
template <typename Q, typename Less>
- bool extract_with( exempt_ptr& dest, Q const& key, Less pred )
+ exempt_ptr extract_with( Q const& key, Less pred )
{
- if ( bucket( key ).extract_with( dest, key, pred )) {
+ exempt_ptr p( bucket( key ).extract_with( key, pred ));
+ if ( p )
--m_ItemCounter;
- return true;
- }
- return false;
+ return p;
}
- /// Finds the key \p key
- /** \anchor cds_intrusive_MichaelHashSet_rcu_find_val
+ /// Checks whether the set contains \p key
+ /**
+
The function searches the item with key equal to \p key
- and returns \p true if \p key found or \p false otherwise.
+ and returns \p true if the key 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.
*/
template <typename Q>
- bool find( Q const& key ) const
+ bool contains( Q const& key )
+ {
+ return bucket( key ).contains( key );
+ }
+ //@cond
+ template <typename Q>
+ CDS_DEPRECATED("use contains()")
+ bool find( Q const& key )
{
- return bucket( key ).find( key );
+ return contains( key );
}
+ //@endcond
- /// Finds the key \p key using \p pred predicate for searching
+ /// Checks whether the set contains \p key using \p pred predicate for searching
/**
- The function is an analog of \ref cds_intrusive_MichaelHashSet_rcu_find_val "find(Q const&)"
- but \p pred is used for key comparing.
+ 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 pred must imply the same element order as the comparator used for building the set.
+ \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& key, Less pred ) const
+ bool contains( Q const& key, Less pred )
+ {
+ return bucket( key ).contains( key, pred );
+ }
+ //@cond
+ template <typename Q, typename Less>
+ CDS_DEPRECATED("use contains()")
+ bool find_with( Q const& key, Less pred )
{
- return bucket( key ).find_with( key, pred );
+ return contains( key, pred );
}
+ //@endcond
/// Find the key \p key
/** \anchor cds_intrusive_MichaelHashSet_rcu_find_func
The function returns \p true if \p key is found, \p false otherwise.
*/
template <typename Q, typename Func>
- bool find( Q& key, Func f ) const
+ bool find( Q& key, Func f )
+ {
+ return bucket( key ).find( key, f );
+ }
+ //@cond
+ template <typename Q, typename Func>
+ bool find( Q const& key, Func f )
{
return bucket( key ).find( key, f );
}
+ //@endcond
/// Finds the key \p key using \p pred predicate for searching
/**
\p pred 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& key, Less pred, Func f ) const
+ bool find_with( Q& key, Less pred, Func f )
{
return bucket( key ).find_with( key, pred, f );
}
+ //@cond
+ template <typename Q, typename Less, typename Func>
+ bool find_with( Q const& key, Less pred, Func f )
+ {
+ return bucket( key ).find_with( key, pred, f );
+ }
+ //@endcond
/// Finds the key \p key and return the item found
/** \anchor cds_intrusive_MichaelHashSet_rcu_get
The function searches the item with key equal to \p key and returns the pointer to item found.
If \p key is not found it returns \p nullptr.
+ Note the type of returned value depends on underlying \p ordered_list.
+ For details, see documentation of ordered list you use.
Note the compare functor should accept a parameter of type \p Q that can be not the same as \p value_type.
typedef cds::intrusive::MichaelHashSet< your_template_parameters > hash_set;
hash_set theSet;
// ...
+ // Result of get() call
+ typename hash_set::raw_ptr ptr;
{
// Lock RCU
hash_set::rcu_lock lock;
- foo * pVal = theSet.get( 5 );
- if ( pVal ) {
- // Deal with pVal
+ ptr = theSet.get( 5 );
+ if ( ptr ) {
+ // Deal with ptr
//...
}
// Unlock RCU by rcu_lock destructor
- // pVal can be retired by disposer at any time after RCU has been unlocked
+ // ptr can be reclaimed by disposer at any time after RCU has been unlocked
}
\endcode
*/
template <typename Q>
- value_type * get( Q const& key ) const
+ raw_ptr get( Q const& key )
{
return bucket( key ).get( key );
}
\p pred must imply the same element order as the comparator used for building the set.
*/
template <typename Q, typename Less>
- value_type * get_with( Q const& key, Less pred ) const
+ raw_ptr get_with( Q const& key, Less pred )
{
return bucket( key ).get_with( key, pred );
}
return m_nHashBitmask + 1;
}
+ /// Returns const reference to internal statistics
+ stat const& statistics() const
+ {
+ return m_Stat;
+ }
+
+ private:
+ //@cond
+ template <typename Stat>
+ typename std::enable_if< Stat::empty >::type construct_bucket( internal_bucket_type * bucket )
+ {
+ new (bucket) internal_bucket_type;
+ }
+
+ template <typename Stat>
+ typename std::enable_if< !Stat::empty >::type construct_bucket( internal_bucket_type * bucket )
+ {
+ new (bucket) internal_bucket_type( m_Stat );
+ }
+
+ /// Calculates hash value of \p key
+ template <typename Q>
+ size_t hash_value( Q const& key ) const
+ {
+ return m_HashFunctor( key ) & m_nHashBitmask;
+ }
+
+ /// Returns the bucket (ordered list) for \p key
+ template <typename Q>
+ internal_bucket_type& bucket( Q const& key )
+ {
+ return m_Buckets[hash_value( key )];
+ }
+ template <typename Q>
+ internal_bucket_type const& bucket( Q const& key ) const
+ {
+ return m_Buckets[hash_value( key )];
+ }
+ //@endcond
};
}} // namespace cds::intrusive
-#endif // #ifndef __CDS_INTRUSIVE_MICHAEL_SET_NOGC_H
-
+#endif // #ifndef CDSLIB_INTRUSIVE_MICHAEL_SET_NOGC_H
projects / libcds.git / blobdiff