-//$$CDS-header$$
+/*
+ This file is a part of libcds - Concurrent Data Structures library
-#ifndef __CDS_CONTAINER_MICHAEL_SET_H
-#define __CDS_CONTAINER_MICHAEL_SET_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_CONTAINER_MICHAEL_SET_H
+#define CDSLIB_CONTAINER_MICHAEL_SET_H
#include <cds/container/details/michael_set_base.h>
+#include <cds/container/details/iterable_list_base.h>
#include <cds/details/allocator.h>
namespace cds { namespace container {
Template parameters are:
- \p GC - Garbage collector used. You may use any \ref cds_garbage_collector "Garbage collector"
from the \p libcds library.
- 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.
- The 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 michael_set::type_traits for explanation.
-
- Instead of defining \p Traits struct you may use option-based syntax with michael_set::make_traits metafunction.
- For michael_set::make_traits the following option may be used:
- - opt::hash - mandatory option, specifies hash functor.
- - opt::item_counter - optional, specifies item counting policy. See michael_set::type_traits for explanation.
- - opt::allocator - optional, bucket table allocator. Default is \ref CDS_DEFAULT_ALLOCATOR.
+ Note the \p GC must be the same as the \p GC used for \p OrderedList
+ - \p OrderedList - ordered list implementation used as bucket for hash set, possible implementations:
+ \p MichaelList, \p LazyList, \p IterableList.
+ The ordered list implementation specifies the type \p T to be stored in the hash-set,
+ the comparing functor for the type \p T and other features specific for the ordered list.
+ - \p Traits - set traits, default is \p michael_set::traits.
+ Instead of defining \p Traits struct you may use option-based syntax with \p michael_set::make_traits metafunction.
There are the specializations:
- for \ref cds_urcu_desc "RCU" - declared in <tt>cd/container/michael_set_rcu.h</tt>,
It is expected that type \p Q contains full key of node type \p value_type, and if keys of type \p Q and \p value_type
are equal 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 {
- std::string key_ ; // key field
+ std::string key_; // key field
// ... other fields
};
};
\endcode
- <b>Iterators</b>
-
- The class supports a forward iterator (\ref iterator and \ref const_iterator).
- The iteration is unordered.
- The iterator object is thread-safe: the element pointed by the iterator object is guarded,
- so, the element cannot be reclaimed while the iterator object is alive.
- However, passing an iterator object between threads is dangerous.
-
- \warning Due to concurrent nature of Michael's set it is not guarantee that you can iterate
- all elements in the set: any concurrent deletion can exclude the element
- pointed by the iterator from the set, and your iteration can be terminated
- before end of the set. Therefore, such iteration is more suitable for debugging purpose only
-
- Remember, each iterator object requires an additional hazard pointer, that may be
- a limited resource for \p GC like \p gc::HP (for gc::PTB the count of
- guards is unlimited).
-
- The iterator class supports the following minimalistic interface:
- \code
- struct iterator {
- // Default ctor
- iterator();
-
- // Copy ctor
- iterator( iterator const& s);
-
- value_type * operator ->() const;
- value_type& operator *() const;
-
- // Pre-increment
- iterator& operator ++();
-
- // Copy assignment
- iterator& operator = (const iterator& src);
-
- bool operator ==(iterator const& i ) const;
- bool operator !=(iterator const& i ) const;
- };
- \endcode
- Note, the iterator object returned by \ref end, \p cend member functions points to \p nullptr and should not be dereferenced.
-
<b>How to use</b>
- Suppose, we have the following type \p Foo that we want to store in our MichaelHashSet:
+ Suppose, we have the following type \p Foo that we want to store in our \p %MichaelHashSet:
\code
struct Foo {
- int nKey ; // key field
- int nVal ; // value field
+ int nKey; // key field
+ int nVal; // value field
};
\endcode
To use \p %MichaelHashSet for \p Foo values, you should first choose suitable ordered list class
- that will be used as a bucket for the set. We will use gc::PTB reclamation schema and
- MichaelList as a bucket type. Also, for ordered list we should develop a comparator for our \p Foo
+ that will be used as a bucket for the set. We will use \p gc::DHP reclamation schema and
+ \p MichaelList as a bucket type. Also, for ordered list we should develop a comparator for our \p Foo
struct.
\code
#include <cds/container/michael_list_dhp.h>
};
// Our ordered list
- typedef cc::MichaelList< cds::gc::PTB, Foo,
+ typedef cc::MichaelList< cds::gc::DHP, Foo,
typename cc::michael_list::make_traits<
cc::opt::compare< Foo_cmp > // item comparator option
>::type
// Declare set type.
// Note that \p GC template parameter of ordered list must be equal \p GC for the set.
- typedef cc::MichaelHashSet< cds::gc::PTB, bucket_list,
+ typedef cc::MichaelHashSet< cds::gc::DHP, bucket_list,
cc::michael_set::make_traits<
cc::opt::hash< foo_hash >
>::type
class GC,
class OrderedList,
#ifdef CDS_DOXYGEN_INVOKED
- class Traits = michael_set::type_traits
+ class Traits = michael_set::traits
#else
class Traits
#endif
class MichaelHashSet
{
public:
- typedef OrderedList bucket_type ; ///< type of ordered list used as a bucket implementation
- typedef Traits options ; ///< Traits template parameters
+ typedef GC gc; ///< Garbage collector
+ 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 GC gc ; ///< Garbage collector
- typedef typename bucket_type::key_comparator key_comparator ; ///< key comparison functor
+ typedef typename ordered_list::value_type value_type; ///< type of value to be stored in the list
+ typedef typename ordered_list::key_comparator key_comparator; ///< key comparison 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 options::hash >::type hash;
- typedef typename options::item_counter item_counter ; ///< Item counter type
+ 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 options::allocator > bucket_table_allocator;
+ static CDS_CONSTEXPR const size_t c_nHazardPtrCount = ordered_list::c_nHazardPtrCount; ///< Count of hazard pointer required
- typedef typename bucket_type::guarded_ptr guarded_ptr; ///< Guarded pointer
+ // 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");
- protected:
- item_counter m_ItemCounter ; ///< Item counter
- hash m_HashFunctor ; ///< Hash functor
+ // atomicity::empty_item_counter is not allowed as a item counter
+ static_assert( !std::is_same<item_counter, atomicity::empty_item_counter>::value,
+ "cds::atomicity::empty_item_counter is not allowed as a item counter");
- bucket_type * m_Buckets ; ///< bucket table
-
- private:
//@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;
+
+ /// Bucket table allocator
+ typedef typename allocator::template rebind< internal_bucket_type >::other bucket_table_allocator;
+
+ typedef typename bucket_stat::stat stat;
//@endcond
- protected:
- /// Calculates hash value of \p key
- template <typename Q>
- size_t hash_value( Q const& key ) const
- {
- return m_HashFunctor( key ) & m_nHashBitmask;
- }
+ /// Guarded pointer - a result of \p get() and \p extract() functions
+ typedef typename internal_bucket_type::guarded_ptr guarded_ptr;
- /// Returns the bucket (ordered list) for \p key
- template <typename Q>
- bucket_type& bucket( Q const& key )
- {
- return m_Buckets[ hash_value( key ) ];
- }
+ protected:
+ //@cond
+ size_t const m_nHashBitmask;
+ internal_bucket_type * m_Buckets; ///< bucket table
+ item_counter m_ItemCounter; ///< Item counter
+ hash m_HashFunctor; ///< Hash functor
+ stat m_Stat; ///< Internal statistics
+ //@endcond
public:
+ ///@name Forward iterators
+ //@{
/// Forward iterator
- typedef michael_set::details::iterator< bucket_type, false > iterator;
+ /**
+ The forward iterator for Michael's set has some features:
+ - it has no post-increment operator
+ - to protect the value, the iterator contains a GC-specific guard + another guard is required locally for increment operator.
+ For some GC (like as \p gc::HP), a guard is a limited resource per thread, so an exception (or assertion) "no free guard"
+ may be thrown if the limit of guard count per thread is exceeded.
+ - The iterator cannot be moved across thread boundary because it contains thread-private GC's guard.
+
+ 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.
+
+ 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
+ */
+
+ /// Forward iterator
+ typedef michael_set::details::iterator< internal_bucket_type, false > iterator;
/// Const forward 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( bucket_begin()->begin(), bucket_begin(), bucket_end());
}
/// 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( bucket_end()[-1].end(), bucket_end() - 1, bucket_end());
}
/// Returns a forward const iterator addressing the first element in a set
- //@{
const_iterator begin() const
{
return get_const_begin();
}
- const_iterator cbegin()
+
+ /// Returns a forward const iterator addressing the first element in a set
+ const_iterator cbegin() const
{
return get_const_begin();
}
- //@}
/// Returns an const iterator that addresses the location succeeding the last element in a set
- //@{
const_iterator end() const
{
return get_const_end();
}
- const_iterator cend()
- {
- return get_const_end();
- }
- //@}
- private:
- //@cond
- const_iterator get_const_begin() const
- {
- return const_iterator( const_cast<bucket_type const&>(m_Buckets[0]).begin(), m_Buckets, m_Buckets + bucket_count() );
- }
- const_iterator get_const_end() const
+ /// Returns an const iterator that addresses the location succeeding the last element in a set
+ const_iterator cend() const
{
- return const_iterator( const_cast<bucket_type const&>(m_Buckets[bucket_count() - 1]).end(), m_Buckets + bucket_count() - 1, m_Buckets + bucket_count() );
+ return get_const_end();
}
- //@endcond
+ //@}
public:
/// Initialize hash set
when you create an object.
\p nLoadFactor parameter defines average count of items per bucket and it should be small number between 1 and 10.
Remember, since the bucket implementation is an ordered list, searching in the bucket is linear [<tt>O(nLoadFactor)</tt>].
- Note, that many popular STL hash map implementation uses load factor 1.
- The ctor defines hash table size as rounding <tt>nMacItemCount / nLoadFactor</tt> up to nearest power of two.
+ The ctor defines hash table size as rounding <tt>nMaxItemCount / nLoadFactor</tt> up to nearest power of two.
*/
MichaelHashSet(
size_t nMaxItemCount, ///< estimation of max item count in the hash set
size_t nLoadFactor ///< load factor: estimation of max number of items in 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
+ /// Clears hash set and destroys 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
Returns \p true if \p val is inserted into the set, \p false otherwise.
*/
template <typename Q>
- bool insert( Q const& val )
+ bool insert( Q&& val )
{
- const bool bRet = bucket( val ).insert( val );
+ const bool bRet = bucket( val ).insert( std::forward<Q>( val ));
if ( bRet )
++m_ItemCounter;
return bRet;
\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. It may be passed by reference
- using \p std::ref
+ where \p val is the item inserted.
+ The user-defined functor is called only if the inserting is success.
+
+ @warning For \ref cds_nonintrusive_MichaelList_gc "MichaelList" and \ref cds_nonintrusive_IterableList_gc "IterableList"
+ as the bucket see \ref cds_intrusive_item_creating "insert item troubleshooting".
+ @ref cds_nonintrusive_LazyList_gc "LazyList" provides exclusive access to inserted item and does not require any node-level
+ synchronization.
*/
template <typename Q, typename Func>
- bool insert( Q const& val, Func f )
+ bool insert( Q&& val, Func f )
{
- const bool bRet = bucket( val ).insert( val, f );
+ const bool bRet = bucket( val ).insert( std::forward<Q>( val ), f );
if ( bRet )
++m_ItemCounter;
return bRet;
}
- /// Ensures that the item exists in the set
+ /// Updates the element
/**
The operation performs inserting or changing data with lock-free manner.
- If the \p val key not found in the set, then the new item created from \p val
- is inserted into the set. Otherwise, the functor \p func is called with the item found.
- The functor \p Func should be a function with signature:
- \code
- void func( bool bNew, value_type& item, const Q& val );
- \endcode
- or a functor:
+ 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 \p func signature depends of \p OrderedList:
+
+ <b>for \p MichaelList, \p LazyList</b>
\code
- struct my_functor {
- void operator()( bool bNew, value_type& item, const Q& val );
+ struct functor {
+ void operator()( bool bNew, value_type& item, Q const& 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 key passed into the \p ensure function
+ - \p val - argument \p val passed into the \p %update() function
- The functor may 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 may change non-key fields of the \p item.
- You may pass \p func argument by reference using \p std::ref
+ <b>for \p IterableList</b>
+ \code
+ void func( value_type& val, value_type * old );
+ \endcode
+ where
+ - \p val - a new data constructed from \p key
+ - \p old - old value that will be retired. If new item has been inserted then \p old is \p nullptr.
- Returns <tt> std::pair<bool, bool> </tt> where \p first is true if operation is successfull,
- \p second is true if new item has been added or \p false if the item with \p key
+ @return <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_hp "MichaelList" and \ref cds_nonintrusive_IterableList_gc "IterableList"
+ 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 Q, typename Func>
+ std::pair<bool, bool> update( Q&& val, Func func, bool bAllowUpdate = true )
+ {
+ std::pair<bool, bool> bRet = bucket( val ).update( std::forward<Q>( val ), func, bAllowUpdate );
+ if ( bRet.second )
+ ++m_ItemCounter;
+ return bRet;
+ }
+ //@cond
+ template <typename Q, typename Func>
+ CDS_DEPRECATED("ensure() is deprecated, use update()")
std::pair<bool, bool> ensure( const Q& val, Func func )
{
- std::pair<bool, bool> bRet = bucket( val ).ensure( val, func );
- if ( bRet.first && bRet.second )
+ 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.
+
+ 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.
+ */
+ template <typename Q>
+#ifdef CDS_DOXYGEN_INVOKED
+ std::pair<bool, bool>
+#else
+ typename std::enable_if<
+ std::is_same< Q, Q>::value && is_iterable_list< ordered_list >::value,
+ std::pair<bool, bool>
+ >::type
+#endif
+ upsert( Q&& val, bool bAllowInsert = true )
+ {
+ std::pair<bool, bool> bRet = bucket( val ).upsert( std::forward<Q>( val ), bAllowInsert );
+ if ( bRet.second )
++m_ItemCounter;
return bRet;
}
- /// Inserts data of type \ref value_type constructed with <tt>std::forward<Args>(args)...</tt>
+ /// Inserts data of type \p value_type constructed from \p args
/**
Returns \p true if inserting successful, \p false otherwise.
*/
template <typename... Args>
bool emplace( Args&&... args )
{
- bool bRet = bucket
( value_type(std::forward<Args>(args)...) ).emplace( std::forward<Args>(args)... );
+ bool bRet = bucket
_emplace<internal_bucket_type>( std::forward<Args>(args)... );
if ( bRet )
++m_ItemCounter;
return bRet;
}
/// Deletes \p key from the set
- /** \anchor cds_nonintrusive_MichaelSet_erase_val
-
- Since the key of MichaelHashSet's item type \ref value_type is not explicitly specified,
+ /**
+ Since the key of MichaelHashSet's item type \p value_type is not explicitly specified,
template parameter \p Q defines the key type searching in the list.
The set item comparator should be able to compare the type \p value_type
and the type \p Q.
- Return \p true if key is found and deleted, \p false otherwise
+ Return \p true if key is found and deleted, \p false otherwise.
*/
template <typename Q>
bool erase( Q const& key )
/// Deletes the item from the set using \p pred predicate for searching
/**
- The function is an analog of \ref cds_nonintrusive_MichaelSet_erase_val "erase(Q const&)"
- but \p pred is used for key comparing.
+ The function is an analog of \p erase(Q const&) 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.
*/
}
/// Deletes \p key from the set
- /** \anchor cds_nonintrusive_MichaelSet_erase_func
-
+ /**
The function searches an item with key \p key, calls \p f functor
and deletes the item. If \p key is not found, the functor is not called.
The functor \p Func interface:
\code
struct extractor {
- void operator()(value_type const& val);
+ void operator()(value_type& item);
};
\endcode
- The functor may be passed by reference using <tt>boost:ref</tt>
+ where \p item - the item found.
Since the key of %MichaelHashSet's \p value_type is not explicitly specified,
template parameter \p Q defines the key type searching in the list.
/// Deletes the item from the set using \p pred predicate for searching
/**
- The function is an analog of \ref cds_nonintrusive_MichaelSet_erase_func "erase(Q const&, Func)"
- but \p pred is used for key comparing.
+ The function is an analog of \p erase(Q const&, Func) 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.
*/
/// Extracts the item with specified \p key
/** \anchor cds_nonintrusive_MichaelHashSet_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 guadd pointer.
Note the compare functor should accept a parameter of type \p Q that may be not the same as \p value_type.
- The extracted item is freed automatically when returned \ref guarded_ptr object will be destroyed or released.
+ The extracted item is freed automatically 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:
michael_set theSet;
// ...
{
- michael_set::guarded_ptr gp;
- theSet.extract( gp, 5 );
- // Deal with gp
- // ...
-
+ typename michael_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 )
{
- const bool bRet = bucket( key ).extract( dest, key );
- if ( bRet )
+ guarded_ptr gp( bucket( key ).extract( key ));
+ if ( gp )
--m_ItemCounter;
- return bRet;
+ return gp;
}
/// Extracts the item using compare functor \p pred
/**
- The function is an analog of \ref cds_nonintrusive_MichaelHashSet_hp_extract "extract(guarded_ptr&, Q const&)"
+ The function is an analog of \p 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
- in any order.
+ \p Less functor has the semantics like \p std::less but should take arguments
+ of type \p value_type and \p Q in any order.
\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 )
{
- const bool bRet = bucket( key ).extract_with( dest, key, pred );
- if ( bRet )
+ guarded_ptr gp( bucket( key ).extract_with( key, pred ));
+ if ( gp )
--m_ItemCounter;
- return bRet;
+ return gp;
}
- /// Finds the key \p val
- /** \anchor cds_nonintrusive_MichaelSet_find_func
-
- The function searches the item with key equal to \p val and calls the functor \p f for item found.
+ /// Finds the key \p key
+ /**
+ 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 may pass \p f argument by reference using \p std::ref.
+ where \p item is the item found, \p key is the <tt>find</tt> function argument.
The functor may 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's \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
+ The \p key 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 may 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 bucket( key ).find( key, f );
+ }
+ //@cond
+ template <typename Q, typename Func>
+ bool find( Q const& key, Func f )
{
- return bucket( val ).find( val, f );
+ return bucket( key ).find( key, f );
}
+ //@endcond
- /// Finds the key \p val using \p pred predicate for searching
+ /// Finds \p key and returns iterator pointed to the item found (only for \p IterableList)
/**
- The function is an analog of \ref cds_nonintrusive_MichaelSet_find_func "find(Q&, Func)"
- but \p pred is used for key comparing.
+ 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 )
+ {
+ internal_bucket_type& b = bucket( key );
+ typename internal_bucket_type::iterator it = b.find( key );
+ if ( it == b.end())
+ return end();
+ return iterator( it, &b, bucket_end());
+ }
+ //@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 )
+ {
+ internal_bucket_type& b = bucket( key );
+ typename internal_bucket_type::iterator it = b.find( key );
+ if ( it == b.end())
+ return end();
+ return iterator( it, &b, bucket_end());
+ }
+ //@endcond
+
+ /// Finds the key \p key using \p pred predicate for searching
+ /**
+ The function is an analog of \p find(Q&, Func) 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, typename Func>
- bool find_with( Q& val, Less pred, Func f )
+ bool find_with( Q& key, Less pred, Func f )
{
- return bucket( val ).find_with( val, pred, f );
+ return bucket( key ).find_with( key, pred, f );
}
-
- /// Finds the key \p val
- /** \anchor cds_nonintrusive_MichaelSet_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 may pass \p f argument by reference using \p std::ref.
-
- The functor may 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's \p item. If such access is
- possible you must provide your own synchronization schema on item level to exclude unsafe item modifications.
-
- Note the hash functor specified for class \p Traits template parameter
- should accept a parameter of type \p Q that may be not the same as \p value_type.
-
- The function returns \p true if \p val is found, \p false otherwise.
- */
- template <typename Q, typename Func>
- bool find( Q const& val, Func f )
+ //@cond
+ template <typename Q, typename Less, typename Func>
+ bool find_with( Q const& key, Less pred, Func f )
{
- return bucket( val ).find( val, f );
+ return bucket( key ).find_with( key, pred, f );
}
+ //@endcond
- /// Finds the key \p val using \p pred predicate for searching
+ /// 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 \ref cds_nonintrusive_MichaelSet_find_cfunc "find(Q const&, Func)"
- but \p pred is used for key comparing.
+ 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 Less must imply the same element order as the comparator used for building the set.
+ \p pred must imply the same element order as the comparator used for building the set.
+
+ 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, typename Less, typename Func>
- bool find_with( Q const& val, Less pred, 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 bucket( val ).find_with( val, pred, f );
+ internal_bucket_type& b = bucket( key );
+ typename internal_bucket_type::iterator it = b.find_with( key, pred );
+ if ( it == b.end())
+ return end();
+ return iterator( it, &b, bucket_end());
}
+ //@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 )
+ {
+ internal_bucket_type& b = bucket( key );
+ typename internal_bucket_type::iterator it = b.find_with( key, pred );
+ if ( it == b.end())
+ return end();
+ return iterator( it, &b, bucket_end());
+ }
+ //@endcond
- /// Finds the key \p val
- /** \anchor cds_nonintrusive_MichaelSet_find_val
- The function searches the item with key equal to \p val
- and returns \p true if it is found, and \p false otherwise.
+ /// Checks whether the set contains \p key
+ /**
+ The function searches the item with key equal to \p key
+ 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 may be not the same as \ref value_type.
+ 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& val )
+ bool contains( Q const& key )
{
- return bucket( val ).find( val );
+ return bucket( key ).contains( key );
}
- /// Finds the key \p val 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_nonintrusive_MichaelSet_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 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 bucket( val ).find_with( val, pred );
+ return bucket( key ).contains( key, pred );
}
- /// Finds the key \p val and return the item found
+ /// Finds the key \p key and return the item found
/** \anchor cds_nonintrusive_MichaelHashSet_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 guarded pointer to the item found.
+ If \p key is not found the functin returns an empty guarded pointer.
@note Each \p guarded_ptr object uses one GC's guard which can be limited resource.
michael_set theSet;
// ...
{
- michael_set::guarded_ptr gp;
- if ( theSet.get( gp, 5 )) {
+ typename michael_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 bucket( val ).get( ptr, val );
+ return bucket( key ).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_nonintrusive_MichaelHashSet_hp_get "get( guarded_ptr& ptr, Q const&)"
+ The function is an analog of \ref cds_nonintrusive_MichaelHashSet_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 bucket( val ).get_with( ptr, val, pred );
+ return bucket( key ).get_with( key, pred );
}
/// Clears the set (non-atomic)
return m_ItemCounter;
}
+ /// Returns const reference to internal statistics
+ stat const& statistics() const
+ {
+ return m_Stat;
+ }
+
/// Returns the size of hash table
/**
Since MichaelHashSet cannot dynamically extend the hash table size,
{
return m_nHashBitmask + 1;
}
+
+ protected:
+ //@cond
+ /// 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
+
+ private:
+ //@cond
+ internal_bucket_type* bucket_begin() const
+ {
+ return m_Buckets;
+ }
+
+ internal_bucket_type* bucket_end() const
+ {
+ return m_Buckets + bucket_count();
+ }
+
+ const_iterator get_const_begin() const
+ {
+ return const_iterator( bucket_begin()->cbegin(), bucket_begin(), bucket_end());
+ }
+ const_iterator get_const_end() const
+ {
+ return const_iterator(( bucket_end() -1 )->cend(), bucket_end() - 1, bucket_end());
+ }
+
+ 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 );
+ }
+
+ template <typename List, typename... Args>
+ typename std::enable_if< !is_iterable_list<List>::value, bool>::type
+ bucket_emplace( Args&&... args )
+ {
+ class list_accessor: public List
+ {
+ public:
+ using List::alloc_node;
+ using List::node_to_value;
+ using List::insert_node;
+ };
+
+ auto pNode = list_accessor::alloc_node( std::forward<Args>( args )... );
+ assert( pNode != nullptr );
+ return static_cast<list_accessor&>( bucket( list_accessor::node_to_value( *pNode ))).insert_node( pNode );
+ }
+
+ template <typename List, typename... Args>
+ typename std::enable_if< is_iterable_list<List>::value, bool>::type
+ bucket_emplace( Args&&... args )
+ {
+ class list_accessor: public List
+ {
+ public:
+ using List::alloc_data;
+ using List::insert_node;
+ };
+
+ auto pData = list_accessor::alloc_data( std::forward<Args>( args )... );
+ assert( pData != nullptr );
+ return static_cast<list_accessor&>( bucket( *pData )).insert_node( pData );
+ }
+ //@endcond
};
}} // namespace cds::container
-#endif // ifndef __CDS_CONTAINER_MICHAEL_SET_H
+#endif // ifndef CDSLIB_CONTAINER_MICHAEL_SET_H
projects / libcds.git / blobdiff