-//$$CDS-header$$
+/*
+ This file is a part of libcds - Concurrent Data Structures library
-#ifndef __CDS_INTRUSIVE_MICHAEL_SET_H
-#define __CDS_INTRUSIVE_MICHAEL_SET_H
+ (C) Copyright Maxim Khizhinsky (libcds.dev@gmail.com) 2006-2017
-#include <cds/intrusive/michael_set_base.h>
-#include <cds/details/allocator.h>
+ 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_H
+#define CDSLIB_INTRUSIVE_MICHAEL_SET_H
+
+#include <cds/intrusive/details/michael_set_base.h>
+#include <cds/intrusive/details/iterable_list_base.h>
namespace cds { namespace intrusive {
Template parameters are:
- \p GC - Garbage collector used. Note the \p GC must be the same as the GC used for \p OrderedList
- - \p OrderedList - ordered list implementation used as bucket for hash set, for example, MichaelList, LazyList.
+ - \p OrderedList - ordered list implementation used as bucket for hash set, possible implementations:
+ \p MichaelList, \p LazyList, \p IterableList.
The intrusive ordered list implementation specifies the type \p T stored in the hash-set, the reclamation
schema \p GC used by hash-set, the comparison functor for the type \p T and other features specific for
the ordered list.
- - \p Traits - type traits. See michael_set::type_traits for explanation.
- Instead of defining \p Traits struct you can use option-based syntax with michael_set::make_traits metafunction.
+ - \p Traits - type traits. See \p michael_set::traits for explanation.
+ Instead of defining \p Traits struct you can use option-based syntax with \p michael_set::make_traits metafunction.
There are several specializations of \p %MichaelHashSet for each GC. You should include:
- <tt><cds/intrusive/michael_set_rcu.h></tt> for \ref cds_intrusive_MichaelHashSet_rcu "RCU type"
- - <tt><cds/intrusive/michael_set_nogc.h></tt> for \ref cds_intrusive_MichaelHashSet_nogc for persistent set
- - <tt><cds/intrusive/michael_set.h></tt> for other GC (gc::HP, gc::HRC, gc::PTB)
+ - <tt><cds/intrusive/michael_set_nogc.h></tt> for \ref cds_intrusive_MichaelHashSet_nogc for append-only set
+ - <tt><cds/intrusive/michael_set.h></tt> for \p gc::HP, \p gc::DHP
<b>Hash functor</b>
Some member functions of Michael's hash set accept the key parameter of type \p Q which differs from \p value_type.
It is expected that type \p Q contains full key of \p value_type, and for equal keys of type \p Q and \p value_type
- the hash values of these keys must be equal too.
- The hash functor <tt>Traits::hash</tt> should accept parameters of both type:
+ the hash values of these keys must be equal.
+ 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>How to use</b>
First, you should define ordered list type to use in your hash set:
Like other intrusive containers, you may build several containers on single item structure:
\code
#include <cds/intrusive/michael_list_hp.h>
- #include <cds/intrusive/michael_list_ptb.h>
+ #include <cds/intrusive/michael_list_dhp.h>
#include <cds/intrusive/michael_set.h>
struct tag_key1_idx;
struct tag_key2_idx;
// Your two-key data
- // The first key is maintained by gc::HP, second key is maintained by gc::PTB garbage collectors
+ // The first key is maintained by gc::HP, second key is maintained by gc::DHP garbage collectors
+ // (I don't know what is needed for, but it is correct)
struct Foo
: public cds::intrusive::michael_list::node< cds::gc::HP, tag_key1_idx >
- , public cds::intrusive::michael_list::node< cds::gc::PTB, tag_key2_idx >
+ , public cds::intrusive::michael_list::node< cds::gc::DHP, tag_key2_idx >
{
std::string key1_ ; // first key field
unsigned int key2_ ; // second key field
>::type
> Key1_bucket;
- // Declare bucket type for Michael's hash set indexed by key2_ field and maintained by gc::PTB
- typedef cds::intrusive::MichaelList< cds::gc::PTB, Foo,
+ // Declare bucket type for Michael's hash set indexed by key2_ field and maintained by gc::DHP
+ typedef cds::intrusive::MichaelList< cds::gc::DHP, Foo,
typename cds::intrusive::michael_list::make_traits<
// hook option
- cds::intrusive::opt::hook< cds::intrusive::michael_list::base_hook< cds::opt::gc< cds::gc::PTB >, tag_key2_idx > >
+ cds::intrusive::opt::hook< cds::intrusive::michael_list::base_hook< cds::opt::gc< cds::gc::DHP >, tag_key2_idx > >
// item comparator option
,cds::opt::less< Key2Less >
>::type
// Michael's set indexed by key2_ field
typedef cds::intrusive::MichaelHashSet<
- cds::gc::PTB
+ cds::gc::DHP
,Key2_bucket
,typename cds::intrusive::michael_set::make_traits<
cds::opt::hash< Key2Hash >
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 ordered_list ; ///< type of ordered list used as a bucket implementation
- typedef ordered_list bucket_type ; ///< bucket type
- 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 ordered_list::value_type value_type ; ///< type of value to be stored in the set
+ 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
- typedef typename ordered_list::value_type value_type ; ///< type of value stored in the list
- typedef GC gc ; ///< Garbage collector
- typedef typename ordered_list::key_comparator key_comparator ; ///< key comparison functor
- typedef typename ordered_list::disposer disposer ; ///< Node disposer functor
+ /// Hash functor for \p value_type and all its derivatives that you use
+ typedef typename cds::opt::v::hash_selector< typename traits::hash >::type hash;
+ typedef typename traits::item_counter item_counter; ///< Item counter type
+ typedef typename traits::allocator allocator; ///< Bucket table allocator
- /// 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 ordered_list::guarded_ptr guarded_ptr; ///< Guarded pointer
- typedef typename ordered_list::guarded_ptr guarded_ptr; ///< Guarded pointer
+ /// Count of hazard pointer required for the algorithm
+ static CDS_CONSTEXPR const size_t c_nHazardPtrCount = ordered_list::c_nHazardPtrCount;
- /// Bucket table allocator
- typedef cds::details::Allocator< bucket_type, typename options::allocator > bucket_table_allocator;
+ // 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
+ //@cond
+ typedef typename ordered_list::template select_stat_wrapper< typename ordered_list::stat > bucket_stat;
- bucket_type * m_Buckets ; ///< bucket table
+ 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;
- private:
+ typedef typename allocator::template rebind< internal_bucket_type >::other bucket_table_allocator;
+ //@endcond
+
+ public:
//@cond
- const size_t m_nHashBitmask;
+ typedef typename bucket_stat::stat stat;
//@endcond
protected:
- /// Calculates hash value of \p key
- template <typename Q>
- size_t hash_value( const Q& key ) const
- {
- return m_HashFunctor( key ) & m_nHashBitmask;
- }
-
- /// Returns the bucket (ordered list) for \p key
- template <typename Q>
- bucket_type& bucket( const Q& key )
- {
- return m_Buckets[ hash_value( key ) ];
- }
+ //@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
+ //@{
/// 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
- - 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 set.
-
- Therefore, the use of iterators in concurrent environment is not good idea. Use the iterator for the concurrent container
- for debug purpose only.
+ - The iterator cannot be moved across thread boundary because it may contain GC's guard that is thread-private GC data.
+
+ Iterator thread safety depends on type of \p OrderedList:
+ - for \p MichaelList and \p LazyList: iterator guarantees safety even if you delete the item that iterator points to
+ because that item is guarded by hazard pointer.
+ However, in case of concurrent deleting operations it is no guarantee that you iterate all item in the set.
+ Moreover, a crash is possible when you try to iterate the next element that has been deleted by concurrent thread.
+ Use this iterator on the concurrent container for debugging purpose only.
+ - for \p IterableList: iterator is thread-safe. You may use it freely in concurrent environment.
*/
- typedef 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(), 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:
- //@{
- const_iterator get_const_begin() const
- {
- return const_iterator( 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( m_Buckets[bucket_count() - 1].end(), m_Buckets + bucket_count() - 1, m_Buckets + bucket_count() );
+ return get_const_end();
}
- //@}
+ //@}
public:
/// Initializes hash set
*/
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. Small integer up to 10, default is 1.
+ size_t nLoadFactor ///< load factor: estimation of max number of items in the bucket. Small integer up to 10.
) : 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 );
}
/// Clears hash set object 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
\code
void func( value_type& val );
\endcode
- where \p val is the item inserted. User-defined functor \p f should guarantee that during changing
- \p val no any other changes could be made on this set's item by concurrent threads.
- The user-defined functor is called only if the inserting is success and can be passed by reference
- using <tt>boost::ref</tt>
+ where \p val is the item inserted.
+
+ The user-defined functor is called only if the inserting is success.
+
+ @warning For \ref cds_intrusive_MichaelList_hp "MichaelList" as the bucket see \ref cds_intrusive_item_creating "insert item troubleshooting".
+ \ref cds_intrusive_LazyList_hp "LazyList" provides exclusive access to inserted item and does not require any node-level
+ synchronization.
*/
template <typename Func>
bool insert( value_type& val, Func f )
return bRet;
}
- /// Ensures that the \p val 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 );
- \endcode
- with arguments:
- - \p bNew - \p true if the item has been inserted, \p false otherwise
- - \p item - item of the set
- - \p val - argument \p val passed into the \p ensure function
- If new item has been inserted (i.e. \p bNew is \p true) then \p item and \p val arguments
- refers to the same thing.
-
- The functor 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.
- You may pass \p func argument by reference using <tt>boost::ref</tt> or cds::ref.
-
- Returns <tt> std::pair<bool, bool> </tt> where \p first is \p true if operation is successfull,
+ The functor signature depends of the type of \p OrderedList:
+
+ <b>for \p MichaelList, \p LazyList</b>
+ \code
+ struct functor {
+ void operator()( bool bNew, value_type& item, value_type& val );
+ };
+ \endcode
+ with arguments:
+ - \p bNew - \p true if the item has been inserted, \p false otherwise
+ - \p item - item of the set
+ - \p val - argument \p val passed into the \p %update() function
+ If new item has been inserted (i.e. \p bNew is \p true) then \p item and \p val arguments
+ refers to the same thing.
+
+ The functor may change non-key fields of the \p item.
+ @warning For \ref cds_intrusive_MichaelList_hp "MichaelList" as the bucket see \ref cds_intrusive_item_creating "insert item troubleshooting".
+ \ref cds_intrusive_LazyList_hp "LazyList" provides exclusive access to inserted item and does not require any node-level
+ synchronization.
+
+ <b>for \p IterableList</b>
+ \code
+ void func( value_type& val, value_type * old );
+ \endcode
+ where
+ - \p val - argument \p val passed into the \p %update() function
+ - \p old - old value that will be retired. If new item has been inserted then \p old is \p nullptr.
+
+ Returns <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.
*/
template <typename Func>
+ std::pair<bool, bool> update( value_type& val, Func func, bool bAllowInsert = true )
+ {
+ 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 )
{
- 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
+ by call \p Traits::disposer.
+
+ Returns std::pair<bool, bool> where \p first is \p true if operation is successful,
+ \p second is \p true if \p val has been added or \p false if the item with that key
+ already in the set.
+ */
+#ifdef CDS_DOXYGEN_INVOKED
+ std::pair<bool, bool> upsert( value_type& val, bool bAllowInsert = true )
+#else
+ template <typename Q>
+ typename std::enable_if<
+ std::is_same< Q, value_type>::value && is_iterable_list< ordered_list >::value,
+ std::pair<bool, bool>
+ >::type
+ upsert( Q& val, bool bAllowInsert = true )
+#endif
+ {
+ std::pair<bool, bool> bRet = bucket( val ).upsert( val, bAllowInsert );
+ if ( bRet.second )
++m_ItemCounter;
return bRet;
}
/// Unlinks the item \p val from the set
/**
- The function searches the item \p val in the set and unlink it from the set
+ The function searches the item \p val in the set and unlink it
if it is found and is equal to \p val.
The function returns \p true if success and \p false otherwise.
/// Deletes the item from the set
/** \anchor cds_intrusive_MichaelHashSet_hp_erase
- The function searches an item with key equal to \p val in the set,
- unlinks it from the set, and returns \p true.
- If the item with key equal to \p val is not found the function return \p false.
+ The function searches an item with key equal to \p key in the set,
+ unlinks it, and returns \p true.
+ If the item with key equal to \p key is not found the function return \p false.
Note the hash functor should accept a parameter of type \p Q that can be not the same as \p value_type.
*/
template <typename Q>
- bool erase( Q const& val )
+ bool erase( Q const& key )
{
- if ( bucket( val ).erase( val )) {
+ if ( bucket( key ).erase( key )) {
--m_ItemCounter;
return true;
}
\p pred must imply the same element order as the comparator used for building the set.
*/
template <typename Q, typename Less>
- bool erase_with( Q const& val, Less pred )
+ bool erase_with( Q const& key, Less pred )
{
- if ( bucket( val ).erase_with( val, pred )) {
+ if ( bucket( key ).erase_with( key, pred )) {
--m_ItemCounter;
return true;
}
/// Deletes the item from the set
/** \anchor cds_intrusive_MichaelHashSet_hp_erase_func
- The function searches an item with key equal to \p val in the set,
+ The function searches an item with key equal to \p key in the set,
call \p f functor with item found, and unlinks it from the set.
The \ref disposer specified in \p OrderedList class template parameter is called
by garbage collector \p GC asynchronously.
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 val is not found the function return \p false.
+ If the item with key equal to \p key is not found the function return \p false.
Note the hash functor should accept a parameter of type \p Q that can be not the same as \p value_type.
*/
template <typename Q, typename Func>
- bool erase( const Q& val, Func f )
+ bool erase( Q const& key, Func f )
{
- if ( bucket( val ).erase( val, f )) {
+ if ( bucket( key ).erase( key, f )) {
--m_ItemCounter;
return true;
}
\p pred must imply the same element order as the comparator used for building the set.
*/
template <typename Q, typename Less, typename Func>
- bool erase_with( const Q& val, Less pred, Func f )
+ bool erase_with( Q const& key, Less pred, Func f )
{
- if ( bucket( val ).erase_with( val, pred, f )) {
+ if ( bucket( key ).erase_with( key, pred, f )) {
+ --m_ItemCounter;
+ return true;
+ }
+ return false;
+ }
+
+ /// Deletes the item pointed by iterator \p iter (only for \p IterableList based set)
+ /**
+ Returns \p true if the operation is successful, \p false otherwise.
+ The function can return \p false if the node the iterator points to has already been deleted
+ by other thread.
+
+ The function does not invalidate the iterator, it remains valid and can be used for further traversing.
+
+ @note \p %erase_at() is supported only for \p %MichaelHashSet based on \p IterableList.
+ */
+#ifdef CDS_DOXYGEN_INVOKED
+ bool erase_at( iterator const& iter )
+#else
+ template <typename Iterator>
+ typename std::enable_if< std::is_same<Iterator, iterator>::value && is_iterable_list< ordered_list >::value, bool >::type
+ erase_at( Iterator const& iter )
+#endif
+ {
+ assert( iter != end());
+ assert( iter.bucket() != nullptr );
+
+ if ( iter.bucket()->erase_at( iter.underlying_iterator())) {
--m_ItemCounter;
return true;
}
/// Extracts the item with specified \p key
/** \anchor cds_intrusive_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 an guarded pointer to the item extracted.
+ If \p key is not found the function returns an empty guarded pointer.
Note the compare functor should accept a parameter of type \p Q that may be not the same as \p value_type.
- The \ref disposer specified in \p OrderedList class' template parameter is called automatically
+ The \p disposer specified in \p OrderedList class' template parameter is called automatically
by garbage collector \p GC when returned \ref guarded_ptr object will be destroyed or released.
@note Each \p guarded_ptr object uses the GC's guard that can be limited resource.
michael_set theSet;
// ...
{
- michael_set::guarded_ptr gp;
- theSet.extract( gp, 5 );
- // Deal with gp
- // ...
-
+ 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 )
{
- if ( bucket( key ).extract( dest, key )) {
+ guarded_ptr gp = bucket( key ).extract( key );
+ if ( gp )
--m_ItemCounter;
- return true;
- }
- return false;
+ return gp;
}
/// Extracts the item using compare functor \p pred
/**
- The function is an analog of \ref cds_intrusive_MichaelHashSet_hp_extract "extract(guarded_ptr&, Q const&)"
+ The function is an analog of \ref cds_intrusive_MichaelHashSet_hp_extract "extract(Q const&)"
but \p pred predicate is used for key comparing.
\p Less functor has the semantics like \p std::less but should take arguments of type \ref value_type and \p Q
\p pred must imply the same element order as the comparator used for building the list.
*/
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 )
{
- if ( bucket( key ).extract_with( dest, key, pred )) {
+ guarded_ptr gp = bucket( key ).extract_with( key, pred );
+ if ( gp )
--m_ItemCounter;
- return true;
- }
- return false;
+ return gp;
}
- /// Finds the key \p val
+ /// Finds the key \p key
/** \anchor cds_intrusive_MichaelHashSet_hp_find_func
- The function searches the item with key equal to \p val and calls the functor \p f for item found.
+ The function searches the item with key equal to \p key and calls the functor \p f for item found.
The interface of \p Func functor is:
\code
struct functor {
- void operator()( value_type& item, Q& val );
+ void operator()( value_type& item, Q& key );
};
\endcode
- where \p item is the item found, \p val is the <tt>find</tt> function argument.
-
- You can pass \p f argument by reference using <tt>boost::ref</tt> or cds::ref.
+ where \p item is the item found, \p key is the <tt>find</tt> function argument.
The functor 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 \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
may modify both arguments.
Note the hash functor specified for class \p Traits template parameter
should accept a parameter of type \p Q that can be not the same as \p value_type.
- The function returns \p true if \p val is found, \p false otherwise.
+ The function returns \p true if \p key is found, \p false otherwise.
*/
template <typename Q, typename Func>
- bool find( Q& val, Func f )
+ bool find( Q& key, Func f )
{
- return bucket( val ).find( val, 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 val using \p pred predicate for searching
+ /// Finds \p key and returns iterator pointed to the item found (only for \p IterableList)
+ /**
+ If \p key is not found the function returns \p end().
+
+ @note This function is supported only for the set based on \p IterableList
+ */
+ template <typename Q>
+#ifdef CDS_DOXYGEN_INVOKED
+ iterator
+#else
+ typename std::enable_if< std::is_same<Q,Q>::value && is_iterable_list< ordered_list >::value, iterator >::type
+#endif
+ find( Q& key )
+ {
+ 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 \ref cds_intrusive_MichaelHashSet_hp_find_func "find(Q&, Func)"
but \p pred is used for key comparing.
\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& 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_intrusive_MichaelHashSet_hp_find_cfunc
- The function searches the item with key equal to \p val and calls the functor \p f for item found.
- The interface of \p Func functor is:
- \code
- struct functor {
- void operator()( value_type& item, Q& val );
- };
- \endcode
- where \p item is the item found, \p val is the <tt>find</tt> function argument.
-
- You can pass \p f argument by reference using <tt>boost::ref</tt> or cds::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 \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 can 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_intrusive_MichaelHashSet_hp_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 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
+
+ /// Checks whether the set contains \p key
+ /**
- /// Finds the key \p val
- /** \anchor cds_intrusive_MichaelHashSet_hp_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.
+ 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 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_intrusive_MichaelHashSet_hp_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 & 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_intrusive_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 function returns an empty \p guarded_ptr.
@note Each \p guarded_ptr object uses one GC's guard which can be limited resource.
Usage:
\code
- typedef cds::intrusive::MichaeHashSet< your_template_params > michael_set;
+ typedef cds::intrusive::MichaelHashSet< your_template_params > michael_set;
michael_set theSet;
// ...
{
- michael_set::guarded_ptr gp;
- if ( theSet.get( gp, 5 )) {
+ michael_set::guarded_ptr gp( theSet.get( 5 ));
+ if ( theSet.get( 5 )) {
// 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_intrusive_MichaelHashSet_hp_get "get( guarded_ptr& ptr, Q const&)"
+ The function is an analog of \ref cds_intrusive_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)
/**
The function unlink all items from the set.
The function is not atomic. It cleans up each bucket and then resets the item counter to zero.
- If there are a thread that performs insertion while \p clear is working the result is undefined in general case:
- <tt> empty() </tt> may return \p true but the set may contain item(s).
- Therefore, \p clear may be used only for debugging purposes.
+ If there are a thread that performs insertion while \p %clear() is working the result is undefined in general case:
+ \p empty() may return \p true but the set may contain item(s).
+ Therefore, \p %clear() may be used only for debugging purposes.
For each item the \p disposer is called after unlinking.
*/
m_ItemCounter.reset();
}
-
/// Checks if the set is empty
/**
- Emptiness is checked by item counting: if item count is zero then the set is empty.
- Thus, the correct item counting feature is an important part of Michael's set implementation.
+ @warning If you use \p atomicity::empty_item_counter in \p traits::item_counter,
+ the function always returns \p true.
*/
bool empty() const
{
}
/// Returns item count in the set
+ /**
+ If you use \p atomicity::empty_item_counter in \p traits::item_counter,
+ the function always returns 0.
+ */
size_t size() const
{
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,
- the value returned is an constant depending on object initialization parameters;
- see MichaelHashSet::MichaelHashSet for explanation.
+ Since \p %MichaelHashSet cannot dynamically extend the hash table size,
+ the value returned is an constant depending on object initialization parameters,
+ see \p MichaelHashSet::MichaelHashSet.
*/
size_t bucket_count() const
{
return m_nHashBitmask + 1;
}
+
+ 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( m_Buckets[0].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 * b )
+ {
+ new (b) internal_bucket_type;
+ }
+
+ template <typename Stat>
+ typename std::enable_if< !Stat::empty >::type construct_bucket( internal_bucket_type * b )
+ {
+ new (b) internal_bucket_type( m_Stat );
+ }
+
+ /// Calculates hash value of \p key
+ template <typename Q>
+ size_t hash_value( const Q& key ) const
+ {
+ return m_HashFunctor( key ) & m_nHashBitmask;
+ }
+
+ /// Returns the bucket (ordered list) for \p key
+ template <typename Q>
+ internal_bucket_type& bucket( const Q& key )
+ {
+ return m_Buckets[hash_value( key )];
+ }
+ //@endcond
};
}} // namespace cds::intrusive
-#endif // ifndef __CDS_INTRUSIVE_MICHAEL_SET_H
+#endif // ifndef CDSLIB_INTRUSIVE_MICHAEL_SET_H
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