-//$$CDS-header$$
-
-#ifndef __CDS_INTRUSIVE_MICHAEL_SET_H
-#define __CDS_INTRUSIVE_MICHAEL_SET_H
+/*
+ This file is a part of libcds - Concurrent Data Structures library
+
+ (C) Copyright Maxim Khizhinsky (libcds.dev@gmail.com) 2006-2016
+
+ Source code repo: http://github.com/khizmax/libcds/
+ Download: http://sourceforge.net/projects/libcds/files/
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are met:
+
+ * Redistributions of source code must retain the above copyright notice, this
+ list of conditions and the following disclaimer.
+
+ * Redistributions in binary form must reproduce the above copyright notice,
+ this list of conditions and the following disclaimer in the documentation
+ and/or other materials provided with the distribution.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#ifndef CDSLIB_INTRUSIVE_MICHAEL_SET_H
+#define CDSLIB_INTRUSIVE_MICHAEL_SET_H
#include <cds/intrusive/details/michael_set_base.h>
#include <cds/details/allocator.h>
/// Bucket table allocator
typedef cds::details::Allocator< bucket_type, typename traits::allocator > bucket_table_allocator;
+ /// Count of hazard pointer required for the algorithm
+ static CDS_CONSTEXPR const size_t c_nHazardPtrCount = ordered_list::c_nHazardPtrCount;
+
protected:
item_counter m_ItemCounter; ///< Item counter
hash m_HashFunctor; ///< Hash functor
//@endcond
public:
+ ///@name Forward iterators (only for debugging purpose)
+ //@{
/// 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.
+ - The iterator cannot be moved across thread boundary because 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.
+ Moreover, a crash is possible when you try to iterate the next element that has been deleted by concurrent thread.
- Therefore, the use of iterators in concurrent environment is not good idea. Use the iterator for the concurrent container
- for debug purpose only.
+ @warning Use this iterator on the concurrent container for debugging purpose only.
*/
typedef michael_set::details::iterator< bucket_type, false > iterator;
}
/// Returns a forward const iterator addressing the first element in a set
- //@{
const_iterator begin() const
{
return get_const_begin();
}
+
+ /// 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();
}
+
+ /// Returns an const iterator that addresses the location succeeding the last element in a set
const_iterator cend() const
{
return get_const_end();
}
- //@}
+ //@}
private:
//@cond
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 );
+ 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 may change non-key fields of the \p item.
- Returns <tt> std::pair<bool, bool> </tt> 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.
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
/**
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& key, Func f )
+ bool erase( Q const& key, Func f )
{
if ( bucket( key ).erase( key, f )) {
--m_ItemCounter;
\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& key, Less pred, Func f )
+ bool erase_with( Q const& key, Less pred, Func f )
{
if ( bucket( key ).erase_with( key, pred, f )) {
--m_ItemCounter;
/// 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 key
}
//@endcond
- /// Finds the key \p key
- /** \anchor cds_intrusive_MichaelHashSet_hp_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 it is found, and \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 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_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 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
/// 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 key
- and assigns the item found to guarded pointer \p ptr.
- The function returns \p true if \p key is found, and \p false otherwise.
- If \p key is not found the \p ptr parameter is not changed.
+ 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& key )
+ guarded_ptr get( Q const& key )
{
- return bucket( key ).get( ptr, key );
+ return bucket( key ).get( key );
}
/// 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& key, Less pred )
+ guarded_ptr get_with( Q const& key, Less pred )
{
- return bucket( key ).get_with( ptr, key, 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.
}} // namespace cds::intrusive
-#endif // ifndef __CDS_INTRUSIVE_MICHAEL_SET_H
+#endif // ifndef CDSLIB_INTRUSIVE_MICHAEL_SET_H
projects / libcds.git / blobdiff