-//$$CDS-header$$
+/*
+ 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_RCU_H
#define CDSLIB_INTRUSIVE_MICHAEL_SET_RCU_H
/// Bucket table allocator
typedef cds::details::Allocator< bucket_type, typename traits::allocator > bucket_table_allocator;
- typedef typename bucket_type::rcu_lock rcu_lock; ///< RCU scoped lock
- typedef typename bucket_type::exempt_ptr exempt_ptr; ///< pointer to extracted node
+ typedef typename bucket_type::rcu_lock rcu_lock; ///< RCU scoped lock
+ typedef typename bucket_type::exempt_ptr exempt_ptr; ///< pointer to extracted node
+ typedef typename bucket_type::raw_ptr raw_ptr; ///< Return type of \p get() member function and its derivatives
/// Group of \p extract_xxx functions require external locking if underlying ordered list requires that
static CDS_CONSTEXPR const bool c_bExtractLockExternal = bucket_type::c_bExtractLockExternal;
return bRet;
}
- /// Ensures that the \p item exists in the set
+ /// Updates the element
/**
The operation performs inserting or changing data with lock-free manner.
- If the item \p val not found in the set, then \p val is inserted into the set.
+ If the item \p val not found in the set, then \p val is inserted iff \p bAllowInsert is \p true.
Otherwise, the functor \p func is called with item found.
The functor signature is:
\code
- void func( bool bNew, value_type& item, value_type& val );
+ struct functor {
+ void operator()( bool bNew, value_type& item, value_type& val );
+ };
\endcode
with arguments:
- \p bNew - \p true if the item has been inserted, \p false otherwise
- \p item - item of the set
- - \p val - argument \p val passed into the \p ensure function
+ - \p val - argument \p val passed into the \p %update() function
If new item has been inserted (i.e. \p bNew is \p true) then \p item and \p val arguments
refers to the same thing.
- The functor can change non-key fields of the \p item.
+ The functor may change non-key fields of the \p item.
- Returns std::pair<bool, bool> where \p first is \p true if operation is successfull,
+ Returns <tt> std::pair<bool, bool> </tt> where \p first is \p true if operation is successfull,
\p second is \p true if new item has been added or \p false if the item with \p key
already is in the set.
- @warning For \ref cds_intrusive_MichaelList_rcu "MichaelList" as the bucket see \ref cds_intrusive_item_creating "insert item troubleshooting".
- \ref cds_intrusive_LazyList_rcu "LazyList" provides exclusive access to inserted item and does not require any node-level
+ @warning For \ref cds_intrusive_MichaelList_hp "MichaelList" as the bucket see \ref cds_intrusive_item_creating "insert item troubleshooting".
+ \ref cds_intrusive_LazyList_hp "LazyList" provides exclusive access to inserted item and does not require any node-level
synchronization.
- */
+ */
template <typename Func>
- std::pair<bool, bool> ensure( value_type& val, Func func )
+ std::pair<bool, bool> update( value_type& val, Func func, bool bAllowInsert = true )
{
- std::pair<bool, bool> bRet = bucket( val ).ensure( val, func );
- if ( bRet.first && bRet.second )
+ std::pair<bool, bool> bRet = bucket( val ).update( val, func, bAllowInsert );
+ if ( bRet.second )
++m_ItemCounter;
return bRet;
}
+ //@cond
+ template <typename Func>
+ CDS_DEPRECATED("ensure() is deprecated, use update()")
+ std::pair<bool, bool> ensure( value_type& val, Func func )
+ {
+ return update( val, func, true );
+ }
+ //@endcond
/// Unlinks the item \p val from the set
/**
unlinks it from the set, and returns \ref cds::urcu::exempt_ptr "exempt_ptr" pointer to the item found.
If the item with the key equal to \p key is not found the function returns an empty \p exempt_ptr.
- @note The function does NOT call RCU read-side lock or synchronization,
- and does NOT dispose the item found. It just excludes the item from the set
- and returns a pointer to item found.
- You should lock RCU before calling of the function, and you should synchronize RCU
- outside the RCU lock before reusing returned pointer.
+ Depends on \p bucket_type you should or should not lock RCU before calling of this function:
+ - for the set based on \ref cds_intrusive_MichaelList_rcu "MichaelList" RCU should not be locked
+ - for the set based on \ref cds_intrusive_LazyList_rcu "LazyList" RCU should be locked
+ See ordered list implementation for details.
\code
#include <cds/urcu/general_buffered.h>
// ...
typename rcu_michael_set::exempt_ptr p;
- {
- // first, we should lock RCU
- typename rcu_michael_set::rcu_lock lock;
-
- // Now, you can apply extract function
- // Note that you must not delete the item found inside the RCU lock
- p = theSet.extract( 10 )
- if ( p ) {
- // do something with p
- ...
- }
+
+ // For MichaelList we should not lock RCU
+
+ // Now, you can apply extract function
+ // Note that you must not delete the item found inside the RCU lock
+ p = theSet.extract( 10 )
+ if ( p ) {
+ // do something with p
+ ...
}
// We may safely release p here
return p;
}
- /// Finds the key \p key
- /** \anchor cds_intrusive_MichaelHashSet_rcu_find_val
+ /// Checks whether the set contains \p key
+ /**
+
The function searches the item with key equal to \p key
- and returns \p true if \p key found or \p false otherwise.
+ and returns \p true if the key is found, and \p false otherwise.
+
+ Note the hash functor specified for class \p Traits template parameter
+ should accept a parameter of type \p Q that can be not the same as \p value_type.
*/
template <typename Q>
- bool find( Q const& key ) const
+ bool contains( Q const& key )
+ {
+ return bucket( key ).contains( key );
+ }
+ //@cond
+ template <typename Q>
+ CDS_DEPRECATED("use contains()")
+ bool find( Q const& key )
{
- return bucket( key ).find( key );
+ return contains( key );
}
+ //@endcond
- /// Finds the key \p key using \p pred predicate for searching
+ /// Checks whether the set contains \p key using \p pred predicate for searching
/**
- The function is an analog of \ref cds_intrusive_MichaelHashSet_rcu_find_val "find(Q const&)"
- but \p pred is used for key comparing.
+ The function is an analog of <tt>contains( key )</tt> but \p pred is used for key comparing.
\p Less functor has the interface like \p std::less.
- \p pred must imply the same element order as the comparator used for building the set.
+ \p Less must imply the same element order as the comparator used for building the set.
*/
template <typename Q, typename Less>
- bool find_with( Q const& key, Less pred ) const
+ bool contains( Q const& key, Less pred )
+ {
+ return bucket( key ).contains( key, pred );
+ }
+ //@cond
+ template <typename Q, typename Less>
+ CDS_DEPRECATED("use contains()")
+ bool find_with( Q const& key, Less pred )
{
- return bucket( key ).find_with( key, pred );
+ return contains( key, pred );
}
+ //@endcond
/// Find the key \p key
/** \anchor cds_intrusive_MichaelHashSet_rcu_find_func
The function returns \p true if \p key is found, \p false otherwise.
*/
template <typename Q, typename Func>
- bool find( Q& key, Func f ) const
+ bool find( Q& key, Func f )
{
return bucket( key ).find( key, f );
}
//@cond
template <typename Q, typename Func>
- bool find( Q const& key, Func f ) const
+ bool find( Q const& key, Func f )
{
return bucket( key ).find( key, f );
}
\p pred must imply the same element order as the comparator used for building the set.
*/
template <typename Q, typename Less, typename Func>
- bool find_with( Q& key, Less pred, Func f ) const
+ bool find_with( Q& key, Less pred, Func f )
{
return bucket( key ).find_with( key, pred, f );
}
//@cond
template <typename Q, typename Less, typename Func>
- bool find_with( Q const& key, Less pred, Func f ) const
+ bool find_with( Q const& key, Less pred, Func f )
{
return bucket( key ).find_with( key, pred, f );
}
/** \anchor cds_intrusive_MichaelHashSet_rcu_get
The function searches the item with key equal to \p key and returns the pointer to item found.
If \p key is not found it returns \p nullptr.
+ Note the type of returned value depends on underlying \p bucket_type.
+ For details, see documentation of ordered list you use.
Note the compare functor should accept a parameter of type \p Q that can be not the same as \p value_type.
typedef cds::intrusive::MichaelHashSet< your_template_parameters > hash_set;
hash_set theSet;
// ...
+ // Result of get() call
+ typename hash_set::raw_ptr ptr;
{
// Lock RCU
hash_set::rcu_lock lock;
- foo * pVal = theSet.get( 5 );
- if ( pVal ) {
- // Deal with pVal
+ ptr = theSet.get( 5 );
+ if ( ptr ) {
+ // Deal with ptr
//...
}
// Unlock RCU by rcu_lock destructor
- // pVal can be retired by disposer at any time after RCU has been unlocked
+ // ptr can be reclaimed by disposer at any time after RCU has been unlocked
}
\endcode
*/
template <typename Q>
- value_type * get( Q const& key ) const
+ raw_ptr get( Q const& key )
{
return bucket( key ).get( key );
}
\p pred must imply the same element order as the comparator used for building the set.
*/
template <typename Q, typename Less>
- value_type * get_with( Q const& key, Less pred ) const
+ raw_ptr get_with( Q const& key, Less pred )
{
return bucket( key ).get_with( key, pred );
}
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