-//$$CDS-header$$
+/*
+ This file is a part of libcds - Concurrent Data Structures library
-#ifndef __CDS_CONTAINER_MICHAEL_LIST_RCU_H
-#define __CDS_CONTAINER_MICHAEL_LIST_RCU_H
+ (C) Copyright Maxim Khizhinsky (libcds.dev@gmail.com) 2006-2017
+
+ Source code repo: http://github.com/khizmax/libcds/
+ Download: http://sourceforge.net/projects/libcds/files/
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are met:
+
+ * Redistributions of source code must retain the above copyright notice, this
+ list of conditions and the following disclaimer.
+
+ * Redistributions in binary form must reproduce the above copyright notice,
+ this list of conditions and the following disclaimer in the documentation
+ and/or other materials provided with the distribution.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#ifndef CDSLIB_CONTAINER_MICHAEL_LIST_RCU_H
+#define CDSLIB_CONTAINER_MICHAEL_LIST_RCU_H
#include <memory>
#include <cds/container/details/michael_list_base.h>
//@endcond
public:
- typedef cds::urcu::gc<RCU> gc; ///< RCU
+ typedef cds::urcu::gc<RCU> gc; ///< RCU
typedef T value_type; ///< Type of value stored in the list
- typedef Traits traits; /// List traits
+ typedef Traits traits; ///< List traits
typedef typename base_class::back_off back_off; ///< Back-off strategy used
typedef typename maker::allocator_type allocator_type; ///< Allocator type used for allocate/deallocate the nodes
typedef typename base_class::item_counter item_counter; ///< Item counting policy used
typedef typename maker::key_comparator key_comparator; ///< key comparison functor
typedef typename base_class::memory_model memory_model; ///< Memory ordering. See cds::opt::memory_model option
+ typedef typename base_class::stat stat; ///< Internal statistics
typedef typename base_class::rcu_check_deadlock rcu_check_deadlock ; ///< RCU deadlock checking policy
typedef typename gc::scoped_lock rcu_lock ; ///< RCU scoped lock
- static CDS_CONSTEXPR const bool c_bExtractLockExternal = base_class::c_bExtractLockExternal; ///< Group of \p extract_xxx functions require external locking
+ static CDS_CONSTEXPR const bool c_bExtractLockExternal = base_class::c_bExtractLockExternal; ///< Group of \p extract_xxx functions do not require external locking
+
+ //@cond
+ // Rebind traits (split-list support)
+ template <typename... Options>
+ struct rebind_traits {
+ typedef MichaelList<
+ gc
+ , value_type
+ , typename cds::opt::make_options< traits, Options...>::type
+ > type;
+ };
+
+ // Stat selector
+ template <typename Stat>
+ using select_stat_wrapper = typename base_class::template select_stat_wrapper< Stat >;
+ //@endcond
protected:
//@cond
typedef typename maker::intrusive_traits::compare intrusive_key_comparator;
typedef typename base_class::atomic_node_ptr head_type;
- //@endcond
-
- public:
- typedef cds::urcu::exempt_ptr< gc, node_type, value_type, typename maker::intrusive_traits::disposer > exempt_ptr; ///< pointer to extracted node
-
- private:
- //@cond
- static value_type& node_to_value( node_type& n )
- {
- return n.m_Value;
- }
- static value_type const& node_to_value( node_type const& n )
- {
- return n.m_Value;
- }
- //@endcond
-
- protected:
- //@cond
- template <typename Q>
- static node_type * alloc_node( Q const& v )
- {
- return cxx_allocator().New( v );
- }
-
- template <typename... Args>
- static node_type * alloc_node( Args&&... args )
- {
- return cxx_allocator().MoveNew( std::forward<Args>(args)... );
- }
-
- static void free_node( node_type * pNode )
- {
- cxx_allocator().Delete( pNode );
- }
struct node_disposer {
void operator()( node_type * pNode )
}
};
typedef std::unique_ptr< node_type, node_disposer > scoped_node_ptr;
+ //@endcond
- head_type& head()
+ private:
+ //@cond
+ struct raw_ptr_converter
{
- return base_class::m_pHead;
- }
+ value_type * operator()( node_type * p ) const
+ {
+ return p ? &p->m_Value : nullptr;
+ }
- head_type& head() const
- {
- return const_cast<head_type&>( base_class::m_pHead );
- }
+ value_type& operator()( node_type& n ) const
+ {
+ return n.m_Value;
+ }
+
+ value_type const& operator()( node_type const& n ) const
+ {
+ return n.m_Value;
+ }
+ };
//@endcond
+ public:
+ ///< pointer to extracted node
+ using exempt_ptr = cds::urcu::exempt_ptr< gc, node_type, value_type, typename maker::intrusive_traits::disposer >;
+
+ /// Result of \p get(), \p get_with() functions - pointer to the node found
+ typedef cds::urcu::raw_ptr_adaptor< value_type, typename base_class::raw_ptr, raw_ptr_converter > raw_ptr;
+
protected:
- //@cond
+ //@cond
template <bool IsConst>
class iterator_type: protected base_class::template iterator_type<IsConst>
{
//@endcond
public:
+ ///@name Forward iterators (only for debugging purpose)
+ //@{
/// Forward iterator
+ /**
+ You may safely use iterators in multi-threaded environment only under RCU lock.
+ Otherwise, a crash is possible if another thread deletes the item the iterator points to.
+ */
typedef iterator_type<false> iterator;
/// Const forward iterator
*/
iterator begin()
{
- return iterator( head() );
+ return iterator( head());
}
/// Returns an iterator that addresses the location succeeding the last element in a list
}
/// Returns a forward const iterator addressing the first element in a list
- //@{
const_iterator begin() const
{
- return const_iterator( head() );
+ return const_iterator( head());
}
- const_iterator cbegin()
+
+ /// Returns a forward const iterator addressing the first element in a list
+ const_iterator cbegin() const
{
- return const_iterator( head() );
+ return const_iterator( head());
}
- //@}
/// Returns an const iterator that addresses the location succeeding the last element in a list
- //@{
const_iterator end() const
{
return const_iterator();
}
- const_iterator cend()
+
+ /// Returns an const iterator that addresses the location succeeding the last element in a list
+ const_iterator cend() const
{
return const_iterator();
}
- //@}
+ //@}
public:
/// Default constructor
MichaelList()
{}
+ //@cond
+ template <typename Stat, typename = std::enable_if<std::is_same<stat, michael_list::wrapped_stat<Stat>>::value >>
+ explicit MichaelList( Stat& st )
+ : base_class( st )
+ {}
+ //@endcond
+
/// List destructor
/**
Clears the list
Returns \p true if inserting successful, \p false otherwise.
*/
template <typename Q>
- bool insert( Q const& val )
+ bool insert( Q&& val )
{
- return insert_at( head(), val );
+ return insert_at( head(), std::forward<Q>( val ));
}
/// Inserts new node
The argument \p itemValue of user-defined functor \p func is the reference
to the list's item inserted. User-defined functor \p func should guarantee that during changing
item's value no any other changes could be made on this list's item by concurrent threads.
- The user-defined functor can be passed by reference using \p std::ref
- and it is called only if the inserting is success.
The type \p Q should contain the complete key of the node.
The object of \ref value_type should be constructible from \p key of type \p Q.
it is preferable that the initialization should be completed only if inserting is successful.
The function makes RCU lock internally.
+
+ @warning See \ref cds_intrusive_item_creating "insert item troubleshooting"
*/
template <typename Q, typename Func>
- bool insert( Q const& key, Func func )
+ bool insert( Q&& key, Func func )
{
- return insert_at( head(), key, func );
+ return insert_at( head(), std::forward<Q>( key ), func );
}
- /// Ensures that the \p key exists in the list
+ /// Updates data by \p key
/**
- The operation performs inserting or changing data with lock-free manner.
+ The operation performs inserting or replacing the element with lock-free manner.
If the \p key not found in the list, then the new item created from \p key
- is inserted into the list. 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:
+ will be inserted iff \p bAllowInsert is \p true.
+ Otherwise, if \p key is found, the functor \p func is called with item found.
+
+ The functor \p Func signature is:
\code
struct my_functor {
- void operator()( bool bNew, value_type& item, const Q& val );
+ 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 list
- - \p val - argument \p key passed into the \p ensure function
+ - \p val - argument \p key 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 function makes RCU lock internally.
+ The function applies RCU lock internally.
- Returns <tt> std::pair<bool, bool> </tt> where \p first is true if operation is successfull,
+ Returns <tt> std::pair<bool, bool> </tt> where \p first is true if operation is successful,
\p second is true if new item has been added or \p false if the item with \p key
- already is in the list.
+ already exists.
+
+ @warning See \ref cds_intrusive_item_creating "insert item troubleshooting"
*/
template <typename Q, typename Func>
+ std::pair<bool, bool> update( Q const& key, Func func, bool bAllowInsert = true )
+ {
+ return update_at( head(), key, func, bAllowInsert );
+ }
+ //@cond
+ template <typename Q, typename Func>
+ CDS_DEPRECATED("ensure() is deprecated, use update()")
std::pair<bool, bool> ensure( Q const& key, Func f )
{
- return ensure_at( head(), key, f );
+ return update( key, f, true );
}
+ //@endcond
/// Inserts data of type \ref value_type constructed from \p args
/**
/** \anchor cds_nonintrusive_MichealList_rcu_erase_val
Since the key of MichaelList's item type \p value_type is not explicitly specified,
template parameter \p Q defines the key type searching in the list.
- The list item comparator should be able to compare values of the type \p value_type
+ The list item comparator should be able to compare values of the type \p value_type
and \p Q in any order.
RCU \p synchronize method can be called. RCU should not be locked.
template <typename Q, typename Less>
bool erase_with( Q const& key, Less pred )
{
+ CDS_UNUSED( pred );
return erase_at( head(), key, typename maker::template less_wrapper<Less>::type(), [](value_type const&){} );
}
The functor \p Func interface:
\code
- struct extractor {
+ struct functor {
void operator()(const value_type& val) { ... }
};
\endcode
template <typename Q, typename Less, typename Func>
bool erase_with( Q const& key, Less pred, Func f )
{
+ CDS_UNUSED( pred );
return erase_at( head(), key, typename maker::template less_wrapper<Less>::type(), f );
}
/**
@anchor cds_nonintrusive_MichaelList_rcu_extract
The function searches an item with key equal to \p key in the list,
- unlinks it from the list, and returns pointer to an item found in \p dest argument.
- If the item with the key equal to \p key is not found the function returns \p false.
+ unlinks it from the list, 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 list
- and returns a pointer to item found.
- You should lock RCU before calling this function.
+ @note The function does NOT dispose the item found. It just excludes the item from the list
+ and returns a pointer to the item.
+ You shouldn't lock RCU for current thread before calling this function.
\code
#include <cds/urcu/general_buffered.h>
// ...
rcu_michael_list::exempt_ptr p;
- {
- // first, we should lock RCU
- rcu::scoped_lock sl;
-
- // Now, you can apply extract function
- // Note that you must not delete the item found inside the RCU lock
- if ( theList.extract( p, 10 )) {
- // do something with p
- ...
- }
+
+ // The RCU should NOT be locked when extract() is called!
+ assert( !rcu::is_locked());
+
+ // extract() call
+ p = theList.extract( 10 )
+ if ( p ) {
+ // do something with p
+ ...
}
- // Outside RCU lock section we may safely release extracted pointer.
+
+ // we may safely release extracted pointer here.
// release() passes the pointer to RCU reclamation cycle.
p.release();
\endcode
*/
template <typename Q>
- bool extract( exempt_ptr& dest, Q const& key )
+ exempt_ptr extract( Q const& key )
{
- dest = extract_at( head(), key, intrusive_key_comparator() );
- return !dest.empty();
+ return exempt_ptr( extract_at( head(), key, intrusive_key_comparator()));
}
/// Extracts an item from the list using \p pred predicate for searching
/**
- This function is the analog for \ref cds_nonintrusive_MichaelList_rcu_extract "extract(exempt_ptr&, Q const&)".
+ This function is the analog for \p extract(Q const&).
The \p pred is a predicate used for key comparing.
\p Less has the interface like \p std::less.
\p pred must imply the same element order as \ref key_comparator.
*/
template <typename Q, typename Less>
- bool extract_with( exempt_ptr& dest, Q const& key, Less pred )
+ exempt_ptr extract_with( Q const& key, Less pred )
{
- dest = extract_at( head(), key, typename maker::template less_wrapper<Less>::type() );
- return !dest.empty();
+ CDS_UNUSED( pred );
+ return exempt_ptr( extract_at( head(), key, typename maker::template less_wrapper<Less>::type()));
}
- /// Finds the key \p key
- /** \anchor cds_nonintrusive_MichaelList_rcu_find_val
+ /// Checks whether the list 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.
- The function makes RCU lock internally.
+ The function applies RCU lock internally.
*/
template <typename Q>
- bool find( Q const& key ) const
+ bool contains( Q const& key )
+ {
+ return find_at( head(), key, intrusive_key_comparator());
+ }
+ //@cond
+ template <typename Q>
+ CDS_DEPRECATED("deprecated, use contains()")
+ bool find( Q const& key )
{
- return find_at( head(), key, intrusive_key_comparator() );
+ return contains( key );
}
+ //@endcond
- /// Finds the key \p val using \p pred predicate for searching
+ /// Checks whether the list contains \p key using \p pred predicate for searching
/**
- The function is an analog of \ref cds_nonintrusive_MichaelList_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 list.
*/
template <typename Q, typename Less>
- bool find_with( Q const& key, Less pred ) const
+ bool contains( Q const& key, Less pred )
+ {
+ CDS_UNUSED( pred );
+ return find_at( head(), key, typename maker::template less_wrapper<Less>::type());
+ }
+ //@cond
+ // Deprecatd, use contains()
+ template <typename Q, typename Less>
+ bool find_with( Q const& key, Less pred )
{
- return find_at( head(), key, typename maker::template less_wrapper<Less>::type() );
+ CDS_UNUSED( pred );
+ return contains( key, pred );
}
+ //@endcond
/// Finds the key \p key and performs an action with it
/** \anchor cds_nonintrusive_MichaelList_rcu_find_func
The function returns \p true if \p val is found, \p false otherwise.
*/
template <typename Q, typename Func>
- bool find( Q& key, Func f ) const
+ bool find( Q& key, Func f )
{
return find_at( head(), key, intrusive_key_comparator(), f );
}
+ //@cond
+ template <typename Q, typename Func>
+ bool find( Q const& key, Func f )
+ {
+ return find_at( head(), key, intrusive_key_comparator(), f );
+ }
+ //@endcond
/// Finds the key \p key using \p pred predicate for searching
/**
\p pred must imply the same element order as the comparator used for building the list.
*/
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 )
{
+ CDS_UNUSED( pred );
return find_at( head(), key, typename maker::template less_wrapper<Less>::type(), f );
}
+ //@cond
+ template <typename Q, typename Less, typename Func>
+ bool find_with( Q const& key, Less pred, Func f )
+ {
+ CDS_UNUSED( pred );
+ return find_at( head(), key, typename maker::template less_wrapper<Less>::type(), f );
+ }
+ //@endcond
/// Finds the key \p key and return the item found
/** \anchor cds_nonintrusive_MichaelList_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.
+ If \p key is not found it returns an empty \p raw_ptr.
Note the compare functor should accept a parameter of type \p Q that can be not the same as \p value_type.
typedef cds::container::MichaelList< cds::urcu::gc< cds::urcu::general_buffered<> >, foo, my_traits > ord_list;
ord_list theList;
// ...
+ typename ord_list::raw_ptr rp;
{
// Lock RCU
ord_list::rcu_lock lock;
- foo * pVal = theList.get( 5 );
- if ( pVal ) {
- // Deal with pVal
+ rp = theList.get( 5 );
+ if ( rp ) {
+ // Deal with rp
//...
}
// Unlock RCU by rcu_lock destructor
- // pVal can be freed at any time after RCU has been unlocked
+ // A value owned by rp can be freed at any time after RCU has been unlocked
}
+ // You can manually release rp after RCU-locked section
+ rp.release();
\endcode
*/
template <typename Q>
- value_type * get( Q const& key ) const
+ raw_ptr get( Q const& key )
{
return get_at( head(), key, intrusive_key_comparator());
}
\p pred must imply the same element order as the comparator used for building the list.
*/
template <typename Q, typename Less>
- value_type * get_with( Q const& key, Less pred ) const
+ raw_ptr get_with( Q const& key, Less pred )
{
+ CDS_UNUSED( pred );
return get_at( head(), key, typename maker::template less_wrapper<Less>::type());
}
return base_class::size();
}
+ /// Returns const reference to internal statistics
+ stat const& statistics() const
+ {
+ return base_class::statistics();
+ }
+
/// Clears the list
void clear()
{
protected:
//@cond
+ bool insert_node( node_type * pNode )
+ {
+ return insert_node_at( head(), pNode );
+ }
+
bool insert_node_at( head_type& refHead, node_type * pNode )
{
assert( pNode );
}
template <typename Q>
- bool insert_at( head_type& refHead, Q const& val )
+ bool insert_at( head_type& refHead, Q&& val )
{
- return insert_node_at( refHead, alloc_node( val ));
+ return insert_node_at( refHead, alloc_node( std::forward<Q>( val )));
}
template <typename Q, typename Func>
- bool insert_at( head_type& refHead, Q const& key, Func f )
+ bool insert_at( head_type& refHead, Q&& key, Func f )
{
- scoped_node_ptr pNode( alloc_node( key ));
+ scoped_node_ptr pNode( alloc_node( std::forward<Q>( key )));
- if ( base_class::insert_at( refHead, *pNode, [&f]( node_type& node ) { f( node_to_value(node) ); } )) {
+ if ( base_class::insert_at( refHead, *pNode, [&f]( node_type& node ) { f( node_to_value(node)); } )) {
pNode.release();
return true;
}
template <typename Q, typename Compare, typename Func>
bool erase_at( head_type& refHead, Q const& key, Compare cmp, Func f )
{
- return base_class::erase_at( refHead, key, cmp, [&f](node_type const& node){ f( node_to_value(node) ); } );
+ return base_class::erase_at( refHead, key, cmp, [&f](node_type const& node){ f( node_to_value(node)); } );
}
template <typename Q, typename Func>
- std::pair<bool, bool> ensure_at( head_type& refHead, Q const& key, Func f )
+ std::pair<bool, bool> update_at( head_type& refHead, Q const& key, Func f, bool bAllowInsert )
{
scoped_node_ptr pNode( alloc_node( key ));
- std::pair<bool, bool> ret = base_class::ensure_at( refHead, *pNode,
- [&f, &key](bool bNew, node_type& node, node_type&){ f( bNew, node_to_value(node), key ); });
+ std::pair<bool, bool> ret = base_class::update_at( refHead, *pNode,
+ [&f, &key](bool bNew, node_type& node, node_type&){ f( bNew, node_to_value(node), key );},
+ bAllowInsert );
if ( ret.first && ret.second )
pNode.release();
}
template <typename Q, typename Compare>
- bool find_at( head_type& refHead, Q const& key, Compare cmp ) const
+ bool find_at( head_type& refHead, Q const& key, Compare cmp )
{
return base_class::find_at( refHead, key, cmp, [](node_type&, Q const &) {} );
}
template <typename Q, typename Compare, typename Func>
- bool find_at( head_type& refHead, Q& val, Compare cmp, Func f ) const
+ bool find_at( head_type& refHead, Q& val, Compare cmp, Func f )
{
return base_class::find_at( refHead, val, cmp, [&f](node_type& node, Q& v){ f( node_to_value(node), v ); });
}
template <typename Q, typename Compare>
- value_type * get_at( head_type& refHead, Q const& val, Compare cmp ) const
+ raw_ptr get_at( head_type& refHead, Q const& val, Compare cmp )
+ {
+ return raw_ptr( base_class::get_at( refHead, val, cmp ));
+ }
+
+ static value_type& node_to_value( node_type& n )
+ {
+ return n.m_Value;
+ }
+ static value_type const& node_to_value( node_type const& n )
+ {
+ return n.m_Value;
+ }
+
+ template <typename Q>
+ static node_type * alloc_node( Q&& v )
+ {
+ return cxx_allocator().New( std::forward<Q>( v ));
+ }
+
+ template <typename... Args>
+ static node_type * alloc_node( Args&&... args )
{
- node_type * pNode = base_class::get_at( refHead, val, cmp );
- return pNode ? &pNode->m_Value : nullptr;
+ return cxx_allocator().MoveNew( std::forward<Args>( args )... );
}
+ static void free_node( node_type * pNode )
+ {
+ cxx_allocator().Delete( pNode );
+ }
+
+ head_type& head()
+ {
+ return base_class::m_pHead;
+ }
+
+ head_type& head() const
+ {
+ return const_cast<head_type&>(base_class::m_pHead);
+ }
//@endcond
};
}} // namespace cds::container
-#endif // #ifndef __CDS_CONTAINER_MICHAEL_LIST_RCU_H
+#endif // #ifndef CDSLIB_CONTAINER_MICHAEL_LIST_RCU_H