/// pointer to extracted node
using exempt_ptr = cds::urcu::exempt_ptr< gc, node_type, value_type, typename maker::intrusive_type_traits::disposer >;
+ private:
+ //@cond
+ struct raw_ptr_converter
+ {
+ value_type * operator()( node_type * p ) const
+ {
+ return p ? &p->m_Value : nullptr;
+ }
+
+ 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:
+ /// 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
unsigned int random_level()
{
return base_class::random_level();
}
-
- value_type * to_value_ptr( node_type * pNode ) const CDS_NOEXCEPT
- {
- return pNode ? &pNode->m_Value : nullptr;
- }
//@endcond
public:
return false;
}
- /// Ensures that the \p key exists in the map
+ /// Updates data by \p key
/**
The operation performs inserting or changing data with lock-free manner.
If the \p key not found in the map, then the new item created from \p key
- is inserted into the map (note that in this case the \ref key_type should be
- constructible from type \p K).
- Otherwise, the functor \p func is called with item found.
+ is inserted into the map iff \p bInsert is \p true.
+ Otherwise, if \p key found, the functor \p func is called with item found.
The functor \p Func interface is:
\code
struct my_functor {
void operator()( bool bNew, value_type& item );
};
\endcode
- with arguments:
+ where:
- \p bNew - \p true if the item has been inserted, \p false otherwise
- - \p item - item of the list
+ - \p item - item of the map
The functor may change any fields of \p item.second.
RCU \p synchronize() method can be called. RCU should not be locked.
- 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
- already is in the list.
+ 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 exists.
@warning See \ref cds_intrusive_item_creating "insert item troubleshooting"
*/
template <typename K, typename Func>
- std::pair<bool, bool> ensure( K const& key, Func func )
+ std::pair<bool, bool> update( K const& key, Func func, bool bInsert = true )
{
scoped_node_ptr pNode( node_allocator().New( random_level(), key ));
- std::pair<bool, bool> res = base_class::ensure( *pNode,
- [&func](bool bNew, node_type& item, node_type const& ){ func( bNew, item.m_Value ); }
+ std::pair<bool, bool> res = base_class::update( *pNode,
+ [&func](bool bNew, node_type& item, node_type const& ){ func( bNew, item.m_Value );},
+ bInsert
);
if ( res.first && res.second )
pNode.release();
return res;
}
+ //@cond
+ // Deprecated, use update()
+ template <typename K, typename Func>
+ std::pair<bool, bool> ensure( K const& key, Func func )
+ {
+ return update( key, func, true );
+ }
+ //@endcond
+
/// Delete \p key from the map
/**\anchor cds_nonintrusive_SkipListMap_rcu_erase_val
/// Finds the key \p key and return the item found
/** \anchor cds_nonintrusive_SkipListMap_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.
+ The function searches the item with key equal to \p key and returns a \p raw_ptr object pointing to an item found.
+ If \p key is not found it returns empty \p raw_ptr.
Note the compare functor in \p Traits class' template argument
should accept a parameter of type \p K that can be not the same as \p key_type.
typedef cds::container::SkipListMap< cds::urcu::gc< cds::urcu::general_buffered<> >, int, foo, my_traits > skip_list;
skip_list theList;
// ...
+ typename skip_list::raw_ptr pVal;
{
// Lock RCU
skip_list::rcu_lock lock;
- skip_list::value_type * pVal = theList.get( 5 );
- // Deal with pVal
- //...
-
- // Unlock RCU by rcu_lock destructor
- // pVal can be freed at any time after RCU unlocking
+ pVal = theList.get( 5 );
+ if ( pVal ) {
+ // Deal with pVal
+ //...
+ }
}
+ // You can manually release pVal after RCU-locked section
+ pVal.release();
\endcode
-
- After RCU unlocking the \p %force_dispose member function can be called manually,
- see \ref force_dispose for explanation.
*/
template <typename K>
- value_type * get( K const& key )
+ raw_ptr get( K const& key )
{
- return to_value_ptr( base_class::get( key ));
+ return raw_ptr( base_class::get( key ));
}
/// Finds the key \p key and return the item found
\p pred must imply the same element order as the comparator used for building the map.
*/
template <typename K, typename Less>
- value_type * get_with( K const& key, Less pred )
+ raw_ptr get_with( K const& key, Less pred )
{
CDS_UNUSED( pred );
- return to_value_ptr( base_class::get_with( key, cds::details::predicate_wrapper< node_type, Less, typename maker::key_accessor >() ));
+ return raw_ptr( base_class::get_with( key, cds::details::predicate_wrapper< node_type, Less, typename maker::key_accessor >() ));
}
/// Clears the map (not atomic)
{
return base_class::statistics();
}
-
- /// Clears internal list of ready-to-delete items passing them to RCU reclamation cycle
- /** @copydetails cds_intrusive_SkipListSet_rcu_force_dispose
- */
- void force_dispose()
- {
- return base_class::force_dispose();
- }
};
}} // namespace cds::container
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