- <tt><cds/container/skip_list_map_dhp.h></tt> for \p gc::DHP garbage collector
- <tt><cds/container/skip_list_map_rcu.h></tt> for \ref cds_nonintrusive_SkipListMap_rcu "RCU type"
- <tt><cds/container/skip_list_map_nogc.h></tt> for \ref cds_nonintrusive_SkipListMap_nogc "non-deletable SkipListMap"
-
- <b>Iterators</b>
-
- The class supports a forward iterator (\ref iterator and \ref const_iterator).
- The iteration is ordered.
- The iterator object is thread-safe: the element pointed by the iterator object is guarded,
- so, the element cannot be reclaimed while the iterator object is alive.
- However, passing an iterator object between threads is dangerous.
-
- \warning Due to concurrent nature of skip-list map it is not guarantee that you can iterate
- all elements in the map: any concurrent deletion can exclude the element
- pointed by the iterator from the map, and your iteration can be terminated
- before end of the map. Therefore, such iteration is more suitable for debugging purpose only
-
- Remember, each iterator object requires 2 additional hazard pointers, that may be
- a limited resource for \p GC like \p gc::HP (for gc::DHP the count of
- guards is unlimited).
-
- The iterator class supports the following minimalistic interface:
- \code
- struct iterator {
- // Default ctor
- iterator();
-
- // Copy ctor
- iterator( iterator const& s);
-
- value_type * operator ->() const;
- value_type& operator *() const;
-
- // Pre-increment
- iterator& operator ++();
-
- // Copy assignment
- iterator& operator = (const iterator& src);
-
- bool operator ==(iterator const& i ) const;
- bool operator !=(iterator const& i ) const;
- };
- \endcode
- Note, the iterator object returned by \ref end, \ cend member functions points to \p nullptr and should not be dereferenced.
-
*/
template <
typename GC,
typedef typename traits::random_level_generator random_level_generator ; ///< random level generator
typedef typename traits::stat stat; ///< internal statistics type
+ static size_t const c_nHazardPtrCount = base_class::c_nHazardPtrCount; ///< Count of hazard pointer required for the skip-list
+
protected:
//@cond
typedef typename maker::node_type node_type;
{}
public:
+ ///@name Forward iterators (only for debugging purpose)
+ //@{
/// Iterator type
+ /**
+ The forward iterator has some features:
+ - it is ordered
+ - it has no post-increment operator
+ - to protect the value, the iterator contains a GC-specific guard + another guard is required locally for increment operator.
+ For some GC (like as \p gc::HP), a guard is a limited resource per thread, so an exception (or assertion) "no free guard"
+ may be thrown if the limit of guard count per thread is exceeded.
+ - The iterator cannot be moved across thread boundary because it contains thread-private GC's guard.
+ - Iterator ensures thread-safety even if you delete the item the iterator points to. However, in case of concurrent
+ deleting operations there is no guarantee that you iterate all item in the list.
+ Moreover, a crash is possible when you try to iterate the next element that has been deleted by concurrent thread.
+
+ @warning Use this iterator on the concurrent container for debugging purpose only.
+
+ @note \p end() and \p cend() are not dereferenceable.
+
+ The iterator interface:
+ \code
+ class iterator {
+ public:
+ // Default constructor
+ iterator();
+
+ // Copy construtor
+ iterator( iterator const& src );
+
+ // Dereference operator
+ value_type * operator ->() const;
+
+ // Dereference operator
+ value_type& operator *() const;
+
+ // Preincrement operator
+ iterator& operator ++();
+
+ // Assignment operator
+ iterator& operator = (iterator const& src);
+
+ // Equality operators
+ bool operator ==(iterator const& i ) const;
+ bool operator !=(iterator const& i ) const;
+ };
+ \endcode
+ */
typedef skip_list::details::iterator< typename base_class::iterator > iterator;
- /// Const iterator type
- typedef skip_list::details::iterator< typename base_class::const_iterator > const_iterator;
+ /// Const forward iterator type
+ typedef skip_list::details::iterator< typename base_class::const_iterator > const_iterator;
/// Returns a forward iterator addressing the first element in a map
iterator begin()
{
return cbegin();
}
+
/// Returns a forward const iterator addressing the first element in a map
const_iterator cbegin() const
{
{
return cend();
}
+
/// Returns a forward const iterator that addresses the location succeeding the last element in a map.
const_iterator cend() const
{
return const_iterator( base_class::cend() );
}
+ //@}
public:
/// Inserts new node with key and default value
template <typename K, typename V>
bool insert( K const& key, V const& val )
{
- return insert_with( key, [&val](value_type& item) { item.second = val ; } );
+ return insert_with( key, [&val]( value_type& item ) { item.second = val; } );
}
/// Inserts new node and initialize it by a functor
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