ConcurrentSkipListMap

public class ConcurrentSkipListMap extends AbstractMap<K, V>
implements ConcurrentNavigableMap<K, V> Cloneable Serializable

A scalable concurrent ConcurrentNavigableMap implementation. The map is sorted according to the {@linkplain Comparable natural ordering} of its keys, or by a Comparator provided at map creation time, depending on which constructor is used.

This class implements a concurrent variant of SkipLists providing expected average log(n) time cost for the containsKey, get, put and remove operations and their variants. Insertion, removal, update, and access operations safely execute concurrently by multiple threads.

Iterators and spliterators are weakly consistent.

Ascending key ordered views and their iterators are faster than descending ones.

All Map.Entry pairs returned by methods in this class and its views represent snapshots of mappings at the time they were produced. They do not support the Entry.setValue method. (Note however that it is possible to change mappings in the associated map using put, putIfAbsent, or replace, depending on exactly which effect you need.)

Beware that, unlike in most collections, the size method is not a constant-time operation. Because of the asynchronous nature of these maps, determining the current number of elements requires a traversal of the elements, and so may report inaccurate results if this collection is modified during traversal. Additionally, the bulk operations putAll, equals, toArray, containsValue, and clear are not guaranteed to be performed atomically. For example, an iterator operating concurrently with a putAll operation might view only some of the added elements.

This class and its views and iterators implement all of the optional methods of the Map and Iterator interfaces. Like most other concurrent collections, this class does not permit the use of null keys or values because some null return values cannot be reliably distinguished from the absence of elements.

Public Constructor Summary

ConcurrentSkipListMap()
Constructs a new, empty map, sorted according to the {@linkplain Comparable natural ordering} of the keys.
ConcurrentSkipListMap(Comparator<? super K> comparator)
Constructs a new, empty map, sorted according to the specified comparator.
ConcurrentSkipListMap(Map<? extends K, ? extends V> m)
Constructs a new map containing the same mappings as the given map, sorted according to the {@linkplain Comparable natural ordering} of the keys.
ConcurrentSkipListMap(SortedMap<K, ? extends V> m)
Constructs a new map containing the same mappings and using the same ordering as the specified sorted map.