How do you make a concurrent hash set?

A new method is added into ConcurrentHashMap in JDK 8, newKeySet(), which allows you to create a concurrent hash set backed by a concurrent hash map. If you remember, whenever you get keys from the map, they are returned in a Set e.g. for the old keySet() method, because the map only has unique keys.

What is concurrent HashSet?

ConcurrentHashSet can be created by using ConcurrentHashMap as it allows us to use keySet(default value) and newKeySet() methods to return the Set, which happens to be a proper Set. This gives us access to necessary functions like contains(), remove(), etc.

Is there a concurrent set in Java?

It looks like Java provides a concurrent Set implementation with its ConcurrentSkipListSet. A SkipList Set is just a special kind of set implementation. It still implements the Serializable, Cloneable, Iterable, Collection, NavigableSet, Set, SortedSet interfaces.

How to make a concurrent HashSet < T >?

The tricky part about making an ISet concurrent is that the set methods (union, intersection, difference) are iterative in nature. At the very least you have to iterate over all n members of one of the sets involved in the operation, while locking both sets.

How is a concurrent hash table group created?

Concurrent accesses grouped into distinct phases. A phase concurrent hash table groups accesses by creating phases in which only one type of operation is allowed (i.e. a pure write-phase), followed by a synchronization of the table state across all threads. A formally proven algorithm for this is given by Shun and Blelloch. .

What’s the difference between Hashtable and ConcurrentHashMap?

Internal working of HashTable This diagram is seems to be similar to the internal implementation of HashMap, but Hashtable is synchronized and provides thread safety like concurrentHashMap but in the performance point of view,Hashtable write operation uses map wide lock which means it locks the complete map object.

How is a HashSet based on a hashmap?

HashSet is based on HashMap. If we look at HashSet implementation, everything is been managed under HashMap . is used as a key of HashMap.