What is AtomicInteger in Java?

An AtomicInteger is used in applications such as atomically incremented counters, and cannot be used as a replacement for an Integer . However, this class does extend Number to allow uniform access by tools and utilities that deal with numerically-based classes.

How do you declare AtomicInteger in Java?

Creating an AtomicInteger AtomicInteger atomicInteger = new AtomicInteger(); This example creates an AtomicInteger with the initial value 0 . If you want to create an AtomicInteger with an initial value, you can do so like this: AtomicInteger atomicInteger = new AtomicInteger(123);

Is AtomicInteger set thread-safe?

7. Atomic Objects. It’s also possible to achieve thread-safety using the set of atomic classes that Java provides, including AtomicInteger, AtomicLong, AtomicBoolean and AtomicReference. Atomic classes allow us to perform atomic operations, which are thread-safe, without using synchronization.

Where is AtomicInteger used?

The primary use of AtomicInteger is when you are in a multithreaded context and you need to perform thread safe operations on an integer without using synchronized . The assignation and retrieval on the primitive type int are already atomic but AtomicInteger comes with many operations which are not atomic on int .

Is AtomicInteger volatile?

This is source code of AtomicInteger. The value is Volatile. So,AtomicInteger uses Volatile inside.

How AtomicInteger is implemented?

AtomicInteger uses combination of volatile & CAS (compare and swap) to achieve thread-safety for Integer Counter. It is non-blocking in nature and thus highly usable in writing high throughput concurrent data structures that can be used under low to moderate thread contention.

Is AtomicInteger synchronized?

Yes, you are correct. AtomicInteger would not grant any benefit if all access to the object is synchronized (only one thread, at most, would be accessing its contents at any given moment).

Is LongAdder thread-safe?

LongAdder provides methods add() and increment() just like the atomic number classes and is also thread-safe.