Volatile boolean vs AtomicBoolean

java concurrency boolean volatile atomicboolean
JeffV picture JeffV · Sep 24, 2010 · Viewed 103.1k times · Source

What does AtomicBoolean do that a volatile boolean cannot achieve?

Answer

teto picture teto · Sep 24, 2010

I use volatile fields when said field is ONLY UPDATED by its owner thread and the value is only read by other threads, you can think of it as a publish/subscribe scenario where there are many observers but only one publisher. However if those observers must perform some logic based on the value of the field and then push back a new value then I go with Atomic* vars or locks or synchronized blocks, whatever suits me best. In many concurrent scenarios it boils down to get the value, compare it with another one and update if necessary, hence the compareAndSet and getAndSet methods present in the Atomic* classes.

Check the JavaDocs of the java.util.concurrent.atomic package for a list of Atomic classes and an excellent explanation of how they work (just learned that they are lock-free, so they have an advantage over locks or synchronized blocks)

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