Usage of lazySet on AtomicXXX in Java

Question

From this question : AtomicInteger lazySet vs. set and form this link : https://docs.oracle.com/javase/7/docs/api/java/util/concurrent/atomic/package-summary.html

I could gather following points

• lazySet could be faster than set
• lazySet uses store-store barrier (writes before are honored but not the contended writes, which were yet to happen)

I could find one use-case where it could be applied, from the documentation :

• Use lazySet when you want to null out a pointer to aid GC.

Are there any other practical use-cases for lazySet ?

Answer 1

Caffeine uses lazy or relaxed writes in many of its data structures.

• When nulling out a field (e.g. ConcurrentLinkedStack)
• When writing to volatile fields before publishing (e.g. SingleConsumerQueue)
• When publish is safely delayable (e.g. BoundedBuffer)
• When races are benign (e.g. cache expiration timestamps)
• When inside a lock (e.g. BoundedLocalCache)

ConcurrentLinkedQueue uses relaxed writes prior to publishing a node and may lazily sets a node's next field (prior to publishing or to indicate a stale traversal).

You may also enjoy reading the Linux Kernel Memory Barriers paper.