Java volatile for concurrency

Question

Ok so I just read this question Do you ever use the volatile keyword in Java?, and I get using a volatile variable in order to stop a loop. Also I\'ve seen this reference, h

Answer 1

There's a numebr of things wrong in your question: You can do a reliable read-update-write with volatile so long as you use Atomic*FieldUpdater and a cas-loop. Volatiles can be "cached", they just need to obey the relevant happens-before semantics specified.

Synchronisation typically involves obtaining a lock, which is relatively expensive (although may actually be quite cheap). Simple concurrent optimisations may use non-naive implementation techniques.