RFR: JDK-8074578 Document memory visibility effects of some Unsafe methods

[David Holmes]

On 7/03/2015 6:49 AM, Martin Buchholz wrote:
> A wee code review fer ya:
>
> https://bugs.openjdk.java.net/browse/JDK-8074578
> http://cr.openjdk.java.net/~martin/webrevs/openjdk9/Unsafe-CAS-spec/

Sorry Martin but this is neither accurate nor meaningful. It isn't 
accurate because the actual Atomic::cmpxchg operations have full 
bi-directional fences, and in the long case if locking is used you get 
locking related barriers not volatile access barriers. It isn't 
meaningful because you haven't said what variable the volatile semantics 
apply to (not that that would help in the lock-based case).

David