RFR: jsr166 jdk9 integration wave 9

[Aleksey Shipilev]

On 08/11/2016 04:34 AM, Martin Buchholz wrote:
> Again, no spec changes, but larger than expected.
> 
> http://cr.openjdk.java.net/~martin/webrevs/openjdk9/jsr166-jdk9-integration/

Why doesn't AtomicBoolean.getAndSet use VarHandle.getAndSet, which is
hopefully intrinsified completely?

I like the single-CAS version too, but it probably warrants some
explanation. Suggestion: "Since there are only two boolean values,
single CAS is enough, because there are only two possibilities: a) CAS
succeeds: the actual value needed change, and therefore it was a
complement of new value; b) CAS fails: the actual value was exactly the
new value."

Any benchmarks backing up this optimization?

Thanks,
-Aleksey