Request for approval: 8140483, Atomic*FieldUpdaters final fields should be trusted

[Aleksey Shipilev]

Thanks Rob!
Added "noreg-perf".

Looking for a sponsor!

Cheers,
-Aleksey

On 11/16/2015 11:15 PM, Rob McKenna wrote:
> Approved. Please add an appropriate noreg label to the bug.
> 
>     -Rob
> 
> On 16/11/15 18:23, Aleksey Shipilev wrote:
>> Hi,
>>
>> There is a simple Hotspot compiler change that improves the
>> Atomic*FieldUpdater performance by a large margin, and thus provides a
>> migration path with the eventual demise of sun.misc.Unsafe. Therefore,
>> I'd like us to consider this in 8u76 to expose users to this improvement
>> earlier than JDK 9 release. I am not a 8u Committer, so if the change is
>> approved, I'd need a sponsor.
>>
>> Bug:
>>    https://bugs.openjdk.java.net/browse/JDK-8140483
>>
>> Webrev:
>>    http://cr.openjdk.java.net/~shade/8140483/webrev.02/
>>
>> JDK 9 Changeset:
>>    http://hg.openjdk.java.net/jdk9/jdk9/hotspot/rev/0835ef4e6232
>>
>> JDK 9 Review:
>>
>> http://mail.openjdk.java.net/pipermail/hotspot-compiler-dev/2015-October/019549.html
>>
>>
>> The change was in jdk9/hs-comp for two weeks now, and a few days in
>> jdk9/jdk9.
>>
>> The patch applies automatically with a bit of the fuzz. jdk8u builds and
>> runs fine at least on Linux x86_64, the performance improvement is the
>> same as in JDK 9.
>>
>> Thanks,
>> -Aleksey
>>