RFR (S): 7127700: G1: Replace G1PLAB with PLAB

[Stefan Johansson]

Hi Thomas,

On 2018-02-12 10:30, Thomas Schatzl wrote:
> Hi all,
>
>    can I have reviews for this small change that removes G1PLAB and uses
> the PLAB class throughout?
>
> Although the CR indicates that the remaining _retired member of G1PLAB
> might be useful, I think the additional check it provides is not worth
> the effort, so I removed it.
>
> CR:
> https://bugs.openjdk.java.net/browse/JDK-7127700
> Webrev:
> http://cr.openjdk.java.net/~tschatzl/7127700/webrev/
Looks good, just one thing. Please remove the virtual declarations from 
PLAB in plab.hpp.

I have no strong opinion regarding keeping _retired, but if no one else 
see a strong reason for having it let's remove it.

Thanks,
Stefan

> Testing:
> hs-tier 1-5
>
> P.S: there is an alternate webrev at http://cr.openjdk.java.net/~tschat
> zl/7127700/webrev.alt that keeps the _retired flag and moves it to the
> PLAB class. If you think this is better, we can also use this for
> pushing. I am tending to just removing it.
>
> Thanks,
>    Thomas
>