RFR (XS): 8027553 - Change the in_cset_fast_test functionality to use the G1BiasedArray abstraction

[Bengt Rutisson]

Hi Thomas,

Looks good.

One minor question. In the two places where we call 
clear_cset_fast_test() we have this comment.

         // Clear the _cset_fast_test bitmap in anticipation of adding
         // regions to the incremental collection set for the next
         // evacuation pause.
         clear_cset_fast_test();

Strictly speaking _cset_fast_test is not a bitmap anymore. On the other 
hand conceptually it is is, so maybe the comment is still ok. But then 
again, I am not sure we need this comment at all. From the name of the 
method it is pretty clear what the method does and from the placement of 
it I think the reason is pretty natural. I would be fine with just 
removing these two comments.

Anyway, I'm fine with the change as it is. If you want to do something 
about the comment thats fine too.

Reviewed. :)

Bengt


On 2014-03-14 10:25, Thomas Schatzl wrote:
> Hi all,
>
>    can I have reviews for the following small change? It cleans up the
> in_cset_fast_test functionality to use the G1BiasedMappedArray
> abstraction introduced long ago.
>
> This removes lots of clutter in the code caused by lots of explanation
> that is part of the G1BiasedMappedArray class description, manual
> management and asserts all handled by that class.
>
> It is intentional to name the class handling the in_cset_fast_test type
> G1FastCSetBiasedMappedArray, and not e.g. BoolBiasedMappedArray. The
> plan is to extend its use for "JDK-8027959: Investigate early
> reclamation of large objects in G1".
>
> Webrev:
> http://cr.openjdk.java.net/~tschatzl/8027553/webrev/
>
> CR:
> https://bugs.openjdk.java.net/browse/JDK-8027553
>
> Testing:
> jprt
>
> Thanks,
>    Thomas
>