RFR: 8057658: Enable G1 FullGC extensions

[Mikael Gerdin]

Hi Stefan,

On Friday 05 September 2014 13.43.57 Stefan Johansson wrote:
> Hi,
> 
> Please review this change for RFE:
> https://bugs.openjdk.java.net/browse/JDK-8057658
> 
> Webrev:
> http://cr.openjdk.java.net/~sjohanss/8057658/webrev.00/

space.hpp:
While you're there, can you change the name of the constructor parameter from 
_gen to something else? The common style is to prefix member variables with an 
underscore so this class is in direct opposition to this. You don't need to 
change the names of the members of CompactPoint though.

g1MarkSweep:
Can you move G1PrepareCompactClosure::execute to the G1MarkSweep class?
It's uncommon for other "closures" in hotspot to have static methods to invoke 
them like that.
Something like 

G1MarkSweep::prepare_compaction_work(G1PrepareCompactClosure* blk) {
g1h->heap_region_iterate(blk)
blk->update_sets()
}

and have 
G1MarkSweep::prepare_compaction() {
G1PrepareCompactClosure blk;
prepare_compaction_work(&blk);
}

Otherwise it looks good.
/Mikael

> 
> Summary:
> Refactored the G1 mark sweep code to enable specialized FullGC
> implementations. Also prepared for doing context specific FullGC related
> to the work for JDK-8057536.
> 
> Testing:
> * JPRT
> * Manual sanity testing
> 
> Thanks,
> Stefan