RFR (M): 8189737: Make HeapRegion not derive from Space

[Thomas Schatzl]

Hi,

On 06.11.19 12:03, Stefan Johansson wrote:
> Hi Thomas,
[...]
>>>
>>> I think this looks really good in general, so nice to get rid of this 
>>> inheritance.
>>>
>>> I have one question/comment though. I took a look at the HeapRegion 
>>> implementation in the SA and there it still extends CompactibleSpace 
>>> (which extends Space), I think we should remove this and add _bottom 
>>> and _top for HeapRegion in vmStructs_g1.hpp. This also has the effect 
>>> that the PrintRegionClosure needs to be updated to not depend on 
>>> space either. It is only used by G1 so I think it should simply be 
>>> moved from shared to g1 and changed to not depend on space.
>>
>> Good catch. Changed in
>>
>> http://cr.openjdk.java.net/~tschatzl/8189737/webrev.0_to_1/ (diff)
>> http://cr.openjdk.java.net/~tschatzl/8189737/webrev.1 (full)
> 
> Thanks for fixing this, looks good. I don't think we need to add 
> _compaction_top, from what I can see it is not used. I don't need a new 
> webrev for this if I'm right.

Updated in place.

Thanks,
   Thomas