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

[Thomas Schatzl]

Hi Kim,

  thanks for your review.

On Thu, 2019-10-31 at 18:12 -0400, Kim Barrett wrote:
> > On Oct 31, 2019, at 9:43 AM, Thomas Schatzl <
> > thomas.schatzl at oracle.com> wrote:
> > 
> > Hi all,
> > 
> >  can I get reviews for this refactoring that removes the
> > inheritance of HeapRegion from Space?
> > 
> > 
[...]
> > CR:
> > https://bugs.openjdk.java.net/browse/JDK-8189737
> > Webrev:
> > http://cr.openjdk.java.net/~tschatzl/8189737/webrev/
> > Testing:
> > hs-tier-1-5
> > 
> > Thanks,
> >  Thomas
> 
> It's a little unfortunate that you needed to touch the #includes in a
> couple of cms files.  Looks like it should be an easy merge for
> whichever of you or Leo goes second though.
> 

Yeah, np for either of us I guess.

> -------------------------------------------------------------------
> -----------
>  102 inline HeapWord* HeapRegion::par_allocate(size_t min_word_size,
>  103                                                  size_t
> desired_word_size,
>  104                                                  size_t*
> actual_size) {
> 
> Parameter list indentation needs fixing.

Will do.

> 
> -------------------------------------------------------------------
> -----------
> src/hotspot/share/gc/g1/heapRegion.hpp
> 
> There's a big comment block about BlockOffsetTable divergence, time
> stamps, &etc in front of G1ContiguousSpace that seems to have simply
> disappeared. I take it this was leftover commentary that should have
> been removed with JDK-8199326 and maybe others?

The first one about the divergence is obsolete because with that change
we officially and intentionally abandon any way to converge.

The other about the time stamps should have, as you correctly noticed,
been removed with JDK-8199326.

> 
> -------------------------------------------------------------------
> -----------
> 
> Looks good.
> 
> I don't need a new webrev for the parameter list indentation fix.
> 

I will update the webrev later in place.

Thanks,
  Thomas