RFR: JDK-8204685: Abstraction for TLAB dummy object

[Thomas Schatzl]

Hi,

On Mon, 2018-06-11 at 18:02 +0200, Roman Kennke wrote:
> Similar to how object allocations should be owned by the GC, so does
> TLAB dummy object 'allocation'. TLABs and PLABs are filling their
> remaining blocks with dummy objects. GCs like Shenandoah might need a
> slightly differet layout for this, and therefore we need an
> abstraction.
> 
> The proposed change adds a new virtual method
> CollectedHeap::fill_with_dummy_object(), the default implementation
> calls the existing CH::fill_with_object() from TLAB and PLAB like it
> was
> done before.
> 
> Tested: hotspot-tier1, Shenandoah tests with appropriate impl
> 
> http://cr.openjdk.java.net/~rkennke/JDK-8204685/webrev.00/
> 
> Ok?
> 

  looks good.

Thomas