RFR: Concurrent preclean

[Aleksey Shipilev]

On 05/31/2017 01:59 PM, Roman Kennke wrote:
> - what's that commented part in referenceProcessor.cpp ?

Ah, leftover I had from performance experiments that exacerbate the issue to
extreme. That commented block is the initial filtering on reference discovery.

Removed:
 http://cr.openjdk.java.net/~shade/shenandoah/preclean/webrev.02/


> - is precleaning single-threaded? if yes, can it be made multithreaded?

RP has only single-threaded precleaning. But it can be multi-threaded if RP
supported it, like it supports MT reference processing. Trying to do this
outside of RP would be incorrect.

> - isn't experimental flag defaulting to true pointless? shouldn't it be
> diagnostic-> default true, experimental -> default false? (not very
> important to me...)

I thought we mark all our kill-switches "experimental", regardless of their
default value. Kept as is.

-Aleksey