RFR(S): Refactor parallel ClassLoaderData iterator

[Aleksey Shipilev]

On 04/27/2017 09:56 PM, Zhengyu Gu wrote:
> Using additonal atomic variable and atomic operations to have all workers to
> walk CLD once, does not seem very profitable. ClassLoaderData itself supports
> parallel walking.
> 
> Also, cleanup a unnecessary ClassLoaderDataGraph::clear_claimed_marks()
> 
> Webrev: http://cr.openjdk.java.net/~zgu/shenandoah/par_cld/webrev.00/index.html

Looks good to me.

How do you figure CLDG::clear_claimed_marks() is not needed in the places you
purged it? That's because ShenandoahRootProcessor will construct
ParallelCLDRootIterator and do CLDG::c_c_m()?

Thanks,
-Aleksey