RFR (XS): 8204618: The parallel GC reference processing task executor enqueues a wrong number of tasks into the queue

[Kim Barrett]

> On Jun 8, 2018, at 10:52 AM, Thomas Schatzl <thomas.schatzl at oracle.com> wrote:
> 
> Hi all,
> 
>  can I have reviews for this change that fixes some issue with
> parallel gc reference processing task executor putting too many (always
> max number of threads) reference processing tasks into the work queue?
> 
> The effects are benign (at least we have not observed any bad effects
> so far since enabling -XX:UseDynamicNumberOfGCThreads) in that
> reference processing will be called multiple times by the same active
> threads, basically doing nothing (because the corresponding ref proc
> queues are empty after the first time they are processed).
> 
> CR:
> https://bugs.openjdk.java.net/browse/JDK-8204618
> Webrev:
> http://cr.openjdk.java.net/~tschatzl/8204618/webrev/
> Testing:
> hs-tier1-4,jdk-tier1-3 with +/-ParallelRefProcEnabled
> 
> Thanks,
>  Thomas

Looks good.