RFR(XS) 8212074: Add method to peek the remaining tasks in task queues

[Zhengyu Gu]

Hi Thomas,

Thanks for reviewing.

On 10/15/2018 05:06 AM, Thomas Schatzl wrote:
> Hi Zhengyu,
> 
> On Fri, 2018-10-12 at 09:28 -0400, Zhengyu Gu wrote:
>> Hi All,
>>
>> Shenandoah implemented an variant of termination protocol based on
>> [1], which requires to peek into task queues for remaining tasks, so
>> that it can wake just enough workers to steal tasks.
>>
>> The patch adds methods for this purpose, and allow subclasses of
>> ParallelTaskTerminator to access it members.
>>
>> Bug: https://bugs.openjdk.java.net/browse/JDK-8212074
>> Webrev: http://cr.openjdk.java.net/~zgu/8212074/webrev.00/
> 
>    could you please move line 451 of taskqueue.hpp in the obviously
> following patch that adds the ShenandoahTaskTerminator to the
> Shenandoah specific code? It does not seem to fit here.

Agree.

Updated webrev: http://cr.openjdk.java.net/~zgu/8212074/webrev.01/

> 
> Otherwise it looks good. Btw, feel free to take over JDK-8204947 - I
> just did not get the time due to other more important changes.

Will do.

Thanks,

-Zhengyu


> 
> Thanks,
>    Thomas
> 
>