RFR: 8140393: Move WorkerDataArray to its own file

[Erik Helin]

Tom,

are you ok with me pushing this patch as two commits (see my reply to
Mikael)?

Thanks,
Erik

On 2015-10-27, Erik Helin wrote:
> On 2015-10-26, Tom Benson wrote:
> > Hi Eric,
> > Looks good to me.
> 
> Hi Tom,
> 
> thanks for reviewing!
> 
> On 2015-10-26, Tom Benson wrote:
> > One very minor comment - In set_thread_work_item, the
> > assertion comment "No sub count" (which you didn't change) seems a little
> > off.
> 
> Yeah, I agree, "No thread_work_items present" would be better, let me
> change that as a follow-up patch.
> 
> On 2015-10-26, Tom Benson wrote:
> > I agree removing the caching code is good, though I was wary at first.
> > Not because of the expense of walking the array, but the potential expense
> > of dfloat ops (as on a previous platform I worked on).  But in reality I
> > don't think the value will be recomputed much, if ever.
> 
> I also don't think this patch will have any performance impact and the
> benchmark runs seem to verify that hypothesis.
> 
> Thanks,
> Erik
> 
> > Tom
> > 
> > 
> > On 10/26/2015 8:23 AM, Erik Helin wrote:
> > >Hi all,
> > >
> > >this patch moves the class WorkerDataArray into its own file. While
> > >moving to the code, I also refurbished it a bit. WorkerDataArray used
> > >to cache the results for calls to max(), min(), sum() etc because it
> > >might be expensive too loop over the array. However, the array we are
> > >iterating over will at most be as big as the number of GC threads (it is
> > >very rare to use more than 1000 GC threads). Performance runs shows no
> > >regressions at all, so I prefer to go with the simpler code.
> > >
> > >Enhancement:
> > >https://bugs.openjdk.java.net/browse/JDK-8140393
> > >
> > >Webrev:
> > >http://cr.openjdk.java.net/~ehelin/8140393/webrev.00/
> > >
> > >Testing:
> > >- JPRT
> > >- Perf Aurora for performance regressions
> > >
> > >Thanks,
> > >Erik
> >