RFR: 8138920: Refactor the sampling thread from ConcurrentG1RefineThread

[Thomas Schatzl]

Hi,

On Wed, 2015-10-21 at 12:42 +0200, Per Liden wrote:
> Hi Derek,
> 
> On 2015-10-20 21:56, Derek White wrote:
> > 4th Webrev for review please:
> >
> > This version includes the cleanups suggested by Per.
> >
> > RFE: JDK-8138920 <https://bugs.openjdk.java.net/browse/JDK-8138920>
> > Refactor the sampling thread from ConcurrentG1RefineThread
> >
> > Webrev: http://cr.openjdk.java.net/~drwhite/8138920/webrev.04/
> 
> 
> Looks good over all. Just a few minor things I noticed.
> 
> concurrentG1Refine.cpp
> ----------------------
> 
>   92     vm_shutdown_during_initialization("Could not create 
> ConcurrentSampleThread");
> 
> Should be "G1YoungListSampleThread" now.
> 
>   160 void ConcurrentG1Refine::print_worker_threads_on(outputStream* st) 
> const {
>   161   for (uint i = 0; i < _n_worker_threads; ++i) {
>   162     _threads[i]->print_on(st);
>   163     st->cr();
>   164   }
>   165   _sample_thread->print_on(st);
>   166   st->cr();
> 
> You didn't introduce this, but shouldn't there be a if (_threads != 
> NULL) here around this, similar to the other functions which access 
> _threads?

Actually I think all the _threads != NULL checks could go away. We
terminate the VM if we cannot initialize any threads.

Thanks,
  Thomas