[Mulgara-general] NPE running embedded server at DEBUG log level - causes failure to start

Stephen Bayliss stephen.bayliss at acuityunlimited.net
Mon Dec 12 22:16:06 UTC 2011


Hi Paul

Nothing specific with that class, it was just a case of blanket turn-on of
debugging to investigate something else, which resulted in not quite getting
to the something else due to this NPE!

Steve

> -----Original Message-----
> From: mulgara-general-bounces at mulgara.org 
> [mailto:mulgara-general-bounces at mulgara.org] On Behalf Of Paul Gearon
> Sent: 12 December 2011 16:44
> To: Mulgara General
> Subject: Re: [Mulgara-general] NPE running embedded server at 
> DEBUG log level - causes failure to start
> 
> 
> Hi Stephen,
> 
> Thanks for finding this. This bug is something left over from 
> the days of needing to debug the free list. Since it's worked 
> correctly for so many years now, no one has needed to run 
> this class with debugging enabled, so the bug was never triggered.
> 
> (I'll check in a patch shortly)
> 
> Was there a particular problem you were encountering with the 
> free list that required you to enable debugging, or are you 
> just interested to see how it works? The data structure and 
> algorithm is obtuse, and it isn't publicly documented. But I 
> can help out if there's anything you need.
> 
> Paul
> 
> On Mon, Dec 12, 2011 at 6:52 AM, Stephen Bayliss 
> <stephen.bayliss at acuityunlimited.net> wrote:
> > When running the server embedded, it looks like there's an NPE that 
> > only occurs in DEBUG logging which is causing the server to fail to 
> > start.
> >
> > The culprit seems to be:
> >
> > org.mulgara.store.xa.FreeList.Phase
> >
> > Method: public sychronized Token use()
> >
> > If debug is enabled, it's doing a stack.add(new StackTace()) - but 
> > stack is set to null on construction (and not set anywhere else).  
> > Liine 1147. Possibly another NPE due to the same cause around line 
> > 1242 (these from the 2.1.11 released source code).
> >
> >
> >
> > Regards
> >
> > Steve
> >
> >
> >
> > _______________________________________________
> > Mulgara-general mailing list
> > Mulgara-general at mulgara.org 
> > http://lists.mulgara.org/mailman/listinfo/mulgara-general
> >
> _______________________________________________
> Mulgara-general mailing list
> Mulgara-general at mulgara.org 
> http://lists.mulgara.org/mailman/listinfo/mulgara-general
> 



More information about the Mulgara-general mailing list