Charm++ parallel programming system

[Evghenii Gaburov <e-gaburov AT northwestern.edu>]

> > Also look at possible race conditions in the code. For example, after
> > calling AtSync() (assuming you are using periodic load balancing), the
> > caller should not send new messages. It should wait for the resume
> > from resumefromSync() call.
Regarding the Race conditions, is possible to have any in the following code:

...

[threaded] void Main::startSimulation()
{
   ... 
   CkWaitQD();
   arrayProxy.doAtSync();
   CkWaitQD();
   ...
}

void myChare::doAtSync()
{ 
  AtSync();
}

void myChare::ResumeFromSync()
{
}

...

Cause this does not prevent freezes either. I am continuing bug-hunting...

Thanks!

Cheers,
 Evghenii


> Okay, I will double check that.
> 
> Thanks,
>  Evghenii
> 
> >
> > Gengbin
> >
> > On Tue, Oct 4, 2011 at 10:43 AM, Evghenii Gaburov
> > <e-gaburov AT northwestern.edu>
> >  wrote:
> >>> This program does not PUP the MainCB callback member variable
> >>> Variables which are not PUP'd will not retain their value after
> >>> migration.  Therefore every migrated element will be calling an
> >>> uninitialized callback in ResumeFromSync.
> >> So, the freeze still occur even after MainCB is passed to PUP.
> >>
> >> The test program I posted in the previous listing
> >> sometimes freezes with Greedy[Comm]LB, Refine[Comm]LB & MetisLB, but not 
> >> with RotateLB,
> >>
> >> when ckAboutToMigrate() & ckJustMigrated() are defined.
> >>
> >> #if 1
> >>     void ckAboutToMigrate() {}
> >>     void ckJustMigrated() {}
> >> #endif
> >>
> >> Any idea what may happen here?
> >>
> >> While in my simulation code I do not use these, I still experience 
> >> freezes at ResumeFromSync()
> >> after having the code run for about an hour and after a dozens of 
> >> AtSync() calls. I cannot reproduce
> >> this behaviour in that simple test code, but may be this is related to 
> >> the fact that in production code
> >> I move a lot of data...
> >>
> >> Any help will be of great value!
> >>
> >> Cheers,
> >>  Evghenii
> >>
> >>
> >>
> >> --
> >> Evghenii Gaburov, 
> >> e-gaburov AT northwestern.edu
> >>
> >>
> >>
> >>
> >>
> >>
> >>
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> 
> --
> Evghenii Gaburov, 
> e-gaburov AT northwestern.edu
> 
> 
> 
> 
> 
> 
> 
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> 
> -- 
> Pritish Jetley
> Doctoral Candidate, Computer Science
> University of Illinois at Urbana-Champaign

--
Evghenii Gaburov, 
e-gaburov AT northwestern.edu