[Carpet] endless loop in bboxset.cc

[Erik Schnetter]

On Apr 6, 2007, at 16:10:42, Frank Löffler wrote:

> Hi,
>
> I have a problem with Carpet doing an endless loop and I try to  
> understand
> the code. So far, I feel a bit lost. Maybe someone here can help me.
>
> The problem seems to be in CarpetLib/src/bboxset.cc in
> void bboxset<T,D>::normalize ()
> After the first call to that function, the first loop over the  
> outermost
> for-loop (dimension?) is still fine. However, the next one then loops
> forever in the inner
>
> for (typename bset::const_iterator si = bs.begin(); si != bs.end();  
> ++ si) {}
>
> (but bs.size is 1)
>
> I checked that the same loop using nbs before the swap of bs and  
> nbs also
> has that problem, so my guess would be that nbs might not be  
> initialized
> correctly during the first run. Could that be?

No, that cannot be.  This variable is declared as

	bset nbs;

where the type bset is set<box>.  The constructor of the STL set  
class initialises nbs to the empty set.

> This using the Carpet version from
> http://www.carpetcode.org/~darcs/carpet/ (the one, which Thomas  
> uses for
> his Integration builds) and is on an Alpha CPU machine with OpenMPI.
> Runs using Carpet are fine.

What C++ compiler are you using?  What happens when you run the same  
parameter file on a different architecture?  The function normalize()  
is called very often, and I believe that it is very well tested.   
Could it be an error in your version of your compiler or STL?

How does the bboxset look like when this problem occurs?  You can  
also try enabling the somewhat expensive invariant() routine by  
removing the #if 0 there.

-erik

-- 
Erik Schnetter <schnetter at cct.lsu.edu>

My email is as private as my paper mail.  I therefore support encrypting
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