[gecode-users] Random Behavior

[Max Ostrowski]

I have a problem with my software clingcon, that uses gecode.

This piece of software is an SMT solver, that uses gecode as a theory
solver.
But i can also use it as a solver for arithmetic, without any SAT component.

Now my question: Is the behavior of Gecode reproducible.
Whenever i start my program with exactly the same parameters, i do get
the same result (same gecode statistics).
When i change a parameter (like not printing the solution) i do get a
different result (in terms of fails, nodes, etc... ).

The parameter i change should not affect Gecode at all (everything
related to gecode is done with exactly the same input and in the same
order).
So do you use some memory position for hashing or some random generator
initialized according to some position in memory or something else that
explains this behavior.

Currently i get between 3 and 8615650 fails for a simple LatinSquare
program, just because i change output formatting.


PS:
I tried this with gecode 3.5, 3.7 and trunk.
I also tested the whole program with "valgrind --leak-check=full" and
nothing uninitialized was used or lost.


Any ideas?

Best,
Max