Michael Weber: Random Bits and Pieces

If we knew what it was we were doing, it would not be called research, would it?

Albert Einstein

New Paper

A Multi-Core Solver for Parity Games (accepted for publication to PDMC 2008).


We describe a parallel algorithm for solving parity games, with applications in, e.g., modal μ-calculus model checking with arbitrary alternations, and (branching) bisimulation checking. The algorithm is based on Jurdzinski's Small Progress Measures. Actually, this is a class of algorithms, depending on a selection heuristics.

Our algorithm operates lock-free, and mostly wait-free (except for infrequent termination detection), and thus allows maximum parallelism. Additionally, we conserve memory by avoiding storage of predecessor edges for the parity graph through strictly forward-looking heuristics.

We evaluate our multi-core implementation's behaviour on parity games obtained from μ-calculus model checking problems for a set of communication protocols, randomly generated problem instances, and parametric problem instances from the literature.