A Parallelization Scheme Based on Work Stealing for a Class of SAT Solvers

Because of the inherent NP-completeness of SAT, many SAT problems currently cannot be solved in a reasonable time. Usually, in order to tackle a new class of SAT problems, new ad hoc algorithms must be designed. Another way to solve a new problem is to use a generic solver and employ parallelism to reduce the solve time. In this paper we propose a parallelization scheme for a class of SAT solvers based on the DPLL procedure. The scheme uses a dynamic load-balancing mechanism based on work-stealing techniques to deal with the irregularity of SAT problems. We parallelize Satz, one of the best generic SAT solvers, with our scheme to obtain a parallel solver called PSatz. The first experimental results on random 3-SAT problems and a set of well-known structured problems show the efficiency of PSatz. PSatz is freely available and runs on any networked workstations under Unix/Linux.