Model checking is an efficient technique for verifying properties on reactive systems. Partial-order reduction (POR) and symbolic model checking are two common approaches to deal with the state space explosion problem in model checking. Traditionally, symbolic model checking uses BDDs which can suffer from space blowup. More recently bounded model checking (BMC) using SAT-based procedures has been used as a very successful alternative to BDDs. However, this approach gives poor results when it is applied to models with a lot of asynchronism. This paper presents an algorithm which combines partial order reduction methods and bounded model checking techniques in an original way that allows efficient verification of temporal logic properties (LTLX) on models featuring asynchronous processes. The encoding to a SAT problem strongly reduces the complexity and non-determinism of each transition step, allowing efficient analysis even with longer execution traces. The starting-point of our work is the Two-Phase algorithm (Namalesu and Gopalakrishnan) which performs partial-order reduction on process-based models. At first, we adapt this algorithm to the bounded model checking method. Then, we describe our approach formally and demonstrate its validity. Finally, we present a prototypal implementation and report encouraging experimental results on a small example.
IOS Press, Inc.
6751 Tepper Drive
Clifton, VA 20124
Tel.: +1 703 830 6300
Fax: +1 703 830 2300 email@example.com
(Corporate matters and books only) IOS Press c/o Accucoms US, Inc.
For North America Sales and Customer Service
West Point Commons
Lansdale PA 19446
Tel.: +1 866 855 8967
Fax: +1 215 660 5042 firstname.lastname@example.org