Model checking with fairness assumptions using PAT

Abstract

Recent development on distributed systems has shown that a variety of fairness constraints (some of which are only recently defined) play vital roles in designing self-stabilizing population protocols. Existing model checkers are deficient in verifying the systems as only limited kinds of fairness are supported with limited verification efficiency. In this work, we support model checking of distributed systems in the toolkit PAT (process analysis toolkit), with a variety of fairness constraints (e.g., process-level weak/strong fairness, event-level weak/strong fairness, strong global fairness). It performs on-the-fly verification against linear temporal properties. We show through empirical evaluation (on recent population protocols as well as benchmark systems) that PAT has advantage in model checking with fairness. Previously unknown bugs have been revealed against systems which are designed to function only with strong global fairness.