Tighter Reachability Criteria for Deadlock-Freedom Analysis

We combine a prior incomplete deadlock-freedom-checking approach with two new reachability techniques to create a more precise deadlock-freedom-checking framework for concurrent systems. The reachability techniques that we propose are based on the analysis of individual components of the system; we use static analysis to summarise the behaviour that might lead components to this system state, and we analyse this summary to assess whether components can cooperate to reach a given system state. We implement this new framework on a tool called DeadlOx. This implementation encodes the proposed deadlock-freedom analysis as a satisfiability problem that is later checker by a SAT solver. We demonstrate by a series of practical experiments that this tool is more accurate than (and as efficient as) similar incomplete techniques for deadlock-freedom analysis.