Efficient Saturation-based Bounded Model Checking of Asynchronous Systems

Formal verification is becoming a fundamental step in assuring the correctness of safety-critical systems. However, due to these systems being often asynchronous and even distributed, their behaviour can be very complex. Thus, their verification necessitates methods that can deal with huge or even infinite state spaces. In this paper we present how the integration of two advanced algorithms for asynchronous systems —namely bounded saturation and constrained saturation-based structural model checking— can be used to verify such systems. Model checking is one of the current advanced techniques to analyse the behaviour of systems, as part of the verification process. The so-called saturation algorithm has an efficient iteration strategy combined with symbolic data structures, providing a powerful state space generation and model checking solution for asynchronous systems. Bounded saturation utilizes the efficiency of saturation in bounded state space exploration. Constrained saturation is an efficient structural model checking algorithm. Our work is the first approach to integrate these algorithms. Our measurements confirm that the new approach does not only offer a way dealing with even infinite state spaces, but in many cases even outperforms the original methods.