Techniques to improve testing scalability on concurrent programs: combining static analysis and testing for Deadlock detection

Static deadlock analyzers might be able to verify the absence of deadlock, but when they detect a potential deadlock cycle, they provide little (or even none) information on their output. Due to the complex ow of concurrent programs, the user might not be able to find the source of the anomalous behaviour from the abstract information computed by static analysis.This paper proposes the combined use of static analysis and testing for effective deadlock detection in asynchronous programs. Our main contributions are: (1)We present an enhanced semantics which allows an early detection of deadlocks during testing and that can give to the user a precise description of the deadlock trace. (2) We combine our testing framework with the abstract descriptions of potential deadlock cycles computed by an existing static deadlock analyzer. Namely, such descriptions are used by our enhanced semantics to guide the execution towards the potential deadlock paths (while other paths are pruned). When the program features a deadlock, our combined use of static analysis and testing provides an effective technique to find deadlock traces. While if the program does not have deadlock, but the analyzer inaccurately spotted it, we might be able to prove deadlock freedom