Testing concurrent programs to achieve high synchronization coverage

The effectiveness of software testing is often assessed by measuring coverage of some aspect of the software, such as its code. There is much research aimed at increasing code coverage of sequential software. However, there has been little research on increasing coverage for concurrent software. This paper presents a new technique that aims to achieve high coverage of concurrent programs by generating thread schedules to cover uncovered coverage requirements. Our technique first estimates synchronization-pair coverage requirements, and then generates thread schedules that are likely to cover uncovered coverage requirements. This paper also presents a description of a prototype tool that we implemented in Java, and the results of a set of studies we performed using the tool on a several open-source programs. The results show that, for our subject programs, our technique achieves higher coverage faster than random testing techniques; the estimation-based heuristic contributes substantially to the effectiveness of our technique.