Abstract
Eliminating concurrency errors is increasingly important as systems rely more on parallelism for performance. Exhaustively exploring the state-space of a program's thread interleavings finds concurrency errors and provides coverage guarantees, but suffers from exponential state-space explosion. Two prior approaches alleviate state-space explosion. (1) Dynamic partial-order reduction (DPOR) provides full coverage and explores only one interleaving of independent transitions. (2) Bounded search provides bounded coverage by enumerating interleavings that do not exceed a bound. In particular, we focus on preemption-bounding. Combining partial-order reduction with preemption-bounding had remained an open problem.
We show that preemption-bounded search explores the same partial orders repeatedly and consequently explores more executions than unbounded DPOR, even for small bounds. We further show that if DPOR simply uses the preemption bound to prune the state space as it explores new partial orders, it misses parts of the state space reachable in the bound and is therefore unsound. The bound essentially induces dependences between otherwise independent transitions in the DPOR state space. We introduce Bounded Partial Order Reduction (BPOR), a modification of DPOR that compensates for bound dependences. We identify properties that determine how well bounds combine with partial-order reduction. We prove sound coverage and empirically evaluate BPOR with preemption and fairness bounds. We show that by eliminating redundancies, BPOR significantly reduces testing time compared to bounded search. BPOR's faster incremental guarantees will help testers verify larger concurrent programs.
Supplemental Material
Available for Download
Definitions, Theorems and Proofs
- Apt, K. R., Francez, N., and Katz, S. Appraising fairness in languages for distributed programming. In Distributed Computing (1988), vol. 2, pp. 226--241.Google Scholar
Digital Library
- Coons, K. E. Fast Error Detection with Coverage Guarantees for Concurrent Software. PhD thesis, The University of Texas at Austin, 2013.Google Scholar
- Coons, K. E., Musuvathi, M., and McKinley, K. S. Bounded partial order reduction (Proof source material in the ACM Digital Library). In ACM Conference on Object-Oriented Programming, Systems, Languages, and Applications (2013). Google Scholar
Digital Library
- Dwyer, M. B., Hatcliff, J., and Ranganath, R. V. P. Exploiting object escape and locking information in partial-order reductions for concurrent object-oriented programs. In Formal Methods in System Design (2004), vol. 25, pp. 199--240. Google Scholar
Digital Library
- Emmi, M., Qadeer, S., and Rakamaric, Z. Delay-bounded scheduling. In ACM SIGACT-SIGPLAN Principles of Programming Languages (POPL) (2011), pp. 411--422. Google Scholar
Digital Library
- Flanagan, C., and Godefroid, P. Dynamic partial-order reduction for model checking software. In ACM SIGPLAN-SIGACT Principles of Programming Languages (POPL) (2005), pp. 110--121. Google Scholar
Digital Library
- Godefroid, P. Partial-Order Methods for the Verification of Concurrent Systems: An Approach to the State-Explosion Problem. Springer-Verlag, 1996. Google Scholar
Digital Library
- Godefroid, P. Model checking for programming languages using Verisoft. In ACM SIGACT-SIGPLAN Principles of Programming Languages (POPL) (1997), pp. 174--186. Google Scholar
Digital Library
- Godefroid, P., and Pirottin, D. Refining dependencies improves partial-order verification methods (extended abstract). In International Conference on Computer Aided Verification (CAV) (1993), pp. 438--449. Google Scholar
Digital Library
- Katz, S., and Peled, D. Defining conditional independence using collapses. In Theoretical Computer Science (1992), vol. 101, Elsevier Science Publishers, pp. 337--359. Google Scholar
Digital Library
- Mazurkiewicz, A. Trace theory. In Advances in Petri nets 1986, part II on Petri nets: Applications and relationships to other models of concurrency (1986), Springer-Verlag, pp. 279--324. Google Scholar
Digital Library
- Musuvathi, M., and Qadeer, S. Iterative context bounding for systematic testing of multithreaded programs. In ACM Conference on Programming Language Design and Implementation (2007), pp. 446--455. Google Scholar
Digital Library
- Musuvathi, M., and Qadeer, S. Partial-order reduction for context-bounded state exploration. Tech. Rep. MSR-TR-2007-12, Microsoft Research, 2007.Google Scholar
- Musuvathi, M., and Qadeer, S. Fair stateless model checking. In ACM Conference on Programming Language Design and Implementation (2008), pp. 362--371. Google Scholar
Digital Library
- Musuvathi, M., Qadeer, S., Ball, T., Basler, G., Nainar, A., and Neamtiu, I. Finding and reproducing heisenbugs in concurrent programs. In USENIX Symposium on Operating Systems Design and Implementation (2009). Google Scholar
Digital Library
- Overman, W. T. Verification of concurrent systems: Function and timing. PhD thesis, University of California, Los Angeles, 1981. Google Scholar
Digital Library
- Valmari, A. A stubborn attack on state explosion. In International Workshop on Computer Aided Verification (CAV '90) (1990), Springer-Verlag, pp. 156--165. Google Scholar
Digital Library
- Visser, W., Havelund, K., Brat, G., and Park, S. Model checking programs. In Automated Softeware Engineering Journal (2000), pp. 3--12. Google Scholar
Digital Library
Index Terms
Bounded partial-order reduction
Recommendations
Bounded partial-order reduction
OOPSLA '13: Proceedings of the 2013 ACM SIGPLAN international conference on Object oriented programming systems languages & applicationsEliminating concurrency errors is increasingly important as systems rely more on parallelism for performance. Exhaustively exploring the state-space of a program's thread interleavings finds concurrency errors and provides coverage guarantees, but ...
Fair stateless model checking
PLDI '08Stateless model checking is a useful state-space exploration technique for systematically testing complex real-world software. Existing stateless model checkers are limited to the verification of safety properties on terminating programs. However, ...
Fair stateless model checking
PLDI '08: Proceedings of the 29th ACM SIGPLAN Conference on Programming Language Design and ImplementationStateless model checking is a useful state-space exploration technique for systematically testing complex real-world software. Existing stateless model checkers are limited to the verification of safety properties on terminating programs. However, ...







Comments