SPLASH 2014
Mon 20 - Fri 24 October 2014 Portland, Oregon, United States
Thu 23 Oct 2014 14:37 - 15:00 at Salon F - Concurrency Chair(s): David Grove

We describe an algorithm to perform symbolic execution of a multithreaded program starting from an arbitrary program context. We argue that this can enable more efficient symbolic exploration of deep code paths in multithreaded programs by allowing the symbolic engine to jump directly to program contexts of interest.

The key challenge is modeling the initial context with reasonable precision—an overly approximate model leads to exploration of many infeasible paths during symbolic execution, while a very precise model would be so expensive to compute that computing it would defeat the purpose of jumping directly to the initial context in the first place. We propose a \emph{context-specific dataflow analysis} that approximates the initial context cheaply, but precisely enough to avoid some common causes of infeasible-path explosion. This model is necessarily approximate—it may leave portions of the memory state unconstrained, leaving our symbolic execution unable to answer simple questions such as which thread holds lock A?''. For such cases, we describe a novel algorithm for evaluating \emph{symbolic synchronization} during symbolic execution. Our symbolic execution semantics are sound and complete up to the limits of the underlying SMT solver. We describe initial experiments on an implementation in Cloud9.

#### Thu 23 Oct

 13:30 - 15:00: OOPSLA - Concurrency at Salon F Chair(s): David GroveIBM Research 13:30 - 13:52Talk Atlas: Leveraging Locks for Non-volatile Memory ConsistencyDhruva ChakrabartiHP Labs, Hans-J. BoehmGoogle, Kumud BhandariRice University Link to publication 13:52 - 14:15Talk Fast Splittable Pseudorandom Number GeneratorsGuy L. Steele Jr.Oracle Labs, Doug LeaState University of New York (SUNY) Oswego, Christine H. FloodRed Hat Link to publication 14:15 - 14:37Talk Multithreaded Test Synthesis for Deadlock DetectionMalavika SamakIndian Institute of Science, Bangalore, Murali Krishna RamanathanIndian Institute of Science, Bangalore Link to publication 14:37 - 15:00Talk Symbolic Execution of Multithreaded Programs from Arbitrary Program ContextsTom BerganUniversity of Washington, Dan GrossmanUniversity of Washington, Luis CezeUniversity of Washington Link to publication