Accentuating the positive

Concurrency bugs are often due to inadequate synchronization that fail to prevent specific (undesirable) thread interleavings. Such errors, often referred to as Heisenbugs, are difficult to detect, prevent, and repair. In this paper, we present a new technique to increase program robustness against Heisenbugs. We profile correct executions from provided test suites to infer fine-grained atomicity properties. Additional deadlock-free locking is injected into the program to guarantee these properties hold on production runs. Notably, our technique does not rely on witnessing or analyzing erroneous executions. The end result is a scheme that only permits executions which are guaranteed to preserve the atomicity properties derived from the profile. Evaluation results on large, real-world, open-source programs show that our technique can effectively suppress subtle concurrency bugs, with small runtime overheads (typically less than 15%).