A Unified Approach to Eliminating Concurrency Bugs via Control Synthesis

Concurrency bugs threaten the safety of shared-memory multithreaded programs. The automated fixing techniques add new synchronization constructs; existing techniques may add too many synchronization constructs, sacrifice too much concurrency, or introduce deadlocks. The underlying problem is that existing techniques cannot simultaneously fix different bugs, especially different types of bugs, while restricting concurrency as little as possible. We present a unified concurrency bug avoidance approach to fix different types of bugs simultaneously. Our approach minimizes the number of synchronization constructs added while restricting concurrency as little as possible and guaranteeing that no new deadlocks are introduced. Our approach employs a unified vector representation of different types of bugs and reduces bug fixing to the well-studied problem of vector separation. Experiments on 14 real Java programs show that our solution incurs around 5% overhead, and typically incurs 6%-10% smaller overhead as compared to our previous Axis solution.