A System for Detecting, Preventing and Exposing Atomicity Violations in Multithreaded Programs

Multi-core machines have become common and have led to an increase in multithreaded software. In turn, the number of concurrency bugs has also increased. Such bugs are elusive and remain difficult to solve, despite existing research. Thus, this thesis proposes a system which detects, prevents and optionally helps expose concurrency bugs. Specifically, we focus on bugs caused by atomicity violations, which occur when thread interleaving violates the programmer’s assumption that a code section executes atomically. At compile-time, our system performs static analysis to identify code sections where violations could occur. At run-time, we use debug registers to monitor these sections for interleaving thread accesses which would cause a violation. If detected, we undo their effects and thus prevent the violation. Optionally, we help expose atomicity violations by perturbing thread scheduling during execution. Our results demonstrate that the system is effective and imposes low overhead. ii