Non-concurrency analysis

TLDR: This work presents a framework for non-concurrency analysis, capable of incorporating previous analysis algorithms [CS88, DS92] and improving upon them and exhibits dramatic accuracy improvements over [DS91], when the latter is used as a stand-alone algorithm.

Abstract: Non-concurrency analysis is a set of techniques for statically identifying pairs (or sets) of statements in a concurrent program which can never happen together. This information aids programmers in debugging and manually optimizing programs, improves the precision of data flow analysis, enables optimized translation of rendezvous, facilitates dead code elimination and other automatic optimizations, and allows anomaly detection in explicitly parallel programs. We present a framework for non-concurrency analysis, capable of incorporating previous analysis algorithms [CS88, DS92] and improving upon them. We show general theoretical results which are useful in estimating non-concurrency, and examples of non-concurrency analysis frameworks for two synchronization primitives: the Ada rendezvous and binary semaphores. Both of these frameworks have a low-order polynomial bound on worst-case solution time. We provide experimental evidence that static non-concurrency analysis of Ada programs can be accomplished in a reasonable time, and is generally quite accurate. Our framework, and the set of refinement components we develop, also exhibits dramatic accuracy improvements over [DS91], when the latter is used as a stand-alone algorithm, as demonstrated by our experiments.