Static Analysis of Atomicity for Programs with Lock-Free Synchronization∗

In concurrent programming, lock-free synchronization is veryefficient but difficult to design correctly. This paper presentsa static analysis to show that code blocks are atomic, i.e.,that every execution of the program is equivalent to onein which those code blocks execute without interruption byother threads. Our analysis determines commutativity ofoperations based primarily on how synchronization prim-itives (including locks, load-linked, store-conditional, andcompare-and-swap) are used. A reduction theorem statesthat certain patterns of commutativity imply atomicity. Atom-icity is itself an important correctness requirement for manyconcurrent programs. Furthermore, an atomic code blockcan be treated as a single transition during subsequent anal-ysis of the program; this can greatly improve the efficiency ofthe subsequent analysis. We demonstrate the effectivenessof our approach on several concurrent lock-free programs.