Precise Detection of Atomicity Violations

Concurrent programs that are free of unsynchronized accesses to shared data may still exhibit unpredictable concurrency errors called atomicity violations, which include both high-level dataraces and stale-value errors. Atomicity violations occur when programmers make wrong assumptions about the atomicity scope of a code block, incorrectly splitting it in two or more atomic blocks and allow them to be interleaved with other atomic blocks. In this paper we propose a novel static analysis algorithm that works on a dependency graph of program variables and detects both high-level dataraces and stale-value errors. The algorithm was implemented for a Java Bytecode analyzer and its effectiveness was evaluated with some well known faulty programs. The results obtained show that our algorithm performs better than previous approaches, achieving higher precision for small and medium sized programs, making it a good basis for a practical tool.