Verifying Programs under Snapshot Isolation and Similar Relaxed Consistency Models

We present a static verification approach for programs running under snapshot isolation (SI) and similar relaxed transactional semantics. Relaxed conflict detection schemes such as snapshot isolation (SI) are used widely. Under SI, transactions are no longer guaranteed to be serializable, and the simplicity of reasoning sequentially within a transaction is lost. In this paper, we present an approach for statically verifying properties of transactional programs operating under SI. Differently from earlier work, we handle transactional programs even when they are designed not to be serializable. We present a source-to-source transformation which augments the program with an encoding of the SI semantics. Verifying the resulting program with transformed user annotations and specifications is equivalent to verifying the original transactional program running under SI – a fact we prove formally. Our encoding preserves the modularity and scalability of VCC’s verification approach. We applied our method successfully to benchmark programs from the transactional memory literature.