Deterministically Executing Concurrent Programs for Testing and Debugging

Non-determinism is a serious problem in the testing and debugging of concurrent programs. Thread interleavings may be different on each run, changing the order of events. Testing a concurrent program requires many of these orders to be run, either to determine that all orders produce correct results or to identify the presence of timing-dependent errors called race conditions. This paper presents preliminary work in deterministically executing a concurrent program using a combination of an intermediate compiler form and aspect-oriented programming. Specifically, we execute the code generated for the intermediate compiler form using aspects to control the value returned for the read of any shared variable. This allows us to deterministically execute specific test cases. This work is preliminary, with many outstanding issues, but we feel the technique shows promise.