Conformance Checking for Models of Asynchronous Message Passing Software

We propose a notion of conformance between a specification S and an implementation model I extracted from a message-passing program. In our framework, S and I are CCS processes, which soundly abstract the externallyv isible communication behavior of a message-passing program. We use the extracted models to check that programs do not get stuck, waiting to receive or trying to send messages in vain.We show that our definition of stuckness and conformance capture important correctness conditions of message-passing software. Our definition of conformance was motivated byt he need for modular reasoning over models, leading to the requirement that conformance preserve substi-tutabilitywith respect to stuck-freeness: If I conforms to S, and P is any environment such that P | S is stuck-free, then it follows that P | I is stuck-free. We present a simple algorithm for checking if I conforms to S, when I and S obeycert ain restrictions.