Reproducible execution of SR programs

Abstract

Reproducing the execution of a concurrent program is important in debugging and testing. It requires that, regardless of the actual order in which processes may execute, the reproduced execution is identical, with respect to the order in which certain activities occur, to a previously recorded execution. This paper presents a solution to the reproducibility problem for programs written in the SR concurrent programming language. Our solution transforms an arbitrary SR program into one for recording an event sequence and one for replaying from an event sequence. SR provides a rich collection of synchronization mechanisms, including rendezvous, asynchronous message passing, remote procedure call, and dynamic process creation. SR language features allow: exible invocation servicing (e.g., use of invo-cation parameters in selecting an invocation to service in message passing or rendezvous); dynamically created processes and resource (module) instances; dynamic communication paths between processes; and dynamic distribution of programs across multiple machines. Because of these features, adaptations of previous solutions to the reproducibility problem for other languages and notations do not work for SR. Our solution handles all the above features. It results in a naturally distributed control algorithm for programs that are distributed. This paper also describes the implementations of our transformation tools.