Global consensus through local synchronization: A formal basis for partially-distributed coordination

In ongoing work, we are developing compilers for a coordination language, Reo, based on that language's automata semantics. As part of the compilation process, our tool computes the product of a number of automata, each of which models a constituent of the protocol to generate code for. This approach ensures that implementations of those automata at run-time reach a consensus about their global behavior in every step. However, this approach has two problems: state space explosion at compile-time and oversequentialization at run-time. In this paper, we provide a solution by defining a new, local product operator on those automata that avoids these problems. We then identify a sufficiently large class of automata for which using our new product instead of the existing one is semantics-preserving.