Encoding Synchrony

Abstract: Synchronous and asynchronous interactions are the two basic paradigms of interactions in distributed systems. While synchronous interactions are widely used in specification languages, asynchronous interactions are often better suited to implement real systems. It would be desirable -- from a programming standpoint -- to design systems in a synchronous fashion, yet reap the benefits of parallelism by means of an (ideally automatically generated) asynchronous implementation executed on multiple processing units in parallel. Thus, we are interested in the conditions under which synchronous interactions can be implemented using just asynchronous interactions, while preserving the original degree of distribution. To partially answer this question, we examine the role of causality for encoding synchrony. We formalise this problem by means of the pi-calculus.