On deciding synchronizability for asynchronously communicating systems

Abstract

Asynchronously communicating systems involve peers or entities that communicate by exchanging messages via buffers. In general, the size of such buffers is not known apriori, i.e., they are considered to be unbounded. As a result, models of asynchronously communicating systems typically exhibit infinite state spaces and it is well-known that reachability and boundedness problems for such models are undecidable. This, in turn, makes automatic verification of asynchronous systems undecidable as well. We discuss a particular class of asynchronous systems over peers for which the interaction behaviors do not change when the peers are made to communicate synchronously. Such systems are referred to as Synchronizable. Automatic verification of synchronizable systems is decidable as the verification of the system can be performed using its synchronous counterpart. Recently, we have proved that checking whether or not a system is synchronizable is decidable. In this paper, we consider different types of asynchronous communication, where the type is described in terms of the nature of buffering and the number of buffers, and discuss how/if synchronizability is decidable for each type. The new results subsume the existing ones and present a comprehensive synchronizability study of asynchronous systems.