COBS — A MODEL REFLECTING THE DUALITY OF THE TWO PARADIGMS OF ASYNCHRONOUS COMMUNICATION

Abstract

We present COBS — a model of a concurrent object-based computational system with handshakes as elementary actions of inter-process communication. Processes are considered to be partial views of the system. Their communication by asynchronous message passing and variable sharing is modeled by elementary processes on the same abstraction level. The same acts of computation and communication can be observed in two ways — from the point of view of each of the two principal paradigms of asynchronous communication. The choice of one of the two dual views may influence the programming style and/or the efficiency of programs, based on availability of the supporting hardware and software tools. However, the model documents that there is no principal obstacle in re-programming any asynchronous system of processes using the dual paradigm