Evolving concurrent systems - Behavioural theory and logic

Abstract

A concurrent system can be characterised by autonomously acting agents, where each agent executes its own program, uses shared resources and communicates with the others, but otherwise is totally oblivious to the behaviour of the other agents. In an evolving concurrent system agents may change their programs, enter or leave the collection at any time thereby changing the behaviour of the overall system. In this paper we present a behavioural theory of evolving concurrent systems, i.e. we provide (1) a small set of postulates that characterise evolving concurrent systems in a precise conceptual way without any reference to a particular language, (2) an abstract machine model together with a plausibility proof that the abstract machines satisfy the postulates, and (3) a characterisation proof that any system stipulated by the postulates can be step-by-step simulated by an abstract machine. The theory integrates the behavioural theories for unbounded (synchronous) parallel algorithms, asynchronous concurrent systems, and reective algorithms, respectively. However, in the latter two theories only sequential agents and sequential reective algorithms were considered. Furthermore, linguistic reection has not been integrated with parallelism. We will show how these research gaps can be closed.