Effective handling of exceptional situations in robust software agents

Software agents are normally expected to operate in open and dynamic environments, and therefore they are often supposed to face situations that significantly deviate from the nominal course of events. The effective management of exceptional situations is of paramount importance to provide agents with the needed means to operate in their environments, mostly because these situations should be considered as the norm in open and dynamic environments. This paper presents some recent additions to the Jadescript agent-oriented programming language that were specifically designed to provide agents with the needed capabilities to effectively detect and manage exceptional situations. The first part of this paper motivates the need of sophisticated exception handling capabilities, also by relating the proposed language features with the state of the art documented in the literature. Then, the second part of this paper discusses the proposed language features, also considering the conceptual similarities and differences with the related features normally available in mainstream programming languages. In particular, the proposed language features are presented in terms of three language improvements: the general-purpose support to handle exceptions, the specific support to handle behaviour failures, and the specific support to handle stale messages. Finally, before concluding with some indications on future research activities, the third part of this paper describes a concrete example intended to practically present the actual use of the new language features.