SYNTAX AND SEMANTICS OF REAL-TIME AND PERFORMANCE EVALUATION EXTENSIONS OF SPECIFICATION LANGUAGE LOTOS

Article type: Research Article

Authors: Huzar, Zbigniew | Magott, Jan

Affiliations: Computer Science Department, Technical University of Wrocław, Poland | Institute of Engineering Cybernetics, Technical University of Wrocław, Poland

Abstract: The paper contains extensions of specification language LOTOS in three directions: time-consuming actions, real-time and performance evaluation constructions. Time-consuming actions seem to be more natural than instantaneous actions and they are well suited for real-time system specification and for its performance evaluation. The notions of beginning and termination of the time-consuming action enable to impose time restrictions on beginning and termination times of activities. From performance evaluation point of view it is often important to know explicit how long a specific action has been executed (not when the action has been completed only). We have also introduced a time-out as a specific action. An expressive power of this action has been discussed. We have defined such a performance evaluation extension of LOTOS that can be used as a modelling language for performance evaluation of distributed systems. A true concurrency semantics (in the sense that it refers to the fact that actions with durations may overlap in time) for this extension is defined.

DOI: 10.3233/FI-1997-291204

Journal: Fundamenta Informaticae, vol. 29, no. 1-2, pp. 77-96, 1997