Uma biblioteca de padrões de especificação em Event-B para mecanismos de troca de mensagens em sistema distribuídos

Abstract

The development of distributed systems and communication protocols is not a trivial task and the use of formal specification and verification techniques becomes necessary to assure the correctness of such systems. While model-checking techniques face the state space explosion problem, the use of theorem provers is an important resource for verification of systems with unlimited number of states. The formal method Event-B, increasingly being used in both industry and academia, is based on the technique of theorem proving and also supports refinement. The contribution of this work is a library of reusable formal specification patterns, in Event-B, for message passing mechanisms commonly employed in distributed systems. A specification pattern defines the desired communication semantics of a channel, having its properties formally proven. During the development of a distributed system, the developer may use these patterns by applying guided refinement steps on the target model. The resulting system is assured to have the communication semantics as defined by the pattern, thus freeing the developer of defining the communication system from scratch and of proving its properties.