Abstract 

We developed XAL, a framework that, in our opinion, allows to build web-oriented applications and services in a more productive way. The core of the framework is a programming language based upon timed-automata. We believe this formalism reflects the nature of many web-oriented applications, each page being a state, and each link being a transition toward another state. Once the programmer defined the set of states that characterize the application, she/he can provide a behavior to each single state, binding the state to a small program written in its favorite programming language. Furthermore, we realized that often companies require an application to behave differently depending on some conditions over real-time. Our language, being a modified version of the timed-automata, allows the programmer to specify constraints over real-time in a declarative way, rather than mix them within the logic of the application.

Abstract 

We introduce Dynamic Networks of Timed Automata, an extension of (Networks of) Timed Automata useful for specifying concurrently executing timed-processes. The main difference with Timed Automata is that we allow the instantiation at run-time of multiple copies of automata. In this paper we also show an industrial case study where a system for monitoring a network of wireless devices is built applying Dynamic Networks of Timed Automata. The network is characterized by a high degree of dynamism, since its infrastructure is fixed but a big amount of its hosts continuously connect and disconnect. We see how extending XAL, an executable language for Timed Automata, we can first model our system, made of cooperating timed processes, and finally transform such model into an executable application. We also show how to model-check relevant properties of our application, expressing them through a temporal logic called TCTL and using existing formal methods and tools.