A study of two Languages for Active Objects with Futures

In computer systems, specifically in multithread, parallel and distributed systems, a deadlock is both a very subtle problem - because difficult to pre- vent during the system coding - and a very dangerous one: a deadlocked system is easily completely stuck, with consequences ranging from simple annoyances to life-threatening circumstances, being also in between the not negligible scenario of economical losses. Then, how to avoid this problem? A lot of possible solutions has been studied, proposed and implemented. In this thesis we focus on detection of deadlocks with a static program analysis technique, i.e. an analysis per- formed without actually executing the program. To begin, we briefly present the static Deadlock Analysis Model devel- oped for coreABS−− in chapter 1, then we proceed by detailing the Class- based coreABS−− language in chapter 2. Then, in Chapter 3 we lay the foundation for further discussions by ana- lyzing the differences between coreABS−− and ASP, an untyped Object-based calculi, so as to show how it can be possible to extend the Deadlock Analysis to Object-based languages in general. In this regard, we explicit some hypotheses in chapter 4 first by present- ing a possible, unproven type system for ASP, modeled after the Deadlock Analysis Model developed for coreABS−−. Then, we conclude our discussion by presenting a simpler hypothesis, which may allow to circumvent the difficulties that arises from the definition of the ”ad-hoc” type system discussed in the aforegoing chapter.

Smart contracts per acquisto e gestione di assicurazioni sanitarie

In questo elaborato vengono introdotte le caratteristiche fondamentali della blockchain ed in particolare dello sviluppo di smart contract tramite Solidity nella Blockchain Ethereum. Successivamente, sono illustrate le applicazioni di questa tecnologia in ambito sanitario e viene presentato il progetto sviluppato. In seguito, viene spiegata nel dettaglio l’implementazione del già menzionato progetto e si mostrano i test svolti; viene, inoltre, mostrata una semplice analisi sul costo computazionale, in termini di gas, del codice scritto. Questa tecnologia si presta efficacemente a sviluppi di applicazioni in ambito sanitario per le sue proprietà, come l’immutabilità e la privacy; nel sistema sviluppato la profonda sicurezza delle transazioni (data dalla blockchain) rende possibile l’acquisto e la gestione di un’assicurazione sanitaria senza la necessità di appoggiarsi a terze parti. In conclusione, vengono discusse possibili modifiche e miglioramenti al sistema proposto.