Modello B - Università degli Studi di Genova

Ministero dell'Istruzione dell'Università e della Ricerca
Applications of the approach are in our focus as well, in particular we intend to investigate the implementation of Featherweight Java [IPW01] through our
framework; this should provide all the project units with the right testbed for testing the extensions we are proposing in this project. Other programming languages
that could be considered are Java [GJSB05] and Linda [CG89].
First Year. In the first year we intend to develop and realize the core idea behind the proposal (the slice language and the composition mechanism); in parallel we
will develop the case study programming languages.
Second Year. In the second year the development will be continued together with the framework implementation and the case study analysis; moreover we are going
to formally model the decomposition/composition mechanism.
Results.
- a mechanism to define basic programming features (the slices) that can be selectively composed to form a novel programming language;
- a framework to generate the compiler and interpreter for programs written in the programming language resulting from the composition;
- a bunch of slices necessary to define well-known programming languages, such as Java [GJSB05], Featherweight Java [IPW01] and Linda [CG89].
Task 2. Interaction and Distribution
Task 2.4 Mobility and dynamic evolution
The work of the unit in this subtask mainly focuses on the reflective Petri net formalism [CC06,CC07b] we developed to model the evolution of a dynamic
discrete-event system (e.g. a mobile network), and its application.
The reflective Petri net formalism has been designed to easily model distributed applications that can evolve without polluting the model with "what could be" instead
of simply model "what it currently is". This is realized exploiting the reflection concept [Mae87] and layering the model in two levels: i) a classic Petri net
representing the current situation and ii) how the model can evolve through strategies that will change the current representation when triggered.
The multi-layer structure of the model keeps it extremely simple but limits the possible usage of classical Petri nets analysis techniques (mainly structural analysis and
state-space inspection) to intervals between consecutive evolutions, i.e., without considering the model before its last evolution, or the potential new evolutions.
Analogously, the existing tools that support the editing and the simulation of Petri net models cannot work with reflective Petri nets since they were designed without
considering the presence of a second layer coordinating the evolution, thus not permitting any dynamical change to the Petri net layout during simulation runs. In the
project, we are going to overcome these restrictions by first providing a state-transitions semantics by which it will be possible to simulate and analyze these kind of
nets, then developing an ad-hoc support tool by extending the GreatSPN package, finally investigating structural analysis techniques for reflective Petri nets.
Another interesting open question is the possibility of characterizing the behavior of (stochastic) reflective Petri nets in terms of Markov processes. In particular we
aim at investigating possible links existing between the stochastic behavior of reflective Petri nets and dynamic Markovian models, e.g., Markovian evolving graphs.
This issue could be explored in collaboration with the unit of Firenze.
Beyond the work about providing sound mathematical foundations for this novel formalism, in the project we are going to use reflective Petri nets to model highly
mutable mobile networks, like a wide class of sensor networks. In particular we are going to model the gossiping algorithm described in [GPR08] with the intent of
evaluating and optimizing its performances; moreover such a work will be the perfect testbed for the analysis techniques we will develop in the project.
First Year. In the first year we are going to work on the analysis capability of the reflective Petri nets and in parallel on their application to the sensor networks
application domain. Moreover we will analyze how to extend the GreatSPN tool to get a simulation tool supporting the reflective Petri nets as well.
Second Year. In the second year we are continuing the work made in the first year and implementing the simulation tool.
Results.
- Reflective Petri nets extensions in particular related to the analysis part;
- the implementation of the simulation tool;
- application to the highly mutable mobile networks, in particular in relation to gossiping algorithms in sensor networks.
14 - Descrizione delle attrezzature già disponibili ed utilizzabili per la ricerca proposta
Testo italiano
Nessuna
Testo inglese
Nessuna
15 - Descrizione delle Grandi attrezzature da acquisire (GA)
Testo italiano
Nessuna
Testo inglese
Nessuna
MIUR - BANDO 2008 - MODELLO B - 10 -