1 Domain Management in a Hierarchical Generic Models Library University Pascal Paoli of Corsica SPE Laboratory Fabrice BERNARDI, Jean-François SANTUCCI 20 Décembre 2002 UMR CNRS 6134

2 Introduction Modeling and simulating complex systems involves some complementary works Costly to build a system (model or environment) from scratch Preferable to reuse predefined elements : –Pre-validated models for simulation –Modules for a modeling and simulation environment Basic modules : GUI, models library,... This presentation : How to integrate a new model format in a generic models library

3 Topics Basics of the Approach –Notion of modeling component –Objectives of the models library –The notion of context –Elements of the architecture The Domain Parser –Definition –XML Document Type Definition Case Study : the JDEVS Domain Conclusion and Perspectives

4 Basics of the Approach Notion of Modeling Component Basic concept of our work : the component Two complementary notions : –Software component : Software object Presents well-defined interfaces –Modeling Component : Software component Described using a specific formalism Interfaces Communication ports

5 Basics of the Approach A Component-Oriented Modeling and Simulation Process Problem Formulation Simulation of the complete model Design of the complete model Storage of the Components Selection or Creation of the Components Components Identification Application Builder Librarian Final User

6 Basics of the Approach Models and Modeling Components Complete model : –Set of modeling components –Can be seen as a modeling component In the following : Model Modeling component

7 Basics of the Approach Two Types of Models Non-Decomposable Model : atomic model for modeling Decomposable Model : model constituted by other interconnected models M3 M4 M5 Decomposable Model M2 M1 Non-Decomposable Model Input Ports Output Ports

8 Basics of the Approach Objectives of our Work To define a generic architecture to store modeling components Main functionnalities : –Abstraction hierarchy management –Inheritance hierarchy management –Reusable storage format –Human-understandable storage format

9 Basics of the Approach The Notion of Context – Definition Storage architecture : a model is passive Modeling environment : a model is (can be) active Two representations of a same model : –Context-out model : Abstraction of a model Encapsulated in a special format Directly storable in its storage architecture –Context-in model : Context-out model extracted from the storage architecture Directly usable in its modeling and simulation environment

10 Basics of the Approach The Notion of Context – Illustration Library IEEE; use IEEE.std_logic_1164.all ENTITY counter PORT(clk, en, clr: IN std_logic; rco: OUT std_logic; q: OUT INTEGER RANGE 0 TO 9); END counter; ARCHITECTURE behav OF counter IS SIGNAL cnt: INTEGER RANGE 0 TO 9; BEGIN... END behav; library IEEE; use IEEE.std_logic_1164.all ENTITY counter PORT(clk, en, clr: IN std_logic; rco: OUT std_logic; q: OUT INTEGER RANGE 0 TO 9); END counter;... Context-in model Context-out model

11 Basics of the Approach Elements of the Architecture Element : object that can be stored in a library Completely independent from the modeling environment (notion of context) Common characteristics : –Associated with keys –Associated with a documentation Two categories : –Classification elements –Storage elements

12 Basics of the Approach Classification Elements –Library : high level element –Domain : theoretical domain of the elements. Usually, a formalism or a modeling and simulation environment –Application Domain : domain of use of the models –Classification Intermediate Model : simple element for the structuration of a library

13 Basics of the Approach Storage Elements –Inheritance Intermediate Model : allow a share of characteristics between models –Model File : basic storage element Decomposable Model File Non-Decomposable Model File

14 Basics of the Approach Relationships between Elements InheritanceIntermediateModel DecomposableModelFile ClassificationIntermediateModel NonDecomposableModelFile ApplicationDomain Domain Library 0..1 * * * * * * * * *

15 The Domain Parser Notion of Domain Parser Essential point : unique storage format Two different and domain-oriented procedures : –Context Transition : “context-in” towards “context-out” –Context Reconstitution : “context-out” towards “context-in” Domain Parser : –Analysis Mode Context Transition –Creation Mode Context Reconstitution

16 The Domain Parser Basics Relies on a Distinction Methodology : –Separate the extent of the model from its format –Specific to each defined domain –Defined by the librarian Difference between decomposable models and non-decomposable models => Type Selector

17 The Domain Parser The DomainParser Class ParserTypeSelector NonDecomposableModelFileParser DecomposableModelFileParser DomainParser DecomposableModelFileParser1 NonDecomposableModelFileParser1 TypeSelector1 Parser1

18 The Domain Parser Format of the Context-Out Models Use of the XML language Multiple advantages : –Text format easily readable –Facility for reusability (can be translated in other various formats) –Web-enabled

19 The Domain Parser Context-Out Models Document Type Definition ]>

20 Case Study : the JDEVS Domain Example of a JDEVS Non-Decomposable Model public class DevsAtom extends AtomicModel { Port i1 = new Port(this, ''i1'', ''IN''); Port o1 = new Port(this, ''o1'', ''OUT''); public DevsAtom() { super(''DevsAtom''); states.setProperty(''A'', '' ''); } EventVector outFunction(Message m) { return new EventVector(); } void intTransition() {} EventVector extTransition(Message m) { return new EventVector(); } double advanceTime() { return Double.MAXVALUE; }

21 Case Study : the JDEVS Domain Generation of the Context-Out Model Two steps : –Context-in model analysis –Context-out generation Implementation of the DecomposableModelFileParser abstract class : –Four methods for the analysis –Four methods for the generation

22 Case Study : the JDEVS Domain The Context-Out Model JDEVS this public { super(''DevsAtom''); states.setProperty(''A'', '' ''); } Message m EventVector { return new EventVector(); }...

23 Conclusion and Perspectives Main point : notion of context Implementation using the J2EE TM technology (HMLib Prototype) : –Validation using the JDEVS M&S Environment –Applications : environmental studies, VHDL fault simulation, CORBA-based architectures modeling and simulation Perspectives : –Management of other formalisms –Improvement of the performances of the storage engine –Study of the distribution of storage engines over a network