UC Berkeley: Chess Vanderbilt University: ISIS University of Memphis: MSI CHESS Review May 10, 2004 Berkeley, CA Model-Based Design Edited by Janos Sztipanovits,

UC Berkeley: ChessVanderbilt University: ISISUniversity of Memphis: MSI

CHESS ReviewMay 10, 2004Berkeley, CA

Model-Based Design

Edited by Janos Sztipanovits, Presented by Gabor Karsai ISIS, Vanderbilt University

CHESS Review, May 10, 2004 2

Objectives

Model-based design focuses on the formal representation, composition, and manipulation of models during the design process.

Specific research areas:1. Composition of Domain Specific Modeling

Languages2. Model Transformation3. Model Synthesis


ConcreteSyntax

C

AbstractSyntax

A

SemanticDomain

S

Semantic

Mapping

Parsing

Concepts

Relations

Well formed-nessrules

Mathematical abstraction for specifying the meaning of models

Notation forrepresenting models

L = < C, A, S, MS, MC>

MC

MS

1. Composition of Domain Specific Modeling Languages


Research Agenda

Research Agenda:1. Using the Meta-Object Facility (OMG) as

the meta-metamodel2. Specification of DSML semantics via meta-

modeling3. Foundation for composing DSML-s4. New Semantic Domains5. Extension of meta-programmable tools

Baseline: − Modeling of Abstract Syntax using UML class diagrams

and OCL as meta language;− Meta-programmable Graphical Model Editor (GME)


Semantics via Meta-Modeling: Baseline

Concrete

Syntax

Abstract

Syntax

Semantic

DomainSemantics

parses to

Meta-modeling language withwell-defined semantics

Concrete

Syntax

Abstract

Syntax

Semantic

DomainSemantics

parses to

Represented by

Meta-modelSemantics

DSML

Meta-modelStructural

SemanticsDSML:StateFlow

DOMAIN-MODEL

META-MODEL

Meta-Model of StateFlow using uml/OCLas meta modeling language.


New Direction: Precise Meta-Modeling

CS

A MC MS

DSML

MOFADSML

GMEMC,DSML

GMEADSML

GMECDSMLTLAAMOF TLASMOFTLAMS,MOF

C

SA MS

MC

MOF

TLA+TLA+ TLA+

GMEMOF

GMEMOF

GMEMOF

MOF

TLAAMOF TLASMOFTLAMS,MOF

C

SA MS

MC

MOF

TLA+TLA+ TLA+

Modeled by

Mapped into

Concrete

syntax

modeling

Abstract syntax modeling with MOF

Set-valued semantics for MOF

Meta-model

MOF/TLA+ Model

(meta-meta model)

GME

Meta-

Programmable

Model BuilderOngoing Work: (Poster: Compositional Metamodeling for DSMLs)

• Changing from UML-CD/OCL to MOF in abstract syntax modeling•Developing set-valued semantics for MOF using TLA+ as meta-language• Developing MOFADSML TLAADSML translator


Semantics via Translation: Baseline

Concrete

Syntax

Abstract

Syntax

Semantic

DomainSemantics

parses to

Concrete

Syntax

Abstract

SyntaxSemantics

parses to

Semantic

Domain

translator

DSML

Semantics

Modeling language with

well-defined semantics

Synchronous Dataflow (SDF)

translatorBehavioral

Semantics

ASF

Hierarchical Signal Flow (HSF)

Lee, Sangiovanni-Vincentelli


MHMA,MA

SC

A

MC MS

MACS

A

MC MS

HMA

MOFAHMA MOFAMA

HMADM

TLA+

TLASMA

MOF’THMA,MA

MOF MOF’ MOF

TLA+

TLA+TLAAMA

TLAMS,MA

MS: AHMASMA

MS= MS1○ MS2 ○ MS3

MS1: MOFAHMAMOFAMA MS2: MOFAMATLAAMA

MS3: TLAAMATLASMA

MADM

Metapr.transformer

New Direction: Translational Specification of DSML Semantics

Ongoing Work: (Poster: Compositional Metamodeling for DSMLs)

• TLA+ specification of the semantics of selected models of computations (reference models)• Specifying DSML semantics via specifying mapping between the abstract syntax of DSML and the reference models• Developing modeling and translation tools


New Semantic Domains: HyVisual – Hybrid System Modeling Tool Based on Ptolemy II

HyVisual is a DSML designed for hybrid system modeling, specialized from Ptolemy II by combining its CT and FSM domains.


Major Applications of Meta Modeling: Metropolis Meta Model (Formal Model)

•How are designs represented in Metropolis?Metropolis “meta-model”: a language + modeling mechanisms

–represents all key ingredients: function, architecture, refinement, platforms

–parser and API to browse designs, interact with tools


• Must describe objects at different levels of abstraction

– Do not commit to the semantics of any particular model of computation

• Define a set of “building blocks”

– specifications with many useful Models of Computations can be described using the building blocks

– Processes, communication media and schedulers separate computation, communication and coordination

P1 P2M

S

P1.pZ.write( ) P2.pX.read( )

pX pZ pX pZ

M’ M’

Computation

Communication

Coordination

Metropolis Meta-Model


Core Metropolis “Meta Model”

• Processes– Concurrent Computation, sequential execution within each

process– Execution within a process can be suspended with the

AWAIT statement • Interfaces

– The types of Ports, bundle function declarations• Media

– Model Communication by providing definitions of Interface Functions

– Passive, cannot run in their own threads• Netlists

– STRUCTURE and CONCURRENCY• Quantity Managers

– Performance modeling• Constraints

– Specification & Synchronization• Formal Semantics

– Operational Semantics based on Action Automata


2. Model Transformations

Platform-BasedDesign of Embedded Systems

MatlabCode-Gen.

if (inactiveInterval != -1) { int thisInterval = (int)(System.currentTimeMillis() - lastAccessed) / 1000;

if (thisInterval > inactiveInterval) { invalidate();

ServerSessionManager ssm = ServerSessionManager.getManager();

ssm.removeSession(this); } } }

private long lastAccessedTime = creationTime;

/** * Return the last time the client sent a request associated with this * session, as the number of milliseconds since midnight, January 1, 1970 * GMT. Actions that your application takes, such as getting or setting * a value associated with the session, do not affect the access time. */ public long getLastAccessedTime() {

return (this.lastAccessedTime);

}

this.lastAccessedTime = time;

/** * Update the accessed time information for this session. This method * should be called by the context when a request comes in for a particular * session, even if the application does not reference it. */ public void access() {

this.lastAccessedTime = this.thisAccessedTime; this.thisAccessedTime = System.currentTimeMillis(); this.isNew=false; }

lastAccessedTime = 0L;

lastAccessedTime = ((Long) stream.readObject()).longValue(); maxInactiveInterval = ((Integer) stream.readObject()).intValue(); isNew = ((Boolean) stream.readObject()).booleanValue();

MatlabCode-Gen.

Domain-Specific Modeling Languages

GeneratorModel-Based GeneratorTechnology - Modeling of generators - Generating generators - Provably correct generators - Embeddable generators

ConfigurationSpecification

Analysis Tool

Code

Pi-1

Pi

Pi+1


Research Agenda

Research Agenda:1. Meta Generators: Specification and

generation of model transformations using graph rewriting technology

2. Embeddable generators3. Generative extensions to modeling languages

Baseline: − Meta-models of the Abstract Syntax of the source and

target DSML-s;− Tools helping the procedural implementation of translators


Model Transformation UsingMeta-Models and Graph Rewriting

RewriteEngineInput

ModelsTargetModels

Ph

ysi

cal in

terf

ace

Ph

ysi

cal in

terf

ace

Inp

ut

ab

stra

ct s

ynta

x

Outp

ut

ab

stra

ct s

ynta

xInput

InterfaceOutput InterfaceA

PI API

UDMUDM

GREGRE

Metamodel of Input

Metamodel of Output

Metamodel of

Transformation

Meta

-level: T

ransl

ato

r desi

gn

Imple

menta

tion:

Execu

tion

Formal, explicit, and precise model of the transformations

Karsai/Agrawal, ISIS


Component Specialization

Model of Computation semantics defines communication, flow of control

Ptolemy II model

scheduler

Schedule:

- fire Gaussian0

- fire Ramp1

- fire Sine2

- fire AddSubtract5

- fire SequenceScope10

parsermethod call

if

block

method call

block

…

for (int i = 0; i < plus.getWidth(); i++) {

if (plus.hasToken(i)) {

if (sum == null) {

sum = plus.get(i);

} else {

sum = sum.add(plus.get(i));

}

}

}

…

Java actor definitions are parsed and then specialized for their context.

target code

abstract syntax tree

Specialize for data types parameter values scheduling

By token unboxing inlining partial evaluation dead code elimination

specializer


3. Model Synthesis

ModelingControllerSynthesis

System Analysis

CodeSynthesis

ValidationVerification

TargetAnalysis

Platform

Platform Models

Plant Model Integrated Model

Design Feedback

Valid Model Code/Model

Test Vectors

Valid Code/Model

Design Feedback

Download

Valid Model

Challenge:Compose plant and controller models usinglibrary components with alternatives so as to satisfy design constraints

Example design flow:


Research Agenda

Baseline: − Constraint-based design space exploration

coupled to a dataflow language

Research Agenda:1. Pattern-based model synthesis2. Models of Computations as design patterns3. Design constraints and design patterns for

multiple Models of Computations


Pattern-based Model Synthesis

ComponentAbstraction (TA)

Design SpaceModeling (MD)

Design SpaceEncoding (TE)

Design SpacePruning

Design Decoding

ComponentReconstruction

SimulinkBehavioral

Models And

ModelComponents

Main Design Flow

Main Design Flow Design Space Modeler

DESERT Model Synthesis Flow

Using meta-modeling and model transformations we made the constraint based design space explorationtool suite composable with different design flows.

Neema, Sztipanovits, Karsai at EMSOFT 2003


Example: Use of Model Translation in the DESERT Tool Chain

-Name : String

Model

BlockDefaultsAnnotationDefault

s LineDefaults

-Name : String

System

-Name : String

Block

Subsystem Reference Primitive

1

1

1 *

1

1

Port

Masked Normal

Line

InputPort OutputPort

1

*

1*

1

-dstPort

1

1

-srcPort1

11

1

1

Annotation

11

1*

Branch

DirectLineBranchedLine

DirectBranch NestedBranch

1

1..*

11..*

1

-dstPort

1

-Name : String

Parameter

-Value : String

Text

-Value : Boolean

Boolean

-Value : String

Enumeration

-Value : Integer

Integer

-Value : Double

Double

-Value : Variant

Vector

-Value : Variant

Type

1

0..*

ComponentAbstraction (TA)

Simulink®Metamodel

Abstracted Simulink Model Components

Design SpaceMetamodel

Documents

UC Berkeley: Chess Vanderbilt University: ISIS University of Memphis: MSI CHESS Review May 10, 2004 Berkeley, CA Model-Based Design Edited by Janos Sztipanovits,