NSF/ITR: Foundations of Hybrid and Embedded Software Systems

Model-Integrated Computing:Foundations

DSML Composition Model Synthesis and Model Transformation

Janos Sztipanovits March 11, 2003

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Middleware Services and OS

ComponentLibraries

MiddlewareOS

FrameworkLibraries

PlatformQoS ORBOS

SchedulingFault

Tolerance

CORBAIDL

QoSAPI

POSIXAPI

ReplicationAPI

LibraryComponents

LibraryComponents

LibraryComponents

LibraryComponents

Model-Based Design andComposition

Auto-Generated Code Model-basedGenerators

GeneratorTechnology

Domain-Independent Models(models of computations: SDF, FSM, CSP, …)

User Interface

DecisionSupport

ControlSensorSystem

Application-Specific Models

DS ModelLibraries/Patterns

DI ModelLibraries/Patterns

Domain-Specific

ModelingTechnology

ToolsApplication

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Platforms(There are many…)

Hardware CPU, MEM, I/O

Operating System

QoS Middleware

Application

Hardware CPU, MEM, I/O

Operating System

QoS Middleware

Application

ControlAlgorithm

QoS parameters

Measuredvars.

Controlvars.

Application

OS

Strong isolationbetween SW andHW by Active Control

TTP Bus

ServoController

ServoController

CNI

ControlData Processor

BG BG

TTPController

CNI

ControlData

Processor

BG BG

TTPController

ServoController

ServoController

CNI

ControlData Processor

BG BG

TTPController

CNI

ControlData Processor

BG BG

TTPController

Time-Triggered Architecture (distributed, hard real-time, safe)

QoS Middleware (such as CORBA)

Integration framework, composition mechanisms, components

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MDA View of Model-Based Design

Platform-Independent

Model

CORBA Model

CORBA Java/EJB XML/SOAP Other

Java/EJBModel

XML/SOAPModel

OtherModel

MDA Tool generates all or most of the implementation code for deployment technology selected by the developer.

Richard Mark Soley, Model Driven Architecture: An Introduction

A Detailed Model, stating Pre- and Post-Conditions in OCL, and Semantics in Action Language

Map a PIM to Specific Middleware Technologies via OMG Standard Mappings

Map a PIM to Many Middleware Technologies via OMG Standard Mappings

Map PSM to application interfaces, code, GUI descriptors, SQL queries, etc.

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Model-Based Design for Embedded Systems

ImplementationSpace

Mapping

ApplicationSpace

Challenges: • Domain Specific Modeling Languages (DSML)

• Model Synthesis

• Model Transformation

Design

Gen./Synth.

DSML

ApplicationModels

DSML

Implement.Models

Model-BasedDesign

FM ARCH SYNL HY

CON IMP

ODEPi-1

Pi

Pi+1

Model-BasedDesign of Embedded Systems

FSM

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Specification of Domain Specific Modeling Languages (DSML)

ConcreteSyntax

C

AbstractSyntax

A

SemanticDomain

SSemantics

parses to

Concepts

Relations

Well formed-nessrules

Mathematical abstraction for specifying the meaning of models

Notation forrepresenting models

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

MC

MS

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Concrete Syntax and Abstract Syntax

Notation forrepresenting models:E.g.: Block Diagram

Concrete

Syntax

C

Abstract

Syntax

A

Semantic

DomainS

Semantics

parses to

MC

MS

Mathematical abstraction

for specifying the meaning of models

But What About S?

Signal Flow Language (SF)Concepts, Relations

Well formed-ness rules:

Self.InputPorts()forAll(ipip.src()forAll(x1,x2x1=x2))

UML-CD/OCL

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Semantics via Meta-Modeling

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.

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Semantics via Translation

Concrete

Syntax

Abstract

Syntax

Semantic

DomainSemantics

parses to

Concrete

Syntax

Abstract

SyntaxSemantics

parses to

Semantic

Domain

translator

DSML

Semantics

Modeling language with

well-defined semanticsSynchronous Dataflow (SDF)

translatorBehavioral

Semantics

ASF

Hierarchical Signal Flow (HSF)

Lee, Sangiovanni-Vincentelli

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Consistency!

DSML Composition

Semantic domain impact!

Composed

Behavioral

Semantics:

HYBRIDSYSTEM

Concrete

Syntax

Abstract

Syntax

Semantic

DomainSemantics

parses to

AL1

L1||L2

Concrete

Syntax

Semantic

DomainSemantics

parses to

Structural

Semantics

Abstract

Syntaxtranslation

HSF+ SDF+Cont.Dyn

AL2

Concrete

Syntax

Abstract

Syntax

Semantic

DomainSemantics

parses to

Concrete

Syntax

Semantic

DomainSemantics

parses to

Abstract

Syntaxtranslation

FSM CSP

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Support for Compositional Meta-Modeling

`

Child inherits all associations except containment associations where parent functions as container.

Interface Inheritance

Child inherits all of the parent’s attributes and those containment associations where parent functions as container.

Implementation Inheritance

Complete equivalence of two classes Equivalence

Informal semantics Symbol Operator

Composition Operators

Metamodel composition with GME

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Model Synthesis and Transformations

• Model Synthesis

• Model Transformation

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

FM ARCH SYNL HY

CON IMP

ODEPi-1

Pi

Pi+1

Model-BasedDesign of Embedded Systems

FSM

NSF

Meta-ProgrammableModel Builder

(GME) Instance of

ASDF

Meta-model-2

lSFLSF

HSF Domain model

lSDF LSDF

SDF Executable modelSDF Platform

ASF

Meta-model-1

instance of

GENGEN

GeneratorSpecification

G: ASF →ASDF

Transformer

Ongoing Work: Meta-generators

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Ongoing Work: Constraint-Based Model Synthesis

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Ongoing Work: Combining MIC & Component Middleware

QoS Policies

QoS PropertyAdaptor

Real-time POA

ORB QoS Interfaces

Container

CORBAComponent

Client/Peer

Server/PeerApplication

CodeComponentHome

CORBAComponent

CORBAComponent

CORBAComponent

CCM Component Library

Model-BasedGenerator

SelectComponent

Synthesize & Assemble

CORBAComponent

CORBAComponent

CORBAComponent

CCM Model Library

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Tools for Model-Integrated Computing Technology

Services

Platform Specific Models(SDF, FSM, CSP, …)

Auto-Generated Code

SecurityModels

FaultModels

Middleware Services and OS

ORBOS

SchedulingFault

Tolerance

CORBAIDL

QoSAPI

VehicleControllers

SensorSystemModels

Application Specific Models

LibraryComponents

LibraryComponents

LibraryComponents

LibraryComponents

POSIXAPI

REPLICATIONAPI

DS ModelLibraries/Patterns

Component & Platform

Models

Model-basedGenerators

Middleware Component

Libraries

Application Component

Libraries

Domain-SpecificModeling &AnalysisEnvironment

GeneratorTechnology

MiddlewareTechnology

MetaModel

Libraries

ToolMetadata

MetaGenererator

ComponentLibraries

ECLIPSE

OTIFLibraries

MetaModelingEnvironment

Meta-Generator

Technology

Open ToolIntegrationFramework

Integrated Tools

Embedded Computing Applications

Domain Specific Tools

Domain Independent Tools

Domain Independent Tools

OTIFToolIntegration

Platform

MetamodelRepository

Summary

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Research Agenda on DomainSpecific Modeling Languages

Precise, compositional meta-modeling

Multiple aspect modeling in the compositional meta-modeling framework

Practical issues:– Examples, meta-model libraries

– Meta-programmable tools

– Link to UML-2

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Meta-generators: Model Transformations in Tool Integration

Approach (Karsai): Meta-models for source and target models plus transformations, then generating the transformer

Transformer

Domain-specific model

Target model

Meta- model for source

Meta- model for target

Meta- model for transform

GENGEN

Roles transformations play in model-based design:

•Refining a design into an implementation

•Code generation

•PIM -> PSM mapping

•Support for model interchange for tool integration

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Generative modeling: Extensions to Meta-Modeling Languages

Iterative (“for”) and conditional (“if”)constructs in models can greatly enhance expressiveness while reducing complexity.

Input design: with “for” loopWhat it means:

Transformer

Replicate the middle of pipeline “Order” times!

Order = 3

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Other Uses of Transforms on Models: Design Patterns

Design patterns capture prototypical solutions to a design problem. As such, they are parametric and reusable.

+operation()+add(in c : Component)+remove(in c : Component)+getChild(in index : int)

Component

+operation()

Leaf

-children

1

*

+operation()+add(in c : Component)+remove(in c : Component)+getChild(in index : int)

Composite

forall g in children g.Operation()

COMPOSITE PATTERN

+run()

Primitive

Compound

+run()+add(in c : PC_Component)+remove(in c : PC_Component)+getChild(in index : int)

PC_Component

+run()

Primitive

-children

1

*

+run()+add(in c : PC_Component)+remove(in c : PC_Component)+getChild(in index : int)

Compound

forall g in children g.run()

COMPOSITE PATTERNapplied to Compound and Primitive

Design pattern (as a transform)

Input designDesign with pattern applied

Transformer

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Research Agenda on ModelTransformations

Languages and tools for meta generators

Model synthesis using explicit design patterns

Model synthesis using constraint-based design-space exploration

Generative modeling extensions to languages

Embeddable generators

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Conclusion

The hard problems of building large embedded systems are Semantics and Compositionality

Model-based integration technology has the power to solve the problem

Model-Integrated Computing evolves to be a mature technology for the development of complex applications