QPE A Graphical Editor for Modeling using Queueing Petri Nets Christofer Dutz.

QPE

A Graphical Editor for Modeling using Queueing Petri Nets

Christofer Dutz

Agenda

• Motivation

• XML Format

• Approaches to Java GUI development

• QPE Design & Architecture

• Demo

• Conclusion

• Future Work

Motivation

• Benefits of QPNs over ordinary PNs

• Problems analyzing QPNs

• How SimQPN solves these problems

• HiQPN as editor and its disadvantages

• QPE closing the gap

Benefits of QPNs over ordinary PNs

Motivation

Problems analyzing QPNs

• State space explosion problems

• Analysis techniques not scalable

Motivation

SimQPN simulator

• Scales much better

• Allows simulation of far more complex nets

• Unfortunately no GUI

Motivation

HiQPN

• currently only GUI tool for QPNs

• Not portable (Solaris)

• Problematic integration with SimQPN – C Java

• Screenshots

Motivation

HiQPN net editor

Motivation

HiQPN incidence functioneditor

Motivation

QPE

• Pure Java

• Developed directly for QPN support

• Available on all major platforms

• Integrates perfectly with SimQPN

• Screenshots

Motivation

QPE net editor

Motivation

QPE incidence function editor

Motivation

XML Format

• Why XML

• Format extension vs. new definition

• Demo

• Schema definition

Why XML?

• Portable

• Human readable

• Transformable

XML Format

Format extension vs. new definition

• PNML– Filled with unnecessary features– Unable to integrate global color definitions

• QPE format – Lightweight– Optimized for QPNs

• Conversion PNML QPE using XSL

XML Format

Format Demo

• ..\test-data\test2.xml

XML Format

Schema definition

• Schema– Good tool support widely spread– No support for type definition based on name

and attribute

• RelaxNG– Easy format– Able to define QPE format

XML Format

Schema Demo

• ..\qpn.rng

XML Format

Approaches to Java GUI development

• SWING & AWT

• Extending existing tools– PIPE

• Graphic frameworks and libraries– Touchgraph – Eclipse & GEF

SWING & AWT

• AWT fast but little features

• SWING slow but many features

• Implement Framework for QPN visualization by myself

• Reinventing the wheel is no solution

dropped


PIPE

• High level code object oriented• Low level code procedural• Class names had nothing to do with their function• Hacking against my understanding of software

quality• Reimplementation more time-consuming than

reimplementing from scratch using visualization framework

dropped


PIPE based QPN editor


Touchgraph

• Library for visualizing net structures

• Amazing visualization

• Homogeneous elements– No constraints– No attribute types bound to certain node types

dropped because of GEF


Touchgraph application


Eclipse & GEF

• RCP (Rich Client Platform)– Minimal Eclipse– Usage of all Eclipse plug-ins– Application generally usable as standalone

application or plug-in

• GEF = Graphical Editing Framework– Visualization framework for building graphical

editors


QPE Design & Architecture

• RCP Perspective

• Problems

• Main patterns

• Model

• Controller

• View

RCP Perspective


Problems

• Change from 3.0 to 3.1 – Major changes in plug-in mechanism– Samples and how-to's for 3.1 hard to find– Google not yet indexed a lot of 3.1 content

• No Architecture Map

• How-to's mainly show samples without explanation


Main patterns

• MVC – Model Model

– View Controller

• Observer– PropertyChangeListener

• Reflection– Parameters of type Object

– Implementing additional interface results in entirely different behavior


Model

• XML (Dom4J and XPath for navigation)• Write access wrapped to enable event-listeners• General structure of read and write operations• Screenshots of sample actions

– Registering a new document

– Registering as event listener for an element

– Modify an element


General structure

Document-Manager

Controller

read

acc

ess

writ

e ac

cess

Eve

nt n

otifi

catio

n

EventWrapperXmlDocument


Registering a new document

Net

Colors Places Transitions Connections Meta-Attributes

Color Place Trnasition Connection Meta-Attribute

EventWrapper

ControllerContorller Contoller

Document-Manager

2. generate id and add as event-wrapper-id attribute

1. register document

4. fire document registerd

3. create EventWrapper and store using id as key


Registering as event listener

Net



EventWrapper


Document-Manager

Wants to listen to element 1. Register request

2. get element3. get document

4. get event-wrapper-id 5. get event wrapper with id and register as listener for element


Modify an element

Net



4. get event-wrapper-id

1. tell

DocumentManager to

modify element

EventWrapper

5. get event wrapper with id


7. fire element modified

7. fire element modified

Document-Manager

2. get element

Wants to modify

8. fire child modified

3. get document

6. modify


Controller

• EditParts – interacting with Platform– Keeping model and view in sync– Register as event listeners to platform and

model events

• Screenshot of EditPart structure


EditPart stucture

NetEditPart

PlaceTransitionEditPart

(base class)

PlaceEditPart TransitionEditPart

children

ConnactionEditPart

TargetConnections

Source- connections

TargetConnections

Source- connections

IncidenceFunctionEditPart

PlaceEditPart ModeEditPart

ColorRefEditPart

children children

children

NamedConnactionEditPart

TargetConnections

Source- connections

TargetConnections

Source- connections

NetEditPart Structure

Incidence function

EditPart Structure


View

• Figures = Visual components• Problem

– Lists in Java only allow one reference to a single Object

– How to distinguish between input and output place?

• Solution: Wrapping in wrapper objects• Screenshot of I.F. editor figures


Incidence function view structure

Wrapper Elements

Color-ref

Place A

Color-ref Color-ref

Place B

Color-ref Mode

Place A

Place A

Place B

Dom Elements

Editor

Demo

• QPE– Show everything

• SimQPN plug-in– Show wizard


Conclusion

• Multiplatform QPN editor

• Integration of SimQPN simulator

• Together form QPME:– Queueing Petri Net Modeling Environment

• Able to be widely spread

• Because of simulator performance will be highly accepted by users

Future work

• Implementation of subnet editor– QPN HQPN editor

• Final adjustments in simulator integration.• Validation of simulator integration• Implementation of custom problem view for

RuleEngine• Branding to make executable binary

package for each supported platform

Fin

QPE A Graphical Editor for Modeling using Queueing Petri Nets Christofer Dutz.

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