Travelling Reporter

UML for Global Computing Martin Wirsing LMU München in cooperation with Hubert Baumeister, Piotr Kosiuczenko, Nora Koch Stephan Merz, Julia Zappe

GC Summer School, Edinburgh, July 2003

M. Wirsing: UML for Global Computing

Global Computing

Current ...

„massive networked infrastructure composed of highly diversed interconnected objects“

„

Software Engineering Standards (UML) ¾

support only particular features of GC such as concurrency and real time

EU Initiative „Global Computing“ „

Systems which support dynamic configuration complex topologies autonomous and mobile objects

Programming Languages (C++, Java, ML, Haskell, ...) ¾

„

Middleware (CORBA, Jini, COM, SOAP, .Net, ...) improves on client server model but ¾ are based on simple topology assumptions (e.g. TCP) ¾ support only particular aspects of GC ¾ have no (good) support for validation&verification ¾

Mobile Computing (Mobile Hardware) Mobile Computation (Mobile Code) M. Wirsing: UML for Global Computing

M. Wirsing: UML for Global Computing

Global Computing needs ...

„

New support for software development ¾ ¾

The AGILE Project

„

Goal: Architectural approach to mobile systems development over a uniform mathematical framework supporting

New features for modeling languages Adequate development processes

„

„

New features for programming languages and middleware

„ „

and „

Coupling of pragmatic and formal techniques for analysis, validation, verification of GC systems

support only particular features of GC such as concurrency and distribution

sound methodological principles, formal analysis, and refinement across levels of development

„

2002-2005, sponsored by EC Initiative on “Global Computing”

„

Partner: LMU München, ATX Lissabon, U. Pisa, U. Lissabon, U. Florenz, ISTI Pisa, U. Warschau, U. Leicester

M. Wirsing: UML for Global Computing

M. Wirsing: UML for Global Computing

1

Agile Approach Case Studies

Mobile Applications

Existing Modeling Languages

Contents

„

Lecture 1: Introducing UML for Mobility

Mobile UML

„ „ „ „

„

Structural View on Distribution&Mobility

Architectural Views

+

Algebraic Models of System Evolution

M. Wirsing: UML for Global Computing

Unified Modeling Language

„ „

„

„ „ „ „ „

between developers developers and users (?)

„

„

Definition of different views

A number of modelling concepts A concrete notation

Supports “Unified Process” development method

M. Wirsing: UML for Global Computing

M. Wirsing: UML for Global Computing

UML Description Techniques

Structure: „

„

Description of essential program characteristics like a construction plan Structuring the problem as well as the solution Abstracting from implementation details

„

„

“Unification” of several predecessor methods First standardization attempt Sep. 1997 by OMG Current version 2.0 (Notation of Lecture 1.5) Developed by Booch, Rumbaugh (OMT), Jacobson (OOSE)... Consist of: „

„

Goals of the UML

Graphical modelling language for OO systems Means of communication „

„

Lecture 2: Refining Mobility Designs Lecture 3: Property-Driven Development of Mobile Systems

Graph-Orientied Semantic Framework (Categ. Dgrms + Graph Transform. + Tile Logic + Institutions)

Uniform Mathem. Basis

„

„

Use Case Driven design Class Diagrams Sequence Diagrams Activity Diagrams

„

Class diagram

(UML) Software Engineering Principles

system

Requirements, Functionality: „

Use Case Diagram

„

Activity Diagram

View-oriented system modelling partial views

Interaction, Behaviour: „

Object diagram

„

Sequence diagram

„

Collaboration

„

Statechart

„

Implementation: „

M. Wirsing: UML for Global Computing

„

„

Component Diagram Deployment Diagram

Object Constraint Language (OCL)

Use case Arrival Includes Landing Description The plane is landing. Then the passengers deplane and the luggage is unloaded. If the passenger has luggage then the passenger claims its luggage.

Airport

Flight

Passenger

UML documents

A system is described by several documents from several viewpoints M. Wirsing: UML for Global Computing

2

(UML) SE Principles (cont‘d)

„ „

„ „

Use Case Driven Design

Principle of underspecification Data encapsulation and separation of interfaces and implementations Incremental development by refinement steps Hierarchical composition and decomposition

„

„

M. Wirsing: UML for Global Computing

Use cases serve as functional requirement description and provide test cases

M. Wirsing: UML for Global Computing

Use Case Diagram: Example Airport

Major Development Steps Identify use cases

Identify classes of the application domain

Use case diagram, scenarios, activity diagrams

Class diagram oo view

Use Case an interaction between user and system which serves to fulfill a task where “system” = software to be developed “user” = person or external system called “actor”

use case use case

TakingOff

Departure

functional view

Specify the overall system

actoractor Airport

Class diagram + behavior specifications

oo view Passenger

Develop system architecture Architectural design M. Wirsing: UML for Global Computing

refinement

Use Case Description: Example

M. Wirsing: UML for Global Computing



Landing

Plane

Flight M. Wirsing: UML for Global Computing

Class Diagram „

Use case Arrival Includes Landing Actors plane, passenger Description The plane is landing. Then the passengers deplane and the luggage is unloaded. If the passenger has luggage then the passenger claims its luggage.

Arrival

A class diagram defines the static structure of the system consisting of classes and interfaces connected by static relationships such as association, aggregation and inheritance

M. Wirsing: UML for Global Computing

3

Classes for Mobile Objects

Example: Class Diagram for Airport Country name

„

Goal of the extension

„

Extensions

1

„

* has Airport

„

name origin 1

* Flight

type numberOfSeats land() takeOff()

run *

*

UML profile for mobility with stereotypes for locations, mobile objects, and mobile locations

1 destination

* Plane

Explicit notations for mobile objects and locations

Passenger

number date boardingTime gate

*

*

name eat() board() deplane()

M. Wirsing: UML for Global Computing

M. Wirsing: UML for Global Computing

Abstract Classes for Mobility: 1st Approach

Abstract Classes for Mobility: 2nd Approach *

atLoc

0..1 *



Spatial

atLoc



0..1

*

atLoc

Location



0..1

Mobile Object





Location

Mobile Object



Mobile Location

Mobile Location

Problem: Mobile Location inherits „atLoc“ twice: from Location and from Mobile Object

Improvement: Due to the introduction of the abstract class „Spatial“, Mobile Location inherits „atLoc“ only once, but ...

M. Wirsing: UML for Global Computing

M. Wirsing: UML for Global Computing

Spatial

Solution: UML Profile for Locations Location

Abstract classes lead to complex class diagrams

Mobile Object



Each instance has at most one attribute atLoc; atLoc has no cycles

Class

Mobile Location

spatial

Country

Airport

Plane

Flight





location

mobile

Passenger



mobile location M. Wirsing: UML for Global Computing

4

Sequence Diagram

Example: Class Diagram for Airport Country name

A sequence diagram describes a scenario, i.e. an exemplary message flow where primary scenario: the typical case secondary scenario: variant, exceptional case Scenarios can describe different levels of abstraction e.g. for use case, components, operations Other description technique for scenarios: collaboration diagrams

„ 1

* has Airport name origin

Plane type run numberOfSeats * land() takeOff()

1

1 destination

*

*

„ Passenger

Flight

*

number date boardingTime gate

*

name eat() board() deplane()

*

„

M. Wirsing: UML for Global Computing

M. Wirsing: UML for Global Computing

Sequence Diagram

Example: Check In

: Passenger object symbol

name : Class

lifeline

checksIn ()

stimulus

whichSeat

name (...)

activation

new (...)

returnChoice ()

: Class delete

return

Sequence Diagrams for Mobility

ap [at = JFK] ps [at = ap]

Complex model, mobility not explicit M. Wirsing: UML for Global Computing

: Ticket

send ()

M. Wirsing: UML for Global Computing

Mobile runs with SD: A first approach

board( )

print ()

new ()

create

M. Wirsing: UML for Global Computing

ps [at = JFK]

: CheckIn Machine

other

notice( )

notice( )

fly( )

„

ap [at = MUC] deplane( )

„ ps [at = MUC]

SDM are an extension of SD for modelling „ the interaction between objects „ topology - the containment relation „ the migration of objects Idea „ blow up lifelines and message arrows for modelling topology „ generalize the concept of lifeline to contain object flow for modelling mobility

M. Wirsing: UML for Global Computing

5

Migration of an Object ps

Copying Objects

pl c

942 : PC

131: PC

b

virus

virus

ps

A person ps migrates into the plane pl and leaves it .

c migrates through a firewall into b and terminates at the same time as b.

The mobile Object virus in PC 131 is copied; the copy lifes in PC 942

M. Wirsing: UML for Global Computing

M. Wirsing: UML for Global Computing

Advanced Features

Opening and Destroying an Object

a

b

c

b

a d



An „open“ message terminates b; the inner objects c and d continue to life

c

d

Zoom-in/zoom-out view

„

Matching action boxes

„

Lifeline of a migrating object

A „destroy“message terminates b, c und d.

M. Wirsing: UML for Global Computing

M. Wirsing: UML for Global Computing

Pattern Matching

Zoom-Out View

„

131: PC

„

Representation of mobile objects and object configurations by terms „

942 : PC

„

virus

„ „

virus „

[cf. Maude]

Object constructor: f : Names x Objects ---> Objects Configuration constructor * : Objects x Objects ---> Objects Empty configuration ε : ----> Objects Variables X: Names

Unification modulo commutativity and associativity for computing the names of migrated objects

Using Zoom-Out one may hide details of inner objects; only the communication with outer objects remains visible.

M. Wirsing: UML for Global Computing

M. Wirsing: UML for Global Computing

6

Pattern Matching Beispiel

The Traveling Reporter Example c

c before migration: f(c, f(e, ε) * f(d, f(z, ε)) a after migration of c : f(a, f(b, ε) * f(X1, f(X2,f(X3,ε))* f(X4,ε)))

d z

e

a b

The traveling reporter flies from New York to Munich

x e

x after migration of a : f(x, f(Y1, f(Y2, f(Y3,ε)*f(Y4, ε)) * f(Y5, ε)))

Pattern matching of the 3 terms gives: {X1 −> c, X2 −> d, X3 −> z, X4 −> e, Y1 −> a, Y2 −> c, Y3 −> z, Y4 −> e, Y5 −> b} M. Wirsing: UML for Global Computing

M. Wirsing: UML for Global Computing

Flight from New York to Munich

Flight from New York to Munich

USA JFK LH1 : Plane

USA

EU JFK

: Pass

D

x

LH1 : Plane

flight99

D

x

WAN

GB

M. Wirsing: UML for Global Computing

GB

M. Wirsing: UML for Global Computing

Flight from New York to Munich

Flight from New York to Munich USA

LH1 : Plane

: Pass

flight99

WAN

JFK

EU

EU

USA

„ JFK

: Pass

D

x

LH1 : Plane

EU : Pass

D

x

MUC

MUC

flight99

flight99

: Pass WAN

GB

WAN

x

M. Wirsing: UML for Global Computing

LH1 nb dc p

x dc dc

: Pass GB

p

x

M. Wirsing: UML for Global Computing

7

Flight from New York to Munich

Activity Diagrams

USA

„

EU „

JFK LH1 : Plane

: Pass

D

x

„

MUC „

flight99

LH1 nb dc

WAN

„

x dc dc

p

: Pass

Activity diagrams are intended for applications that need control flow or object/data flow models An activity graph describes a flow of actions which are connected by transitions Concurrency is expressed by fork and join states Swimlanes represent responsibilities of parts of the activity diagram

GB

p

x

M. Wirsing: UML for Global Computing

M. Wirsing: UML for Global Computing

Activity Diagram Example: Arrival

Activity Diagram with Flow States MW

MW

LH1

boarding

take off

Fork state

Action

LH1

MW [atLoc = JFK]

Flow state

boarding

Take off

MW [atLoc = LH1]

send mail

flying

deplaning

send mail

landing

Join state

M. Wirsing: UML for Global Computing

Activity diagrams for Mobility

flying

deplaning

landing

M. Wirsing: UML for Global Computing

Responsibility Centered View MW

„

Goal of the extension „

„

To model how actions change the location of mobile objects

Extensions „ „

LH1

MW [atLoc = JFK]

LH1 [atLoc = JFK]

boarding

„

Take off

MW [atLoc = LH1]

LH1

Stereotypes / for actions Two Notations „



send mail

flying

Responsibility Centred Location Centred MW [atLoc = MUC]

M. Wirsing: UML for Global Computing





deplaning

landing

LH1 [atLoc = MUC]

M. Wirsing: UML for Global Computing

8

Move Actions

Modeling the Flight

JFK : Airport MW [atLoc = JFK]



MW [atLoc =LH1]

boarding

MUC : Airport flying

LH1 : Plane

MW



boarding

LH1 : Plane

landing

MW

MW

LH1 : Plane JFK

LH1

send mail

MW

MW



Take off

MW



deplaning

boarding MW

M. Wirsing: UML for Global Computing

M. Wirsing: UML for Global Computing

Summary and Current Work „

Summary „ „ „

„

First approach for explicit modeling of mobility in UML Simple solution Used already in industry and for teaching (DEGAS-Project, SWE-Praktikum)

Current Work „

Semantic Foundation (Translation to GTS and Tiles with Corradini/Montanari, Coordinated Categories with Fiadeiro, Mobile TLA with Merz)

M. Wirsing: UML for Global Computing

9