Modeling and Analyzing Software Behavior in UML

191 Pages·2001·0.62 MB·English

Modeling and Analyzing
Software Behavior in UML
Ivan Porres
To be presented |with the permission of the Faculty of Chemical Engineer-
ing at ”Abo Akademi University| for public criticisms in Auditorium 3102 at
DataCity in Turku, Finland, on November 23, 2001, at 12 noon.
Department of Computer Science
”Abo Akademi University
Supervised by
Professor Ralph Back
Department of Computer Science
”Abo Akademi University
Lemmink˜aisenkatu 14A
20520 Turku
Finland
Reviewed by
Professor Michael Butler
Declarative Systems & Software Engineering Group
University of Southampton
Highfleld Southampton SO17 1BJ
United Kingdom
Professor Wang Yi
Department of Computer Science
Uppsala University
Box 325, SE-75105 Uppsala
Sweden
ISBN 951-29-2169-3
ISSN 1239-1883
Painosalama Oy, 2001
Turku, Finland
To my family
The Heart of Gold’s Improbability Drive made it the most powerful
and unpredictable ship in existence. There was nothing it couldn’t
do, provided you knew exactly how improbable it was the thing you
wanted it to do would ever happend.
| Douglas Adams, The Hitch Hiker’s Guide to the Galaxy
Acknowledgements
This thesis is not the product of the work of a single person. After several years
on the making, I am now really glad to be able to thank to everybody that has
contributed in one or another way to this thesis.
I think of researching as a similar experience as steering Douglas Adam’s
Heart of Gold: There is nothing impossible, provided you know exactly what
you really want to do. Fortunately, I had my supervisor Professor Ralph-Johan
Backhelpingmeonthistask. Hehasbeenaconstantsourceofadvice,guidance
and support during all this time.
I also want to thank Professor Michael Butler of the University Southamp-
ton, United Kingdom, and Professor Wang Yi of the University of Uppsala,
Sweden, who kindly reviewed the thesis. They provided many constructive
comments to improve it and I hope that I have been able to follow and in-
tegrate all their suggestions in this manuscript. Damon Tringham patiently
corrected all the misuses of beautiful English language.
Most of the ideas presented in this thesis appeared in their initial form in
several conference proceedings and a journal publication. These publications
were coauthored by Professor Ralph-Johan Back and also by Professor Johan
Lilius and Luigia Petre. My collaboration with them was not only scientiflcally
fruitful but also a warm personal experience.
Other colleagues from ”Abo Akademi University have also help me greatly
in my research. Christina Cerschi, Professor Hannu Toivonen, Mauno Ro˜nkk˜o
and Professor Joakim von Wright provided many interesting comments in our
enlighteningdiscussionsonthetopicsdiscussedinthethesis. RobertGyllenberg
and Marat Vagapov built the hardware of the digital sound recorder and made
the validation of its design possible.
The Turku Centre for Computer Science and the Department of Computer
Science provided an excellent working environment and generous flnancial sup-
port. I want to express my sincere thanks to all my colleagues for contributing
toaninspiringworkingatmosphere. Dr. MatsAspn˜asprovidedreliableanswers
to the most diverse questions. Dr. Martin Bu˜chi, Dr. Anna Mikhajlova and
Dr. LeonidMikhajlovwereanexcellentrolemodeltofollow. Icanonlywishto
all my fellow PhD. students and specially to Dag Bjo˜rklund, Luka Milovanov,
i
Franck Tetard, Vioerel Preoteasa, Seppo Virtanen and of course, Christina,
Luigia and Mauno the best for their studies.
Finally, I want to thank my family and friends and specially to ”Asa, for
their continuous and unconditional love and support, wherever I am.
Turku, October 4 2001
Ivan Porres
ii
Contents
1 Introduction 1
1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 UML . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2.1 Semantics of UML . . . . . . . . . . . . . . . . . . . . . . 3
1.2.2 Formal semantics . . . . . . . . . . . . . . . . . . . . . . . 5
1.3 The Quality of UML models . . . . . . . . . . . . . . . . . . . . . 6
1.4 Analyzing UML Models . . . . . . . . . . . . . . . . . . . . . . . 7
1.4.1 Analyzing Use Cases . . . . . . . . . . . . . . . . . . . . . 9
1.4.2 Analyzing Statecharts . . . . . . . . . . . . . . . . . . . . 10
1.4.3 Hybrid Statecharts . . . . . . . . . . . . . . . . . . . . . . 11
1.5 List of Publications . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2 Modeling in UML 13
2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.2 Object-Oriented Software Development . . . . . . . . . . . . . . 14
2.3 UML . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.3.1 OCL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.3.2 Tool Support . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.3.3 Proflles . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2.3.4 UML is just a Modeling Language . . . . . . . . . . . . . 19
2.4 Requirements of the Sound Recorder . . . . . . . . . . . . . . . . 19
2.5 Analysis: Object Structure . . . . . . . . . . . . . . . . . . . . . 24
2.5.1 Identifying Objects . . . . . . . . . . . . . . . . . . . . . . 28
2.5.2 Building the Class Diagrams . . . . . . . . . . . . . . . . 29
2.6 Analysis: Deflning Object Behavior . . . . . . . . . . . . . . . . . 38
2.6.1 The User Interface . . . . . . . . . . . . . . . . . . . . . . 39
2.7 Architectural Design . . . . . . . . . . . . . . . . . . . . . . . . . 39
2.7.1 Architectural Patterns . . . . . . . . . . . . . . . . . . . . 42
2.7.2 Concurrency Design . . . . . . . . . . . . . . . . . . . . . 43
2.8 Mechanistic Design . . . . . . . . . . . . . . . . . . . . . . . . . . 43
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2.8.1 Collaboration Between the Hardware and the Reactive
Objects. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
2.8.2 CollaborationBetweentheReactiveObjectsandtheUser
Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
2.8.3 Pattern: Reactive Subject . . . . . . . . . . . . . . . . . . 44
2.8.4 Scheduler . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
2.8.5 Changing the Time . . . . . . . . . . . . . . . . . . . . . . 46
2.8.6 Playing a Message . . . . . . . . . . . . . . . . . . . . . . 47
2.9 Detailed Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
2.9.1 Objects Modeling the Hardware . . . . . . . . . . . . . . 47
2.9.2 Sound Compression Algorithm . . . . . . . . . . . . . . . 49
2.9.3 Using Direct Memory Access Channels . . . . . . . . . . . 49
2.9.4 Memory Allocation . . . . . . . . . . . . . . . . . . . . . . 52
2.10 Comments on the Implementation . . . . . . . . . . . . . . . . . 52
2.11 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
3 Analyzing Use Case Models as Contracts 57
3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
3.2 Use Cases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
3.2.1 Why Use Cases? . . . . . . . . . . . . . . . . . . . . . . . 60
3.3 Contracts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
3.4 Example: Library . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
3.5 Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
3.5.1 Proving properties . . . . . . . . . . . . . . . . . . . . . . 77
3.6 Related Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
3.7 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
4 Statecharts 87
4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
4.2 Structure of State Machines . . . . . . . . . . . . . . . . . . . . . 88
4.3 Dynamics of State Machines . . . . . . . . . . . . . . . . . . . . . 94
4.3.1 Calculation of the Step . . . . . . . . . . . . . . . . . . . 95
4.3.2 The Run-To-Completion Step . . . . . . . . . . . . . . . . 99
4.3.3 Other model elements . . . . . . . . . . . . . . . . . . . . 103
4.4 Interaction diagrams . . . . . . . . . . . . . . . . . . . . . . . . . 103
4.4.1 Particular Comments on the Semantics . . . . . . . . . . 104
4.5 Conclusions and Related work . . . . . . . . . . . . . . . . . . . . 105
5 Veriflcation of Collaborations of Statecharts 107
5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
5.2 Modeling Concurrent Systems with Statecharts . . . . . . . . . . 108
5.2.1 Describing Properties of a Model . . . . . . . . . . . . . . 111
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5.2.2 Collaboration of objects . . . . . . . . . . . . . . . . . . . 113
5.3 The vUML Tool . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
5.3.1 Open Models . . . . . . . . . . . . . . . . . . . . . . . . . 116
5.3.2 Structure of the PROMELA Model . . . . . . . . . . . . . 117
5.3.3 Veriflcation with SPIN . . . . . . . . . . . . . . . . . . . . 122
5.3.4 Representation of Counter-Examples . . . . . . . . . . . . 123
5.4 Example: The Production Cell . . . . . . . . . . . . . . . . . . . 124
5.4.1 Modeling the Press . . . . . . . . . . . . . . . . . . . . . . 126
5.4.2 Modeling the robot . . . . . . . . . . . . . . . . . . . . . . 129
5.4.3 Veriflcation . . . . . . . . . . . . . . . . . . . . . . . . . . 130
5.5 Conclusions and Related Work . . . . . . . . . . . . . . . . . . . 133
5.5.1 Evaluation of the tool . . . . . . . . . . . . . . . . . . . . 133
5.5.2 Related work . . . . . . . . . . . . . . . . . . . . . . . . . 135
6 Real-Time and Hybrid Behavior in Statecharts 137
6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
6.2 Hybrid Statecharts . . . . . . . . . . . . . . . . . . . . . . . . . . 138
6.3 Action Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
6.4 Continuous Action Systems . . . . . . . . . . . . . . . . . . . . . 143
6.4.1 Semantics of Continuous Action Systems . . . . . . . . . 145
6.4.2 Systems Using Difierential Equations . . . . . . . . . . . . 148
6.4.3 Real-Time Systems . . . . . . . . . . . . . . . . . . . . . . 148
6.4.4 Composition of Continuous Action Systems . . . . . . . . 148
6.5 From Statecharts to Continuous Action Systems . . . . . . . . . 149
6.5.1 Transitions . . . . . . . . . . . . . . . . . . . . . . . . . . 151
6.5.2 Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
6.6 Safety Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
6.6.1 Proving the Safety of the Press . . . . . . . . . . . . . . . 156
6.7 Conclusions and Related Work . . . . . . . . . . . . . . . . . . . 161
7 Conclusions 163
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