Patterns and Anti-Patterns: History and accomplished work

Transcription

1 Architecture and Urban Design Patterns and Anti-Patterns: History and accomplished work Venera Arnaoudova E cole Polytechnique de Montre al, Que bec, Canada March 5th, 2013 Venera Arnaoudova March 5th, / 21

2 Christopher Alexander Christopher Alexander His work Why patterns? What is a Pattern? What is a Pattern Language? Who is he? Born in 1936 in Vienna, Austria Architect Image from wikipedia.org Emeritus Professor of Architecture at the University of California, Berkeley Venera Arnaoudova March 5th, / 21

3 Architecture and Urban Design Christopher Alexander His work Why patterns? What is a Pattern? What is a Pattern Language? Christopher Alexander and his work Images from Venera Arnaoudova March 5th, / 21

4 Why patterns? Architecture and Urban Design Christopher Alexander His work Why patterns? What is a Pattern? What is a Pattern Language? You have a problem? Maybe there is a solution out there Built on experience By experts Venera Arnaoudova March 5th, / 21

5 What is a Pattern? Architecture and Urban Design Christopher Alexander His work Why patterns? What is a Pattern? What is a Pattern Language? What is a Pattern? A recurring problem The core of the solution to that problem You can use this solution a million times over, without ever doing it the same way twice. [Alexander et al., 1977] Image Example Entrance transition Venera Arnaoudova March 5th, / 21

6 What is a Pattern Language? Christopher Alexander His work Why patterns? What is a Pattern? What is a Pattern Language? Entrance transition Intimacy Gradient... Light on two sides of every room... Venera Arnaoudova March 5th, / 21

7 (DPs) Who introduced them? What is a Software Design Pattern? Architectural vs Introduced Interfaces in Smalltalk [Beck and Cunningham, 1987] C++ Idioms [Coplien, 1992] ET++ [Gamma, 1992] First draft in ECOOP in 1993 by Gamma et al. Popularized Design Patterns: Elements of Reusable Object-Oriented Software, by GoF [Gamma et al., 1994] 23 solutions to common software design problems Venera Arnaoudova March 5th, / 21

8 Who introduced them? What is a Software Design Pattern? Architectural vs What is a Software Design Pattern? A recurring design problem in object-oriented systems A general design solution that addresses this problem Purpose Creational Structural Behavioral Scope Class Object Venera Arnaoudova March 5th, / 21

9 Who introduced them? What is a Software Design Pattern? Architectural vs Architectural... CA Top down approach - pattern language Each pattern sits at the center of a network of connections which connect it to certain other patterns that help to complete it... and it is the network of these connections between patterns which creates the language [Alexander, 79] Software... GoF Bottom up approach - micro-architectures If you have a problem, we have the solution for that, but we don t have the next step. [Gamma, 05] Venera Arnaoudova March 5th, / 21

10 Detection Architecture and Urban Design Detection Experience in industry Maintenance Fault and Change proneness Pattern detection for Smalltalk programs [Brown, 96] Pat system [Krämer and Prechelt, 96] Metrics and graph (AOL) [Antoniol et al., 98, 01] Columbus-Maisa [Ferenc et al., 02] Constraint programming [Guéhéneuc et al., 01, 04, 08] Static and dynamic analysis [Heuzeroth et al., 02, 03] Similarity scoring between graph vertices [Tsantalis, 06] DPRE [Costagliola et al., 05], [De Lucia et al., 09] LAMBDES-DP [Bayley and Zhu, 10] Venera Arnaoudova March 5th, / 21

11 Experience in Industry Detection Experience in industry Maintenance Fault and Change proneness Patterns sound very promising, but how are they actually used in the industry and what benefits, if any, do they bring in practice? [Beck et al., 1996] [Beck et al., 1996] Kent Beck, Ron Crocker, Gerard Meszaros, John Vlissides, James O. Coplien, Lutz Dominick, and Frances Paulisch. Industrial experience with design patterns (ICSE 96) Venera Arnaoudova March 5th, / 21

12 Maintenance Architecture and Urban Design Detection Experience in industry Maintenance Fault and Change proneness Controlled experiments DP versus simpler solutions for maintenance tasks [Prechelt et al., 01] Explicit documentation [Prechelt et al., 02] Replications with variations [Vokáč et al., 2004], [Krein et al., 11], [Gravino et al., 11, 12] Impact of Visitor on modification tasks and comprehension (eye-tracker) [Jeanmart et al., 09] Different DP representations in UML class diagrams for comprehension (eye-tracker) [Porras and Guéhéneuc, 10] Venera Arnaoudova March 5th, / 21

13 Maintenance Architecture and Urban Design Detection Experience in industry Maintenance Fault and Change proneness Re-engineering Re-classification [Tahvildari and Kontogiannis, 2002] Maintainability Impact of DP on maintainability (as defined by ISO/IEC 9126 standard) [Hegedűs et al., 2012] Opinion of Experts On the help of DP during maintenance [Khomh and Guéhéneuc, 2008] Venera Arnaoudova March 5th, / 21

14 Fault and Change Proneness Detection Experience in industry Maintenance Fault and Change proneness Fault proneness Defect rate of classes [Vokáč, 2004] Do Maintainers Utilize Deployed Design Patterns Effectively? [Ng et al., 2007] Change proneness Do DP promote adaptable and reusable code? [Bieman, 03] Type, frequency of changes, co-changes [Aversano et al., 07] Roles played in DP and change proneness [Di Penta et al., 08] Venera Arnaoudova March 5th, / 21

15 Software Anti-Patterns Introduced... Patterns and Anti-Patterns [Koenig, 1995] Pitfalls Of Object Oriented Development [Webster, 1995] Popularized... AntiPatterns: Refactoring Software, Architectures, and Projects in Crisis [Brown et al., 1998] AntiPatterns clarify problems for software developers, architects, and managers by identifying the symptoms and consequences that lead to the dysfunctional software development processes. [Brown et al., 1998] Venera Arnaoudova March 5th, / 21

16 Anti-Patterns What is an Anti-Pattern? A problem Types A recurring solution that addresses this problem but with negative consequences A refactored good solution Architectural Design Management Venera Arnaoudova March 5th, / 21

17 Detection Architecture and Urban Design Detection Relation with quality jcosmo [Van Emden and Moonen, 02] PRODEOOS, iplasma [Marinescu et al., 01, 02, 04, 05] Van [Raţiu et al., 04] DECOR, DETEX [Moha et al., 10] IDS [Hassaine et al., 10] BDETEX [Khom et al., 09, 11] SMURF [Maiga et al., 12] Venera Arnaoudova March 5th, / 21

18 Relation with Quality Detection Relation with quality Understandability and maintainability [Deligiannis et al., 03, 04] Program comprehension [Bois et al., 06], [Abbes et al., 11] Change proneness [Khom et al., 09, 11], [Olbrich et al. 09], [Romano et al., 12] Fault proneness [Wei and Shatnawi, 07], [Khom et al., 11] Track the evolution [Raţiu et al., 04], [Vaucher et al., 09] Relations with patterns [Jaafar, 13] Venera Arnaoudova March 5th, / 21

19 Only a small subset of pattern families Requirement [Duran, 99], [Withall, 07] Architectural [Gamma et al., 94], [Fowler, 02] Design [Gamma et al, 94] Testing [Binder, 94], [Meszaros, 07] User Interface [Tidwell, 02, 10], [Duyne, 03] SOA [Rotem-Gal-Oz, 12], [Erl et al., 12] SQL [Tropashko, 07] Security [Wheeler, 99], [Bishop, 03] Venera Arnaoudova March 5th, / 21

20 Only a small subset of AP families Architectural, design [Brown et al., 98, 99, 00] Java, J2EE [Tate, 02], [Tate et al., 03], [Dudney et al., 03] Performance [Smith, 03] Requirement [Shoemaker, 07] SQL [Karwin, 10] API: API Evolution [Kim et al., 2007], Python API Design [Martelli, 11], Web API Evolution [Daigneau, 12] Linguistic [Abebe et al., 09], [Arnaoudova et al., 10, 13] Venera Arnaoudova March 5th, / 21

21 Thank you for your attention! Venera Arnaoudova March 5th, / 21