18 March

1. 18 March Implementation

2. Tools • Do you need them? • When do you need them? • What can they do better then you?

3. Tools • Version Management • Build Systems • Integrated Development Environments • Documentation Extraction

4. Version Management • Both during and after development • Both code and documentation • Uses • Multi-developer change control • Releases • Support for different environments • Computers • Operating systems

5. Top Reasons for Using Version Management • Bugs which were fixed reappear • Latest versions of code overwritten by old versions • Which version is the right one? I have so many • I have lost my latest changes

6. Questions Addressed • Development Issues • How do we integrate parallel work? • How do I know which changes were in the code that was being tested? • Who changed this module? When? Why? • Multi-version Issues • What versions have been made available to people? • How do I assure that all versions get the changes that they need? • What versions need to be re-released to support changes made?

7. Documentation that Needs Version Control • Manuals: need to reflect the variations of the different releases • Test data: what tests have been run and what was the result • Bug reports • Planned changes • Any document being edited by multiple people

8. Basic Functions • Ability to add and remove changes • Ability to identify differences • Record of changes made • Storage of different versions • Ability to get access to one or more versions • Identification of all the components needed to build any version

9. Need a Baseline • Agreed upon document or code level • in large project, formally reviewed and agreed upon • in your project, requires consensus agreement • Basis for further development • in large project, changed only through formal change control procedure • In your project, changed when the developer is “comfortable”

10. When To Start Using Version Control • Should you use it during unit testing? • What is unit testing? • How much structure does your unit testing require? • If unit testing requires significant infrastructure or scaffolding, it makes sense to start using it very early

11. No Special Tools Needed • Identify procedures and data needed to • add and remove changes • identify differences • record changes made • store different versions • get access to one or more versions • build any version

12. But there are tools … • CVS: Concurrent Version System • Subversion (SVN) • SourceForge • Actually uses CVS and SVN, but a different model

13. Concurrent Versioning System • Developed in the mid 80s • Predecessor RCS (Revision Control System) • Vrije University, Amsterdam • Now open source • Until recently, the most commonly used tool • ximbiot.com/cvs/wiki

14. What CVS Does • Supports hierarchical directories • manages changes on a per file basis • Remote repository access • import locally for use • Supports parallel development • merges changes • identifies, does not resolve, conflicts • Basic tasks • getting a working copy • committing changes • reverting to prior level • adding or removing a file • synchronizing to the latest code • tagging versions of files

15. Subversion • http://subversion.tigris.org/ • improved version of CVS • consistent interfaces except for “compelling reasons” • key changes • everything is versioned: directories and file meta-data as well as files • atomic commits • guarantee that all aspects are completed or none are • better performance

16. SourceForge • Open source development environment • Free web-based facility • Purchasable software as well • SourceForge.net supports • CVS and SVN • Compile farm • Trackers • Web site

17. Lots of Others • Google code • TRAC

18. Tools • Version Management • Build Systems • Integrated Development Environments • Document Extraction

19. Build System Functions • System configuration • Executing • preprocessors • compilers • linkers • Manage paths and libraries • Create executables and libraries

20. Types of Build Systems • Platform • specific • independent • Part of • version management systems • integrated development environments • nothing (standalone)

21. Platform Specific System: Unix make • Uses a makefile • Can build full systems or parts • Defines dependencies • Simplest example: object file depends on its source file • Executes commands for any (and only) pieces that need to be rebuilt

22. Open Source Systems:Lots of Them • GNU make • Been around for a while • Cons • Built in Perl • SCons • Python scripts • CMake • cross-platform • used in conjunction with the native build environment • Jam • C and C++ • See also FT Jam (additional platforms)

23. Apache Ant: build +++ • http://ant.apache.org • Introduction • Workflow elements • XML-based configuration files • Java based • contains features specifically for J2EE

24. Ant Control Commands (sample) • Ant: Runs Ant on a supplied buildfile • AntCall: Runs another target within the same buildfile • Exec: Executes a system command (can be OS specific) • Java: Executes a Java class • Parallel: Forks a new thread for another Ant tasks • Sequential: Grouping of commands • Waitfor: Blocks execution until a set of specified conditions become true

25. Tools • Version Management • Build Systems • Integrated Development Environments • Document Extraction

26. Integrated Development Environment • What is an IDE? • A programming environment integrated into a software application • Normally includes • Source code editor • Compiler and or interpreter • GUI development tools • Build system • May also include • Graphical tools (e.g., class hierarchy diagram) • Debugger • Class browser • Version management system

27. History • Early programming was not done with IDEs • Coding sheets and keypunches • Line command make files • Hardware enhancements • typewriter-like terminals • computer screens • Which of these enabled IDEs? Why?

28. Dartmouth Time Sharing System (1964) • Command line system • Supported Basic, Algol and FORTRAN • DTSS commands: • NEW, OLD, LIST, SAVE, RUN • Line starting with number replaced that line in the current program • All other commands implied execution • Considered by most people the first IDE

29. Today’s IDEs • Menu-driven • Proprietary • Microsoft Visual Studio (C#, C++, Visual BASIC) • Borland JBuilder (Java) • Apple XCode (Mac OS X) • Open Source • SharpDevelop (.NET) • GNU Emacs (Unix) – major modes for languages

30. Eclipse • www.eclipse.org • Both an IDE and an architecture • IDEs • Java, C++, C, C#, Python, PHP, Perl, Smalltalk, CMFL (Coldfusion), Cobol, Fortran, Prolog, Erlang • (you get the idea) • IDE built using architecture • Enhancements through plug-ins

31. Tools • Version Management • Build Systems • Integrated Development Environments • Documentation Extraction

32. What can be extracted? • Documentation • Signatures • Building interfaces first • Initial documentation • Tools avoid update issues • Are there drawbacks?

33. Tools • Doxygen – open source • Javadoc – from Sun

34. Software Engineering Elaborated Steps • Concept • Requirements • Architecture • Design • Implementation • Unit test • Integration • System test • Maintenance

35. Models of Software Development • Process or people oriented • Early Watts Humphrey work: people, later process • Different balances from each model • Number of iterations • Waterfall • Spiral • Agile

36. Software Craftmanship • Software craftsmanship (McBreen 2001) • Craft of writing software • Craft of using software • Distinguish from software engineering • Scope • Rigor • Relevant distinction?