An Introduction to SCM GForge.ppt

An Introduction to SCM & e
Lin Guo
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1
Roadmap
What is SCM
Why do we need SCM
Interesting SCM features
SCM tools
e
Conclusion
2
What is SCM
Source Control Management
Maintain a repository of source files
Track all changes
Control changes
Software Configuration Management
More than source control
Manage source repositories
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Why we need SCM
Source Control
Sharing: supports concurrent development
Versioning: provide version number and dates
Change tracking: find details of a change
Archival: reproduce any file from any point
Documentation, drawing, etc.
Configuration Management
Branch: release version vs. develop version
Snapshot of the whole system
Prohibit further check-in before release
4
Roadmap
What is SCM
Why do we need SCM
Interesting SCM features
Source control vocabulary
Code Sharing
Branch
Label
SCM tools
e
Conclusion
5
Source Control Vocabulary
Update: obtain the latest versions of the code
Check-out: obtain the writable version of files
Check-in: commit the changes to files
Lock/unlock: one only person may modify a file
Integrate: combines the changes with others’
Add/delete: add/remove files to repositories
Top-of-trunk: most updated
6
Roadmap
What is SCM
Why do we need SCM
Interesting SCM features
Source control vocabulary
Code Sharing
Lock
Sharing
SCM tools
e
Conclusion
7
Code Sharing
Multiple people can work on the same source base without colliding ---
(1) Lock: locks individual files so only one person at a time can modify it or
(2) Merge: Allows multiple people to modify a source file and the system will automatically merge the changes (usually)
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Locking
Only one person can modify certain source files.
Works fairly well if developers work on different areas of the project and don’t conflict often
Problem 1: People forget to unlock files when they are done
Problem 2: People work around locking by editing a private copy and checking in when the file is finally unlocked - easy to lose changes.
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Me