1. File Locking
3. Typical Use of File Locking
4. Trap #1: LOCK_UN
5. Trick #1: Unlocking
6. Trick #2: Only one process running at a time
7. Trap #2: Failing to check for failure
8. Trick #3: Warning when Waiting
9. Trap #3: Shutting the Barn Door etc.
12. Thank You!