Simon Willison’s Weblog

Thread Synchronization Mechanisms in Python. Locks, RLocks, Semaphores, Events and Conditions as explained by Fredrik Lundh.

Posted 29th July 2007 at 9:32 pm

Recent articles

Introducing Showboat and Rodney, so agents can demo what they’ve built - 10th February 2026
How StrongDM's AI team build serious software without even looking at the code - 7th February 2026
Running Pydantic's Monty Rust sandboxed Python subset in WebAssembly - 6th February 2026

conditions 1 effbot 4 events 108 fredrik-lundh 7 locks 1 python 1227 rlocks 1 semaphores 1 threads 18 tutorial 18

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