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

Your job is to deliver code you have proven to work - 18th December 2025
Gemini 3 Flash - 17th December 2025
I ported JustHTML from Python to JavaScript with Codex CLI and GPT-5.2 in 4.5 hours - 15th December 2025

conditions 1 effbot 4 events 108 fredrik-lundh 7 locks 1 python 1216 rlocks 1 semaphores 1 threads 18 tutorial 18

Monthly briefing

Sponsor me for $10/month and get a curated email digest of the month's most important LLM developments.

Pay me to send you less!

Sponsor & subscribe