python runtime_error ai_generated true

RuntimeError: Semaphore released too many times

ID: python/asyncio-invalid-state-semaphore

Also available as: JSON · Markdown · 中文
80%Fix Rate
84%Confidence
0Evidence
2024-06-20First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
3.8 active — — —
3.9 active — — —
3.10 active — — —

Root Cause

A semaphore was released more times than it was acquired, often due to releasing in a finally block without checking if acquired.

generic

中文

信号量被释放的次数超过了获取次数，通常是由于在 finally 块中释放而未检查是否已获取。

Workarounds

  1. 95% success Use context manager for semaphore to ensure proper acquire/release 
    async with semaphore: await some_coroutine()
  2. 90% success Use a try-finally block with a flag to track acquisition 
    acquired = await semaphore.acquire(); try: await some_coroutine(); finally: if acquired: semaphore.release()

Dead Ends

Common approaches that don't work:

  1. Increasing the initial semaphore value 60% fail

    This masks the bug but does not fix the logic; over-release still occurs.

  2. Using semaphore.acquire() without await 80% fail

    acquire() returns a coroutine; not awaiting it leads to incorrect behavior.