python runtime_error ai_generated true

asyncio.exceptions.TimeoutError: Lock acquire timed out

ID: python/asyncio-lock-acquire-timeout

Also available as: JSON · Markdown · 中文
80%Fix Rate
84%Confidence
0Evidence
2024-12-01First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
3.9 active — — —
3.10 active — — —

Root Cause

A coroutine tried to acquire an asyncio.Lock with a timeout, but the lock was not released within that time.

generic

中文

协程尝试使用超时获取 asyncio.Lock，但锁未在指定时间内释放。

Workarounds

  1. 95% success Use async with for lock to ensure automatic release 
    async with lock:
    # critical section
  2. 85% success Implement a retry mechanism with backoff 
    async def acquire_with_retry(lock, timeout=5):
    for i in range(3):
        try:
            await asyncio.wait_for(lock.acquire(), timeout=timeout)
            return
        except asyncio.TimeoutError:
            await asyncio.sleep(1)

Dead Ends

Common approaches that don't work:

  1. Increasing the timeout indefinitely 40% fail

    This may cause the application to hang if the lock is never released.

  2. Using a try-finally block without ensuring release on cancellation 60% fail

    If the coroutine is cancelled, the lock may not be released, causing deadlocks.