python runtime_error ai_generated true

asyncio.exceptions.CancelledError:

ID: python/asyncio-cancellederror-not-handled

其他格式: JSON · Markdown 中文 · English
80%修复率
86%置信度
0证据数
2024-05-21首次发现

版本兼容性

版本状态引入弃用备注
3.8+ active — — —
3.9+ active — — —
3.10+ active — — —
3.11+ active — — —
3.12+ active — — —

根因分析

某个任务被取消（超时、关闭或父任务取消），CancelledError 未被捕获并传播，通常被记录为未处理的任务异常。

English

A task was cancelled (timeout, shutdown, or parent cancellation) and the CancelledError propagated uncaught, often logged as an unhandled task exception.

generic

解决方案

  1. 95% 成功率 
    try:
    await long_running()
except asyncio.CancelledError:
    await cleanup()
    raise
  2. 90% 成功率 
    tasks = [asyncio.create_task(w(i)) for i in range(5)]
try:
    await asyncio.gather(*tasks)
except asyncio.CancelledError:
    for t in tasks:
        t.cancel()
    raise

无效尝试

常见但无效的做法:

  1. 85% 失败

    Swallowing cancellation breaks structured concurrency; the parent expects the task to stop.

  2. 80% 失败

    Shield everywhere defeats cancellation and leaves tasks running after shutdown.