go runtime_error ai_generated true

fatal error: sync: unlock of unlocked mutex

ID: go/mutex-unlock-of-unlocked

Also available as: JSON · Markdown · 中文
80%Fix Rate
87%Confidence
0Evidence
2024-06-06First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
1.14+ active — — —

Root Cause

mu.Unlock() is called without a matching Lock(), often from a deferred Unlock in a path where Lock was skipped or Unlock ran twice.

generic

中文

在没有匹配 Lock() 的情况下调用 mu.Unlock()，通常发生在 Lock 被跳过的路径中 defer Unlock，或 Unlock 执行了两次。

Workarounds

  1. 94% success 
    mu.Lock()
defer mu.Unlock()
// critical section
  2. 90% success 
    func (s *Store) Get(k string) V {
    s.mu.Lock()
    defer s.mu.Unlock()
    return s.m[k]
}

Dead Ends

Common approaches that don't work:

  1. 85% fail

    Swallowing the fatal error hides the logic bug and can leave the mutex in an inconsistent state.

  2. 80% fail

    TryLock is not a validity check for Unlock and adds races; the double-unlock still occurs.