go runtime_error ai_generated true

fatal error: concurrent map writes

ID: go/panic-concurrent-map-write

Also available as: JSON · Markdown · 中文
80%Fix Rate
90%Confidence
0Evidence
2024-05-20First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
1.0+ active — — —

Root Cause

Two goroutines mutate the same map without synchronization; the runtime detects the race and aborts.

generic

中文

两个 goroutine 在无同步的情况下同时修改同一个 map，运行时检测到竞态并中止。

Workarounds

  1. 90% success 
    var m sync.Map
m.Store("k", 1)
v, _ := m.Load("k")
  2. 95% success 
    var mu sync.RWMutex
mu.Lock()
m[k] = v
mu.Unlock()

Dead Ends

Common approaches that don't work:

  1. 85% fail

    Narrows the race window but does not eliminate it; still fatal under load.

  2. 80% fail

    atomic.Value requires whole-value replacement; concurrent in-place writes still race.