go runtime_error ai_generated true

fatal error: concurrent map read and map write

ID: go/panic-concurrent-map-read-write

Also available as: JSON · Markdown · 中文
80%Fix Rate
90%Confidence
0Evidence
2024-06-08First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
1.0+ active — — —

Root Cause

One goroutine reads a map while another writes to it without synchronization.

generic

中文

一个 goroutine 读取 map 的同时另一个 goroutine 在写入，且没有同步保护。

Workarounds

  1. 95% success 
    mu.RLock()
v := m[k]
mu.RUnlock()
  2. 90% success 
    var m sync.Map
if v, ok := m.Load(k); ok { _ = v }

Dead Ends

Common approaches that don't work:

  1. 85% fail

    Copy itself races with the writer; the fatal error still fires during copy.

  2. 95% fail

    Go does not serialize concurrent map access; runtime deliberately aborts.