go runtime_error ai_generated true

fatal error: concurrent slice append

ID: go/goroutine-race-on-slice

Also available as: JSON · Markdown · 中文
80%Fix Rate
88%Confidence
0Evidence
2024-03-01First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
1.20 active — — —
1.21 active — — —

Root Cause

Multiple goroutines append to the same slice concurrently without synchronization, causing data races and potential panics.

generic

中文

多个 goroutine 同时向同一个切片追加数据而没有同步，导致数据竞争和潜在的恐慌。

Workarounds

  1. 95% success 
    var mu sync.Mutex; mu.Lock(); slice = append(slice, item); mu.Unlock()
  2. 90% success 
    ch := make(chan int); go func() { for v := range ch { slice = append(slice, v) } }()

Dead Ends

Common approaches that don't work:

  1. 70% fail

    If slice is also accessed directly, race persists.

  2. 85% fail

    Atomic operations don't help with slice growth; underlying array may be replaced.