go resource_error ai_generated true

goroutine leak: N goroutines blocked in chan receive (pprof shows [chan receive])

ID: go/goroutine-leak-blocked-receive

Also available as: JSON · Markdown · 中文
80%Fix Rate
87%Confidence
0Evidence
2024-09-03First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
1.0+ active — — —

Root Cause

Workers were started to read from a channel that was never closed and never written to, so they block on receive forever.

generic

中文

启动了从 channel 读取的 worker，但该 channel 从未被关闭也从未写入，导致它们永久阻塞在接收上。

Workarounds

  1. 96% success 
    go func() {
    defer close(ch)
    for _, x := range items { ch <- x }
}()
for v := range ch { process(v) }
  2. 94% success 
    for {
    select {
    case v, ok := <-ch:
        if !ok { return }
        process(v)
    case <-ctx.Done():
        return
    }
}

Dead Ends

Common approaches that don't work:

  1. 60% fail

    If the loop uses for v := range ch, time.After cannot be applied; converting to select changes semantics and still leaks if done incorrectly.

  2. 85% fail

    Masks the leak; goroutine count still grows within the interval and can OOM under bursts.