go network_error ai_generated true

error: context deadline exceeded (from select ctx.Done())

ID: go/context-deadline-exceeded-in-select

Also available as: JSON · Markdown · 中文
80%Fix Rate
88%Confidence
0Evidence
2024-08-05First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
1.7+ active — — —

Root Cause

A select statement observes ctx.Done() because the parent context's deadline elapsed. The downstream operation is cancelled, but the caller treats it as a generic error.

generic

中文

select 语句观察到 ctx.Done()，因为父上下文的截止时间已到。下游操作被取消，但调用方将其视为通用错误。

Workarounds

  1. 96% success 
    select {
case <-ctx.Done():
    return ctx.Err()
case res := <-ch:
    return res
}
  2. 90% success 
    for i := 0; i < 3; i++ {
    ctx, cancel := context.WithTimeout(parent, 2*time.Second)
    err := call(ctx)
    cancel()
    if err == nil { return nil }
}

Dead Ends

Common approaches that don't work:

  1. 95% fail

    The deadline is fixed; every retry burns the same expired context and returns instantly.

  2. 90% fail

    Callers receive silently wrong results and downstream logic corrupts data.