go runtime_error ai_generated true

fatal error: all goroutines are asleep - deadlock! (select with no ready case)

ID: go/select-no-case-ready-timeout

Also available as: JSON · Markdown · 中文
80%Fix Rate
88%Confidence
0Evidence
2024-09-01First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
1.0+ active — — —

Root Cause

A select statement has no default and none of its channel cases are ready, and no other goroutine can make them ready, causing a global deadlock.

generic

中文

select 语句没有 default 分支，且其 channel 分支都未就绪，也没有其他 goroutine 能使它们就绪，导致全局死锁。

Workarounds

  1. 90% success 
    Add a timeout case with time.After and return an error on expiry.
  2. 85% success 
    Ensure at least one case is a send that can always proceed, or restructure so the producer runs before the select.

Dead Ends

Common approaches that don't work:

  1. 70% fail

    Busy-looping burns CPU and may still never see data if the producer is also blocked.