go runtime_error ai_generated true

panic: send on closed channel

ID: go/channel-close-on-sender-panic

Also available as: JSON · Markdown · 中文
80%Fix Rate
82%Confidence
0Evidence
2024-05-20First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
1.20 active — — —

Root Cause

Sending to a channel after it has been closed causes a runtime panic.

generic

中文

在通道关闭后向其发送数据会导致运行时恐慌。

Workarounds

  1. 85% success 
    ch := make(chan int)
close(ch)
// Use select with a done channel to avoid sending after close
select {
case ch <- 1:
default:
    fmt.Println("channel closed")
}
  2. 90% success 
    var mu sync.RWMutex
closed := false
// In sender:
mu.RLock()
if !closed { ch <- 1 }
mu.RUnlock()
// In closer:
mu.Lock()
close(ch)
closed = true
mu.Unlock()

Dead Ends

Common approaches that don't work:

  1. 60% fail

    Recovery doesn't prevent data loss or inconsistency; the sender state is corrupted.

  2. 80% fail

    len() doesn't indicate closed status; a closed channel can still have buffered items.

  3. 50% fail

    Mutex doesn't prevent closing while sending; race condition remains.