go runtime_error ai_generated true

panic: 重复关闭 channel

panic: close of closed channel

ID: go/close-of-closed-channel

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80%修复率
90%置信度
0证据数
2024-01-19首次发现

版本兼容性

版本状态引入弃用备注
1.0+ active — — —

根因分析

两个 goroutine 都调用了 close(ch)，或函数被重试导致 defer close 执行了两次。Go 在第二次 close 时 panic。

English

Two goroutines both called close(ch), or a deferred close ran twice because the function was retried. Go panics on the second close.

generic

解决方案

  1. 97% 成功率 
    var closeOnce sync.Once
closeOnce.Do(func() { close(ch) })
  2. 95% 成功率 
    // Only the producer closes
func produce(ch chan<- int, n int) {
    defer close(ch)
    for i := 0; i < n; i++ { ch <- i }
}

无效尝试

常见但无效的做法:

  1. 80% 失败

    The flag itself is racy without a mutex; two goroutines can both read false and both call close.

  2. 60% 失败

    If the main goroutine is not the sole owner or the function can run concurrently, this does not guarantee single close.