# 恐慌：关闭已关闭的通道

- **ID:** `go/close-channel-multiple-times`
- **领域:** go
- **类别:** runtime_error
- **验证级别:** ai_generated
- **修复率:** 80%

## 根因

尝试关闭一个已经关闭的通道，通常是由于没有同步的并发关闭调用。

## 版本兼容性

| 版本 | 状态 | 引入 | 弃用 |
|------|------|------|------|
| 1.20 | active | — | — |
| 1.21 | active | — | — |

## 解决方案

1. **** (95% 成功率)
   ```
   var closeOnce sync.Once; closeOnce.Do(func() { close(ch) })
   ```
2. **** (90% 成功率)
   ```
   var closed bool; if !closed { close(ch); closed = true }
   ```

## 无效尝试

- **** — Recover only prevents crash but doesn't fix the logic; can mask bugs. (60% 失败率)
- **** — Defer executes on function exit; if close happens earlier, panic occurs. (80% 失败率)