go runtime_error ai_generated true

panic: WaitGroup 在上次 Wait 返回前被重用

panic: sync: WaitGroup is reused before previous Wait has returned

ID: go/waitgroup-added-after-wait

其他格式: JSON · Markdown 中文 · English

80%修复率

88%置信度

0证据数

2024-04-22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

在一个 goroutine 阻塞于 wg.Wait() 期间，另一个 goroutine 调用了 wg.Add()，或 WaitGroup 在未同步的情况下跨批次重用。

English

wg.Add() was called from a goroutine while another goroutine was blocked in wg.Wait(), or the WaitGroup was reused across batches without synchronization.

generic

解决方案

97% 成功率

var wg sync.WaitGroup
for _, item := range items {
    wg.Add(1)
    go func(it Item) {
        defer wg.Done()
        process(it)
    }(item)
}
wg.Wait()

93% 成功率

for _, batch := range batches {
    var wg sync.WaitGroup
    for _, x := range batch {
        wg.Add(1)
        go func(v X) { defer wg.Done(); work(v) }(x)
    }
    wg.Wait()
}

无效尝试

常见但无效的做法:

75% 失败
The ordering of Add vs Wait is the actual constraint; moving Wait just changes where the race manifests and can cause premature return.
80% 失败
No happens-before guarantee; under load the Add still races with Wait.