40 lines
661 B
Go
40 lines
661 B
Go
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package main
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import (
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"context"
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"fmt"
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"sync"
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"time"
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)
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// context.WithTimeout
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var Wg sync.WaitGroup
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func worker(ctx context.Context) {
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LOOP:
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for {
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fmt.Println("db connecting ...")
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time.Sleep(time.Millisecond * 10) // 假设正常连接数据库耗时10毫秒
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select {
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case <-ctx.Done(): // 50毫秒后自动调用
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break LOOP
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default:
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}
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}
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fmt.Println("worker done!")
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Wg.Done()
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}
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func main() {
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// 设置一个50毫秒的超时
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ctx, cancel := context.WithTimeout(context.Background(), time.Millisecond*50)
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Wg.Add(1)
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go worker(ctx)
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time.Sleep(time.Second * 5)
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cancel() // 通知子goroutine结束
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Wg.Wait()
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fmt.Println("over")
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}
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