golang超时写法

一、使用ctx.WithTimeout()

func doWithTimeOut1(timeout time.Duration)string{
	ctx,cancel := context.WithTimeout(context.Background(),timeout)
	defer cancel()
	signal := make(chan int,1)
	go func() {
		time.Sleep(time.Second*3)
		signal <- 1
	}()
	select {
	case <-signal:
		return "singal"
	case <-ctx.Done():
		return "timeout"
	}
}

二、使用time.After()

func doWithTimeOut(timeout time.Duration)string{
	out :=  time.After(timeout)
	signal := make(chan int,1)
	go func() {
		time.Sleep(time.Second*3)
		signal <- 1
	}()
	select {
	case <-signal:
		return "singal"
	case <-out:
		return "timeout"
	}
}

第二种没有第一种更好，应进一步处理未完成的协程，cancel会提前结束由该上下文开启的上下文