go 实现timeout功能

package main

import (
	"fmt"
	"math/rand"
	"time"
)

func init() {
	rand.Seed(time.Now().UnixNano())
}

func main() {

	ch1 := make(chan bool)
	timeout := make(chan bool)

	go func() {
		time.Sleep(time.Second * 5)
		ch1 <- true
	}()

	go func() {
		second := rand.Intn(10)
		fmt.Println(second)
		time.Sleep(time.Second * time.Duration(second))
		timeout <- true
	}()

	//select 的 case 里的操作语句只能是【IO 操作】
	select {
	case <-ch1:
		fmt.Print("ch1 timeout")
	case <-timeout:
		fmt.Println("timeout")

	}
}