func doSomething() {

    var i int

    for {

        i++

    }

}

func main() {

    cpu := runtime.NumCPU()

    fmt.Println("本机cpu核数:", cpu)

    fmt.Println("输入模拟的cpu数：")

    reader := bufio.NewReader(os.Stdin)

    buf, _ := reader.ReadBytes('\n')

    cmdStr := (string)(buf)

    num, err := strconv.Atoi(strings.Trim(cmdStr, "\r\n"))

    if err != nil || num > cpu || num <=  {

        fmt.Println("输入的数字不正确 err:{0}", err)

        return

    }

    //设置核数

    runtime.GOMAXPROCS(num)

    for i := ; i < ; i++ {

        //做个死循环

        go doSomething()

    }

    fmt.Println("程序已经开始执行")

    time.Sleep(time.Second * )

    for j := ; j > ; j-- {

        fmt.Printf("程序倒计时退出: %ds...\n", j)

        time.Sleep(time.Second)

    }

    fmt.Printf("程序退出")

}