go channel select如何屏蔽已关闭通道

go channel select如何屏蔽已关闭通道(如果不屏蔽的话，select 一直会处于选择状态)

func main() {
    channel := make(chan int ,20)
    selectChannel(channel)
    getChannel(channel)
    time.Sleep(time.Hour)
}

func selectChannel(channel chan  int)  {
    go func() {
        for{
            select{
                case _,ok := <- channel:
                    if !ok{
                        fmt.Println("channel is close")
                        channel = make(chan int) //设置为非缓冲通道已做阻塞
                        time.Sleep(time.Second)
                    }
            }
        }
    }()
}

func getChannel(channel chan  int)  {
    go func() {
        channel <- 2
        close(channel)
    }()
}