请教这段 go 代码哪里造成阻塞

func process_kuaidaili() chan Proxy {
	var wg1 sync.WaitGroup
	result := make(result_list, 500)
	index_url := "https://www.kuaidaili.com/free"
	queue := make(task_list, 10) //change count
	for i := 1; i <= 4; i++ {
		queue <- index_url + "/inha/" + strconv.Itoa(i)
		queue <- index_url + "/intr/" + strconv.Itoa(i)
	}
	fmt.Println(len(queue))
	wg1.Add(len(queue))
	for i := 0; i < len(queue); i++ {
		go func() {
			defer wg1.Done()
            //request 函数传 channel 进去，取出一个 URL 发起请求
			resp := request(queue, "www.kuaidaili.com")		
			defer resp.Body.Close()
			defer fmt.Println("exit")
			doc, _ := goquery.NewDocumentFromResponse(resp)
			doc.Find("tr").Each(func(i int, contentSelection *goquery.Selection) {
				_IP := contentSelection.Find("td").Eq(0).Text()
				if reg_ip.Find([]byte(_IP)) != nil {
					_Port := contentSelection.Find("td").Eq(1).Text()
					_Anonymous := contentSelection.Find("td").Eq(2).Text()
					if _Anonymous == "高匿名" {
						_Anonymous = "1"
					} else {
						_Anonymous = "0"
					}
					_SSL := contentSelection.Find("td").Eq(3).Text()
					if _SSL == "HTTPS" {
						_SSL = "1"
					} else {
						_SSL = "0"
					}
					append_proxy := Proxy{
						IP:        _IP,
						Port:      _Port,
						Anonymous: _Anonymous,
						SSL:       _SSL,
					}
					result <- append_proxy
					fmt.Printf("-----%v------\n", len(result))
				}
			})
		}()
	}
	wg1.Wait()
	fmt.Println("return")
	return result
}

main 函数调用

func main() {
	fmt.Println("start")
	aa := process_kuaidaili()
	fmt.Println(len(aa))
}

程序阻塞，输出：

start
8
https://www.kuaidaili.com/free/inha/1
-----1------
-----2------
-----3------
-----4------
-----5------
-----6------
-----7------
-----8------
-----9------
-----10------
-----11------
-----12------
-----13------
-----14------
-----15------
exit
https://www.kuaidaili.com/free/intr/1
exit
https://www.kuaidaili.com/free/inha/2
exit
https://www.kuaidaili.com/free/intr/2
exit
--*--block here--*--