关于Go中Channel和Goroutine实现工作池的问题

**如代码所示，十个下载任务，三个工作池，工作池中线程执行为串行，总运行时间大于任一线程的下载时间，比较可得工作效率比十个goroutine并行低很多，是不是说明工作池的作用只有限制线程数，是不是只有在高并发环境下才适用** ```go package main import ( "fmt" "io" "net/http" "os" "strings" "time" ) func main() { t1 := time.Now() Queue := make(chan error, 10) result := make(chan string, 10) //十个任务 urls := []string{ "http://dlsw.baidu.com/sw-search-sp/soft/44/17448/Baidusd_Setup_4.2.0.7666.1436769697.exe", "http://dlsw.baidu.com/sw-search-sp/soft/3a/12350/QQ_V7.4.15197.0_setup.1436951158.exe", "http://dlsw.baidu.com/sw-search-sp/soft/9d/14744/ChromeStandalone_V43.0.2357.134_Setup.1436927123.exe", "http://dlsw.baidu.com/sw-search-sp/soft/6f/15752/iTunes_V12.2.1.16_Setup.1436855012.exe", "http://dlsw.baidu.com/sw-search-sp/soft/70/17456/BaiduAn_Setup_5.0.0.6747.1435912002.exe", "http://dlsw.baidu.com/sw-search-sp/soft/40/12856/QIYImedia_1_06_v4.0.0.32.1437470004.exe", "http://dlsw.baidu.com/sw-search-sp/soft/42/37473/BaiduSoftMgr_Setup_7.0.0.1274.1436770136.exe", "http://dlsw.baidu.com/sw-search-sp/soft/49/16988/YoudaoNote_V4.1.0.300_setup.1429669613.exe", "http://dlsw.baidu.com/sw-search-sp/soft/55/11339/bdbrowserSetup-7.6.100.2089-1212_11000003.1437029629.exe", "http://dlsw.baidu.com/sw-search-sp/soft/53/21734/91zhushoupc_Windows_V5.7.0.1633.1436844901.exe", } for id := range urls { //遍历下载 result <- urls[id] } for i := 1; i <= 3; i++ { go WorkPool(1, result, Queue) } for i := 1; i <= 10; i++ { fmt.Println(<-Queue) } elapsed := time.Since(t1) fmt.Println("总运行时间", elapsed) } //下载操作 func Download(id int, url string) error { t1 := time.Now() fmt.Println("开始下载。。。", url) sp := strings.Split(url, "/") filename := sp[len(sp)-1] //创建文件夹 file, err := os.Create("static/" + filename) if err != nil { return err } res, err := http.Get(url) if err != nil { return err } lenth, err := io.Copy(file, res.Body) if err != nil { return err } elapsed := time.Since(t1) fmt.Println(id, "线程池中下载完成", filename, "文件大小为", lenth, "下载时间时间", elapsed) return nil } //工作池方法 func WorkPool(id int, result chan string, Queue chan error) { for url := range result { err := Download(id, url) Queue <- err } } ```