Asynchronous http request in golang

async_get.go

type HttpResp struct {
    Id   string
    Resp *http.Response
    Err  error
}
 
func AsyncGet(urls map[string]string) []*HttpResp {
    ch := make(chan *HttpResp)
    responses := []*HttpResp{}
 
    for track_id, url := range urls {
 
        go func(i, u string) {
            resp, err := http.Get(u)
            ch <- &HttpResp{i, resp, err}
        }(track_id, url)
    }
 
loop:
    for {
        select {
        case r := <-ch:
            responses = append(responses, r)
            if len(responses) == len(urls) {
                break loop
            }
        case <-time.After(50 * time.Millisecond):
            fmt.Printf(".")
        }
    }
    return responses
}