sync.WaitGroup doesnt waits

Question

May be I can not see obvious thing, what am I doing wrong:

func printSize (listOfUrls []string){
    var wg sync.WaitGroup
    wg.Add(len(listOfUrl))
    for         


        

Answer 1

All of the goroutines are sharing the single myurl variable. See https://golang.org/doc/faq#closures_and_goroutines for more information.

Change the code to:

func f(listOfUrls []string){
  var wg sync.WaitGroup
  wg.Add(len(listOfUrl))
  for _, myurl := range(listOfUrls){
    go func(myurl string){
           body := getUrlBody(myurl)
           fmt.Println(len(body))
           wg.Done()
       }(myurl)    
  } 
  wg.Wait()
}

or

func f(listOfUrls []string){
  var wg sync.WaitGroup
  wg.Add(len(listOfUrl))
  for _, myurl := range(listOfUrls){
    myurl := myurl
    go func(){
           body := getUrlBody(myurl)
           fmt.Println(len(body))
           wg.Done()
       }()    
  } 
  wg.Wait()
}