我創建了一個全局通道，并且每當 ExampleNewWatcher 內部發生新事件時都會向它發送消息。第一次發生事件時，消息會在通道的接收端收到。但是，第二次發生事件時，我在通道的接收端沒有收到消息。var messages = make(chan string)func ExampleNewWatcher(){  watcher, err := fsnotify.NewWatcher()  if err != nil{    log.Fatal(err)  }  defer watcher.Close(0  done := make(chan bool)  go func(){     for {        select{           case event := <- watcher.Events:              if event.Op&fsnotify.Write == fsnotify.Write{                 log.Println("this logs twice if I create two write events")                 messages <- "this message only gets sent once even if I create two events"              }           case err := <- watcher.Errors:               log.Println("error", err)        }     }  }()  err = watcher.Add("/tmp/watchedfile")  <-done}func Websock(ws *websocket.Conn){   msg := <-messages   log.Println("only one message arrives, even if I create for two events", msg)   err := websocket.Message.Send(ws, msg)}func main(){ go ExampleNewWatcher() //for some reason, the server doesn't run unless I prefix a go routine to this watcher function, but that's another issue ...  http.Handle("/websock", websocket.Handler(Websock)) log.Fatal(http.ListenAndServe(":8000", nil))}