ping

app/echo.go

@@ -1,6 +1,8 @@
 package main
 
 import (
+	"fmt"
+	"time"
 	"net/http"
 
 	"github.com/gorilla/websocket"
@@ -24,23 +26,38 @@ var (
 		Count chan int
 		Send  chan []byte
 		Add   chan *websocket.Conn
+		Del   chan *websocket.Conn
 	}{
 		Count: make(chan int, 100),
 		Send:  make(chan []byte, 100),
 		Add:   make(chan *websocket.Conn, 100),
+		Del:   make(chan *websocket.Conn, 100),
 	}
 )
 
 func broadcast() {
+	ticker := time.NewTicker(30 * time.Second)
 	for {
 		select {
 		case conn := <-ws.Add:
 			wsClients[conn] = struct{}{}
 
+		case conn := <-ws.Del:
+			delete(wsClients, conn)
+
 		case <-ws.Count:
 			ws.Count <- len(wsClients)
 
 		case message := <-ws.Send:
+			sendMessage(message)				
+			
+		case <-ticker.C:
+			sendMessage([]byte("ping"))
+		}
+	}
+}
+
+func sendMessage(message []byte) {
 	for conn := range wsClients {
 		if err := conn.WriteMessage(1, message); err != nil {
 			conn.Close()
@@ -48,13 +65,29 @@ func broadcast() {
 		}
 	}
 }
-	}
-}
 
 func wsHandler(w http.ResponseWriter, r *http.Request) {
 	conn, err := upgrader.Upgrade(w, r, nil)
 	if err != nil {
 		return
 	}
-	ws.Add <- conn
+	go readWS(conn)
+}
+
+func readWS(conn *websocket.Conn) {
+	defer conn.Close()
+	
+	ws.Add <- conn
+	
+	defer func() {
+		ws.Del <- conn
+	}()
+	
+	for {
+		_, _, err := conn.ReadMessage()
+		if err != nil {
+			fmt.Println("readWS", err.Error())
+			return
+		}
+	}
 }