conn에 msg를 쓰는 쓰레드 단일화

wshandler/room.go

@@ -14,16 +14,18 @@ type room struct {
 	messageChan chan *UpstreamMessage
 	name        string
 	destroyChan chan<- string
+	sendMsgChan chan<- send_msg_queue_elem
 }
 
 // 만약 destroyChan가 nil이면 room이 비어도 파괴되지 않는다. 영구 유지되는 room
-func makeRoom(name string, destroyChan chan<- string) *room {
+func makeRoom(name string, destroyChan chan<- string, sendMsgChan chan<- send_msg_queue_elem) *room {
 	return &room{
 		inChan:      make(chan *wsconn, 10),
 		outChan:     make(chan *wsconn, 10),
 		messageChan: make(chan *UpstreamMessage, 100),
 		name:        name,
 		destroyChan: destroyChan,
+		sendMsgChan: sendMsgChan,
 	}
 }
 
@@ -85,7 +87,11 @@ func (r *room) loop(ctx context.Context, conns *map[string]*wsconn) (normalEnd b
 			bt, _ := json.Marshal(ds)
 
 			for _, conn := range *conns {
-				conn.Conn.WriteMessage(websocket.TextMessage, bt)
+				r.sendMsgChan <- send_msg_queue_elem{
+					to:  conn,
+					mt:  websocket.TextMessage,
+					msg: bt,
+				}
 			}
 		}
 	}