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,
+				}
 			}
 		}
 	}

wshandler/wshandler.go

@@ -93,6 +93,12 @@ type EventReceiver interface {
 	OnRoomDestroyed(region, name string)
 }
 
+type send_msg_queue_elem struct {
+	to  *wsconn
+	mt  int
+	msg []byte
+}
+
 type subhandler struct {
 	redisMsgChanName  string
 	redisCmdChanName  string
@@ -100,6 +106,7 @@ type subhandler struct {
 	connInOutChan     chan *wsconn
 	deliveryChan      chan any
 	localDeliveryChan chan any
+	sendMsgChan       chan send_msg_queue_elem
 	callReceiver      EventReceiver
 	connWaitGroup     sync.WaitGroup
 	region            string
@@ -151,6 +158,23 @@ func NewWebsocketHandler() (*WebsocketHandler, error) {
 			return nil, err
 		}
 
+		sendchan := make(chan send_msg_queue_elem, 1000)
+		go func() {
+			sender := func(elem *send_msg_queue_elem) {
+				defer func() {
+					r := recover()
+					if r != nil {
+						logger.Println(r)
+					}
+				}()
+				elem.to.WriteMessage(elem.mt, elem.msg)
+			}
+
+			for elem := range sendchan {
+				sender(&elem)
+			}
+		}()
+
 		sh := &subhandler{
 			redisMsgChanName:  fmt.Sprintf("_wsh_msg_%s", region),
 			redisCmdChanName:  fmt.Sprintf("_wsh_cmd_%s", region),
@@ -158,6 +182,7 @@ func NewWebsocketHandler() (*WebsocketHandler, error) {
 			connInOutChan:     make(chan *wsconn),
 			deliveryChan:      make(chan any, 1000),
 			localDeliveryChan: make(chan any, 100),
+			sendMsgChan:       sendchan,
 			region:            region,
 		}
 
@@ -336,7 +361,7 @@ func (sh *subhandler) mainLoop(ctx context.Context) {
 	findRoom := func(name string, create bool) *room {
 		room := rooms[name]
 		if room == nil && create {
-			room = makeRoom(name, roomDestroyChan)
+			room = makeRoom(name, roomDestroyChan, sh.sendMsgChan)
 			rooms[name] = room
 			room.start(ctx)
 			go sh.callReceiver.OnRoomCreated(sh.region, name)
@@ -370,8 +395,11 @@ func (sh *subhandler) mainLoop(ctx context.Context) {
 							Body:  usermsg.Body,
 							Tag:   usermsg.Tag,
 						})
-
-						conn.WriteMessage(websocket.TextMessage, ds)
+						sh.sendMsgChan <- send_msg_queue_elem{
+							to:  conn,
+							mt:  websocket.TextMessage,
+							msg: ds,
+						}
 						break
 					}
 				}
@@ -439,7 +467,11 @@ func (sh *subhandler) mainLoop(ctx context.Context) {
 							Body:  usermsg.Body,
 							Tag:   usermsg.Tag,
 						})
-						conn.WriteMessage(websocket.TextMessage, ds)
+						sh.sendMsgChan <- send_msg_queue_elem{
+							to:  conn,
+							mt:  websocket.TextMessage,
+							msg: ds,
+						}
 					}
 				}