🚑 Fix concurrent writes in websocket connection

api.go

@@ -14,6 +14,7 @@ var upgrader = websocket.Upgrader{}
 
 type WsClient struct {
 	SendUpdates bool
+	WriteMutex  *sync.Mutex
 }
 
 var wsClientsMutex = new(sync.Mutex)
@@ -405,7 +406,9 @@ func wsSendRes(conn *websocket.Conn, res gin.H, err gin.H, request *WebsocketMes
 			RequestMethod: request.Method,
 			ResponseData:  err,
 		})
+		wsClients[conn].WriteMutex.Lock()
 		conn.WriteMessage(1, data)
+		wsClients[conn].WriteMutex.Unlock()
 		return
 	}
 
@@ -420,7 +423,9 @@ func wsSendRes(conn *websocket.Conn, res gin.H, err gin.H, request *WebsocketMes
 	}
 
 	data, _ := json.Marshal(response)
+	wsClients[conn].WriteMutex.Lock()
 	conn.WriteMessage(1, data)
+	wsClients[conn].WriteMutex.Unlock()
 }
 
 func handleWs(c *gin.Context) {
@@ -431,7 +436,7 @@ func handleWs(c *gin.Context) {
 	}
 
 	wsClientsMutex.Lock()
-	wsClients[conn] = WsClient{SendUpdates: false}
+	wsClients[conn] = WsClient{SendUpdates: false, WriteMutex: new(sync.Mutex)}
 	wsClientsMutex.Unlock()
 
 	for {
@@ -481,7 +486,9 @@ func onPortChange(port *Port) {
 			continue
 		}
 		jsonData, _ := json.Marshal(WebsocketResponse{Type: "portChange", ResponseData: port})
+		wsClients[conn].WriteMutex.Lock()
 		conn.WriteMessage(1, jsonData)
+		wsClients[conn].WriteMutex.Unlock()
 	}
 	wsClientsMutex.Unlock()
 }
@@ -496,7 +503,9 @@ func onPortListChange() {
 			Type:         "portListChange",
 			ResponseData: gin.H{"inputs": portConfig.Input, "outputs": portConfig.Output},
 		})
+		wsClients[conn].WriteMutex.Lock()
 		conn.WriteMessage(1, jsonData)
+		wsClients[conn].WriteMutex.Unlock()
 	}
 	wsClientsMutex.Unlock()
 }