Fix data race

Kotlin-Elective-at-HSE · Feb 6, 2020 · 7bd0884 · 7bd0884
1 parent fd5f44d
commit 7bd0884
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/src/Main.kt b/src/Main.kt
@@ -8,7 +8,9 @@ class ChatServer(port: Int) : WebSocketServer(InetSocketAddress(port)) {
     private var nextId = 0
 
     override fun onOpen(connection: WebSocket, handshake: ClientHandshake?) {
-        val id = ++nextId
+        val id = synchronized(this) {
+            ++nextId
+        }
 
         val message = "#$id connected"
         sendToAll(message)