From 7bd0884327cc0cefff78bd7e3d68b12e67a72e21 Mon Sep 17 00:00:00 2001
From: SerVB <servbul@yandex.ru>
Date: Thu, 6 Feb 2020 22:15:57 +0300
Subject: [PATCH] Fix data race

---
 src/Main.kt | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/Main.kt b/src/Main.kt
index 718ddee..fbdecaa 100644
--- 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)