From 54a9955e30164ffa3e829be76c57b9f004f3ae1d Mon Sep 17 00:00:00 2001
From: Anuken <arnukren@gmail.com>
Date: Sat, 7 Jan 2023 12:44:29 -0500
Subject: [PATCH] #8126

---
 core/src/mindustry/net/ArcNetProvider.java | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/core/src/mindustry/net/ArcNetProvider.java b/core/src/mindustry/net/ArcNetProvider.java
index 64e43b5cee..3c268755f3 100644
--- a/core/src/mindustry/net/ArcNetProvider.java
+++ b/core/src/mindustry/net/ArcNetProvider.java
@@ -252,8 +252,9 @@ public class ArcNetProvider implements NetProvider{
     public void discoverServers(Cons<Host> callback, Runnable done){
         Seq<InetAddress> foundAddresses = new Seq<>();
         long time = Time.millis();
+
         client.discoverHosts(port, multicastGroup, multicastPort, 3000, packet -> {
-            Core.app.post(() -> {
+            synchronized(foundAddresses){
                 try{
                     if(foundAddresses.contains(address -> address.equals(packet.getAddress()) || (isLocal(address) && isLocal(packet.getAddress())))){
                         return;
@@ -266,7 +267,7 @@ public class ArcNetProvider implements NetProvider{
                     //don't crash when there's an error pinging a a server or parsing data
                     e.printStackTrace();
                 }
-            });
+            }
         }, () -> Core.app.post(done));
     }