From 83e56f745df8927630efbf05ba04164429a7a5da Mon Sep 17 00:00:00 2001
From: Robert Paciorek <robert@opcode.eu.org>
Date: Sat, 9 Mar 2024 19:05:03 +0000
Subject: [PATCH] fix possible race condition in JoinRoom

---
 src/Core/Client.cs | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/src/Core/Client.cs b/src/Core/Client.cs
index 087025d..e7838e3 100644
--- a/src/Core/Client.cs
+++ b/src/Core/Client.cs
@@ -9,11 +9,12 @@ public class Client {
 
     public int ClientID { get; private set; }
     public PlayerData PlayerData { get; set; } = new();
-    public Room Room { get; set; }
+    public Room Room { get; private set; }
 
     private readonly Socket socket;
     SocketBuffer socketBuffer = new();
     private volatile bool scheduledDisconnect = false;
+    private object ClientLock = new();
 
     public Client(Socket clientSocket) {
         socket = clientSocket;
@@ -60,10 +61,12 @@ public class Client {
     }
     
     public void JoinRoom(Room room) {
-        LeaveRoom();
-        InvalidatePlayerData();
-        Room = room;
-        Room.AddClient(this);
+        lock(ClientLock) {
+            LeaveRoom();
+            PlayerData.IsValid = false;
+            Room.AddClient(this);
+            Room = room;
+        }
         Send(Room.SubscribeRoom());
         UpdatePlayerUserVariables();
     }
@@ -79,10 +82,6 @@ public class Client {
         }
     }
 
-    public void InvalidatePlayerData() {
-        PlayerData.IsValid = false;
-    }
-
     public void Disconnect() {
         try {
             socket.Shutdown(SocketShutdown.Both);