From de62f95f457c42f8a8c2e98aed91ac6a6a1cad70 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lukas=20F=C3=BCrderer?= <l.fuerderer@gmail.com>
Date: Mon, 5 Jan 2026 12:02:27 +0100
Subject: [PATCH] Fix a race condition

---
 observer.py | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/observer.py b/observer.py
index 46d10c8..c25efa6 100644
--- a/observer.py
+++ b/observer.py
@@ -11,9 +11,10 @@ class Observer:
             self.__receivers_list[identifier].add(queue)
             return Subscription(self, identifier, queue)
     def publish(self, identifier, message):
-        if identifier in self.__receivers_list:
-            for queue in self.__receivers_list[identifier]:
-                queue.put(message)
+        with self.__lock:
+            if identifier in self.__receivers_list:
+                for queue in self.__receivers_list[identifier]:
+                    queue.put(message)
     def quit(self, identifer, queue):
         with self.__lock:
             self.__receivers_list[identifer].remove(queue)