From c1cc359b5c7b5b5a0da1806f7d3053c54bc7de28 Mon Sep 17 00:00:00 2001
From: David Brochart <david.brochart@gmail.com>
Date: Thu, 27 Feb 2025 10:21:37 +0100
Subject: [PATCH] Make Kernel._eventloop_set not a class attribute

---
 ipykernel/kernelbase.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/ipykernel/kernelbase.py b/ipykernel/kernelbase.py
index ba1a6c5e..08f60e14 100644
--- a/ipykernel/kernelbase.py
+++ b/ipykernel/kernelbase.py
@@ -235,12 +235,14 @@ def _parent_header(self):
         "list_subshell_request",
     ]
 
-    _eventloop_set = threading.Event()
+    _eventloop_set: threading.Event
 
     def __init__(self, **kwargs):
         """Initialize the kernel."""
         super().__init__(**kwargs)
 
+        self._eventloop_set = threading.Event()
+
         # Kernel application may swap stdout and stderr to OutStream,
         # which is the case in `IPKernelApp.init_io`, hence `sys.stdout`
         # can already by different from TextIO at initialization time.