Use class-attribute to track shutdown

uvicorn/server.py

@@ -47,6 +47,8 @@ def __init__(self) -> None:
         self.tasks: set[asyncio.Task[None]] = set()
         self.default_headers: list[tuple[bytes, bytes]] = []
 
+class ShutdownTrigger:
+    is_shutdown_triggered: bool = False
 
 class Server:
     def __init__(self, config: Config) -> None:
@@ -261,7 +263,7 @@ async def on_tick(self, counter: int) -> bool:
     async def shutdown(self, sockets: list[socket.socket] | None = None) -> None:
         if self.config.shutdown_delay:
             logger.info(f"Shutting down in {self.config.shutdown_delay} seconds")
-            self.config.app.uvicorn_shutdown_triggered = True
+            ShutdownTrigger.is_shutdown_triggered = True
             await asyncio.sleep(self.config.shutdown_delay)
 
         logger.info("Shutting down")