try to fix websocket shutdown

backend/src/api/packet_api.py

@@ -9,6 +9,7 @@ from typing import Any, Dict, List, Optional, Union
 from fastapi import APIRouter, HTTPException, Query, WebSocket, WebSocketDisconnect
 from fastapi.responses import JSONResponse
 from pydantic import BaseModel
+from starlette.websockets import WebSocketState
 
 import src.shared_objects as shared
 from src.Models.packets import PacketDBModel
@@ -120,7 +121,41 @@ async def websocket_packets(ws: WebSocket) -> None:
         logger.info("WebSocket subscribed client %s (queue maxsize=%d)", ws.client, queue.maxsize)
 
         while True:
-            message = await queue.get()
+            queue_task = asyncio.create_task(queue.get())
+            receive_task = asyncio.create_task(ws.receive())
+            done, pending = await asyncio.wait(
+                {queue_task, receive_task},
+                return_when=asyncio.FIRST_COMPLETED,
+            )
+
+            for task in pending:
+                task.cancel()
+            if pending:
+                await asyncio.gather(*pending, return_exceptions=True)
+
+            if receive_task in done:
+                try:
+                    inbound = receive_task.result()
+                except WebSocketDisconnect:
+                    logger.info("WebSocket client disconnected: %s", ws.client)
+                    break
+                except Exception:
+                    logger.info("WebSocket receive failed for client %s; unsubscribing", ws.client)
+                    break
+
+                if inbound.get("type") == "websocket.disconnect":
+                    logger.info("WebSocket disconnect received for client %s", ws.client)
+                    break
+
+            if queue_task not in done:
+                if ws.client_state is not WebSocketState.CONNECTED:
+                    break
+                continue
+
+            message = queue_task.result()
+            if isinstance(message, dict) and message.get("type") == "__broadcaster_shutdown__":
+                logger.info("Broadcaster shutdown delivered to client %s", ws.client)
+                break
 
             if isinstance(message, dict):
                 payload: Any = _serialize_row_for_json(message)

backend/src/utilities/packet_broadcaster.py

@@ -6,6 +6,8 @@ from typing import Any, Dict, List, Optional
 
 logger = logging.getLogger("packet_broadcaster")
 
+_SHUTDOWN_SENTINEL: Dict[str, Any] = {"type": "__broadcaster_shutdown__"}
+
 
 class PacketBroadcaster:
     """Manage subscriber queues and publish packet events."""
@@ -96,5 +98,6 @@ class PacketBroadcaster:
             try:
                 while not queue.empty():
                     queue.get_nowait()
+                queue.put_nowait(_SHUTDOWN_SENTINEL)
             except Exception:
                 pass