Work toward graceful shutdown

But not really working because of #24

backend/src/mirror/event_bus.py

@@ -1,10 +1,13 @@
 import json
+import logging
 from asyncio import Queue
 from dataclasses import dataclass
 from typing import *  # pylint: disable=wildcard-import,unused-wildcard-import
 
 _TERMINATE_SENTINEL = "__exit__"
 
+_logger = logging.getLogger(__name__)
+
 
 @dataclass
 class Event:
@@ -39,6 +42,7 @@ def __init__(self) -> None:
 
     async def shutdown(self) -> None:
         for queue in self._listener_queues:
+            _logger.info("queuing terminate sentinel")
             await queue.put(_TERMINATE_SENTINEL)
 
     async def post(self, event: Event) -> None:
@@ -75,6 +79,7 @@ async def listen_for_events(self):
             while True:
                 event = await queue.get()
                 if event == _TERMINATE_SENTINEL:
+                    _logger.info("terminating event generator")
                     return
                 yield event.as_sse_dict()
         finally:

backend/src/mirror/plugins/activity/__init__.py

@@ -33,6 +33,12 @@ def start_plugin(context):
     _state["task"] = task
 
 
+def stop_plugin(context):  # pylint: disable=unused-argument
+    task = _state.get("task")
+    if task:
+        task.cancel()
+
+
 async def _refresh(context):
     """Get the step count data."""
     data = {"stepsGoal": None, "steps": None}

backend/src/mirror/plugins/calendars/__init__.py

@@ -1,2 +1,2 @@
-from .calendars import start_plugin
+from .calendars import start_plugin, stop_plugin
 from .configure import configure_plugin

backend/src/mirror/plugins/calendars/calendars.py

@@ -11,3 +11,9 @@ def start_plugin(context):
     tasks.append(create_task(agenda.refresh(context), name="agenda.refresh"))
     tasks.append(create_task(coming_up.refresh(context), name="coming_up.refresh"))
     tasks.append(create_task(countdown.refresh(context), name="countdown.refresh"))
+
+
+def stop_plugin(context):  # pylint: disable=unused-argument
+    for task in _state.get("tasks"):
+        if task:
+            task.cancel()

backend/src/mirror/plugins/weather/__init__.py

@@ -34,6 +34,12 @@ def start_plugin(context):
     _state["task"] = task
 
 
+def stop_plugin(context):  # pylint: disable=unused-argument
+    task = _state.get("task")
+    if task:
+        task.cancel()
+
+
 async def _refresh(context):
     """Get the weather data for the configured coordinates.
 

backend/src/mirror/plugins/worth/__init__.py

@@ -19,6 +19,12 @@ def start_plugin(context):
     _state["task"] = task
 
 
+def stop_plugin(context):  # pylint: disable=unused-argument
+    task = _state.get("task")
+    if task:
+        task.cancel()
+
+
 async def _refresh(context):
     """Get the net worth data."""
     while True: