Turn Dispatcher into a background service

Signed-off-by: Mathias L. Baumann <[email protected]>

Author: Marenz

src/frequenz/dispatch/_dispatcher.py

@@ -7,11 +7,12 @@
 
 import logging
 from asyncio import Event
-from typing import Any, Callable, Generator
+from typing import Callable
 
 from frequenz.channels import Receiver
 from frequenz.client.dispatch import Client
-from frequenz.sdk.actor import Actor
+from frequenz.sdk.actor import Actor, BackgroundService
+from typing_extensions import override
 
 from ._actor_dispatcher import ActorDispatcher, DispatchInfo
 from ._bg_service import DispatchScheduler, MergeStrategy
@@ -22,7 +23,7 @@
 _logger = logging.getLogger(__name__)
 
 
-class Dispatcher:
+class Dispatcher(BackgroundService):
     """A highlevel interface for the dispatch API.
 
     This class provides a highlevel interface to the dispatch API.
@@ -183,6 +184,8 @@ def __init__(
             server_url: The URL of the dispatch service.
             key: The key to access the service.
         """
+        super().__init__(name="Dispatcher")
+
         self._client = Client(server_url=server_url, key=key)
         self._bg_service = DispatchScheduler(
             microgrid_id,
@@ -192,10 +195,32 @@ def __init__(
         self._empty_event = Event()
         self._empty_event.set()
 
+    @override
     def start(self) -> None:
         """Start the local dispatch service."""
         self._bg_service.start()
 
+    @property
+    @override
+    def is_running(self) -> bool:
+        """Whether the local dispatch service is running."""
+        return self._bg_service.is_running
+
+    @override
+    async def wait(self) -> None:
+        """Wait until all actor dispatches are stopped."""
+        await self._empty_event.wait()
+
+    @override
+    def cancel(self, msg: str | None = None) -> None:
+        """Stop the local dispatch service."""
+        self._bg_service.cancel(msg)
+
+        for instance in self._actor_dispatchers.values():
+            instance.cancel()
+
+        self._actor_dispatchers.clear()
+
     async def start_dispatching(
         self,
         dispatch_type: str,
@@ -256,10 +281,6 @@ async def stop_dispatching(self, dispatch_type: str) -> None:
         if not self._actor_dispatchers:
             self._empty_event.set()
 
-    def __await__(self) -> Generator[Any, None, bool]:
-        """Wait until all actor dispatches are stopped."""
-        return self._empty_event.wait().__await__()
-
     @property
     def client(self) -> Client:
         """Return the client."""