Use blocking function to integrate Python methods and sd-bus

igo95862 · igo95862 · commit 54ffe5bba438 · 2025-09-10T21:18:38.000+01:00
Current asyncio callbacks have an issue of being garbage collected. In order to prevent that add them to a set and use `add_done_callback` to drop refrence once task completes. Make `DbusLocalMethodAsync._dbus_reply_call` a blocking function as in the future the low level API will no longer have asyncio integration. Bug reported by @arkq.
diff --git a/src/sdbus/dbus_common_elements.py b/src/sdbus/dbus_common_elements.py
@@ -30,6 +30,7 @@
 from .sd_bus_internals import is_interface_name_valid, is_member_name_valid
 
 if TYPE_CHECKING:
+    from asyncio import Task
     from collections.abc import Callable, Sequence
     from types import FunctionType
     from typing import Any, Optional
@@ -330,6 +331,16 @@ def __init__(self) -> None:
         self.activated_interfaces: list[SdBusInterface] = []
         self.serving_object_path: Optional[str] = None
         self.attached_bus: Optional[SdBus] = None
+        self._tasks: Optional[set[Task[None]]] = None
+
+    @property
+    def tasks(self) -> set[Task[None]]:
+        tasks_set = self._tasks
+        if tasks_set is None:
+            tasks_set = set()
+            self._tasks = tasks_set
+
+        return tasks_set
 
 
 class DbusClassMeta:
diff --git a/src/sdbus/dbus_proxy_async_interface_base.py b/src/sdbus/dbus_proxy_async_interface_base.py
@@ -452,6 +452,7 @@ def new_proxy(
 
 class DbusExportHandle:
     def __init__(self, local_meta: DbusLocalObjectMeta):
+        self._tasks = local_meta.tasks
         self._dbus_slots: list[SdBusSlot] = [
             i.slot
             for i in local_meta.activated_interfaces
@@ -481,5 +482,8 @@ async def __aexit__(
         self.stop()
 
     def stop(self) -> None:
+        for task in self._tasks:
+            task.cancel("D-Bus export stopped")
+
         for slot in self._dbus_slots:
             slot.close()
diff --git a/src/sdbus/dbus_proxy_async_method.py b/src/sdbus/dbus_proxy_async_method.py
@@ -19,6 +19,7 @@
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
 from __future__ import annotations
 
+from asyncio import get_running_loop
 from contextvars import ContextVar, copy_context
 from inspect import iscoroutinefunction
 from types import FunctionType
@@ -27,6 +28,7 @@
 
 from .dbus_common_elements import (
     DbusBoundAsync,
+    DbusLocalObjectMeta,
     DbusMemberAsync,
     DbusMethodCommon,
     DbusMethodOverride,
@@ -177,16 +179,31 @@ async def _dbus_reply_call_method(
 
         return await local_method(*request_message.parse_to_tuple())
 
-    async def _dbus_reply_call(
+    def _dbus_reply_call(
         self,
         request_message: SdBusMessage
     ) -> None:
         local_object = self.local_object_ref()
         if local_object is None:
             raise RuntimeError("Local object no longer exists!")
+        local_meta = local_object._dbus
+        if not isinstance(local_meta, DbusLocalObjectMeta):
+            raise RuntimeError("D-Bus object is a remote proxy!")
 
-        call_context = copy_context()
+        loop = get_running_loop()
+        reply_task = loop.create_task(
+            self._dbus_reply_call_async(local_object, request_message)
+        )
+        tasks_set = local_meta.tasks
+        tasks_set.add(reply_task)
+        reply_task.add_done_callback(tasks_set.discard)
 
+    async def _dbus_reply_call_async(
+        self,
+        local_object: DbusInterfaceBaseAsync,
+        request_message: SdBusMessage
+    ) -> None:
+        call_context = copy_context()
         try:
             reply_data = await call_context.run(
                 self._dbus_reply_call_method,
diff --git a/src/sdbus/sd_bus_internals.py b/src/sdbus/sd_bus_internals.py
@@ -23,7 +23,7 @@
 from typing import TYPE_CHECKING
 
 if TYPE_CHECKING:
-    from collections.abc import Callable, Coroutine, Sequence
+    from collections.abc import Callable, Sequence
     from typing import Any, Optional, Union
 
     DbusBasicTypes = Union[str, int, bytes, float, Any]
@@ -63,7 +63,7 @@ def add_method(
         signature: str, input_args_names: Sequence[str],
         result_signature: str, result_args_names: Sequence[str],
         flags: int,
-        callback: Callable[[SdBusMessage], Coroutine[Any, Any, None]], /
+        callback: Callable[[SdBusMessage], None], /
     ) -> None:
         raise NotImplementedError(__STUB_ERROR)
 
