test(dbus): Add support for testing driver reset notification

Introduce `FakeResetDriverWatchdog` to simulate driver reset triggers.
Update existing tests and add a new test, `test_notify_reset_driver`, to
verify reset notifications using the event signaling mechanism.

src/revpi_middleware/cli_commands/cli_picontrol.py

@@ -44,10 +44,11 @@ def method_reset():
     log.info("ResetDriver called via D-Bus")
 
 
-def method_await_reset(timout: int = 0):
+def method_await_reset(timeout: int = 0):
     detected_signal = await_signal(
         "NotifyDriverReset",
-        timout, extend_interface("picontrol"),
+        timeout,
+        extend_interface("picontrol"),
         bus_type=BusType.SESSION if pi.pargs.use_session_bus else BusType.SYSTEM,
     )
     if detected_signal:

src/revpi_middleware/cli_commands/dbus_helper.py

@@ -96,7 +96,6 @@ def await_signal(
     detected_signal = False
     timeout = int(timeout)
     loop = GLib.MainLoop()
-    th_sleep = Thread()
 
     def th_timeout():
         sleep(timeout)

src/revpi_middleware/dbus_middleware1/bus_provider.py

@@ -34,10 +34,19 @@ class BusProvider(Thread):
     def run(self):
         log.debug("enter BusProvider.run")
 
+        # The 2nd, 3rd, ... arguments can be objects or tuples of a path and an object
+        #   Example(),
+        #   ("Subdir1", Example()),
+        #   ("Subdir2", Example()),
+        #   ("Subdir2/Whatever", Example())
+        lst_interfaces = [
+            InterfacePiControl(self.picontrol_device, self.config_rsc),
+        ]
+
         try:
             self._bus.publish(
                 REVPI_DBUS_NAME,
-                InterfacePiControl(self.picontrol_device, self.config_rsc),
+                *lst_interfaces,
             )
         except Exception as e:
             log.error(f"can not publish dbus {REVPI_DBUS_NAME}: {e}")
@@ -47,6 +56,12 @@ class BusProvider(Thread):
         except Exception as e:
             log.error(f"can not run dbus mainloop: {e}")
 
+        # Clean up all interfaces
+        for interface in lst_interfaces:
+            if type(interface) is tuple:
+                _, interface = interface
+            interface.cleanup()
+
         log.debug("leave BusProvider.run")
 
     def stop(self):

src/revpi_middleware/dbus_middleware1/dbus_helper.py

@@ -11,6 +11,18 @@ REVPI_DBUS_NAME = "com.revolutionpi.middleware1"
 REVPI_DBUS_BASE_PATH = "/com/revolutionpi/middleware1"
 
 
+class DbusInterface:
+
+    def cleanup(self):
+        """
+        Represents a method responsible for performing cleanup operations. This method is executed to properly
+        release resources, close connections, or perform other necessary finalization tasks.
+
+        This method does not take any arguments or return a value.
+        """
+        pass
+
+
 def extend_interface(*args) -> str:
     """
     Extends an interface name by appending additional segments to a pre-defined base name.

src/revpi_middleware/dbus_middleware1/process_image/interface_picontrol.py

@@ -2,18 +2,17 @@
 # SPDX-FileCopyrightText: 2025 KUNBUS GmbH
 # SPDX-License-Identifier: GPL-2.0-or-later
 """D-Bus interfaces for piControl."""
-import os
-from fcntl import ioctl
 from logging import getLogger
 
 from pydbus.generic import signal
 
-from .process_image_helper import ResetDriverWatchdog
+from .process_image_helper import PiControlIoctl, ResetDriverWatchdog
+from ..dbus_helper import DbusInterface
 
 log = getLogger(__name__)
 
 
-class InterfacePiControl:
+class InterfacePiControl(DbusInterface):
     """
     <node>
         <interface name='com.revolutionpi.middleware1.picontrol'>
@@ -34,6 +33,9 @@ class InterfacePiControl:
         self.wd_reset_driver = ResetDriverWatchdog(self.picontrol_device)
         self.wd_reset_driver.register_call(self.notify_reset_driver)
 
+    def cleanup(self):
+        self.wd_reset_driver.stop()
+
     def notify_reset_driver(self):
         self.NotifyDriverReset()
 
@@ -41,21 +43,9 @@ class InterfacePiControl:
         log.debug("enter InterfacePiControl.ResetDriver")
 
         try:
-            fd = os.open(self.picontrol_device, os.O_WRONLY)
+            picontrol_ioctl = PiControlIoctl(self.picontrol_device)
-        except Exception as e:
+            picontrol_ioctl.ioctl(PiControlIoctl.IOCTL_RESET_DRIVER)
-            log.warning(f"could not open ${self.picontrol_device} to reset driver")
-            raise e
-
-        execption = None
-        try:
-            # KB_RESET _IO('K', 12 )  // reset the piControl driver including the config file
-            ioctl(fd, 19212)
             log.info("reset piControl driver")
         except Exception as e:
             log.warning(f"could not reset piControl driver: ${e}")
-            execption = e
+            raise e
-        finally:
-            os.close(fd)
-
-        if execption:
-            raise execption

src/revpi_middleware/dbus_middleware1/process_image/process_image_helper.py

@@ -8,6 +8,7 @@ The ResetDriverWatchdog class is a copy of revpipyload project module "watchdogs
 https://github.com/naruxde/revpipyload/blob/b51c2b617a57cc7d96fd67e1da9f090a0624eacb/src/revpipyload/watchdogs.py
 """
 import os
+from ctypes import c_int
 from fcntl import ioctl
 from logging import getLogger
 from threading import Thread
@@ -100,3 +101,24 @@ class ResetDriverWatchdog(Thread):
         rc = self._triggered
         self._triggered = False
         return rc
+
+
+class PiControlIoctl:
+    IOCTL_RESET_DRIVER = 19212
+
+    def __init__(self, picontrol_device: str):
+        self.picontrol_device = picontrol_device
+
+    def ioctl(self, request, arg=0):
+        if type(arg) is c_int:
+            arg = arg.value
+
+        _fd = os.open(self.picontrol_device, os.O_WRONLY)
+        return_value = ioctl(_fd, 19212, arg)
+        os.close(_fd)
+
+        return return_value
+
+    @property
+    def name(self):
+        return self.picontrol_device

tests/__init__.py

@@ -0,0 +1,3 @@
+# -*- coding: utf-8 -*-
+# SPDX-FileCopyrightText: 2025 KUNBUS GmbH
+# SPDX-License-Identifier: GPL-2.0-or-later

tests/dbus_middleware1/__init__.py

@@ -0,0 +1,7 @@
+# -*- coding: utf-8 -*-
+# SPDX-FileCopyrightText: 2025 KUNBUS GmbH
+# SPDX-License-Identifier: GPL-2.0-or-later
+from os import environ
+
+# D-BUS needs a DISPLAY variable to work with the session bus
+environ["DISPLAY"] = ":0"

tests/dbus_middleware1/bus_provider.py

@@ -0,0 +1,36 @@
+# -*- coding: utf-8 -*-
+# SPDX-FileCopyrightText: 2025 KUNBUS GmbH
+# SPDX-License-Identifier: GPL-2.0-or-later
+from time import sleep
+
+from tests.dbus_middleware1.fake_devices import PiControlDeviceMockup
+
+
+class TestBusProvider(PiControlDeviceMockup):
+
+    def setUp(self):
+        super().setUp()
+
+        # Do not import things on top of the module. Some classes or functions need to be mocked up first.
+        from revpi_middleware.dbus_middleware1 import BusProvider
+
+        # Prepare the bus provider and start it
+        self.bp = BusProvider(
+            self.picontrol.name,
+            use_system_bus=False,
+        )
+        self.bp.start()
+
+        # Wait 5 seconds until the bus provider has started the main loop
+        counter = 50
+        while not self.bp.running and counter > 0:
+            counter -= 1
+            sleep(0.1)
+
+    def tearDown(self):
+        self.bp.stop()
+        self.bp.join(10.0)
+        if self.bp.is_alive():
+            raise RuntimeError("Bus provider thread is still running")
+
+        super().tearDown()

tests/dbus_middleware1/fake_devices.py

@@ -0,0 +1,120 @@
+# -*- coding: utf-8 -*-
+# SPDX-FileCopyrightText: 2025 KUNBUS GmbH
+# SPDX-License-Identifier: GPL-2.0-or-later
+from ctypes import c_int
+from queue import Empty, Queue
+from tempfile import NamedTemporaryFile
+from threading import Event, Thread
+from unittest import TestCase
+
+IOCTL_QUEUE = Queue()
+RESET_DRIVER_EVENT = Event()
+
+
+class FakePiControlDevice:
+    IOCTL_RESET_DRIVER = 19212
+
+    def __init__(self, picontrol_device: str):
+        self._fh = NamedTemporaryFile("wb+", 0, prefix="fake_device_")
+        self.name = self._fh.name
+
+    def __del__(self):
+        self._fh.close()
+
+    def reset_process_image(self):
+        self._fh.write(b"\x00" * 4096)
+        self._fh.seek(0)
+
+    def ioctl(self, request, arg=0) -> int:
+        if type(arg) is c_int:
+            arg = arg.value
+
+        if request == self.IOCTL_RESET_DRIVER:
+            pass
+        else:
+            raise NotImplementedError(f"Unknown IOCTL request: {request}")
+
+        IOCTL_QUEUE.put_nowait((request, arg))
+        return arg
+
+    def close(self):
+        self._fh.close()
+
+    def read(self, size):
+        return self._fh.read(size)
+
+    def seek(self, offset, whence):
+        self._fh.seek(offset, whence)
+
+    def write(self, buffer):
+        return self._fh.write(buffer)
+
+
+class FakeResetDriverWatchdog(Thread):
+
+    def __init__(self, picontrol_device: str):
+        super().__init__()
+        self.daemon = True
+        self._calls = []
+        self._exit = False
+        self.not_implemented = True
+        self._triggered = False
+        self.start()
+
+    def run(self):
+        while not self._exit:
+            if RESET_DRIVER_EVENT.wait(0.1):
+                RESET_DRIVER_EVENT.clear()
+                self._triggered = True
+                for func in self._calls:
+                    func()
+
+    def register_call(self, function):
+        """Register a function, if watchdog triggers."""
+        if not callable(function):
+            raise ValueError("Function is not callable.")
+        if function not in self._calls:
+            self._calls.append(function)
+
+    def stop(self):
+        """Stop watchdog for reset_driver."""
+        self._exit = True
+
+    def unregister_call(self, function=None):
+        """Remove a function from the watchdog trigger."""
+        if function is None:
+            self._calls.clear()
+        elif function in self._calls:
+            self._calls.remove(function)
+
+    @property
+    def triggered(self):
+        """Will return True one time after watchdog was triggered."""
+        rc = self._triggered
+        self._triggered = False
+        return rc
+
+
+class PiControlDeviceMockup(TestCase):
+
+    def setUp(self):
+        super().setUp()
+
+        # Empty the queue
+        while True:
+            try:
+                IOCTL_QUEUE.get_nowait()
+            except Empty:
+                break
+
+        # Replace classes with mockup classes
+        import revpi_middleware.dbus_middleware1.process_image.interface_picontrol as test_helpers
+        test_helpers.PiControlIoctl = FakePiControlDevice
+        test_helpers.ResetDriverWatchdog = FakeResetDriverWatchdog
+
+        # Create a fake picontrol0 device
+        self.picontrol = FakePiControlDevice(picontrol_device="/dev/fake_device_0")
+
+    def tearDown(self):
+        self.picontrol.close()
+        super().tearDown()

tests/dbus_middleware1/process_image/__init__.py

@@ -0,0 +1,3 @@
+# -*- coding: utf-8 -*-
+# SPDX-FileCopyrightText: 2025 KUNBUS GmbH
+# SPDX-License-Identifier: GPL-2.0-or-later

tests/dbus_middleware1/process_image/test_interface_picontrol.py

@@ -0,0 +1,45 @@
+# -*- coding: utf-8 -*-
+# SPDX-FileCopyrightText: 2025 KUNBUS GmbH
+# SPDX-License-Identifier: GPL-2.0-or-later
+from threading import Thread
+from time import sleep
+
+from revpi_middleware.cli_commands.dbus_helper import BusType, await_signal, simple_call
+from revpi_middleware.dbus_middleware1 import extend_interface
+from tests.dbus_middleware1.bus_provider import TestBusProvider
+from tests.dbus_middleware1.fake_devices import IOCTL_QUEUE, RESET_DRIVER_EVENT
+
+
+class TestObjectPicontrol(TestBusProvider):
+
+    def test_is_active(self):
+        self.assertTrue(self.bp.running)
+
+    def test_reset_driver(self):
+        simple_call(
+            "ResetDriver",
+            interface=extend_interface("picontrol"),
+            bus_type=BusType.SESSION,
+        )
+        ioctl_call = IOCTL_QUEUE.get(timeout=2.0)
+        self.assertEqual((19212, 0), ioctl_call)
+
+    def test_notify_reset_driver(self):
+        timeout = 5
+
+        def target_call_reset_driver():
+            sleep(1.0)
+            RESET_DRIVER_EVENT.set()
+
+        th_wait_for_reset = Thread(target=target_call_reset_driver, daemon=True)
+        th_wait_for_reset.start()
+
+        result = await_signal(
+            "NotifyDriverReset",
+            timeout,
+            extend_interface("picontrol"),
+            bus_type=BusType.SESSION,
+        )
+        self.assertTrue(result)
+
+        th_wait_for_reset.join(timeout=timeout)