diff --git a/tangostationcontrol/tangostationcontrol/devices/abstract_device.py b/tangostationcontrol/tangostationcontrol/devices/abstract_device.py
deleted file mode 100644
index c3c6aea23d0af39f80dd733efb4c911847d93635..0000000000000000000000000000000000000000
--- a/tangostationcontrol/tangostationcontrol/devices/abstract_device.py
+++ /dev/null
@@ -1,32 +0,0 @@
-# -*- coding: utf-8 -*-
-#
-# This file is part of the XXX project
-#
-#
-#
-# Distributed under the terms of the APACHE license.
-# See LICENSE.txt for more info.
-
-"""Abstract Device Meta for LOFAR2.0
-
-"""
-
-import logging
-
-from tango.server import DeviceMeta
-
-logger = logging.getLogger()
-
-
-# TODO(Corne): Fix combining metaclasses by iterating over their variables and
-# methods. https://support.astron.nl/jira/browse/L2SS-551
-# class AbstractDeviceMetas(DeviceMeta, ABCMeta):
-class AbstractDeviceMetas(DeviceMeta):
- """Collects meta classes to allow lofar_device to be both a Device and an ABC. """
-
- def __new__(mcs, name, bases, namespace, **kwargs):
- cls = DeviceMeta.__new__(mcs, name, bases, namespace, **kwargs)
- # temp_cls = ABCMeta.__new__(mcs, name, bases, namespace)
- # setattr(cls, '__abstractmethods__', temp_cls.__abstractmethods__)
- # setattr(cls, '_abc_impl', temp_cls._abc_impl)
- return cls
diff --git a/tangostationcontrol/tangostationcontrol/devices/lofar_device.py b/tangostationcontrol/tangostationcontrol/devices/lofar_device.py
index 690f65104b1ada278b7c09447df47de1817941ce..6fed370c4e714813b1a7ce6768cc93209cff1c5e 100644
--- a/tangostationcontrol/tangostationcontrol/devices/lofar_device.py
+++ b/tangostationcontrol/tangostationcontrol/devices/lofar_device.py
@@ -11,10 +11,8 @@
"""
-from abc import abstractmethod
-
# PyTango imports
-from tango.server import Device, command, attribute
+from tango.server import attribute, command, Device, DeviceMeta
from tango import AttrWriteType, DevState, DebugIt, Attribute, DeviceProxy
import time
import math
@@ -23,7 +21,6 @@ import math
from tangostationcontrol.clients.attribute_wrapper import attribute_wrapper
from tangostationcontrol.common.lofar_logging import log_exceptions
from tangostationcontrol.common.lofar_version import get_version
-from tangostationcontrol.devices.abstract_device import AbstractDeviceMetas
from tangostationcontrol.devices.device_decorators import only_in_states, fault_on_error
@@ -32,7 +29,8 @@ __all__ = ["lofar_device"]
import logging
logger = logging.getLogger()
-class lofar_device(Device, metaclass=AbstractDeviceMetas):
+
+class lofar_device(Device, metaclass=DeviceMeta):
"""
**Properties:**
@@ -217,14 +215,12 @@ class lofar_device(Device, metaclass=AbstractDeviceMetas):
def configure_for_fault(self):
pass
- @abstractmethod
def configure_for_off(self):
pass
def configure_for_on(self):
pass
- @abstractmethod
def configure_for_initialise(self):
pass
diff --git a/tangostationcontrol/tangostationcontrol/devices/opcua_device.py b/tangostationcontrol/tangostationcontrol/devices/opcua_device.py
index 6da1fdf21d635e4f32cf848cb4c8c81287b896d6..eb2e508c35cf6923fb9d121f729465a4eca621e3 100644
--- a/tangostationcontrol/tangostationcontrol/devices/opcua_device.py
+++ b/tangostationcontrol/tangostationcontrol/devices/opcua_device.py
@@ -17,14 +17,15 @@ import numpy
import asyncio
# Additional import
-from tangostationcontrol.common.lofar_logging import log_exceptions
+from tangostationcontrol.common.lofar_logging import log_exceptions
from tangostationcontrol.clients.opcua_client import OPCUAConnection
from tangostationcontrol.devices.lofar_device import lofar_device
import logging
logger = logging.getLogger()
-__all__ = ["opcua_device", "main"]
+__all__ = ["opcua_device"]
+
class opcua_device(lofar_device):
"""
diff --git a/tangostationcontrol/tangostationcontrol/devices/sdp/statistics.py b/tangostationcontrol/tangostationcontrol/devices/sdp/statistics.py
index ae8b663dc61b4eafa17a73acaa4efc548c3d4d95..21286acd44b5a83a8ac3fb904f55b2024bbf03fe 100644
--- a/tangostationcontrol/tangostationcontrol/devices/sdp/statistics.py
+++ b/tangostationcontrol/tangostationcontrol/devices/sdp/statistics.py
@@ -11,8 +11,6 @@
"""
-from abc import abstractmethod
-
# PyTango imports
from tango.server import device_property
@@ -32,15 +30,13 @@ import numpy
__all__ = ["Statistics"]
-# TODO(Corne): Make Statistics use ABCMeta again when L2SS-551 is fixed
-# https://support.astron.nl/jira/browse/L2SS-551
+
class Statistics(opcua_device):
# In derived classes, set this to a subclass of StatisticsCollector
@property
- @abstractmethod
def STATISTICS_COLLECTOR_CLASS(self):
- pass
+ raise NotImplementedError
# -----------------
# Device Properties
diff --git a/tangostationcontrol/tangostationcontrol/devices/sdp/xst.py b/tangostationcontrol/tangostationcontrol/devices/sdp/xst.py
index adef57e3144e297b273ff5b33e77c9fde513ee82..c0b6f7a98894b7c7d660828231935b63c5b0f5da 100644
--- a/tangostationcontrol/tangostationcontrol/devices/sdp/xst.py
+++ b/tangostationcontrol/tangostationcontrol/devices/sdp/xst.py
@@ -28,6 +28,7 @@ import numpy
__all__ = ["XST", "main"]
+
class XST(Statistics):
STATISTICS_COLLECTOR_CLASS = XSTCollector
diff --git a/tangostationcontrol/tangostationcontrol/test/devices/test_abstract_device.py b/tangostationcontrol/tangostationcontrol/test/devices/test_abstract_device.py
deleted file mode 100644
index 742fa9e405d112444239ae30284e51b8452416e8..0000000000000000000000000000000000000000
--- a/tangostationcontrol/tangostationcontrol/test/devices/test_abstract_device.py
+++ /dev/null
@@ -1,91 +0,0 @@
-# -*- coding: utf-8 -*-
-#
-# This file is part of the LOFAR 2.0 Station Software
-#
-#
-#
-# Distributed under the terms of the APACHE license.
-# See LICENSE.txt for more info.
-
-import abc
-from unittest import mock
-
-from tango import server
-from tango.server import attribute
-
-from tangostationcontrol.devices.abstract_device import AbstractDeviceMetas
-
-from tangostationcontrol.test import base
-
-
-class TestAbstractDevice(base.TestCase):
-
- class AbstractExample(object, metaclass=abc.ABCMeta):
- """A pure abc.ABCMeta metaclass with an abstract method
-
- This is an abstract class that inherits object with the abc.ABCMeta as
- metaclass
- """
-
- @abc.abstractmethod
- def example_method(self):
- raise NotImplementedError
-
- class TestHardwareDevice(server.Device, metaclass=AbstractDeviceMetas):
- """This is your overarching abstract class with a combined metaclass
-
- Device is an object with DeviceMeta as metaclass
- We use HardwareDeviceMetas as metaclass
-
- Our metaclass contract is now fulfilled.
- """
-
- @attribute(dtype=float)
- def call_example_method(self):
- return self.example_method()
-
- @abc.abstractmethod
- def example_method(self):
- raise NotImplementedError
-
- class ConcreteHardwareDevice(TestHardwareDevice):
-
- def example_method(self):
- return 12
-
- def setUp(self):
- super(TestAbstractDevice, self).setUp()
-
- # def test_instance_tango(self):
- #
- # try:
- # with DeviceTestContext(self.TestHardwareDevice, process=True) as proxy:
- # # Calling this method raises the NotImplementedError exception
- # proxy.call_example_method()
- # except Exception as e:
- # self.assertIsInstance(e, RuntimeError)
- #
- # with DeviceTestContext(self.ConcreteHardwareDevice, process=True) as proxy:
- # self.assertEqual(12, proxy.call_example_method)
-
- @mock.patch.object(server, 'get_worker')
- @mock.patch.object(server, 'LatestDeviceImpl')
- def test_instance_error(self, m_worker, m_implement):
- # Creating this object should raise a type error but it does not
- # combining metaclasses in this way does not have the desired result.
- # This is a known limitation of this approach
- m_device = self.TestHardwareDevice(mock.Mock(), mock.Mock())
-
- # Raising the NotImplementedError works as expected, however.
- self.assertRaises(NotImplementedError, m_device.example_method)
-
- # Creating this object of a class that has a pure metaclass does raise
- # the expected error.
- self.assertRaises(TypeError, self.AbstractExample)
-
- @mock.patch.object(server, 'get_worker')
- @mock.patch.object(server, 'LatestDeviceImpl')
- def test_isinstance(self, m_worker, m_implement):
- m_device = self.TestHardwareDevice(mock.Mock(), mock.Mock())
-
- self.assertFalse(isinstance(m_device, AbstractDeviceMetas))
diff --git a/tangostationcontrol/tangostationcontrol/test/devices/test_statistics_device.py b/tangostationcontrol/tangostationcontrol/test/devices/test_statistics_device.py
new file mode 100644
index 0000000000000000000000000000000000000000..29c2462fe95047bc6364acd0d4c6a03c945801f2
--- /dev/null
+++ b/tangostationcontrol/tangostationcontrol/test/devices/test_statistics_device.py
@@ -0,0 +1,53 @@
+# -*- coding: utf-8 -*-
+#
+# This file is part of the LOFAR 2.0 Station Software
+#
+#
+#
+# Distributed under the terms of the APACHE license.
+# See LICENSE.txt for more info.
+
+import mock
+
+from tango import server
+from tango.test_context import DeviceTestContext
+
+from tangostationcontrol.test import base
+
+
+class TestStatisticsDevice(base.TestCase):
+
+ def setUp(self):
+ super(TestStatisticsDevice, self).setUp()
+
+ def test_python_bug(self):
+ """Python is bugged and super() calls in ctypes fail
+
+ This is the same type of issues that prevents combining metaclasses
+ DeviceMeta and ABCMeta
+
+ https://github.com/waveform80/picamera/issues/355
+ https://bugs.python.org/issue29270
+ """
+ import ctypes as ct
+
+ try:
+ class TestSubclass(ct.c_uint32):
+ def __repr__(self):
+ return super().__repr__()
+ except Exception as e:
+ self.assertIsInstance(e, TypeError)
+
+ @mock.patch.object(server, 'get_worker')
+ def test_instance_statistics(self, m_worker):
+ """Test that we can import and create a statistics device
+
+ The import of Statistics fails when both ABCMeta and DeviceMeta are
+ combined. Leave this test to prevent regressions when reattempting our
+ combined metaclass.
+ """
+
+ from tangostationcontrol.devices.sdp.statistics import Statistics
+
+ with DeviceTestContext(Statistics, process=True) as proxy:
+ self.assertTrue(proxy.ping() > 0)