Exceptions on killing a device that access other devices

# 7 years ago
sergi_rubio	Hi, While testing Tango9 on Debian9 I discovered that PyPLC (a python device server using a Modbus C++ device to connect to PLC devices) triggered an "omni_thread fatal exception" error (and a coredump) when killing the device. Further debugging the issue I've made disappear the exception just adding a "del" call in the delete_device method: `def init_device(self): … self.modbus = PyTango.DeviceProxy(self.ModbusDeviceName) … def delete_device(self): # Needed to avoid coredump on exit del self.modbus` This issue is completely new in PyTango 9.2 and I haven't seen it with the same device in PyTango 9.1, 8 or 7. Are anyone having the same problem or do you always delete proxies on exit? Sergi - ALBA Keep on dancing, http://www.tango-controls.org/resources/howto/how-fandango/ Edited 7 years ago

# 7 years ago

Hi,

While testing Tango9 on Debian9 I discovered that PyPLC (a python device server using a Modbus C++ device to connect to PLC devices) triggered an "omni_thread fatal exception" error (and a coredump) when killing the device.

Further debugging the issue I've made disappear the exception just adding a "del" call in the delete_device method:


def init_device(self):
 …
 self.modbus = PyTango.DeviceProxy(self.ModbusDeviceName)
 …

def delete_device(self):
  # Needed to avoid coredump on exit
  del self.modbus

This issue is completely new in PyTango 9.2 and I haven't seen it with the same device in PyTango 9.1, 8 or 7.

Are anyone having the same problem or do you always delete proxies on exit?

Sergi - ALBA

Keep on dancing,

http://www.tango-controls.org/resources/howto/how-fandango/

Edited 7 years ago

# 7 years ago
Vincent M	Hi Sergi, I cannot reproduce your issue with pytango-9.2.1. Could you try the following code: `from tango.server import Device from tango import DeviceProxy, DevState from tango.test_context import DeviceTestContext class TestDevice(Device): def init_device(self): self.proxy = DeviceProxy('sys/tg_test/1') def dev_state(self): return self.proxy.state() def test_device(): with DeviceTestContext(TestDevice) as proxy: assert proxy.state() in (DevState.RUNNING, DevState.FAULT) if __name__ == '__main__': test_device()` Thanks

# 7 years ago

Vincent M

Hi Sergi,

I cannot reproduce your issue with pytango-9.2.1. Could you try the following code:

from tango.server import Device
from tango import DeviceProxy, DevState
from tango.test_context import DeviceTestContext


class TestDevice(Device):

    def init_device(self):
        self.proxy = DeviceProxy('sys/tg_test/1')

    def dev_state(self):
        return self.proxy.state()


def test_device():
    with DeviceTestContext(TestDevice) as proxy:
        assert proxy.state() in (DevState.RUNNING, DevState.FAULT)


if __name__ == '__main__':
    test_device()

Thanks

# 7 years ago
sergi_rubio	Hi Vincent, On PyTango-9.2.0 I miss the tango.test_context module. Anyway, my case could be harder to reproduce as I'm using asynchronous commands on a background thread. I'm going to update PyTango and check if the error persists. Sergi Keep on dancing, http://www.tango-controls.org/resources/howto/how-fandango/

# 7 years ago
Vincent M	sergi_rubio On PyTango-9.2.0 I miss the tango.test_context module If you want to run the test with pytango-9.2.0, you can declare a new device in the database and run this code instead: `if __name__ == '__main__': TestDevice.run_server()` sergi_rubio Anyway, my case could be harder to reproduce as I'm using asynchronous commands on a background thread. Yes that is likely to be related. You can report the issue on the pytango tracker once you managed to reproduce it. Cheers Edited 7 years ago

# 7 years ago

Vincent M

sergi_rubio
On PyTango-9.2.0 I miss the tango.test_context module

If you want to run the test with pytango-9.2.0, you can declare a new device in the database and run this code instead:

if __name__ == '__main__':
    TestDevice.run_server()

sergi_rubio
Anyway, my case could be harder to reproduce as I'm using asynchronous commands on a background thread.

Yes that is likely to be related. You can report the issue on the pytango tracker once you managed to reproduce it.

Cheers

Edited 7 years ago