topic_monitor launch_reliability_demo hangs on exit on Windows

[ros2]

topic_monitor launch_reliability_demo hangs on exit on Windows

[sloretz]

I see the same behavior installing from the archive on both launch_reliability_demo and launch_fragmentation_demo.

[dirk-thomas]

The process hangs for me in launcher.py on the loop.close() call. Both subprocesses have been SIGTERMed and the loop is not running anymore. But the close() call still hangs forever.

[dhood]

I think this is a wider launch issue. You can see the same hanging behaviour if you send a keyboard interrupt to a launch script that is used for testing demos, e.g.:

C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC>python C:\Users\osrf\Downloads\r2b3-testing\overlay\build\demo_nodes_cpp\test_add_two_ints_server_add_two_ints_client__rmw_opensplice_cpp_Release.py
(test_executable_0) pid 10048: ['C:/Users/osrf/Downloads/r2b3-testing/overlay/build/demo_nodes_cpp/Release/add_two_ints_server.exe'] (all > console, InMemoryHandler: test_executable_0)
(test_executable_1) pid 4984: ['C:/Users/osrf/Downloads/r2b3-testing/overlay/build/demo_nodes_cpp/Release/add_two_ints_client.exe'] (all > console, InMemoryHandler: test_executable_1)
<manual keyboard interrupt>
(test_executable_0) signal SIGTERM
(test_executable_1) signal SIGTERM
(test_executable_0) rc 1
(test_executable_1) rc 1
<hang>

On one of them, however, you get some more info:

C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC>python C:\Users\osrf\Downloads\r2b3-testing\overlay\build\demo_nodes_cpp\test_set_and_get_parameters__rmw_opensplice_cpp_Release.py
(test_executable_0) pid 2276: ['C:/Users/osrf/Downloads/r2b3-testing/overlay/build/demo_nodes_cpp/Release/set_and_get_parameters.exe'] (all > console, InMemoryHandler: test_executable_0)
[test_executable_0] Parameter name: foo
[test_executable_0] Parameter value (integer): 2
[test_executable_0] Parameter name: baz
[test_executable_0] Parameter value (double): 1.450000
<manual keyboard interrupt>
(test_executable_0) rc 1
() tear down
Exception ignored in: <bound method BaseEventLoop.__del__ of <_WindowsSelectorEventLoop running=False closed=False debug=False>>
Traceback (most recent call last):
  File "C:\Python36\lib\asyncio\base_events.py", line 511, in __del__
    self.close()
  File "C:\Python36\lib\asyncio\selector_events.py", line 110, in close
    self._close_self_pipe()
  File "C:\Python36\lib\asyncio\selector_events.py", line 120, in _close_self_pipe
    self._remove_reader(self._ssock.fileno())
  File "C:\Python36\lib\asyncio\selector_events.py", line 279, in _remove_reader
    key = self._selector.get_key(fd)
  File "C:\Python36\lib\selectors.py", line 189, in get_key
    return mapping[fileobj]
  File "C:\Python36\lib\selectors.py", line 70, in __getitem__
    fd = self._selector._fileobj_lookup(fileobj)
  File "C:\Python36\lib\selectors.py", line 224, in _fileobj_lookup
    return _fileobj_to_fd(fileobj)
  File "C:\Python36\lib\selectors.py", line 41, in _fileobj_to_fd
    raise ValueError("Invalid file descriptor: {}".format(fd))
ValueError: Invalid file descriptor: -1

I think I remember seeing something in a comment somewhere in launch specifically about file descriptors.. I'll see if I can find it again.

[dhood]

The comment I was thinking of was https://github.com/ros2/ci/blob/1c1eb3124c3310c87dbf02154b6decec6460c75b/ros2_batch_job/vendor/osrf_pycommon/docs/process_utils.rst#treatment-of-file-descriptors but FWIU that doesn't apply to launch which uses asyncio.

[dirk-thomas]

@dhood Should this be closed as a duplicate?

[dhood]

Replaced by ros2/launch#64 which has a minimal example