The following problem only occurs when I use ProactorEventLoop. If I use 'asyncio.get_event_loop()' it exits normally, rather than infinite looping in IOCP land.
1. I run the attached 'bug.py' script in a DOS window. It is a slightly modified version of the asyncio echo server example.
2. It reaches 'loop.run_forever()' and blocks. I can make connections here and use it as an echo server. Or make no connections.
3. I press Ctrl-C in the DOS window. Nothing happens.
4. I do a raw connection with Putty and try some input.
5. 'run_forever()' exits and the script proceeds to the 'loop.close()' call. Before this is invoked and the infinite loop entered, I see the script output '<ProactorEventLoop running=False closed=False debug=False>'.
At this point, the script locks up and never reaches the next line. It can be interrupted with another Ctrl-C, and the following stack track is seen:
Traceback (most recent call last):
File "bug.py", line 39, in <module>
loop.close()
File "C:\Program Files (x86)\Microsoft Visual Studio\Shared\Python36_64\lib\asyncio\proactor_events.py", line 437, in close
self._proactor.close()
File "C:\Program Files (x86)\Microsoft Visual Studio\Shared\Python36_64\lib\asyncio\windows_events.py", line 745, in close
if not self._poll(1):
File "C:\Program Files (x86)\Microsoft Visual Studio\Shared\Python36_64\lib\asyncio\windows_events.py", line 673, in _poll
status = _overlapped.GetQueuedCompletionStatus(self._iocp, ms)
KeyboardInterrupt
The following code in 'windows_events.py:IocpProactor.close' is looping infinitely.
while self._cache:
if not self._poll(1):
logger.debug('taking long time to close proactor')
Note that '_poll' does not actually return anything.
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