This repository was archived by the owner on Nov 23, 2017. It is now read-only.
This repository was archived by the owner on Nov 23, 2017. It is now read-only.
asyncio.create_subprocess_exec with IO redirection hangs if no global loop set #478
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Description
If I set global event loop to None (asyncio.set_event_loop(None)) and explicitly pass everywhere event loop, asyncio.create_subprocess_exec with I/O redirection will hang.
In following example proc.communicate() will never return:
import asyncio.subprocess
async def f(loop):
proc = await asyncio.create_subprocess_exec(
'echo',
stdout=asyncio.subprocess.PIPE,
loop=loop)
await proc.communicate()
loop = asyncio.get_event_loop()
asyncio.set_event_loop(None)
date = loop.run_until_complete(f(loop))
loop.close()With PYTHONASYNCIODEBUG=x:
Traceback (most recent call last):
File "asyncio_subprocess_hangs_wo_global_loop.py", line 17, in <module>
date = loop.run_until_complete(f(loop))
File "/usr/lib/python3.5/asyncio/base_events.py", line 387, in run_until_complete
return future.result()
File "/usr/lib/python3.5/asyncio/futures.py", line 274, in result
raise self._exception
File "/usr/lib/python3.5/asyncio/tasks.py", line 239, in _step
result = coro.send(None)
File "asyncio_subprocess_hangs_wo_global_loop.py", line 9, in f
loop=loop)
File "/usr/lib/python3.5/asyncio/coroutines.py", line 105, in __next__
return self.gen.send(None)
File "/usr/lib/python3.5/asyncio/subprocess.py", line 212, in create_subprocess_exec
stderr=stderr, **kwds)
File "/usr/lib/python3.5/asyncio/coroutines.py", line 105, in __next__
return self.gen.send(None)
File "/usr/lib/python3.5/asyncio/base_events.py", line 1079, in subprocess_exec
bufsize, **kwargs)
File "/usr/lib/python3.5/asyncio/coroutines.py", line 105, in __next__
return self.gen.send(None)
File "/usr/lib/python3.5/asyncio/unix_events.py", line 187, in _make_subprocess_transport
self._child_watcher_callback, transp)
File "/usr/lib/python3.5/asyncio/unix_events.py", line 808, in add_child_handler
self._do_waitpid(pid)
File "/usr/lib/python3.5/asyncio/unix_events.py", line 841, in _do_waitpid
if self._loop.get_debug():
AttributeError: 'NoneType' object has no attribute 'get_debug'
Task was destroyed but it is pending!
source_traceback: Object created at (most recent call last):
File "asyncio_subprocess_hangs_wo_global_loop.py", line 17, in <module>
date = loop.run_until_complete(f(loop))
File "/usr/lib/python3.5/asyncio/base_events.py", line 375, in run_until_complete
self.run_forever()
File "/usr/lib/python3.5/asyncio/base_events.py", line 345, in run_forever
self._run_once()
File "/usr/lib/python3.5/asyncio/base_events.py", line 1304, in _run_once
handle._run()
File "/usr/lib/python3.5/asyncio/events.py", line 125, in _run
self._callback(*self._args)
File "/usr/lib/python3.5/asyncio/tasks.py", line 239, in _step
result = coro.send(None)
File "asyncio_subprocess_hangs_wo_global_loop.py", line 9, in f
loop=loop)
File "/usr/lib/python3.5/asyncio/coroutines.py", line 105, in __next__
return self.gen.send(None)
File "/usr/lib/python3.5/asyncio/subprocess.py", line 212, in create_subprocess_exec
stderr=stderr, **kwds)
File "/usr/lib/python3.5/asyncio/coroutines.py", line 105, in __next__
return self.gen.send(None)
File "/usr/lib/python3.5/asyncio/base_events.py", line 1079, in subprocess_exec
bufsize, **kwargs)
File "/usr/lib/python3.5/asyncio/coroutines.py", line 105, in __next__
return self.gen.send(None)
File "/usr/lib/python3.5/asyncio/unix_events.py", line 184, in _make_subprocess_transport
**kwargs)
File "/usr/lib/python3.5/asyncio/base_subprocess.py", line 56, in __init__
self._loop.create_task(self._connect_pipes(waiter))
task: <Task pending coro=<BaseSubprocessTransport._connect_pipes() running at /usr/lib/python3.5/asyncio/base_subprocess.py:171> wait_for=<Future pending cb=[Task._wakeup()] created at /usr/lib/python3.5/asyncio/base_events.py:252> created at /usr/lib/python3.5/asyncio/base_subprocess.py:56>
Future exception was never retrieved
future: <Future finished exception=RuntimeError('Event loop is closed',) created at /usr/lib/python3.5/asyncio/base_events.py:252>
source_traceback: Object created at (most recent call last):
File "asyncio_subprocess_hangs_wo_global_loop.py", line 17, in <module>
date = loop.run_until_complete(f(loop))
File "/usr/lib/python3.5/asyncio/base_events.py", line 375, in run_until_complete
self.run_forever()
File "/usr/lib/python3.5/asyncio/base_events.py", line 345, in run_forever
self._run_once()
File "/usr/lib/python3.5/asyncio/base_events.py", line 1304, in _run_once
handle._run()
File "/usr/lib/python3.5/asyncio/events.py", line 125, in _run
self._callback(*self._args)
File "/usr/lib/python3.5/asyncio/tasks.py", line 239, in _step
result = coro.send(None)
File "asyncio_subprocess_hangs_wo_global_loop.py", line 9, in f
loop=loop)
File "/usr/lib/python3.5/asyncio/coroutines.py", line 105, in __next__
return self.gen.send(None)
File "/usr/lib/python3.5/asyncio/subprocess.py", line 212, in create_subprocess_exec
stderr=stderr, **kwds)
File "/usr/lib/python3.5/asyncio/coroutines.py", line 105, in __next__
return self.gen.send(None)
File "/usr/lib/python3.5/asyncio/base_events.py", line 1079, in subprocess_exec
bufsize, **kwargs)
File "/usr/lib/python3.5/asyncio/coroutines.py", line 105, in __next__
return self.gen.send(None)
File "/usr/lib/python3.5/asyncio/unix_events.py", line 180, in _make_subprocess_transport
waiter = self.create_future()
File "/usr/lib/python3.5/asyncio/base_events.py", line 252, in create_future
return futures.Future(loop=self)
Traceback (most recent call last):
File "/usr/lib/python3.5/asyncio/base_events.py", line 989, in connect_read_pipe
yield from waiter
GeneratorExit
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/usr/lib/python3.5/asyncio/base_subprocess.py", line 171, in _connect_pipes
proc.stdout)
File "/usr/lib/python3.5/asyncio/coroutines.py", line 127, in close
return self.gen.close()
File "/usr/lib/python3.5/asyncio/base_events.py", line 991, in connect_read_pipe
transport.close()
File "/usr/lib/python3.5/asyncio/unix_events.py", line 376, in close
self._close(None)
File "/usr/lib/python3.5/asyncio/unix_events.py", line 404, in _close
self._loop.call_soon(self._call_connection_lost, exc)
File "/usr/lib/python3.5/asyncio/base_events.py", line 497, in call_soon
handle = self._call_soon(callback, args)
File "/usr/lib/python3.5/asyncio/base_events.py", line 506, in _call_soon
self._check_closed()
File "/usr/lib/python3.5/asyncio/base_events.py", line 334, in _check_closed
raise RuntimeError('Event loop is closed')
RuntimeError: Event loop is closed
Tested on Ubuntu 16.04, with Python 3.5.2.
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