[issue36281] OSError: handle is closed for ProcessPoolExecutor and run_in_executor

[Bas Nijholt]

New submission from Bas Nijholt <basnijholt at gmail.com>:

The following code in Python 3.7.1
```
import random
import concurrent.futures
import asyncio

executor = concurrent.futures.ProcessPoolExecutor()
ioloop = asyncio.get_event_loop()

async def func():
    result = await ioloop.run_in_executor(executor, random.random)
    executor.shutdown(wait=False)  # bug doesn't occur when `wait=True`

task = ioloop.create_task(func())
```


prints the following error:
```
Exception in thread QueueManagerThread:
Traceback (most recent call last):
  File "/opt/conda/lib/python3.7/threading.py", line 917, in _bootstrap_inner
    self.run()
  File "/opt/conda/lib/python3.7/threading.py", line 865, in run
    self._target(*self._args, **self._kwargs)
  File "/opt/conda/lib/python3.7/concurrent/futures/process.py", line 368, in _queue_management_worker
    thread_wakeup.clear()
  File "/opt/conda/lib/python3.7/concurrent/futures/process.py", line 92, in clear
    while self._reader.poll():
  File "/opt/conda/lib/python3.7/multiprocessing/connection.py", line 255, in poll
    self._check_closed()
  File "/opt/conda/lib/python3.7/multiprocessing/connection.py", line 136, in _check_closed
    raise OSError("handle is closed")
OSError: handle is closed
```

I think this is related to https://bugs.python.org/issue34073 and https://bugs.python.org/issue34075

This happens in the Adaptive package https://adaptive.readthedocs.io/en/latest/docs.html#examples and the related issue is https://github.com/python-adaptive/adaptive/issues/156

----------
components: asyncio
messages: 337868
nosy: asvetlov, basnijholt, yselivanov
priority: normal
severity: normal
status: open
title: OSError: handle is closed for ProcessPoolExecutor and run_in_executor
versions: Python 3.7, Python 3.8

_______________________________________
Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue36281>
_______________________________________