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

Using `git bisect` I've discovered the commit (b713adf27a) (https://github.com/python/cpython/commit/b713adf27a) that broke the code.

I've used one script:
```test.py
import sys
sys.path.append("/Users/basnijholt/Downloads/cpython/Lib/concurrent/futures/")
from random import random
from process import ProcessPoolExecutor
import asyncio

ioloop = asyncio.get_event_loop()

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

if __name__ == "__main__":
    executor = ProcessPoolExecutor()
    task = ioloop.run_until_complete(func(ioloop, executor))
```
and `test2.py`
```
import pexpect
import sys

child = pexpect.spawn("python /Users/basnijholt/Downloads/cpython/test.py")
try:
    child.expect(["OSError", "AssertionError"], timeout=1)
    raise Exception
except pexpect.EOF as e:
    sys.exit(0)
```

Then did
```
git checkout master
git reset --hard 9b6c60cbce  # bad commit
git bisect start
git bisect bad
git bisect good ad2c2d380e  # good commit
git bisect run python test2.py
```

I will see if I can fix it.

I don't get the error on 3.11, and I think it may have been fixed under Issue39104.

nosy: + iritkatriel
messages: + msg404196

superseder: ProcessPoolExecutor hangs on shutdown nowait with pickling failure
resolution: duplicate