[New-bugs-announce] [issue39257] contextvars.Context.run hangs forever in ProccessPoolExecutor
Ron Serruya
report at bugs.python.org
Wed Jan 8 05:34:34 EST 2020
New submission from Ron Serruya <ron.serruya at gmail.com>:
Sending Context.run to another process via ProccessPoolExecutor hangs forever:
```
from contextvars import ContextVar, copy_context
from concurrent.futures import ProcessPoolExecutor
from multiprocessing import Process
var: ContextVar[int] = ContextVar('var',default=None)
if __name__ == '__main__':
# ***** This hangs forever *****
with ProcessPoolExecutor(max_workers=1) as pp:
ctx = copy_context()
pp.submit(ctx.run, list)
# ****** This throws 'cannot pickle Context' # ***** This hangs forever *****
ctx = copy_context()
p = Process(target=ctx.run, args=(list,))
p.start()
p.join()
```
python version is 3.8.0
running on Mac OSX 10.15.1
----------
messages: 359575
nosy: ronserruya
priority: normal
severity: normal
status: open
title: contextvars.Context.run hangs forever in ProccessPoolExecutor
type: behavior
versions: Python 3.8
_______________________________________
Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue39257>
_______________________________________
More information about the New-bugs-announce
mailing list