Description

assignee = None
closed_at = None
created_at = <Date 2021-09-01.05:10:33.552>
labels = ['type-bug', '3.9', '3.10', 'expert-asyncio']
title = 'asyncio hang in subprocess wait_closed() on Windows, BrokenPipeError'
updated_at = <Date 2021-09-01.05:10:33.552>
user = 'https://bugs.python.org/byllyfish'

activity = <Date 2021-09-01.05:10:33.552>
actor = 'byllyfish'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['asyncio']
creation = <Date 2021-09-01.05:10:33.552>
creator = 'byllyfish'
dependencies = []
files = ['50250']
hgrepos = []
issue_num = 45074
keywords = []
message_count = 1.0
messages = ['400810']
nosy_count = 3.0
nosy_names = ['asvetlov', 'yselivanov', 'byllyfish']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue45074'
versions = ['Python 3.9', 'Python 3.10']

Activity

1. byllyfish commented on Sep 1, 2021

   

   byllyfishmannequin

   on Sep 1, 2021

   MannequinAuthor

   More actions

   I have a reproducible case where stdin.wait_closed() is hanging on
   Windows. This happens in response to a BrokenPipeError. The same code
   works fine on Linux and MacOS.

   Please see the attached code for the demo.

   I believe the hang is related to this debug message from the logs:

   DEBUG <_ProactorWritePipeTransport closing fd=632>: Fatal write error on pipe transport
   Traceback (most recent call last):
     File "C:\hostedtoolcache\windows\Python\3.9.6\x64\lib\asyncio\proactor_events.py", line 379, in _loop_writing
       f.result()
     File "C:\hostedtoolcache\windows\Python\3.9.6\x64\lib\asyncio\windows_events.py", line 812, in _poll
       value = callback(transferred, key, ov)
     File "C:\hostedtoolcache\windows\Python\3.9.6\x64\lib\asyncio\windows_events.py", line 538, in finish_send
       return ov.getresult()
   BrokenPipeError: [WinError 109] The pipe has been ended

   It appears that the function that logs "Fatal write error on pipe transport" also
   calls _abort on the stream. If _abort is called before stdin.close(), everything is okay.
   If _abort is called after stdin.close(), stdin.wait_closed() will hang.

   Please see issue bpo-44428 for another instance of a similar hang in wait_closed().
2. byllyfish

   added

   3.9 (EOL)end of lifeend of life

   3.10 (EOL)end of lifeend of life

   topic-asyncio

   type-bugAn unexpected behavior, bug, or errorAn unexpected behavior, bug, or error

   on Sep 1, 2021
3. ezio-melotti

   transferred this issue fromon Apr 10, 2022
4. ezio-melotti

   added this to asyncioon Jun 20, 2022
5. ezio-melotti

   moved this to Todo in asyncioon Jul 17, 2022
6. kumaraditya303 commented on Oct 23, 2022

   

   kumaraditya303

   on Oct 23, 2022

   Contributor

   More actions

   This bug is another instance of protocol.connection_lost callback not getting called correctly. With #98572 the callback is always called which fixes the issue.

   With fix output:

   Running Debug|x64 interpreter...
   BrokenPipe 1 - correct
   BrokenPipe 2 - correct
   
7. kumaraditya303

   self-assigned this

   on Oct 23, 2022
8. kumaraditya303

   added

   3.11only security fixesonly security fixes

   3.12only security fixesonly security fixes

   and removed

   3.9 (EOL)end of lifeend of life

   on Oct 23, 2022
9. gvanrossum

   added a commit that references this issue on Oct 24, 2022

   GH-89237: fix hang in proactor `subprocess.wait_closed()` (#98572)

   ad1dc3e
10. miss-islington

    added 3 commits that reference this issue on Oct 24, 2022

    pythonGH-89237: fix hang in proactor `subprocess.wait_closed()` (pyth…

    018776c

    pythonGH-89237: fix hang in proactor `subprocess.wait_closed()` (pyth…

    78ca5ae

    GH-89237: fix hang in proactor `subprocess.wait_closed()` (GH-98572)

    8ba086f
11. gvanrossum

    added a commit that references this issue on Oct 25, 2022

    [3.11] GH-89237: fix hang in proactor `subprocess.wait_closed()` (GH-…

    8950689
12. gvanrossum

    closed this as completedon Oct 25, 2022
13. Repository owner moved this from Todo to Done in asyncioon Oct 25, 2022

Issue actions