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Created on2009-02-05 01:52 bybbutler, last changed2022-04-11 14:56 byadmin. This issue is nowclosed.
| Files | ||||
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| File name | Uploaded | Description | Edit | |
| queue_test.py | bbutler,2009-02-05 01:52 | Test script | ||
| Messages (6) | |||
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| msg81183 -(view) | Author: Beau Butler (bbutler) | Date: 2009-02-05 01:52 | |
(Note: This issue only happens on linux - on Windows things work fine.)Please see the attached script.The script creates a process (TestProcess()). That process runs andcreates a sub-process (TestSubProcess()). When TestSubProcess tries toaccess a Queue created by TestProcess, the .get() call fails with thefollowing stack trace:Process Process-1:1:Traceback (most recent call last): File "/opt/python2.6/lib/python2.6/multiprocessing/process.py", line231, in _bootstrap self.run() File "/opt/python2.6/lib/python2.6/multiprocessing/process.py", line88, in run self._target(*self._args, **self._kwargs) File "queue_test.py", line 7, in TestSubProcess item = q.get() # Fails with IOError if queuecreated in TestProcess File "/opt/python2.6/lib/python2.6/multiprocessing/queues.py", line91, in get res = self._recv()IOError: [Errno 9] Bad file descriptorIf the same queue is created by main (top level), TestSubProcessaccesses it with no errors. This behavior can be stimulated byuncommenting the q = multiprocessing.Queue() line in TestProcess.Tested using:Python 2.6.1 (r261:67517, Dec 4 2008, 16:51:00) [MSC v.1500 32 bit(Intel)] on win32(Installed using binary installer, windows XPSP2)*No problems*Python 2.6.1 (r261:67515, Jan 6 2009, 15:23:19) [GCC 4.2.4 (Ubuntu4.2.4-1ubuntu3)] on linux2(Compiled from source due to ubuntu 8.04 (Hardy) not having python2.6 yet)*Fails on q.get() in TestSubProcess* | |||
| msg81184 -(view) | Author: Beau Butler (bbutler) | Date: 2009-02-05 02:30 | |
Also reproduced in Python3.0 on OSX 10.5 | |||
| msg84947 -(view) | Author: Beau Butler (bbutler) | Date: 2009-03-31 23:23 | |
Quick note: Have tracked this down to what appears to be buggy behaviouron the part of os.pipe() when called from within a Process.First invocation of os.pipe() in a Process returns (0,x) - stdin(?)resulting in the 'bad file descriptor' error.Interactive prompt test follows:>>> import multiprocessing as MP, os>>> def r(): print os.pipe(), os.pipe(), os.pipe()... >>> r()(9, 10) (11, 12) (13, 14)>>> MP.Process(target=r).start()(0, 15) (16, 17) (18, 19)>>> MP.Process(target=r).start()(0, 15) (16, 17) (18, 19) | |||
| msg89196 -(view) | Author: OG7 (OG7) | Date: 2009-06-10 11:20 | |
Issue 5313 seems to be the culprit. | |||
| msg89902 -(view) | Author: Jesse Noller (jnoller)* | Date: 2009-06-30 03:04 | |
Patch attached toissue 5313, please review. | |||
| msg89944 -(view) | Author: Jesse Noller (jnoller)* | Date: 2009-06-30 17:14 | |
Committed inr73708 on trunk | |||
| History | |||
|---|---|---|---|
| Date | User | Action | Args |
| 2022-04-11 14:56:45 | admin | set | github: 49405 |
| 2009-06-30 17:14:17 | jnoller | set | status: open -> closed resolution: fixed messages: +msg89944 |
| 2009-06-30 03:04:30 | jnoller | set | messages: +msg89902 |
| 2009-06-10 11:20:25 | OG7 | set | nosy: +OG7 messages: +msg89196 |
| 2009-03-31 23:23:07 | bbutler | set | messages: +msg84947 |
| 2009-03-29 14:38:08 | jnoller | set | priority: normal |
| 2009-02-05 03:30:03 | benjamin.peterson | set | assignee:jnoller nosy: +jnoller |
| 2009-02-05 02:30:43 | bbutler | set | messages: +msg81184 versions: + Python 3.0 |
| 2009-02-05 01:56:40 | bbutler | set | title: Multiprocessing.Queue created by sub-process fails when used in sub-sub-process -> Multiprocessing.Queue created by sub-process fails when used in sub-sub-process ("bad file descriptor" in q.get()) |
| 2009-02-05 01:54:51 | bbutler | set | title: Multiprocessing.Queue created by subprocess fails when used in sub-sub-process -> Multiprocessing.Queue created by sub-process fails when used in sub-sub-process |
| 2009-02-05 01:52:52 | bbutler | create | |