[issue26195] Windows frozen .exe multiprocessing.Queue access is denied exception

[STINNER Victor]

STINNER Victor  added the comment:

No activity since 2016 and Davin considers that we lack information to debug 
this issue, so I close this issue as out of date.

--
nosy: +vstinner
resolution:  -> out of date
stage:  -> resolved
status: open -> closed

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue26195] Windows frozen .exe multiprocessing.Queue access is denied exception

[Alex Robinson]

Alex Robinson added the comment:

Sorry I can't help more than provide a test environment for any fix. I just 
plucked the "fix" from StackOverflow and it fixed the Q problem on my machine.

It appears, at the least, the multiprocessing code should probably not rely on 
the default value for the 'inheritable' argument. That argument does sound like 
one that might be different in the usual case for Win32 and Unix, just because.

--

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue26195] Windows frozen .exe multiprocessing.Queue access is denied exception

[Davin Potts]

Davin Potts added the comment:

Using tools like pyinstaller (and other competing frozen-exe-creating tools) 
unfortunately complicates things for multiprocessing to understand the 
environment it's now in.  It is unclear from this description whether this 
should be regarded as an issue to be addressed in pyinstaller or in 
multiprocessing itself.  Any further information along these lines would be 
much appreciated.

--
nosy: +davin

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue26195] Windows frozen .exe multiprocessing.Queue access is denied exception

[Terry J. Reedy]

Changes by Terry J. Reedy :


--
nosy: +jnoller, sbt

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com

[issue26195] Windows frozen .exe multiprocessing.Queue access is denied exception

[Alex Robinson]

New submission from Alex Robinson:

A pyinstaller 3.0 frozen .exe Python 2.7.10 program under Windows 7 that uses a 
multiprocessing.Queue to send things to a multiprocessing.Process leads to the 
process getting access-is-denied exceptions on every q.get() call.

And, when the program can't exit. Or leaves a dangling process for every 
Process.

An unsatisfying fix for this is to put the following code somewhere in the 
program:

"""
Do what must be done to make multiprocessing work in .exe files.

This involves monkey patching multiprocessing.forking under Windows
so when the a program using a multiprocessing.Process exits,
there won't be processes left running.

Hint from   
http://stackoverflow.com/questions/33764448/pathos-multiprocessing-pipe-and-queue-on-windows

.   The bottom line is we get "access is denied" when trying
.   to get from the multiprocessing.Queue when we're an .exe file.

.   So, in multiprocessing.forking.duplicate(),
.   we change 'inheritable' to default to True
.   from the normal code's False.

"""

import  sys
import  multiprocessing
import  multiprocessing.forking


#
#
#
#
def duplicate(handle, target_process = None, inheritable = True) :
return(multiprocessing.forking.kludge_to_fix_dangling_processes(handle, 
target_process, inheritable))

if  (not hasattr(multiprocessing.forking, 'kludge_to_fix_dangling_processes')) 
and (sys.platform == 'win32') :
multiprocessing.forking.kludge_to_fix_dangling_processes= 
multiprocessing.forking.duplicate
multiprocessing.forking.duplicate   = duplicate

--
components: Library (Lib)
messages: 258895
nosy: alex_python_org
priority: normal
severity: normal
status: open
title: Windows frozen .exe multiprocessing.Queue access is denied exception
type: behavior
versions: Python 2.7

___
Python tracker 

___
___
Python-bugs-list mailing list
Unsubscribe: 
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com