[Python-bugs-list] [Bug #116289] Programs using Tkinter sometimes can't shut down

[noreply@sourceforge.net]

Bug #116289, was updated on 2000-Oct-06 19:25
Here is a current snapshot of the bug.

Project: Python
Category: Tkinter
Status: Open
Resolution: None
Bug Group: None
Priority: 3
Summary: Programs using Tkinter sometimes can't shut down

Details: The following msg from the Tutor list is about 1.6, but I noticed the same thing several times today using 2.0b2+CVS.  In my case, I was running IDLE via

python ../tool/idle/idle.pyw

from a DOS box in my PCbuild directory.  Win98SE.  *Most* of the time, shutting down IDLE via Ctrl+Q left the DOS box hanging.  As with the poster, the only way to regain control was to use the Task Manager to kill off Winoldap.

-----Original Message-----
From: Joseph Stubenrauch <nothingisgoingtochangemyworld@yahoo.com>
Sent: Friday, October 06, 2000 9:23 PM
To: tutor@python.org
Subject: Re: [Tutor] Python 1.6 BUG


Strange, I have been experiencing the same bug myself.
Here's the low down for me:

Python 1.6 with win95
I am running a little Tkinter program
The command line I use is simply: "python foo.py"
About 25-35% of the time, when I close the Tkinter
window, DOS seems to "freeze" and never returns to the
c:\ command prompt.  I have to ctrl-alt-delete
repeatedly and shut down "winoldapp" to get rid of the
window and then shell back into DOS and keep working.
It's a bit of a pain, since I have the habit of
testing EVERYTHING in tiny little stages, so I change
one little thing, test it ... freeze ... ARGH!  Change
one more tiny thing, test it ... freeze ... ARGH! 
However, sometimes it seems to behave and doesn't
bother me for an entire several hour session of python
work.

That's my report on the problem.

Cheers,

Joe


Follow-Ups:

Date: 2000-Oct-07 00:37
By: tim_one

Comment:
More info (none good, but some worse so boosted priority):

+ Happens under release and debug builds.

+ Have not been able to provoke when starting in the debugger.

+ Ctrl+Alt+Del and killing Winoldap is not enough to clean everything up.  There's still a Python (or Python_d) process hanging around that Ctrl+Alt+Del doesn't show.

+ This process makes it impossible to delete the associated Python .dll, and in particular makes it impossible to rebuild Python successfully without a reboot.

+ These processes cannot be killed!  Wintop and Process Viewer both fail to get the job done.  PrcView (a freeware process viewer) itself locks up if I try to kill them using it.  Process Viewer freezes for several seconds before giving up.

+ Attempting to attach to the process with the MSVC debugger (in order to find out what the heck it's doing) finds the process OK, but then yields the cryptic and undocumented error msg "Cannot execute program".

+ The processes are not accumulating cycles.

+ Smells like deadlock.
-------------------------------------------------------

Date: 2000-Oct-12 10:25
By: gvanrossum

Comment:
The recent fix to _tkinter (Tcl_GetStringResult(interp) instead of interp->result) didn't fix this either.

As Tim has remarked in private but not yet recorded here, a workaround is to use pythonw instead of python, so I'm lowering thepriority again.

Also note that the hanging process that Tim writes about apparently prevents Win98 from shutting down properly.
-------------------------------------------------------

For detailed info, follow this link:
http://sourceforge.net/bugs/?func=detailbug&bug_id=116289&group_id=5470