[Python] Python + threads + wxWindows = segfault, help!

D-Man

at Jun 1, 2001 at 3:17 pm

On Thu, May 31, 2001 at 09:53:16PM -0500, Greg Copeland wrote:
I'm working on a project that has a multithreaded wxPython
application. I working on an SMP box. Can anyone tell me
what might be causing this to happen?

Fatal Python error: ceval: orphan tstate

I don't know, but wxWindows might not be thread-safe. I don't yet
know of a GUI toolkit that is. (GTK+, Swing, and Tkinter aren't) My
suggestion is to create a thread that is dedicated to interfacing with
the GUI. All other threads should then send callable objects to that
thread and request that they are executed a la
javax.swing.SwingUtilities.invokeLater() in Swing.

HTH,
-D

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Aahz Maruch

at Jun 1, 2001 at 4:17 pm

⇧

In article <m2y9rcq5b7.fsf at mouse.copelandconsulting.net>,
Greg Copeland wrote:

I'm working on a project that has a multithreaded wxPython
application. I working on an SMP box. Can anyone tell me
what might be causing this to happen?

Fatal Python error: ceval: orphan tstate

If you're using Python 1.5.2, upgrade to Python 2.x; there's a thread
bug in 1.5.2 with SMP combined with creating/destroying large numbers of
threads.

--
--- Aahz <*> (Copyright 2001 by aahz at pobox.com)

Androgynous poly kinky vanilla queer het Pythonista http://www.rahul.net/aahz/
Hugs and backrubs -- I break Rule 6

"Characters exist to suffer, you know. An author needs a little sadism
in her makeup." --Brenda Clough

reply | permalink

Greg Copeland

at Jun 1, 2001 at 6:32 pm

⇧

Arg! In my hurry to get this posted it seems that I left some
important information out. I'm running Python 2.1 with wxPython
2.2.5 and wxWindows 2.2.7, though I get the same results with
2.2.5 as well.

The application design is using the parent for the GUI and
threads for communication. Data is passed back and forth via
Python's Queue class.

Most of the segs that I get seemingly have to do with threads.
I think I'm the only SMP user on the project and oddly enough,
I think I'm the only user seeing issues like this.

Thanks again. Any more ideas or tips would be wonderful!

Greg

aahz at panix.com (Aahz Maruch) writes:

In article <m2y9rcq5b7.fsf at mouse.copelandconsulting.net>,
Greg Copeland wrote:

I'm working on a project that has a multithreaded wxPython
application. I working on an SMP box. Can anyone tell me
what might be causing this to happen?

Fatal Python error: ceval: orphan tstate

If you're using Python 1.5.2, upgrade to Python 2.x; there's a thread
bug in 1.5.2 with SMP combined with creating/destroying large numbers of
threads.
--
--- Aahz <*> (Copyright 2001 by aahz at pobox.com)

Androgynous poly kinky vanilla queer het Pythonista http://www.rahul.net/aahz/
Hugs and backrubs -- I break Rule 6

"Characters exist to suffer, you know. An author needs a little sadism
in her makeup." --Brenda Clough

--
Greg Copeland, Principal Consultant
Copeland Computer Consulting
--------------------------------------------------
PGP/GPG Key at http://www.keyserver.net
DE5E 6F1D 0B51 6758 A5D7 7DFE D785 A386 BD11 4FCD
--------------------------------------------------

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Aahz Maruch

at Jun 1, 2001 at 7:03 pm

⇧

In article <m2vgmgoxtp.fsf at mouse.copelandconsulting.net>,
Greg Copeland wrote:

Arg! In my hurry to get this posted it seems that I left some
important information out. I'm running Python 2.1 with wxPython
2.2.5 and wxWindows 2.2.7, though I get the same results with
2.2.5 as well.

The application design is using the parent for the GUI and
threads for communication. Data is passed back and forth via
Python's Queue class.

Most of the segs that I get seemingly have to do with threads.
I think I'm the only SMP user on the project and oddly enough,
I think I'm the only user seeing issues like this.

Are you calling any extensions other than wxPython? It sounds like some
thread is calling into Python when it doesn't have the Global
Interpreter Lock. Are you sure that threads other than main *don't*
make any wxPython calls?

What OS is this on? (I'm assuming SGI, but....)

--
--- Aahz <*> (Copyright 2001 by aahz at pobox.com)

Androgynous poly kinky vanilla queer het Pythonista http://www.rahul.net/aahz/
Hugs and backrubs -- I break Rule 6

"Characters exist to suffer, you know. An author needs a little sadism
in her makeup." --Brenda Clough

reply | permalink

Greg Copeland

at Jun 1, 2001 at 8:52 pm

⇧

No, I've only started trying to figure out exactly where the
problem is. I haven't been able to spend much time on it yet.
A number of people have told me to get the ActiveState stuff,
which I guess I can try just to make sure, but at this point
I'm pretty sure it's the application and not python and/or
wxWindows (wxPython). BTW, I can't seem to find wxMutexGUI()
in wxPython. Is this me overlooking something or is it simply
not available yet?

BTW, your conclusion is what I've been thinking too, so I guess
I'll have to keep looking for this thing.

Thanks,
Greg

aahz at panix.com (Aahz Maruch) writes:

In article <m2vgmgoxtp.fsf at mouse.copelandconsulting.net>,
Greg Copeland wrote:

Arg! In my hurry to get this posted it seems that I left some
important information out. I'm running Python 2.1 with wxPython
2.2.5 and wxWindows 2.2.7, though I get the same results with
2.2.5 as well.

The application design is using the parent for the GUI and
threads for communication. Data is passed back and forth via
Python's Queue class.

Most of the segs that I get seemingly have to do with threads.
I think I'm the only SMP user on the project and oddly enough,
I think I'm the only user seeing issues like this.

Are you calling any extensions other than wxPython? It sounds like some
thread is calling into Python when it doesn't have the Global
Interpreter Lock. Are you sure that threads other than main *don't*
make any wxPython calls?

What OS is this on? (I'm assuming SGI, but....)
--
--- Aahz <*> (Copyright 2001 by aahz at pobox.com)

Androgynous poly kinky vanilla queer het Pythonista http://www.rahul.net/aahz/
Hugs and backrubs -- I break Rule 6

"Characters exist to suffer, you know. An author needs a little sadism
in her makeup." --Brenda Clough

--
Greg Copeland, Principal Consultant
Copeland Computer Consulting
--------------------------------------------------
PGP/GPG Key at http://www.keyserver.net
DE5E 6F1D 0B51 6758 A5D7 7DFE D785 A386 BD11 4FCD
--------------------------------------------------

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Robin Dunn

at Jun 2, 2001 at 3:50 am

⇧

The application design is using the parent for the GUI and
threads for communication. Data is passed back and forth via
Python's Queue class.

Most of the segs that I get seemingly have to do with threads.
I think I'm the only SMP user on the project and oddly enough,
I think I'm the only user seeing issues like this.

This is a known bug that has been around for some time. It only happens on
SMP hardware, which I don't have yet, so there have been a couple blind
attempts at a fix that have failed.

My new SMP motherboard and processors and etc. arrive next week, so
hopefully soon I'll be able to better understand the problem and then come
up with a solution. (Just don't tell my wife that all this new hardware
($$$) was only bought to squash a bug in free software...)

NT and Win2k users can work around the problem by telling the OS to keep the
process on just one processor:

import win32api, win32process
cp = win32api.GetCurrentProcess()
win32process.SetProcessAffinityMask(cp, 1)

You can keep track of the bug here:
http://sourceforge.net/tracker/?funcÞtail&aid"3169&group_id˜63&atid
9863

--
Robin Dunn
Software Craftsman
robin at AllDunn.com Java give you jitters?
http://wxPython.org Relax with wxPython!

reply | permalink

Greg Copeland

at Jun 2, 2001 at 7:42 pm

⇧

Thanks! My forehead won't be so sore now! BTW, if you need any help
working on it, or you just want someone to help test, please let me
know. I'll be glad to help. Thanks again for the response!!!

Greg

P.S. This application does not use wxPostEvent(), so I'm guessing the
problem doesn't lie there.

"Robin Dunn" <robin at stop.spam.alldunn.com> writes:

The application design is using the parent for the GUI and
threads for communication. Data is passed back and forth via
Python's Queue class.

Most of the segs that I get seemingly have to do with threads.
I think I'm the only SMP user on the project and oddly enough,
I think I'm the only user seeing issues like this.

This is a known bug that has been around for some time. It only happens on
SMP hardware, which I don't have yet, so there have been a couple blind
attempts at a fix that have failed.

My new SMP motherboard and processors and etc. arrive next week, so
hopefully soon I'll be able to better understand the problem and then come
up with a solution. (Just don't tell my wife that all this new hardware
($$$) was only bought to squash a bug in free software...)

NT and Win2k users can work around the problem by telling the OS to keep the
process on just one processor:

import win32api, win32process
cp = win32api.GetCurrentProcess()
win32process.SetProcessAffinityMask(cp, 1)

You can keep track of the bug here:
http://sourceforge.net/tracker/?funcÞtail&aid"3169&group_id˜63&atid
9863

--
Robin Dunn
Software Craftsman
robin at AllDunn.com Java give you jitters?
http://wxPython.org Relax with wxPython!

--
Greg Copeland, Principal Consultant
Copeland Computer Consulting
--------------------------------------------------
PGP/GPG Key at http://www.keyserver.net
DE5E 6F1D 0B51 6758 A5D7 7DFE D785 A386 BD11 4FCD
--------------------------------------------------

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[Python] Python + threads + wxWindows = segfault, help!

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