More info on my Python problem....

[JD]

I hope I didn't post this twice, but I didn't see my earlier posting,
so I've posted it again. Please excuse of me you see a 2nd one,
but I suspect this might be a problem with our mailer.

This is another Python problem, I think might be unrelated to
the earlier bug I found.

This is related to a question I have about Python hanging up
either from a shell, or by importing a module.

If my code causes Python to just hang up, and not allowing me
to break out with control-C or control-D, is there a way to
find out what's going on? I don't think it's going into some
infinite loop, because I can usually break out of them with
control-C. What would cause the Python run-time system
to just loose things? The console is dead, but it echo's
carriage returns but that's all it does.

Is there someone who I might contact
via phone to walk me through this? (Assuming I can't get adequate
information here? Or does anyone care about Python bugs?) This is in
Python 2.3.3c1 on OpenBSD (though I doubt the OS matters). The symptom
is
that I run my program and Python locks up. I cannot control-C or
control-D
to get out of it; I have to log in separately and kill -9 the process.
The
process is listed as "D+" while it is hung, though it doesn't seem to be
accessing the disk, and I'm quite sure there are no disk problems
(though
I'm not physically next to the server, so I can't check the drive LED).

How should I approach debugging this? Are there Python tools? Or should
I
use gdb? ktrace? systrace? I'm assuming I have to do this, as a bug
report
which reads "Python locks up" isn't too useful.

John

 

[Paul Rubin]

If my code causes Python to just hang up, and not allowing me
to break out with control-C or control-D, is there a way to
find out what's going on? I don't think it's going into some
infinite loop, because I can usually break out of them with
control-C. What would cause the Python run-time system
to just loose things? The console is dead, but it echo's
carriage returns but that's all it does.

Can you hit ^Z and escape to the shell? Can you switch to another
virtual console and see what's going on? What does the program do?

Is there someone who I might contact
via phone to walk me through this? (Assuming I can't get adequate
information here? Or does anyone care about Python bugs?)

Yes of course people care about Python bugs, but if you want
personalized phone consulting you'll probably have to pay for it.
If you're willing to do that, I'm sure plenty of us here are available.

How should I approach debugging this? Are there Python tools? Or
should I use gdb? ktrace? systrace? I'm assuming I have to do this,
as a bug report which reads "Python locks up" isn't too useful.

If worse comes to worse you may have to run Python under gdb. Is
your program using multiple threads?