Tcl adept wanted for Stackless problem

Christian Tismer tismer at
Wed Jun 19 09:38:46 EDT 2002

Dear Lists,

there is still some problem with Tcl and Stackless hiding.

Is there anybody around who knows the Tcl/Tk sources
about as I know Python's?

My big question is:
When does Tcl use C stack entries as globals, which
are passed as function arguments to interpreter calls?
This is of special interest when Python callbacks
are invoked.
The problem is, that I use stack slicing, which moves
parts of the C stack away at some times, and I need
to know when I am forbidden to do that. It is solved
to some extent, but not all.

That's unfortunately not all.
A friend is running the Tcl/Tk mainloop in one real thread,
and stackless tasklets are running in another one (of course
calling into Tcl). When tasklet switches are performed
(again, this is moving stack contents around), there appear
to be crashes, too.
This kind of slicing should be allowed IMHO, since these
are different contexts, which shouldn't interact at all.
Are there any structures which are shared between threads
that use Tcl/Tk? Something that may not disappear during
some operations?

Which part of the documentation / the Tcl/Tk source should
I read to find this out wihout learning everything?

This is really an urgent problem which is blocking me.
If somebody has good knowledge, please show up! :-)

thanks & cheers - chris

Christian Tismer             :^)   <mailto:tismer at>
Mission Impossible 5oftware  :     Have a break! Take a ride on Python's
Johannes-Niemeyer-Weg 9a     :    *Starship*
14109 Berlin                 :     PGP key ->
work +49 30 89 09 53 34  home +49 30 802 86 56  pager +49 173 24 18 776
PGP 0x57F3BF04       9064 F4E1 D754 C2FF 1619  305B C09C 5A3B 57F3 BF04
      whom do you want to sponsor today?

More information about the Python-list mailing list