[Stackless] SystemError: error return without exception set

Richard Emslie rxe at ukshells.co.uk
Tue Feb 10 10:06:24 CET 2004


Autoscheduling did work at one point in time.  However, as stackless
internals started to change and a small chat with Christian indicated
there was a much cleaner way to implement this than my nasty hack :-) -
I decided to let things stabalise a little before returning.

I need to catch up on all the recent threads - so if something has been
done about autscheduling recently, apologies.  So to answer Isaac, yup it
is very broken, I would avoid using it (also the interface is very likely
to change to).

So is it now time to revisit autoscheduling?

Cheers,
Richard




On Mon, 9 Feb 2004, Isaac wrote:

> I haven't heard anyone talking about this, but I assume that someone has
> stumbled upon it... Regardless, I think it's worth posting about:
>
>  >>> import stackless as st
>  >>> st.enable_autoschedule(1)
> 0
>  >>> def f(n):
> ...     while 1:
> ...        print n
> ...
>  >>> ta1 = st.tasklet(f)(1)
>  >>> ta2 = st.tasklet(f)(2)
>  >>> st.run()
> 1
> [... Repeated 10 more times ...]
> 2
> [... Repeated 8 more times ...]
> Traceback (most recent call last):
>   File "<stdin>", line 1, in ?
>   File "<stdin>", line 2, in f
> SystemError: error return without exception set
>
> Am I doing something wrong? am I supposed to return something, or is
> this an unresolved bug in stackless, or simply a problem with my
> compile/installation? I'm running on Debian Unstable(sid) with the
> stackless CVS (being as there isn't a linux version for the most recent
> release yet)
>
> Also, a seperate question about autoscheduling: If tasklets are blocked
> on I/O (i.e. a readline from a pipe, or a select call) are they still
> swapped out, or is that too low level of an operation for stackless to
> mess with? This is one of the main reasons for me to want
> autoscheduling, or would that be the appropriate place for an OS thread,
> or maybe some non-blocking polling action?
>
> Thanks,
> Isaac
>
>
> _______________________________________________
> Stackless mailing list
> Stackless at stackless.com
> http://www.stackless.com/mailman/listinfo/stackless
>

_______________________________________________
Stackless mailing list
Stackless at stackless.com
http://www.stackless.com/mailman/listinfo/stackless



More information about the Stackless mailing list