Is Stackless Python DEAD?

Christian Tismer tismer at
Tue Jan 15 13:48:28 EST 2002

John S. Yates, Jr. wrote:

> On 5 Nov 2001 13:53:28 GMT, amk at (A.M. Kuchling) wrote:
>>Not at all.  Stackless would have ramifications not just for a few
>>files in the core, but also for all the extension modules that come
>>with Python and for all the authors of third-party extension modules.
> Is this because those extension modules would break?  Or because they
> would be sub-optimal until they took advantage of continuations?

The extension modules do not break. But unless they support the
stackless way of calling back into an interpreter, they will
block things like microthreads.
In order to allow a C function to cooperate with Stackless, it needs
to free the C stack completely while it calls other python functions.
Everyting must be saved and restored from the frame chain.
There are cases where this is trivial, and other cases where they
are nearly impossible (aka rewrite the whole extension).

But there is no problem for C extensions which don't call back
into Python or if they do this only for short time, and you can
live with not switching coroutines/microthreads during this call.

ciao - chris

Christian Tismer             :^)   <mailto:tismer at>
Mission Impossible 5oftware  :     Have a break! Take a ride on Python's
Kaunstr. 26                  :    *Starship*
14163 Berlin                 :     PGP key ->
PGP Fingerprint       E182 71C7 1A9D 66E9 9D15  D3CC D4D7 93E2 1FAE F6DF
      where do you want to jump today?

More information about the Python-list mailing list