Hi friends, Stackless is changing heavily, once again. After yesterday's move to Python 2.2.2, I am now working on an integration of the old technology (software only) and the new (modifying the hardware stack). This has a number of advantages: - porting of existing applications, which depend on the old changes to Python's interpreter, becomes much easier. They tend to rely on a Python version of 2.0 or lower and use the old structures at the same time. Supporting these, again, makes it possible to do stepwise upgrades. - existing applications like thread pickling (written by TwinSun.com) will be enabled again and merged into Stackless as a feature. While limited to plain frame contexts (no C function or method calls in between), this is very worth doing. - the core Stackless code is using C stack manipulations right now in order to reduce stack size. This is not guaranteed to work with every C extension, since it is hard to check whether a foreign C call is sitting on the stack and relying on variables which must stay in place. The old technology was only able to switch Python stacks, when no recursive C calls were existing. This locks switches of C extensions automagically. - the new technology can be removed from the Python core and be only used for the stackless extension, for tasklet switching. This is not decided yet, but an option. - the amount of C stack space to me moved around is reduced drastically by this hybrid approach, since most of these vanish automatically. Although stack compression has been prepared (and will be supported), this is more time efficient. The reason while I have no longer a problem to make this decision is Python's current state. After generators have been introduced, the core code already has a lot of properties which I need to enable the old technology with ease. Furthermore, this support code will not again try to cover everything, but just the minimum to avoid most recursion. It is neither planned to support stackless map or apply, nor are continuations desired. The target are applications which implemented coroutines on top of the old kernel. This hybrid implementation has started today and will continue over a couple of weeks. The last "plain hardware switching" version is available under the CVS tag "last_hardware_only", which is based on the final 2.2.2 version. I regard this move as the beginning of the re-union of my brain halves :-) continuation-less - ly y'rs chris -- Christian Tismer :^) <mailto:tismer@tismer.com> Mission Impossible 5oftware : Have a break! Take a ride on Python's Johannes-Niemeyer-Weg 9a : *Starship* http://starship.python.net/ 14109 Berlin : PGP key -> http://wwwkeys.pgp.net/ 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? http://www.stackless.com/