On Thu, 9 Jul 2009, Gerhard Fiedler wrote:

> sergio masci wrote:
> 
> > Having a language and compiler that would generate efficient
> > multitasking code on both a 628 and Windows XP in a multicore
> > processor would be a feat. But the hardest part (that of getting it
> > to work on a 628) is done! Surely you can see that doing the same for
> > a system with MUCH better resources is trivial in comparison. 
> 
> No, I can't see that. Portable, safe and efficient multitasking on a
> modern multicore system is in no way trivial. It is IMO more complex
> than multitasking on a 628, by a few magnitudes.

No Gerhard the fundamental principle is still indentical - you switch 
task contexts. Wheather this means that you need to completely save one 
CPU context and load another OR you arrange for the the task contexts to 
co-exist and simply switch between them is upto the implementor.

Having multiple CPUs each potentially executing a different task where the 
task contexts are not protexted from one another (as in a 628) is no 
differnt to having an interrupt coming along and modifying variables 
belonging to a task when it is unsafe.

Friendly Regards
Sergio Masci
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