Re: Coroutines Again :)

["Sebby " <beast@...>]

--- In lua-l@egroups.com, Luiz Henrique de Figueiredo <lhf@t...> 
wrote:
> >Another 
> >solution that would be nice if implemented in Lua would be to make 
> >lua stackless. This way coroutines could easily be implemented in 
a 
> >cross-platform way.
> 
> That's the way we plan to do it in 4.1.

That's good, i'm happy to hear that. I'm sure it will make lots of 
people happy :)

> 
> >Originaly, we wanted to use Lua as our scripting system. So i have 
> >implemented a simple co-routine system on top of Lua. After some 
> >tests, we are hoewver considering making our own scripter because 
of 
> >some performance issues on the Playstation 2 platform.
> 
> That's sad :-(
> Was it the performance of your co-routine layer or was it Lua's 
performance?

Yeah, i wish i could have the 2-3 weeks it will take to write my own 
compiler+VM. Considering that in my test case, i only had 2 co-
routines functioning, i think most of the performance impact came 
from Lua. I had 2 routines running (one at 1 execution per second 
which displayed a message to the console, and the second running 10 
times/sec basibly calling a bunch of dummy stub functions that were 
registered to lua) and considering we wanted to keep a constant 60 
frames per second (we don't have a choice on the Playstation 2 or 
else we get visual artifacts), we had a performance hit of ~7-8% on 
the CPU. This is a lot for us considering we were not doing anything 
else in out code at that point (AI, animations, game logic, ...)

Well we'll give a try with our own staticaly typed language in hopes 
we can get better performance out of it. 

Sebastien St-Laurent
Software Engineer, Z-Axis ltd.
sebby@z-axis.com


> --lhf