Re: [Gcl-devel] Re: a few questions about the status and direction of GCL

[mikel evins]

On Nov 22, 2004, at 7:33 AM, Camm Maguire wrote:

> Greetings!
>
> mikel evins <address@hidden> writes:

> > Yes, and it's still readily available, but its license is unclear, and
> > its implentation is extremely (Classic) MacOS-centric.
>
> I'd think it would be worth your while trying to clarify the license.

Yep; we're doing it. t was released under what all involved remember 
was an extremely liberal open-source license, but no one can find an 
actual copy of the license text (in something of a blunder, the license 
text was distributed separately). The former ATG manager responsible 
asserts that there should be no problem, but then he's not at Apple any 
longer. He has contacted someone for us to try to find the license 
text.

> > Another very important question concerns support for multiple threads
> > of control. Can you help us out here? I think absence of some sort of
> > multithreading with reasonable performance characteristics is a
> > show-stopper.
>
> GCL has no threading capability at present.  Multiple processes and
> MPI are options.  Select based multitasking a la cmucl is a simple
> addition.  But my understanding is that lisp threading issues are
> non-trivial.  This said, if you can outline a clear implementation
> strategy, this will accelerate matters.  We do want to get to it
> eventually

Yah, they are nontrivial. It's hard, for example, to decide exactly 
what special variables mean in the context of multiple threads. One 
approach might be to emulate the OpenMCL treatment, which is documented 
here:

http://openmcl.org/Doc/ch04.html

That might be a pretty convenient model, since it's documented, the 
source is available, and we are using OpenMCL at present for the OSX 
prototype.

--me