Re: JamaicaVM and GNU Classpath

[Mark Wielaard]

Hi,

On Wed, 2002-10-23 at 18:21, Andy Walter wrote:
> at aicas GmbH (http://www.aicas.com), we are developing a Java Virtual 
> Machine, JamaicaVM, that comes with its own (clean room) implementation of 
> the standard classes. Since this is redundant work (and, as I understand it, 
> exactely the reason why the GNU Classpath project started), we are very 
> interested in joining your project.

That would be very nice!

> Our VM is currently "closed source" as well as commercial. As far as I 
> understand the Classpath license agreement, this would not be a problem to 
> you. I'd appreciate if we were welcome to join you and think that everybody 
> could benefit.

For license questions you will have to contact address@hidden since
they can give you advice on legal issues. The GNU Classpath license does
indeed allow certain kinds of derived works that are not Free Software.
This was done because we felt that in the end this would benefit
users/developers the most since it would result in having more free
software available. But we do prefer working with Free Software and we
will certainly not promote proprietary closed source software.

So I would ask you kindly to only distribute you VM as free software.
See for example Ada Core Technologies <http://www.gnat.com/> for an
example of a commercial Free Software business. Or of course
http://wonka.acunia.com/.

> The easiest way would be if we could get write access to the repository, so 
> that we can provide code and bug fixes directly. (Of course, we intend to 
> give something back Classpath). Providing the code to a maintainer would be 
> okay for us, too.

I saw that Brian already send you the information on how to contribute
(see also http://www.gnu.org/software/classpath/doc/hacking.html#SEC2)
It would be nice if you have CVS access to integrate changes yourself
since merging changes from others does sometimes take a long time since
we have only that many developers.

> In our developer branch, we replaced our own Java API (expect from java.lang 
> and java.awt*) by GNU Classpath, to see whether there are any unexpected 
> problems. The result looks quite good: We didn't encounter much problems and 
> in Classpath, much more packages are implemented.

Very nice. What tests did you use?

> The only disadvantage is, 
> that with GNU Classpath, JamaicaVM needs more memory and seems to be somewhat 
> slower. Since JamaicaVM is designed for realtime systems, which are typically 
> rather small, embedded systems with weak CPUs, I would expect that we can 
> provide optimizations here.

There are some speed improvements that were recently contributed by the
Orp developers some have already been integrated. I will be integrating
some more in the next couple of days. But besides that GNU Classpath is
indeed not optimized at all so all help here would be greatly
appreciated.

> Since we need to do this anyway, 
> we'd volunteer to write a platform-independent layer for accessing the 
> operating system. (If you don't like this for some reason, no problem. In 
> that case, we would only use the Java code from a common repository and 
> continue with our own native code).

The native libraries of libgcj are already much better being more
platform-independent. Sadly we don't even have a plan on how to merge
these libraries yet. (libgcj uses the CNI interface for most native code
since JNI is much to slow for them).

> What do you think? Are we welcome?

Sure. I look forward to working with you.

Cheers,

Mark