Re: java layer performance comparisions

[Benedikt Stefansson]

Couple of (actually about ten) questions for Marcus,

>   Sun JDK 1.2.2, Swarm 1999-12-16        36 secs
>   Kaffe 1.0b4, Swarm 1999-12-16          28 secs
>
>   JDK 1.2.2, Swarm 1999-12-16            16 secs

Any idea why there is such a huge difference in the performancs of JDK on
Windows98 vs.  Debian Linux (or is it just the difference in the AMD chip
vs. the Pentium II or the OS? Do you have any comparable machine to the
Pentium II with Linux on it?)

It is  interesting that Kaffe beats JDK by such a large margin, I was
under the impression that JDK (Blackdown?) was faster.

I haven't tried dealing with two VM on Linux, let alone Windows. Wouldn't
this indicate that it is good to keep Kaffe for Swarm work and use
JDK only when it is required (e.g. for JBuilder)?

>   Objective C heatbugs, Swarm 2.0.1       9 secs

In fact I had guestimated the performance hit for the first Java release
to be on the order of 300%, which now is down to about 100% on this
Windows98 machine you were using and the new 1999-12-19 version....That's
still a bit painful for industrial applications (when you are aware hat
you could cut runtime by a half) but there should be enough upside in the
Java version to more than justify using it in an educational setting.

> Further work: no real effort has been made to generate fast JNI stubs,
> and we haven't yet looked at building Swarm models with a native code
> compiler like gcj (http://sourceware.cygnus.com/java).

The gcj stuff would only work on x86 Unix right?

And finally,

On the Java/ObjC point, how hard is it to mix ObjC and Java code from the
user perspective? It is probably just my ignorance, but at the moment I'm
under the impression that an Objective-C programmer can not easily call
Java code from his Swarm  program, and in order to call (user
generated) Objective-C code from Java one would need to go through the
same process you guys went through to generate stubs etc?

--
Benedikt Stefansson      | address@hidden
CASA, Inc.               | Ph : (505) 988-8807 x101
Santa Fe, NM 87501       | Fax: (505) 988-3440




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