Gerald wrote:
>
> Hi all.
>
> Alright. In order to gain a good understand of the issues that have
> arisen during the port of Java2 on Linux, I have read over the past
> messages regarding technical difficulties in the port. There seem to
> be several main ones:
Perhaps answers are to be found in the diffs:
ftp://ftp.tux.org/pub/java/JDK-1.2/common/jdk-1.2-pre-v2.diffs.gz
(or similar locations at other mirrors). It uncompresses to a bit over
.5M.
You can even get the source from Sun under SCL, apply the diffs, and fix
those trivial problems the Blackdown crew seems to keep missing.
Nathan
>
> - Linux threads are screwy and the Java2 source (J2S) uses Solaris threads
> rather than pthreads. The two don't mix well.
>
> - J2S is written for 64-bit Solaris.
>
> - J2S uses system calls that are incompatible with Linux.
>
> - Memory management is "tough to port".
>
> - AWT is also somehow hard to port.
>
> The first point makes a lot of sense.
>
> I don't know enough to accept the second point. Yes Solaris 7 is a
> "64-bit OS", even though it might run on a 32-bit processor. But what
> about 2.6 and 2.5? Are those 64-bit OSs too?
>
> For the third point I can only interpret it to mean that J2S does not
> use POSIX calls but some non-standard ones for if they use POSIX
> calls, they must be the same on Linux if they are implemented.
>
> The fourth point I can't understand at all. It's standard C. C
> provides only the malloc/free pair for dynamic memory. I find it hard
> to believe that there could be any sort of shared memory usage. I
> suppose there could be some use of thread local storage. Of all these,
> I can only see possible problems with the latter. Everything else
> should just "compile". What's the problem with memory management?
>
> The fifth one I also can't understand. Isn't Java2 built on top of
> Motif/X? Aren't X and Motif calls "standardized"?
>
> If anyone can shed some light, it would be great. Please CC a copy to
> [EMAIL PROTECTED] directly. I've been trying to subscribe to the
> mailing list and I get these success responses from the mailing list
> program but I don't get any messages from the list itself.
>
> Thanks.
>
> Andreas Jaeger writes:
> > >>>>> Steve Byrne writes:
> >
> > Steve> [EMAIL PROTECTED] (Nelson Minar) writes:
> >
> > >> Java hits threads very hard. In particular, the native threads port of
> > >> Java stresses the glibc threading framework (and the kernel!) more
> > >> than most systems. So you have to contend not just with portability
> > >> problems, not just bugs in the Java sources, but bugs and misfeatures
> > >> in the Linux implementation too.
> >
> > Steve> Right. LinuxThreads doesn't completely play well with signals. This
> > Steve> causes race conditions. It's messy. We may end up including a (slightly)
> > Steve> custom libpthreads with the release to work around these issues.
> >
> > Jürgen told me already about some of the problems with LinuxThreads.
> > Could anyone from the blackdown team come up with a detailed
> > explanation what's broken - and what's needed? As I'm one of the
> > glibc developers[1] I might try to help get some of these into glibc.
>
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