[minix3] openjdk

[daniel]

Hi everyone... I'd like to start working on porting OpenJDK to minix.
Do you know anyone already working on this?

Thanks.

Daniel.

[pikpik]

Hi,

On Feb 1, 10:42 am, daniel wrote:
> Hi everyone... I'd like to start working on porting OpenJDK to minix.
> Do you know anyone already working on this?

The only relevant things I've heard are that someone else has worked
on porting Kaffe and, as of May 15 2009, there are no known JDK's or
JVM's for MINIX 3.1.8 [1].

Jikes [2] should be available by installing the older packman package
though (available on MINIX 3.1.7 and earlier, or on MINIX 3.1.8 by
backporting it [3]).

I hope this helps,
pikpik

1. Java - http://groups.google.com/group/minix3/browse_thread/thread/71a01e7e04dbbb73/e42869ca84ccd336
2. Jikes - http://jikes.sourceforge.net/
3. Backporting - http://groups.google.com/group/minix3/browse_thread/thread/47c74c1c6a633693

[daniel]

Thanks pikpik, both of them seems not to be updated. So, I think it
worth trying with
OpenJDK.

Thanks again.

Daniel.

On Feb 1, 4:36 pm, pikpik <pikpik.1...@gmail.com> wrote:
> Hi,
>
> On Feb 1, 10:42 am, daniel wrote:
>
> > Hi everyone... I'd like to start working on porting OpenJDK to minix.
> > Do you know anyone already working on this?
>
> The only relevant things I've heard are that someone else has worked
> on porting Kaffe and, as of May 15 2009, there are no known JDK's or
> JVM's for MINIX 3.1.8 [1].
>
> Jikes [2] should be available by installing the older packman package
> though (available on MINIX 3.1.7 and earlier, or on MINIX 3.1.8 by
> backporting it [3]).
>
> I hope this helps,
> pikpik
>

> 1. Java -http://groups.google.com/group/minix3/browse_thread/thread/71a01e7e04...
> 2. Jikes -http://jikes.sourceforge.net/
> 3. Backporting -http://groups.google.com/group/minix3/browse_thread/thread/47c74c1c6a...

[pikpik]

Hi,

On Feb 1, 9:35 pm, daniel wrote:
> Thanks pikpik, both of them seems not to be updated. So, I think it
> worth trying with
> OpenJDK.
>
> Thanks again.
>
> Daniel.

Ok. I hope it goes well!

You're welcome,
pikpik

[srivatsa bhat]

But dont you think it will be a better idea to port JVM/JDK to MINIX after kernel threads are implemented in MINIX?
Since Java has support for threads in the language, I believe you will get better performance if you map them to kernel threads rather than depending upon some user-space thread library.

Regards,
Srivatsa S. Bhat

[Antoine LECA]

srivatsa bhat wrote:
> But dont you think it will be a better idea to port JVM/JDK to MINIX after
> kernel threads are implemented in MINIX?

I am thinking having JVM (or whatever for that matter) to be working
/without/ kernel threads to be a big positive point.

The problem with your point, is that you are heading toward infeodating
JDK to having kernel threads, in other words to have JDK be dependent
from kernel threads; so the day you do NOT have kernel threads (because
you do not want them, because it is brocken, because you want to spare
the overhead, whatever the actual reason), you end not having JVM, nor
any other packages you made depending on that feature.

> Since Java has support for threads in the language, I believe you will get
> better performance if you map them to kernel threads rather than depending
> upon some user-space thread library.

Is it possible to build a limited JVM without any thread support?
('coz embedded target, no MMU, etc.)

Antoine

[srivatsa bhat]

On Thu, Feb 3, 2011 at 9:58 PM, Antoine LECA <Antoine...@gmail.com> wrote:

srivatsa bhat wrote:
> But dont you think it will be a better idea to port JVM/JDK to MINIX after
> kernel threads are implemented in MINIX?

I am thinking having JVM (or whatever for that matter) to be working
/without/ kernel threads to be a big positive point.

The problem with your point, is that you are heading toward infeodating
JDK to having kernel threads, in other words to have JDK be dependent
from kernel threads; so the day you do NOT have kernel threads (because
you do not want them, because it is brocken, because you want to spare
the overhead, whatever the actual reason), you end not having JVM, nor
any other packages you made depending on that feature.

Yes, I agree with you in the case of applications in general. Thank you for pointing it out.

> Since Java has support for threads in the language, I believe you will get
> better performance if you map them to kernel threads rather than depending
> upon some user-space thread library.

Is it possible to build a limited JVM without any thread support?
('coz embedded target, no MMU, etc.)

Well, I am not sure on this.. But I strongly feel that porting JVM to MINIX will be a big headache if you don't wish to depend on any kind of thread support (kernel threads or user-space thread library). This is because internally JVM uses threading very heavily, though the user's Java code might not create/use any threads.
If I recall correctly, even for a simple Hello World program, the JVM internally creates lots of threads. And yes, you will definitely want to have the most important components of JVM such as the interpreter, garbage collector, the Just-In-Time compiler etc all running (almost) simultaneously. So to implement a JVM, I feel one would resort to depending upon atleast a user-space thread library, if not kernel threads.

-Srivatsa S. Bhat