Eclipse Now Runs On Jikes Research Virtual Machine

jscribner writes "IBM reached another key milestone in open source: Eclipse, a completely open source platform, now runs on the Jikes Research Virtual Machine (RVM) improving its teaching/research potential because it provides the community with a significant open source Java benchmark that runs on top of a flexible open testbed (Jikes RVM). The testbed runs on Linux and uses the GNU Classpath implementation of Java libraries (read: complete open source solution). Although Jikes RVM was developed by IBM researchers at the IBM TJ Watson Research Center, it was donated to the community in October 2001 and now has a steering committee and core team that include both IBMers and other university researchers."

Does anyone care?

[Anonymous Coward]

I don't mean to offend, but the fact that after 20 minutes there's not even a FP here seems a little odd.

Re:Does anyone care?

[Elwood P Dowd]

I care. This is rad. There's not much to say about it, though.

Re:IBM PR

[daveho]

It's just yet another IBM PR fluff piece.

I disagree. IBM has put a huge amount of time and resources into free software that lots of people use: Eclipse, Linux, etc. The effort to get Eclipse to work on Jikes RVM gives users a world-class Java IDE which is entirely based on open source software. One of the most interesting things about Eclipse on Jikes RVM is that it does not require any changes to Eclipse; the porting effort consistent entirely of fixing bugs and implementing missing functionality i

Re:IBM PR

[rowanxmas]

Well, I can't get it to compile:
Building the library Making all in lib make[1]: Entering directory `/users/xmas/rvmRoot/classpath/i686-pc-linux-gnu/ l ib' top_builddir=.. /bin/sh ./gen-classlist.sh standard F -bootclasspath '' -extdirs '' -sourcepath '' -classpath ../../classpath:../../classpath/external/jaxp/sour ce:../vm/current:.: -d . @classes make[1]: F: Command not found make[1]: *** [compile-classes] Error 127 make[1]: Leaving directory `/users/xmas/rvmRoot/classpath/i686-pc-linux-gnu/l ib' make:

"Java application runs under [a third] JVM"

[clem.dickey]

Congratulation to all who made this possible. I don't imagine it was easy.

What makes this VM different is

[Anonymous Coward]

- it's 99% written in Java itself (not C).
- it uses a modified reference counting scheme for garbage collection.

A selection of memory managers

[saugart]

Even better than just having a modified reference counting scheme, it has a choice of memory managers you can plug in. You can write your own, too. The API for it is JMTk (the Java Memory management Toolkit).

There's more info on the memory management system in the Jikes RVM user's guide [ibm.com].

The memory managers supported include:

• SemiSpace (copying),
• MarkSweep (non-copying),
• CopyMS (non-generational copy/mark-sweep hybrid)
• GenCopy (classic copying generational),
• GenMS (generational with mark-sweep mature space), or
• RefCount (a reference counting collector with non-concurrent cycle collection)
• NoGC (allocation only, no garbage collection)

Re:well, this is interesting

[Amomynos Coward]

> Now if they can just get x86 binaries to run on my P4, we'll be set!

Hmm, you must be using Windows:

Move the mousepointer to the lower left corner and click the button saying Start. From the opening menu select "Run...", type the name of a program to the appearing window and press Ok. Here is a complete list of the executables you can run:

winmine.exe
sol.exe
pinball.exe
freecell.exe

Re:well, this is interesting

[saugart]

> > Now if they can just get x86 binaries to run on my P4, we'll be set! > Hmm, you must be using Windows: I assume by P4 the author meant "Power 4", the name Apple uses to describe a generation of PowerPC processors.

Re:well, this is interesting

[aled]

If I don't get winmine, pinball, sol and freecell in Java my customers won't be motivated to migrate. Linux is reaching the same usability levels of window by having solitaire...

Eclipse without VM - gcj news last month

[okock]

More options came in August [slashdot.org], when the gcj team announced to compile/run eclipse natively without a vm and much better startup time.

Olaf

why is this great

[Anonymous Coward]

ok, so i program in java and i think i have unknowingly actually used jikes...

but someone please explain the implications...
- speed?
- open source?
- portability?

Re:why is this great

[jkauzlar]

Jikes is reportedly faster than Sun's JVM and may have better memory management. Many have said they were disappointed with their application's performance, but when they ran it under Jikes, it was like a breath of fresh air. I've heard no portability advantages since Sun does a good job developing for just about every popularly used OS. Open source code could be ported anywhere there's a compiler, of course.

My hope is that an open source solution would allow for further experimentation with the JIT compi

Another thing to look forward to with OS java

[jkauzlar]

Oh, and I forgot one giant feature we may get to see if Java goes open-source: Multiple applications under one JVM! Sun is working this out although I think they're reluctant to release anything due to issues with security and stability. An open-source developer may be less reluctant. This may be equivalent to having a JVM running as a service and would allow almost perl-like load-times if you want to script in Jython or JRuby or something. Having an unstable JVM like this may not be such a big deal if you'

Re:why is this great

[dhk42]

The jikes that you "have unknowingly acually used" was most likely just the compiler (which has been available for ages and is excellent).

It probably was not the virtual machine described here.