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Date: Tue, 10 May 2005 13:48:49 +0200
From: Dalibor Topic <robilad@kaffe.org>
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To: harmony-dev@incubator.apache.org
Subject: Re: Isolates support
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Francisco Vega wrote:
> Hi everybody,
> 
> planning the development of a new virtual machine at this moment, it 
> could be interesting to provide support for isolations.
> I supose that most people will know the concept, but in short, the idea 
> is to run several Java programs in parallel in one virtual machine (one 
> OS process) and at the same time:
> - keep all the Java programs in separate and effective sandboxes
> - share the maximum resources (decompiled class code,etc)

Hi Francisco,

Yeah, isolation is pretty nice. There is already an implementation of 
the APIs as Free Software since 2002, called JanosVM, and available at 
http://www.cs.utah.edu/flux/janos/janosvm.html

"Unlike any available virtual machine, the JanosVM supports multiple, 
separate processes (called "teams" in JanosVM) within a single VM. Based 
on KaffeOS (and thus Kaffe), the JanosVM supports per-team separate 
heaps, per-team garbage collection threads, inter-team thread migration, 
safe cross-team reference objects, and a spiffy tutorial. Designed to 
support asynchronous termination of uncooperative or malicious Java 
bytecode applications, the JanosVM provides robust and scalable 
multi-process support within a single virtual machine."

Some of that code has been merged back into Kaffe, but the largest chunk 
that actually implements isolation remains to be merged in, volunteers 
welcome :) Kaffe developer Patrick Tullman is on the JSR committee, 
afaik, and Godmar Back, the author of KaffeOS, is active on the 
isolation JSR mailing lists as well, afaik.

Kaffe is a bit odd that way, as a lot of exciting things exist in some 
Kaffe fork somewhere, be it mixed-mode engines, isolation, efficient 
jits or parallelized virtual machines. It's just merging everthing back 
in that takes  time. :)

cheers,
dalibor topic