[Isolate-interest] Shared-memory based JavaSpace between Isolates?

[Pete Soper]

> Are there any plans to provide a shared-memory based
> JavaSpace between different Isolates?

In a perfect world OO research and JSR-121 might be engaged in a nice rendezvous
related to this just about now, with a proper understanding of how to create
hybrid systems without compromising the primary goals driving addition of
isolation to Java in the first place. As it is I'm not aware of any thinking, 
let alone formal activity, aimed at a connection between JavaSpaces and JSR-121.

The interest-list bibliography contains at least two sets of relevant docs:
one related to a research "java OS" (the underpinnings of "JanosVM") and 
the other pertaining to a mainframe system for middleware ("IBM VMs"). 

	http://bitser.net/isolate-interest/bib.html

> If not, is there a recommended procedure to implement
> something like that, maybe using a native library?

If what you're asking for is an object that is shared between two isolates, this
would be impossible for an application to implement because of the lack of
communication with the Java implementation, especially as it relates to 
garbage collection and keeping an object visible while it's physical storage
is moving all over within one or the other isolate's heap. This is not to 
mention the issues related to one isolate seeing the effect of another isolate's
mutations of the object.  There just aren't any hooks from native code to 
what's needed and of course low level hooks wouldn't be popular with the Java 
vendors as it would inhibit improvement of their implementations. I guess you 
wouldn't be asking about this if RMI was satisfying.

Regards,
Pete