[ANN] Hydra VM (multithreaded squeak VM) showing first results

Igor Stasenko siguctua at gmail.com
Tue Dec 25 05:28:26 UTC 2007


On 25/12/2007, Michael van der Gulik <mikevdg at gmail.com> wrote:
>
>
> On Dec 25, 2007 10:24 AM, Igor Stasenko <siguctua at gmail.com> wrote:
> > Hello everyone,
> > i would like to make anyone know, what i have done during December in
> > a collaboration with Andreas, for creating a VM, which can run
> > multiple squeak images in separate native threads, running in
> > parallel.
> >
>
> Hi Igor.
>
> Good work! However, why are you doing this? Why is this better than running
> multiple Squeak images on the same machine with different VMs? I'm not
> understanding what the advantage is over forking off several VMs in the
> usual way and using some fast inter-process communication between them (such
> as shared memory, pipes or TCP/IP).
>

Good question. Communication within same process can be as fast as
reading memory.
And, of course without being too dependent from OS (shared memory,
pipes or TCP/IP).
Another is, that it's certainly much simpler to manage multiple images
within single process boundaries than manage multiple OS processes.
Next reason, that some external resources can require an exclusive
access , and writing plugin which can manage it for multiple images in
single OS process is much easier than writing a plugin which try
manage access for multiple OS processes.

So, in short: main difference is, that multiple OS processes share
nothing and can communicate only using provided OS facilities.
In Hydra VM you still sharing nothing between images, but different
VM/plugins/OS states are now shareable.


-- 
Best regards,
Igor Stasenko AKA sig.



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