RE: [Swarm-Modelling] True concurrency?

[North, Michael]

As an extra observation, it is possible to use Repast's (shared-memory)
multiprocessing features in distributed memory situations.  However,
this requires extra work on the part of model developers.  For example,
agents can be distributed to different computers (independently of
Repast) using tools such as ProActive
(http://www-sop.inria.fr/oasis/ProActive/) or raw Java RMI.  Once the
agents are distributed, Repast duration-based multithreaded scheduling
can automatically spawn threads of control to the agents since tools
such as ProActive and RMI make the distributed locations of the agents
transparent to Repast.  Of course, this requires work and computational
sophistication on the part of the model developers.

Mike

> -----Original Message-----
> From: address@hidden [mailto:address@hidden
On
> Behalf Of North, Michael
> Sent: Wednesday, August 31, 2005 2:33 PM
> To: Swarm Modelling
> Subject: RE: [Swarm-Modelling] True concurrency?
> 
> Marcus:
> 
> Good point!  As you correctly observe, Repast requires a true
> shared-memory multiprocessor or automatic kernel support for migration
> of threads.  True shared-memory multiprocessors are common, at least
for
> relatively small numbers of CPUS.  Automatic kernel support for
> migration of threads doesn't really exist.
> 
> Mike
> 
> > -----Original Message-----
> > From: address@hidden
[mailto:address@hidden
> On
> > Behalf Of Marcus G. Daniels
> > Sent: Wednesday, August 31, 2005 2:15 PM
> > To: Swarm Modelling
> > Subject: Re: [Swarm-Modelling] True concurrency?
> >
> > North, Michael wrote:
> > >
> > > If you have multiple CPUs available then the tasks will execute in
> > > true parallel form on multiple CPUs.  The Repast scheduler uses
> thread
> > > pooling to make this efficient.
> > >
> > Thread polling still means you need a true shared-memory
> multiprocessor,
> > and not an ordinary cluster..  (Or automatic kernel support for
> > migration of threads over a Infiniband cluster interconnect or
similar
> > -- which unfortunately doesn't really exist.)
> >
> > [which is not to diminish the feature, just so people don't jump to
> > conclusions!]
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> 
> 
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