Re: [Swarm-Support] Concurrent Schedulling

[Paul Johnson]

I'm not sure concurrent scheduling will really get you where you want to 
go.  Recall Swarm is a discrete event simulation, things happen one 
after another.


If you really do mean simultaneous action, it means that each acts 
without observing any actions from the others at the same instant. 
That's not really a scheduling thing, its a model/environment design thing.

If you are working in the Cellular Automata tradition, you can use the 
double-buffering ideas in swarm ca elements to have all cells update 
against a "snapshot" of the situation.  Mostly, we have been trying to 
get away from that synchronous paradigm in agent-based modeling, people 
would rather have agents do their thing one at a time and observe what 
the other guys are doing.

The Swarm Concurrent apparatus is there in case actions are inserted 
into the schedule at the same time.  How should they be processed? 
Should it be "first in first out" or "randomized" or what not. It may 
have been on the agenda to have some sort of approximation to "true 
simultaneous" action on parallel systems, but I don't know if that is 
actively pursued.

In other words, there are plenty of fiddles you can make with schedules, 
to deal with actions thrown in for the same discrete time step, but none 
of them will result in true simultaneity.  If you want something like 
that, you need to diddle the environment and the agent's knowledge of it.

I think the program "activists" that I did with Dave Brichoux has a 
pretty big component that differentiates agent behaviors on this 
premise.  You can run the model in SYNCHRONOUS mode, so that all agents 
update their behavior at each step in light of a "frozen snapshot" of 
the state of all the others, or they can be ASYNCHRONOUS, which means 
that each one who acts plunks his impact on the environment for the next 
guy to see.  Look for it in 
http://lark.cc.ku.edu/~pauljohn/Swarm/MySwarmCode.

good luck

pj


Triki Amel wrote:
> Hi !!
>  I'm a new user of the Swarm libraries. I have been writing a program in 
> java using Swarm and have a problem with the schedulling and 
> specifically concurrent schedulling. I have a List of agents that 
> have to hear, move and scan to displays in the same time.
>  I dont find how to manipulate ConcurrentGroup and  concurrentSchedule.
>  If there is an example in java, it will help me a lot.
>  Thank you very much for your help !!
>  amel
>
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--
Paul E. Johnson                       email: address@hidden
Dept. of Political Science            http://lark.cc.ku.edu/~pauljohn
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