Simulation with Erlang

[David W. Bauer Jr.]

You may want to try a scheme where each process receives messages in
timestamp order.. this would at least insure in order processing of
incoming messages from other processes.  Something like a
timestamp-priority relationship on messages.  How synchronized must the
system be?


David


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On Tue, 12 Dec 2000, Vlad Dumitrescu wrote:

#Hi all!
#
#It feels like it should be Friday, but the week is till young *sigh*
#
#As some of you might remember, I am considering to use Erlang in a robotics 
#application. Since the hardware is way too expensive (unless I find a 
#good-hearted sponsor!) I thought I'd try to simulate it with a program. So 
#far so good.
#
#The problem I stumbled upon is how to handle simulation time. My thought was 
#to have processes run free, and a supervisor one (the "world") to check on 
#them and collisions and such. But that is a completely different paradigm 
#than the one I used before (the "objects" are run in the "world" thread, 
#under it's control) and I can't make it work.
#
#More precisely, the Erlang multitasking strategy gives no control over when 
#to yield execution. An Erlang "timeslice" might include very different 
#lengths of "simulation time".
#
#A solution I came up with is to have the world doing the synchronization by 
#sending "tick" messages to each object. But that gives a lot of traffic! And 
#it's not elegant at all.
#
#Can anyone give me some hints of whether it is possible to synchronize 
#everything in a clean way, and if yes, how? Or at least some pointers for 
#where to look further.
#
#thanks in advance,
#Vlad
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