|
|
13. Petrinet Design of a Whiteboard Voting System
Werner Van Belle1 - werner@yellowcouch.org, werner.van.belle@gmail.com
1- Programming Technology Lab (PROG)
Department of Computer Science (DINF)
Vrije Universiteit Brussel (VUB); Pleinlaan 2; 1050 Brussel; Belgium
Abstract
:
Continues upon the previous excercise. In this exercise we model a voting system using Petrinets. This exercise was givemn in 2002-2003
|
Exercise 1: Design of a voting system
In this exercise we will try to draw the schematics of our
previous used 'vote to continue' strategy. However, we will do
this in steps.
Draw a CPNet of a repeater. This CPNet should have the
following places: 'inmessage', 'outmessage', connected' and
'repeating'.
Extend this Petri-net with the following places: 'timeout”,
'dead', 'connect'. The timeout place receives a token if a
client times out when sending a message. The dead place should
contain all clients that are dead and the connect place
contains a token if a client connects (or reconnects).
Extend the Petri-net to flush outgoing messages to dead
clients.
Extend the Petri-net with a transition that goes from
repeating to blocking in such a way that the Petri-net behaves
correct.
Change the connected and dead places so that, the number of
elements is known.
Extend the popping of incoming messages such that a
differentiation on ordinary messages and voting messages is
possible.
Finish the exercise...
2 Exercise 2: Implementation
Given the Petri-net investigate how you can implement it.
