Parallel DEVS. An Introduction Using PythonPDEVS. Yentl Van Tendeloo, Hans Vangheluwe

Transcription

1 Parallel DEVS An Introduction Using PythonPDEVS Yentl Van Tendeloo, Hans Vangheluwe

2 Introduction

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5 Cellular Automata Process Interaction Discrete Event State Charts Petri Nets Activity Scanning Discrete Event Finite State Automata Event Scheduling Discrete Event DEVS

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7 Experimentation

8 X t S t Y t

9 simple_experiment.py from pypdevs.simulator import Simulator from mymodel import MyModel model = MyModel() simulator = Simulator(model) simulator.setverbose() simulator.simulate()

10 Atomic Models

11 X Red 60s t S Yellow 3s t Y Green 57s t

12 Red 60s Yellow 3s Green 57s M = S, δ int, ta S : set of sequential states S = {red, yellow, green} δ int : S S δ int = {red green, green yellow, yellow red} ta : S R 0,+ ta = {red 60, green 57, yellow 3}

13 S = {red, yellow, green} δ int = { red green, green yellow, yellow red} ta = {red 60, green 57, yellow 3} atomic_int.py from pypdevs.devs import * class TrafficLightAutonomous(AtomicDEVS): def init (self): AtomicDEVS. init (self, Light ) self.state = red def inttransition(self): state = self.state return { red : green, yellow : red, green : yellow }[state] time = 0 current_state = green while True: time += ta(current_state) current_state = δ int (current_state) def timeadvance(self): state = self.state return { red : 60, yellow : 3, green : 57}[state]

14 X Red 60s!red t S Yellow 3s!green!yellow t Y Green 57s t

15 Red 60s!red Yellow 3s Green 57s!yellow!green M = Y, S, δ int, λ, ta S = {red, yellow, green} δ int = { red green, green yellow, yellow red} ta = {red 60, green 57, yellow 3} Y : set of output events Y = { red, green, yellow } λ : S Y b λ = { green [ yellow ], yellow [ red ], red [ green ]}

16 Y = { red, green, yellow } λ = {green yellow, yellow red, red green } atomic_out.py from pypdevs.devs import * class TrafficLightWithOutput(AtomicDEVS): def init (self): AtomicDEVS. init (self, light ) self.state = red self.observe = self.addoutport( observer ) time = 0 current_state = green while True: time += ta(current_state) output(λ(current_state)) current_state = δ int (current_state) def outputfnc(self): state = self.state if state == red : v = green elif state == yellow : v = red elif state == green : v = yellow return {self.observe: [v]}

17 X?manual Red 60s?auto!red S t Manual s Yellow 3s!green?manual!yellow Y t?manual Green 57s t

18 δ ext M = X, Y, S, δ int,, λ, ta?manual Manual s?auto?manual Red 60s!red Yellow 3s!green Y = { red, green, yellow } S = {red, yellow, green, manual} δ int = {red green, green yellow, yellow red} λ = {green yellow, yellow red, red green } ta = {red 60, green 57, yellow 3, manual }!yellow X : set of input events X = { auto, manual }?manual Green 57s δ ext : Q X b S δ ext = {( (*, *), [ manual ]) manual, ( ( manual, *), [ auto ]) red }

19 X = { auto, manual } δ ext = {( (*, *), [ manual ]) manual, ( ( manual, *), [ auto ]) red } time = 0 cur_state = red while True: next_time = time + ta(cur_state) if time_next_ev <= next_time: cur_state = δ ext ((cur_state, e), next_ev) time = time_next_ev else: time = next_time output(λ(current_state)) current_state = δ_int(current_state) atomic_ext.py from pypdevs.devs import * class TrafficLight(AtomicDEVS): def init (self): AtomicDEVS. init (self, light ) self.state = red self.observe = self.addoutport( observer ) self.interrupt = self.addinport( interrupt ) def exttransition(self, inputs): inp = inputs[self.interrupt][0] if inp == manual : return manual elif inp == auto : if self.state == manual : return red

20 M = X, Y, S, δ int, δ ext,, λ, ta X : set of input events Y : set of output events S : set of sequential states δ int : S S δ ext : Q X b S λ : S Y b ta : S R 0,+ δ conf : S X b S δ conf

21 atomic_conf.py from pypdevs.devs import * class TrafficLight(AtomicDEVS): def conftransition(self, inputs): self.elapsed = 0.0 self.state = self.inttransition() self.state = self.exttransition(inputs) return self.state

22 Coupled Models

23 Work 360s!manual!auto Idle 20s

24 ?manual Red 60s Work 360s?auto!red!manual!auto Manual s?manual Yellow 3s!green Idle 20s!yellow?manual Green 57s M = X, Y, D, M i, I i, Z i,j

25 trafficlight_system.py from pypdevs.devs import * from trafficlight import TrafficLight from policeman import Policeman class TrafficLightSystem(CoupledDEVS): def init (self): CoupledDEVS. init (self, system ) self.light = self.addsubmodel(trafficlight()) self.police = self.addsubmodel(policeman()) self.connectports(self.police.out, self.light.interrupt)

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27 City House Road Traffic light Road Commerce Generator Queue Queue Queue Queue Processor Processor Collector Queue Queue

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29 Root coordinator (done, t) (done, t) (*, t) Coordinator Coupled DEVS (*, t) (x, t) (*, t) (y, t) Simulator (done, t) (done, t) Simulator Atomic DEVS Atomic DEVS

30 Applications

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35 Conclusions

36 Conclusions (Y, t) (X, t) (*, t) (done, t) Atomic DEVS Coupled DEVS Closure under coupling Abstract Simulator?manual?auto R 60s!red Work 360s M s Y 3s!green!manual!auto?manual!yellow Idle 20s?manual G 57s

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38 Formalisms Standardization Performance Model libraries Applications Dynamic Structure Tools Algorithms Example Real-time Activity Languages Cell DEVS Distribution Reusable Verification Interoperable Parallel