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from SimPy.Simulation import *
import random
"""
Demo of SimPy's event signalling synchronization constructs
"""
print 'demoSimPyEvents'
##Pavlov's dogs
"""Scenario:
Dogs start to drool when Pavlov rings the bell.
"""
class BellMan(Process):
def ring(self):
while True:
bell.signal()
print "%s %s rings bell"%(now(),self.name)
yield hold,self,5
class PavlovDog(Process):
def behave(self):
while True:
yield waitevent,self,bell
print "%s %s drools"%(now(),self.name)
random.seed(111333555)
initialize()
bell=SimEvent("bell")
for i in range(4):
p=PavlovDog("Dog %s"%(i+1))
activate(p,p.behave())
b=BellMan("Pavlov")
activate(b,b.ring())
print "\n Pavlov's dogs"
simulate(until=10)
##PERT simulation
"""
Scenario:
A job (TotalJob) requires 10 parallel activities with random duration to be completed.
"""
class Activity(Process):
def __init__(self,name):
Process.__init__(self,name)
self.event=SimEvent("completion of %s"%self.name)
allEvents.append(self.event)
def perform(self):
yield hold,self,random.randint(1,100)
self.event.signal()
print "%s Event '%s' fired"%(now(),self.event.name)
class TotalJob(Process):
def perform(self,allEvents):
for e in allEvents:
yield waitevent,self,e
print now(),"All done"
random.seed(111333555)
initialize()
allEvents=[]
for i in range(10):
a=Activity("Activity %s"%(i+1))
activate(a,a.perform())
t=TotalJob()
activate(t,t.perform(allEvents))
print "\n PERT network simulation"
simulate(until=100)
## US-style4-way stop intersection
"""
Scenario:
At a US-style 4-way stop intersection, a car may only enter the intersection when it is free.
Cars enter in FIFO manner.
"""
class Car(Process):
def drive(self):
print "%4.1f %s waiting to enter intersection"%(now(),self.name)
yield queueevent,self,intersectionFree
# Intersection free, enter . .
### Begin Critical Section
yield hold,self,1 #drive across
print "%4.1f %s crossed intersection"%(now(),self.name)
### End Critical Section
intersectionFree.signal()
random.seed(111333555)
initialize()
intersectionFree=SimEvent("Intersection free")
intersectionFree.signal()
arrtime=0.0
for i in range(20):
c=Car("Car %s"%(i+1))
activate(c,c.drive(),at=arrtime)
arrtime+=0.2
print "\n 4-way stop intersection"
print simulate(until=100)
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