"""bank18: A Resource with Priority to vary the number of units"""
## Model components ------------------------
from SimPy.SimulationTrace import *
from random import expovariate,seed
class Source(Process):
""" Source generates customers randomly"""
def generate(self,number,rate):
for i in range(number):
c = Customer(name = "Customer%02d"%(i,),sim=self.sim)
self.sim.activate(c,c.visit(timeInBank=12.0))
yield hold,self,expovariate(rate)
class Customer(Process):
""" Customer arrives, is served and leaves """
def visit(self,timeInBank):
print "%8.4f %s: Arrived "%(self.sim.now(),self.name)
yield request,self,self.sim.counter
print "%8.4f %s: Got counter "%(self.sim.now(),self.name)
tib = expovariate(1.0/timeInBank)
yield hold,self,tib
yield release,self,self.sim.counter
print "%8.4f %s: Finished "%(self.sim.now(),self.name)
class ClerkProcess(Process):
""" This process removes a clerk from the counter
after an average of 20 minutes.
The clerk returns after 5 minutes """
def serverProc(self):
while True:
# The clerk starts working. Leave after an average of 10 minutes
yield hold,self,expovariate(1.0/15.0)
print "%8.4f %s: urgent. Free:"\
"%d, %d waiting"%(self.sim.now(),self.name,
self.sim.counter.n,len(self.sim.counter.waitQ))
# The first free clerk is removed
yield request,self,self.sim.counter,100
print "%8.4f %s: leaves. Free:"\
"%d, %d waiting"%(self.sim.now(), self.name,
self.sim.counter.n,len(self.sim.counter.waitQ))
#period away is 3 minutes
yield hold,self,3.0
#clerk returns
yield release,self,self.sim.counter
print "%8.4f %s: returns. Free:"\
"%d, %d waiting"%(self.sim.now(), self.name,
self.sim.counter.n,len(self.sim.counter.waitQ))
## Experiment data -------------------------
maxTime = 200.0 # minutes
tracing = 0
## Model ----------------------------------
if tracing:
library=SimulationTrace
else:
library=Simulation
class BankModel(library):
def run(self):
self.initialize()
self.counter = Resource(1,name="Clerk",qType=PriorityQ,sim=self)
clerk1 = ClerkProcess('Clerk',sim=self)
self.activate(clerk1, clerk1.serverProc())
source = Source('Source',sim=self)
self.activate(source,source.generate(number=20,rate=0.1),at=0.0)
self.simulate(until=maxTime)
## Experiment ----------------------------------
seed(393939)
BankModel().run()
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