MM1排队系统

#coding=utf-8

import time

import random as rd

#import math

import pylab as pl

def simulate(nameda,u):

    arriveInternal=0

    serviceTime=0

    serverCondition=0  #0表示服务台空闲，1表示忙碌

    waitTime=0

    stayTime=[]

    tempArriveEventTime=[10000000]

    tempLeaveEventTime=[10000000]

    #tempArriveEventTime.append(10000000)

    simulateTotalTime=1000000 #仿真时长

    simulateClock=0

    EntityNumber=0

    queneLength=0

    averageStayTime=0

    currentArriveTime=0

    currentLeaveTime=0

    formerArriveTime=0

    formerLeaveTime=0

    lossMessage=0

    #生成仿真表，包括实体的到达时间和离开时间

    while simulateClock<=simulateTotalTime:

            #保存上一个实体的到达、离开时间

            formerArriveTime=currentArriveTime

            formerLeaveTime=currentLeaveTime

            #tempFormerLeaveTime=currentLeaveTime

            ####################随机数生成

            arriveInternal=rd.expovariate(nameda)

            serviceTime=rd.expovariate(u)

            #######到达时间

            if EntityNumber==0:

                currentArriveTime=arriveInternal

            else:

                currentArriveTime=formerArriveTime+arriveInternal

            #仿真结束与否判断

            if currentArriveTime>=simulateTotalTime:

                break

            #等待时间

            if EntityNumber>0 and currentArriveTime<formerLeaveTime:

                waitTime=formerLeaveTime-currentArriveTime

            else:

                waitTime=0

            ##离开时间

            currentLeaveTime=currentArriveTime+waitTime+serviceTime

            #仿真结束与否判断

            if currentLeaveTime>simulateTotalTime:

                break

            ###仿真时钟

            if EntityNumber==0:

                simulateClock=currentLeaveTime#表示实体接受服务，并离开。

                stayTime.append(currentLeaveTime)

            elif queneLength>=10:

                #print("message missed")

                currentLeaveTime=formerLeaveTime

                lossMessage+=1

            ###排队的实体

            if currentArriveTime>=simulateClock and EntityNumber!=0:#开始处理队列的实体

                if len(tempArriveEventTime)>1:

                    minValue=min(tempArriveEventTime)

                    minIndex=tempArriveEventTime.index(minValue)

                    while minValue<=simulateClock:

                        simulateClock=tempLeaveEventTime[minIndex]#实体接受了服务的情况下才会重置仿真时钟

                        tempArriveEventTime.pop(minIndex)

                        tempLeaveEventTime.pop(minIndex)

                        if queneLength>0:

                            queneLength-=1

                        minValue=min(tempArriveEventTime)

                        minIndex=tempArriveEventTime.index(minValue)

                        #print("one processed")

                else:

                    simulateClock=currentLeaveTime

                    stayTime.append(currentLeaveTime-currentLeaveTime)

                    #print("one processed")

            if currentArriveTime<simulateClock and EntityNumber!=0 :

                tempArriveEventTime.append(currentArriveTime)

                tempLeaveEventTime.append(currentLeaveTime)

                queneLength+=1

                stayTime.append(currentLeaveTime-currentArriveTime)

            ###############

            EntityNumber+=1

            if EntityNumber%1000000==0:

                print("arriveTime:"+str(currentArriveTime)+"，leaveTime:"+str(currentLeaveTime))

    lossRate=lossMessage/EntityNumber

    averageStayTime=sum(stayTime)/len(stayTime)

    print("loss rate:"+str(lossMessage/EntityNumber))

    print("lossMessage:"+str(lossMessage))

    print("entity:"+str(EntityNumber))

    return lossRate,averageStayTime

pl.figure(1) #创建图表1，并选择图表1

ax1=pl.subplot(211) #在图表1中创建子图1

ax2=pl.subplot(212) #在图表1中创建子图2

start=time.clock()

for i in range(100):

    a,b=simulate(8, 10)

    print(str(i+1)+" simulate")

    pl.sca(ax1)

    #pl.plot(i,a,'o')

    pl.ylabel("loss rate")

    pl.scatter(i,a)

    #pl.ylim(0,1)

    pl.sca(ax2)

    #pl.plot(i,b,'o')

    pl.scatter(i,b)

    pl.ylabel("stay time")

minutes=(time.clock()-start)/60

print("cost minutes:"+str(minutes))

pl.show()

            
理论部分参考：http://mi.gxu.edu.cn/jpkc/yunchouxue/resource_1info.php?id=29