【PPT精品课件】北京邮电大学讲义-计算机通信基础7-2-大

计算机通信基础北京邮电大学计算机科学与技术学院通信技术中心魏更宇2第四编II计算机仿真2一、smpl定义系统二、功能描述三、模型初始化四、装置定义和控制五、事件调度和产生六、随机变量生成七、排队网络的仿真模型3smpl八、调试九、数据采集和报告十、输出控制十一、小结4一、smpl定义系统1、三个smpl的实体2、facilities3、tokens4、events5二、功能描述1、smplfunctions2、two-linesynopsisFunctionandformalparametersTypesofparameters3、include“smpl.h”6三、模型初始化1、smpl(m,s)intm;chars;2、reset;7四、装置定义和控制1、f=facility(s,n)char*s;intn;2、r=request(f,tkn,pri)intf,tkn,pri;3、r=preempt(f,tkn,pri)intf,tkn,pri;8四、装置定义和控制(续)4、release(f,tkn)intf,tkn;5、n=inq(f)r=status(f)u=realU(f)b=realB(f)l=realLq(f)intf;9五、事件调度和产生1、schedule(ev,te,tkn)intev,tkn;realte;2、cause(ev,tkn)int*ev,*tkn;3、tkn=cancel(ev)intev;4、t=realtime();10六、随机变量生成1、r=realranf();2、i=stream(n);intn;3、r=realexpntl(x);r=realerlang(x,s);r=hyperx(x,s);intx,s;11六、随机变量生成（续）4、r=realuniform(a,b)reala,b;5、k=random(i,j)inti,j;r=realnormal(x,s)intx,s;12七、排队网络的仿真模型1、openandclosedsystem2、仿真程序13仿真程序Includesmpl.h#definen06/*no.clase0tasks*/#definen13/*no.clase1tasks*/#definentn0+n1/*totalno.oftasks*/#definend4/*no.ofdiskunits*/#defineqd1/*queuedreq.return*/structtoken{intcls;/*task’sclass(&priority)*/intun;/*unitforcurrentIOreq.*/realts;/*tourstarttimestamp*/}task[nt+1];14仿真程序intdisk[nd+1],/*diskfacilitydescriptors*/cpu,/*cpufacilitydescriptor*/nts=10000;/*no.oftourstosimulate*/realtc[2]={10.0,5.0},/*class0,1meancputime*/td=30.0,sd=7.5;/*disktimemean,std.Dev*/main(){inti,j,event,n[2];realt,s[2];structtoken*p;n[0]=n[1]=0,s[0]=s[1]=0.0;for(i=1;i=nt;i++)taks[i].cls=(in0)?1:015仿真程序smpl(0,“centralservermodel”);cpu=facility(“CPU”,1);for(i=1;i=nd;i++)disk[i]=facility(“disk”,1);for(I=1;i=nt;i++)schedule(1,0.0,i);while(nts){casuse(&event,&i);p=&task[i];switch(event){case1:/*begintour*/p-ts=time();schedule(2,0.0,i)break;16仿真程序case2:/*requestcpu*/j=p-cls;if(preempt(cpu,i,j)!=qd)thenschedule(3,expntl(tc[j]),i);break;case3:/*releasecpu,selectdisk*/release(cpu,i);p-un=random(1,nd);schedule(4,0.0,i);break;case4:/*requestdisk*/if(request(disk[p-un],i,0)!=qd)thenschedule(5,erlang(td,sd),i);break;17仿真程序case5:/*releasedisk,endtour*/release(disk[p-un],i);j=p-cls;t=time();s[j]+=t-p-ts;p-ts=t;n[j]++;schedule(1,0.0,i);nts--;break;}}printf(“class0tourtime=%.2f\n”,s[0]/n[0]);printf(“class1tourtime=%.2f\n”,s[1]/n[1]);}18八、调试1、错误信息error-messageEmptyelementpoolEmptynamespaceFacilitydefinedafterqueue/scheduleNegativeeventtimeEmptyeventlistPreemptedtokennotineventlist19调试Releaseofidle/unownedfacilityStreamargumenterrorUniformargumenterror:abRandomargumenterror:ijErlangargumenterror:sxHyperxargumenterror:snotx20调试2、跟踪trace3、调试手段21九、数据采集和报告1、report();2、smpl报告手段；3、自定义报告；22十、输出控制1、标准输出2、p=FILE*sendto(dest)FILE*dest;23十一、小结SmplfunctionsSimulationDebuggingReporting24十一、小结（续）Smplfuctionsummary