【PPT精品课件】北京邮电大学讲义-计算机通信基础7-2-大.ppt

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1、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第四编 II 计算机仿真2n一、smpl定义系统n二、功能描述n三、模型初始化n四、装置定义和控制n五、事件调度和产生n六、随机变量生成n七、排队网络的仿真模型2smpln八、调试n九、数据采集和报告n十、输出控制n十一、小结3一、smpl定义系统n1、三个smpl的实体n2、facilitiesn3、tokensn4、events4二、功能描述n1、smpl functionsn2、two-line synopsisnFunction and formal parametersnTypes of parametersn3、inc

2、lude“smpl.h”5三、模型初始化n1、smpl(m,s)n int m;char s;n2、reset;6四、装置定义和控制n1、f=facility(s,n)n char*s;int n;n2、r=request(f,tkn,pri)n int f,tkn,pri;n3、r=preempt(f,tkn,pri)n int f,tkn,pri;7四、装置定义和控制(续)n4、release(f,tkn)n int f,tkn;n5、n=inq(f)n r=status(f)n u=real U(f)b=real B(f)l=real Lq(f)n int f;8五、事件调度和产生n1、

3、schedule(ev,te,tkn)n int ev,tkn;real te;n2、cause(ev,tkn)n int*ev,*tkn;n3、tkn=cancel(ev)n int ev;n4、t=real time();9六、随机变量生成n1、r=real ranf();n2、i=stream(n);n int n;n3、r=real expntl(x);n r=real erlang(x,s);n r=hyperx(x,s);n int x,s;10六、随机变量生成（续）n4、r=real uniform(a,b)n real a,b;n5、k=random(i,j)n int i,j

4、;n r=real normal(x,s)n int x,s;11七、排队网络的仿真模型n1、open and closed systemn2、仿真程序12仿真程序nInclude n#define n0 6 /*no.clase 0 tasks*/n#define n1 3 /*no.clase 1 tasks*/n#define nt n0+n1 /*total no.of tasks*/n#define nd 4 /*no.of disk units */n#define qd 1 /*queued req.return*/nstruct tokenn n int cls;/*tasks

5、 class(&priority)*/n int un;/*unit for current IO req.*/n real ts;/*tour start time stamp */n tasknt+1;13仿真程序nint n disknd+1,/*disk facility descriptors*/n cpu,/*cpu facility descriptor */n nts=10000;/*no.of tours to simulate*/nrealn tc2=10.0,5.0,/*class 0,1 mean cpu time*/n td=30.0,sd=7.5;/*disk ti

6、me mean,std.Dev */nmain()n n int i,j,event,n2;real t,s2;struct token*p;n n0=n1=0,s0=s1=0.0;n for(i=1;in0)?1:014仿真程序n smpl(0,“central server model”);n cpu=facility(“CPU”,1);n for(i=1;i=nd;i+)diski=facility(“disk”,1);n for(I=1;its=time();schedule(2,0.0,i)n break;15仿真程序n case 2:/*request cpu*/n j=p-cls

7、;n if(preempt(cpu,i,j)!=qd)then n schedule(3,expntl(tcj),i);n break;n case 3:/*release cpu,select disk*/n release(cpu,i);p-un=random(1,nd);n schedule(4,0.0,i);n break;n case 4:/*request disk*/n if(request(diskp-un,i,0)!=qd)then n schedule(5,erlang(td,sd),i);n break;16仿真程序n case 5:/*release disk,end

8、tour*/n release(diskp-un,i);j=p-cls;n t=time();sj+=t-p-ts;p-ts=t;nj+;n schedule(1,0.0,i);nts-;n break;n n n printf(“class 0 tour time=%.2fn”,s0/n0);n printf(“class 1 tour time=%.2fn”,s1/n1);n17八、调试n1、错误信息 error-messagenEmpty element poolnEmpty name spacenFacility defined after queue/schedulenNegativ

9、e event timenEmpty event listnPreempted token not in event list18调试nRelease of idle/unowned facilitynStream argument errornUniform argument error:abnRandom argument error:ijnErlang argument error:sxnHyperx argument error:s not x 19调试n2、跟踪 trace n3、调试手段20九、数据采集和报告n1、report();n2、smpl 报告手段；n3、自定义报告；21十、输出控制n1、标准输出n2、p=FILE*sendto(dest)n FILE*dest;22十一、小结nSmpl functionsnSimulationnDebuggingnReporting 23十一、小结（续）nSmpl fuction summary24