最新计算机操作系统试验模拟比较面置换算法及缺率

1、成绩计算机操作系统实验模拟比较页面置换页算法及缺页率学号 200510020220姓名乔峰 班级 信息052实验名称：模拟比较页面置换页算法及缺页率实验目的：(1)掌握先进先出页面置换算法；(2) 掌握最近未用页面置换算法；(3) 了解最近最久未使用页面置换算法以及其他页面置换算法：(4) 熟悉C/C+编程。实验学时：6学时实验内容：编写程序，设置不同的贝面数，使用不同的页面替换策略算法进行 模拟页面替换。先进先出，最近未用页面置换算法等，并计算缺页 率。实验环境：(1) . PC微机(2) . Windows操作系统(3) . C/C+开发环境实验原理及算法参考程序段：#includc #i

2、ncludc #include #include include int add256/* 地址 */,page256/* 页而*/;int k.j,ram,t;float rale;/*缺页率*/struct si int page;int free;int tag; fifo33,opt33Jru33;stmet s2j int time;void addressO;float FIFO(int ram)尸先进先出勺float LRU(int ram);/*最近最久未使用页而置换*/void addrcssO/*产生指令地址*/ int i;add0=1000;for (i=l; i=0)

3、&(x=512)&(x=768)&(x1024)add i=add i-l+random(30* 1024-add i-l-l)+l;float FIFO(int ram) int absent=O.t=O.i,z,Lyn;for (i=0; iram; i+) fifoi.page=-l;fifoij.free=l;fifoi.tag=0;i=0;while (ij) yn=o；for (z=0; zram; z+) /*the page is in the ram?*/if (fifbz.page=pageij)yn=l；for (z=0; zvram; z+)if (fifoz.free

4、=0) fifoz.tag+=l; jif (yn!=l) absent+= 1; /*count the absent page*/1=0;while (lvram)&(fifolfrcc=0)1+;if (lvram)&(fifolfrcc=l)/*any free ram?*/ fifol.page=pagei:fifol.free=0;for (1=0; lvram; 1+)if (fifol.firee=0) fifol.tag+=l;)else /*there is no free ram*/t=0;for (1=0; lram; 1+)if ( fifol.tagfifo|t.t

5、ag)t=l; fifot.page=pagei; fifot.free=0; fifot.tag=l;1=0;)i+;rate=( float )absent/j * 100; return rate; float LRU(int ram) int absent=0,yn.tj,l.z,now=0;struct s2 P250;for (i=0;ij;i+)P(i.time=0;for (i=0; iram; i+) lrui.page=-l;lru(i.free=l;i=0;while(ij) for(l=0; lram; 1+)yn=0; for(z=0; zram; z+)if (lr

6、uz.page=pageij) now+=l;Plruz.page.time=now;yn=l;)if (yn!=l) absent+=l; now+=l;1=0;while (l=ram)&(lrul.frec=O)1+；if (I=ram)&(Irul.free=l) /*any free ram?*/ Irul.page=pagei:Plrul.page.time=now: lrul.free=0;else /*there is no ram*/t=0；for (1=0: lram; 1+)if (Plrul.page.timePlrut.page.time)t=I;lrut.page=

7、pagei;PlrutJ.pageJ.time=now;)i+；rate=(float)absent/j* 100:return rate;void main() int i,p2567* 页号 */clrscr();address();for (k=l; k=8;)/#页面大小:lk,2k,4k,8K*/ printf(Mthe size of a page is %d kn ,k); printf(uthe page num is .An”)； for (i=0; i256; i+)(pi=addi/(k*1024)尸将指令地址生成相应的页号*/ printf(H%dj=0；for (i=

8、0; i256; i+) while (pi=pi+lj)i+；pagej=pi;j+； printf(unafter connect the same pages the page num is:nH);for (i=0; ij; i+)printf(H%d *pagei);printf(HnH);getch();for (ram=l; ramhead-nextpagey/当前页struct page * replacedpage;/要淘汰的页在当前页中寻找要访问的页号while(currentpage¤tpage-number!=accesspage)currcntpage=c

9、urrentpage ncx(pagc;)找到页号则打印J,并返回0if(currcntpage!=NULL&cinrcmpagcnumber=acccsspagc)print Jf,);return 0;没找到则判断页表是否已经满了，没满则调入新页并打印X返回1 else if(pt-pagenumpagetablesize)newpage=(struct page *)malloc(sizeof(struct page); newpage-number=accesspage;newpage-nextpage=newpage-priorpage=NULL; newpage-nextpage=

10、pt-head-nextpage;if(pt-head-nextpage)pt-head-nextpage priorpagc=ncwpagc;pt-head-nextpage=newpage;newpage-priorpage=pt-head;pt-pagenum+;printf(MxH);return 1:如页表已经满,则采用fifo算法进行淘汰选择elsecurrentpage=pt-head-nextpage; replacedpage=NULL;while(currentpage-nextpage)currentpage=currentpage-ncxtpage;replacedpa

11、ge=currentpage;if(replaccdpage-nextpage)(replacedpage-nextpage-priorpage=replacedpage-priorpage;replacedpage-prioipage ncx(page=rcplaccdpagcncx(pagc; free(replaccdpage);newpage=(struct page *)malloc(sizeof(stnict page); newpage-number=accesspage; newpage-nextpage=newpage-priorpage=NULL; newpage-next

12、page=pt-head-nextpage; if(pt-head-nextpage)pt-head-nextpage-priorpage=newpage;pt-head-nextpage=newpage;ne wpage-priorpage=pt-head:printf(MxH);return 1;main()struct pagetable pt;unsigned int totalabsence=0,totalpagenum= 10;unsigned int restpage 100;unsigned int i=0;pt.pagenum=O;pt.pagetablesize=3;pt.

13、head=(struct page*)malloc(sizeof(struct page); pt.head-nextpage=pt.head-priorpage=NULL;从文件获取要读入的页而流HLE *fp:fp=fopen(MIN.dafVru);if(fp=NULL)printf(Hcan not open file IN.DAT!H);retum: while(!feof(fp)fscanf(fp/,%d,&restpagei);i+；fclose(fp);totalpagenum=i;printffthis program for fifo nnM);打印要访问的页for(i=0;itotalpagenum;i+)printf(,%2dH,restpa