操作系统实验2.doc

实验二 模拟比较页面置换页算法及缺页率班级： 信息092 学号： 200912030204 姓名： 郭梦瑶 实验日期： 6月6日一、实验目的和学时1. 实验目的（1）掌握先进先出页面置换算法；（2）掌握最近最久未使用页面置换算法；（3）掌握改进的CLOCK页面置换算法，了解其他页面置换算法；（4）熟悉C/C+或其他语言编程。2、实验学时：6学时二、实验内容编写程序，设置不同的页面数，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，最近最久未使用页面置换算法等，并计算缺页率。三、实验环境1PC微机2Windows 操作系统3C/C+或其他语言开发环境四、实验算法程序及结果1. 程序运行输出的部分界面如下2. C语言程序源代码#include #include #includeint add256/*地址*/,page256/*页面*/;int k,j,ram,t;float rate;/*缺页率*/struct s1 int page; int free; int tag; fifo33,opt33,lru33;struct s2 int time;void address();float FIFO(int ram);/*先进先出*/float LRU(int ram);/*最近最久未使用页面置换*/float OPT(int ram);/*理想型*/int main() int i,p256;/*页号*/ address(); for (k=1; k=8;) /*页面大小: 1k,2k,4k,8K*/ printf(the size of a page is %d kn ,k); printf(the page num is .n); for (i=0; i256; i+) pi=addi/(k*1024); printf(%d ,pi); j=0; for (i=0; i256; i+) while (pi=pi+1)i+; pagej=pi; j+; printf(nafter connect the same pages the page num is:n); for (i=0; ij; i+) printf(%d ,pagei); printf(n); getchar(); for (ram=1; ram=32; ram+) if (ram=10) getchar(); printf(nblock=%d pages= %d,absent rate: ,ram,j); printf(FIFO=%0.2f% ,FIFO(ram); printf(LRU =%0.2f% ,LRU(ram); printf(OPT =%0.2f% ,OPT(ram); k=k*2; getchar(); return 0;void address() int i,x; add0=1000; srand(int)time(0); for (i=1; i=0)&(x=512)&(x=768)&(x1024)addi=addi-1+rand()%(30*1024-addi-1-1)+1; float FIFO(int ram) int absent=0,t=0,i,z,l,yn; for (i=0; iram; i+) fifoi.page=-1; fifoi.free=1; fifoi.tag=0; i=0; while (ij) yn=0;for (z=0; zram; z+) /*the page is in the ram?*/if (fifoz.page=pagei) yn=1; for (z=0; zram; z+) if (fifoz.free=0) fifoz.tag+=1; if (yn!=1) absent+=1; /*count the absent page*/ l=0; while (lram)&(fifol.free=0) l+; if (lram)&(fifol.free=1) fifol.page=pagei; fifol.free=0; for (l=0; lram; l+) if (fifol.free=0 ) fifol.tag+=1; else /*there is no free ram*/ t=0; for (l=0; lram; l+)if ( fifol.tagfifot.tag) t=l; fifot.page=pagei; fifot.free=0; fifot.tag=1; l=0; i+; rate=(float)absent/j*100; return rate;float LRU(int ram) int absent=0,yn,t,i,l,z,now=0; struct s2 P250; for (i=0;ij;i+) Pi.time=0; for (i=0; iram; i+) lrui.page=-1; lrui.free=1; i=0; while(ij) for(l=0; lram; l+) yn=0; for(z=0; zram; z+) if (lruz.page=pagei) now+=1; Plruz.page.time=now; yn=1; if (yn!=1) absent+=1; now+=1; l=0; while (l=ram)&(lrul.free=0) l+;if (l=ram)&(lrul.free=1) lrul.page=pagei; Plrul.page.time=now; lrul.free=0; else /*there is no ram*/ t=0; for (l=0; lram; l+)if ( Plrul.page.timePlrut.page.time) t=l; lrut.page=pagei; Plrut.page.time=now; i+; rate=(float)absent/j*100; return rate;float OPT(int ram)int yn,t,absent=0,i,l1,k,l;for(i=0;iram;i+)opti.page=-1;opti.free=1;opti.tag=0;i=0;while(ij) /*the page in the ram?*/yn=0;for(l1=0;l1ram;l1+)if(pagei=optl1.page)yn=1;for(k=0;kram;k+)optk.tag-=1;if(yn!=1)absent+=1;l=0;while(lram)&(optl.free=0)l+;if(l=ram)&(optl.free=1)optl.page=pagei;optl.free=0;optl.tag-=1;for(l=0;lram;l+)optl.tag-=1;elsefor(l=0;lram;l+)t=i;while(tj&optl.page!=paget)t+;optl.tag+=1;t=0;for(l=0;loptt.tag)t=l;optt.page=pagei;optt.tag=1;i+;rate=(flo