页面置换算法OPT+FIFO+LRU+clock(共8页).doc

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1、精选优质文档-倾情为你奉上#include#includeusing namespace std;#define BlockSize 10#define PageSize 100int pagePageSize; /页面数组存放页面 int blockBlockSize; /物理块数组int resultPageSizeBlockSize; /存放页面和物理块二维数组int pSize = 0; /用户使用页面数 int bSize = 0; /用户使用物理块数int blockFlagBlockSize; /用于LRU与最佳置换算法中，辅助判断该换出的页面int noPageCount =

2、0; /缺页次数/输入数据void inputData() coutendl请输入物理块数(1=bSize=BlockSize)bSize; cout请输入页面数 (1=pSize=PageSize)pSize; while(bSizeBlockSize|pSizePageSize)/判断用户输入是否在范围内 cout输入范围错误，请重新输入：endl; cout请输入物理块数(1=F=BlockSizebSize; coutendl请输入页面数 (1=p=PageSizepSize; cout请输入页面走向endl; for(int i = 0;i pagei;/初始化page数组void

3、initPage()for(int i = 0;iPageSize;i+) pagei = -1; /初始化block与result数组void initBlockResult() int i = 0; for(i = 0;iBlockSize;i+) blocki = -1; for(i = 0;i PageSize;i+) for(int j = 0; j BlockSize;j+) resultij = -1;/查找物理块中是否存在要调用的页面int Exist(int i) for(int j = 0;j bSize;j+) if(blockj = i) return j; retur

4、n -1;/显示结果void display(int noPageCount) for(int i =0 ;i pSize;i+) cout pagei ; for(int j = 0;j bSize;j+) if(resultij = -1) break; else coutresultij ; coutendl; cout_endl;coutendl缺页次数：noPageCountendl;cout缺页率：(double)noPageCount/pSize)*100%endl;cout=endl;/最佳置换算法OPTvoid OPT()int i = 0,j = 0;int positio

5、n = 0,noPageCount = 0;int pageFlag = 0,resultFlag = 0; /页面标记（下标）指向下一个页面,结果标记表示结果的行，即result数组的行标 for(i = 0;i BlockSize;i+)blockFlagi = 0;while(pageFlag pSize)if(Exist(pagepageFlag) != -1) /判断页面是否已经存在resultFlag+;elseif(position bSize) /判断有无空闲物理块 /若有则将页面放入空闲块blockposition = pagepageFlag;position+;noPag

6、eCount+;for(i = 0;i position;i+)resultresultFlagi = blocki;resultFlag+;elsefor(i = 0;i bSize;i+)for(j = pageFlag+1;j pSize;j+)if(blocki = pagej)blockFlagi = j;break;if(j = pSize) blockFlagi = 999;int optPos = 0,max = blockFlag0;for(int i = 0;i bSize;i+)if(max blockFlagi)max = blockFlagi;optPos = i;b

7、lockoptPos = pagepageFlag;noPageCount+;for(i = 0;i bSize;i+)resultresultFlagi = blocki;resultFlag+;pageFlag+;coutendl最佳置换算法:endl;display(noPageCount);return;/先进先出页面置换算法FIFOvoid FIFO() int blockFlag = 0,pageFlag = 0,resultFlag = 0; /物理块标记，确定该换出的物理块下标 int i = 0,j = 0,noPageCount = 0; int position = 0;

8、 /指示物理块，查找有无空闲 while (pageFlag pSize) if(Exist(pagepageFlag) != -1) resultFlag+; else if(position bSize) blockposition = pagepageFlag; position+; noPageCount+; for(i = 0;i = position;i+) resultresultFlagi = blocki; resultFlag+; else blockblockFlag = pagepageFlag; /blockFlag指示要换出的页面 noPageCount+; for

9、(i = 0;i bSize;i+) resultresultFlagi = blocki; resultFlag+; blockFlag+; blockFlag = blockFlag % bSize; pageFlag+; coutendl先进先出页面置换算法FIFO:endl;display(noPageCount);return;/最近最久未用算法LRUvoid LRU()int i = 0,noPageCount = 0;int pageFlag = 0,resultFlag = 0,position = 0;for(i = 0;i BlockSize;i+) /初始化时间记录数组b

10、lockFlagi = 0;while(pageFlag pSize)if(Exist(pagepageFlag) != -1) /判断页面是否已经在主存中resultFlag+;blockFlagExist(pagepageFlag) = 0; /若在则将时间记录数组对应位置为0elseif(position bSize)blockposition = pagepageFlag;blockFlagposition = 0;position+;noPageCount+;for(i = 0;i = position;i+)resultresultFlagi = blocki;resultFlag

11、+;elseint last = 0,min = blockFlag0;for(int i = 0;i bSize;i+)if(min blockFlagi)min = blockFlagi;last = i;blocklast = pagepageFlag; /置换最久未用页面blockFlaglast = 0;noPageCount+;for(i = 0;i bSize;i+)resultresultFlagi = blocki;resultFlag+;for(i = 0;i bSize;i+)blockFlagi+;pageFlag+;coutendl最近最久未用算法LRU:endl;d

12、isplay(noPageCount);return;/时钟(clock)置换算法void clock()int i = 0,position = 0,noPageCount = 0;bool boolBlockFlagBlockSize;int flag = 0; /访问位循环标记int pageFlag = 0,resultFlag = 0;while(pageFlag pSize)if(Exist(pagepageFlag) != -1)resultFlag+;boolBlockFlagExist(pagepageFlag) = true;elseif(position bSize)bl

13、ockposition = pagepageFlag;noPageCount+;boolBlockFlagposition = true;position+;for(i = 0;i position;i+)resultresultFlagi = blocki;resultFlag+;elsewhile(true) /无限循环，找出访问位为false的页面if(boolBlockFlagflag = false) break;boolBlockFlagflag = false; /若为true，置为falseflag+;flag = flag%bSize;blockflag = pagepage

14、Flag;boolBlockFlagflag = true;flag+;flag = flag%bSize;noPageCount+;for(i = 0;i position;i+)resultresultFlagi = blocki;resultFlag+;pageFlag+;coutendl时钟(clock)置换算法:endl;display(noPageCount);return;int main()initPage();int func;while(func!=5)cout请选择所需要的功能：endl;cout0.输入数据endl;cout1.最佳（optimal）置换算法endl;c

15、out2.先进先出（FIFO）置换算法endl;cout3.最近最久未用（LRU）置换算法endl;cout4.时钟（clock）置换算法endl;cout5.退出endl;switch(func)case 0:inputData();break;case 1:initBlockResult();OPT();break;case 2:initBlockResult();FIFO();break;case 3:initBlockResult();LRU();break;case 4:initBlockResult();clock();break;case 5:break;coutfunc;system(cls); return 0;专心-专注-专业