操作系统原理实验教程内存页面置换算法设计.doc

#include#include#include#include#define Bsize 3#define Psize 20struct pageInforint content;int timer;class LRU public: LRU(int qstring);int findSpace(void);int findExist(int curpage);int findReplace(void);void display(void);int LRUpro(void);void BlockClear(void);pageInfor * block;pageInfor * page;LRU:LRU(int qstring)int i;block = new pageInforBsize;for(i=0;iBsize;i+) blocki.content=-1; blocki.timer=0;page=new pageInforPsize;for(i=0;iPsize;i+)pagei.content=qstringi;pagei.timer=0;int LRU:findSpace(void) for(int i=0;iBsize;i+) if(blocki.content = -1)return i;return -1;int LRU:findExist(int curpage)for(int i=0;iBsize;i+)if(blocki.content = pagecurpage.content) return i; return -1;int LRU:findReplace(void)int pos=0;for(int i=0;i=blockpos.timer) pos= i;return pos;void LRU:display(void) for(int i = 0;iBsize;i+) if(blocki.content != -1) coutblocki.content ; coutendl;void LRU:BlockClear(void) for(int i = 0;iBsize;i+) blocki.content = -1; blocki.timer = 0; int LRU:LRUpro(void) int exist,space,position; int noscarBsize=0; for(int i = 0;iPsize;i+) exist = findExist(i); if(exist != -1) noscarBsize+; coutno scarpageendl; blockexist.timer=-1; else space=findSpace(); if(space != -1) blockspace=pagei; display(); else position = findReplace(); blockposition=pagei; display(); for(int j = 0;jBsize;j+) blockj.timer+; return noscarBsize;int main(void) cout| -页面置换算法-|endl; coutplease select:endl; cout1.applying algorithm LRUendl; cout0.exitselect; switch(select) case 0: break; case 1: coutthe amout of page block is 3:endl; coutproduce the sequence of 20 length randomlyendl; srand(unsigned)time(NULL); for(i=0;iPsize;i+) if(! (i%10) coutendl; qstringi = rand() %8; cout*qstringi; coutendl; LRU test(qstring); coutthe result of LRU algorithm is:endl; scarBsize=20 - test.LRUpro(); coutthe amout of scarpage is:scarBsizeendl; f=scarBsize/20.0; coutthe ratio of the scarpage:fendl; tes