计算三种缺页中断的缺页数，缺页率和命中率FIFO,LRU,OPT

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/*   计算三种缺页中断的缺页数，缺页率和命中率   FIFO,LRU,OPT*/#include<stdio.h>#include<malloc.h>#include<stdlib.h>#include<time.h>#include<string.h>/*** 默认页表大小为3*/#define PAGETABLELENGTH 3//输出函数，四个参数，缺页数，缺页率和命中率,算法名称//无返回值void output( int pageFault, double pageFaultRate, double hitProbability , char *name){printf("\n=====================\n%s:\n",name);   printf("缺页数是: %d\n",pageFault);   printf("缺页率是: %2.2lf%\n",pageFaultRate*100);   printf("命中率是: %2.2lf%\n",hitProbability*100);}//判断是否命中 int pageHited(int *arr,int begin, int length, int equNum){for(int i=begin;i<length;++i){if(arr[i]==equNum)return i;}return -1;}void arrayInit( int *arr, int length){for(int i=0;i<length;++i)arr[i] = 0;}//FIFO//参数是一个指针以及数组长度//无返回参数//输出，缺页数，缺页率和命中率void fifo( const int *const arr, int length){int pageTable[PAGETABLELENGTH];int hitCount = 0;int firstIn = 0;int pageCount = 0;arrayInit(pageTable, PAGETABLELENGTH);for(int i=0; i< length; ++i){//判断是否命中int hit = pageHited( pageTable, 0, pageCount, arr[i]);if(hit!=-1){++hitCount;}else{//page已经填满   if(pageCount== PAGETABLELENGTH)   {pageTable[firstIn] = arr[i];firstIn = (++firstIn)%PAGETABLELENGTH;   }     //pagetable未填满else{   pageTable[pageCount] = arr[i];   pageCount++;}}}output(length-hitCount,(length-hitCount)/(double)length, (double)hitCount/length, "FIFO" );} //LRU//参数是一个指针以及数组长度//无返回参数//输出，缺页数，缺页率和命中率void lru( const int *const arr, int length){int hitCount = 0;int pageTable[PAGETABLELENGTH];//记录page元素里最近使用的位置int pageLastUsed[PAGETABLELENGTH];int pageCount = 0;arrayInit(pageTable, PAGETABLELENGTH);arrayInit(pageLastUsed, PAGETABLELENGTH);for(int i=0;i<length;++i){int hit = pageHited(pageTable,0,pageCount,arr[i]);if(hit!=-1){++hitCount;pageLastUsed[hit] = i;}else{    if(pageCount==PAGETABLELENGTH){int min = 0;for(int plu = 1; plu<PAGETABLELENGTH; ++plu){min = pageLastUsed[min] < pageLastUsed[plu]?min:plu;}pageTable[min] = arr[i];}else{pageTable[pageCount] = arr[i];pageLastUsed[pageCount++] = i;}}}output(length-hitCount,(length-hitCount)/(double)length, (double)hitCount/length ,"LRU");}//OPT//参数是一个指针以及数组长度//无返回参数//输出，缺页数，缺页率和命中率void opt( int *arr, int length){int hitCount = 0;int pageTable[PAGETABLELENGTH];int pageFuture[PAGETABLELENGTH];int pageCount = 0;arrayInit(pageTable,PAGETABLELENGTH);arrayInit(pageFuture,PAGETABLELENGTH);for(int i=0; i<length; ++i){int hit = pageHited(pageTable, 0, pageCount, arr[i]);if(hit!=-1){++hitCount;}else{//table 满 ,计算在最近的将来谁不会被用到     if(pageCount == PAGETABLELENGTH) {    for(int pi=0; pi<pageCount; ++pi){int find = pageHited(arr,i+1,length,pageTable[pi]);if(find!=-1){pageFuture[pi] = find;}    else{      pageFuture[pi] = length+1;}}    int max = 0;    for(int pii=1; pii<pageCount; ++pii){    max = pageFuture[max] > pageFuture[pii]? max:pii;}      pageTable[max] = arr[i]; } //table未满     else {     pageTable[pageCount++] = arr[i]; }}}output(length-hitCount,(length-hitCount)/(double)length, (double)hitCount/length,"OPT");}//参数是一个int型指针，数组长度//随机生成一个长度为11-20的数组，代表着页的执行顺序,//数字大小为1-9，随机生成，返回数组head指针int* productRandomArray( int *length){//随机数种子srand(int(time(0)));*length =  rand()%10+11;//数组长度int *head = (int *)malloc(sizeof(int)*(*length));    if(head ==NULL){printf("malloc error!\n");return NULL;}//数组赋值for(int i=0;i<(*length);++i){head[i] = rand()%9+1;}return head;}int main(){int length;int *head;head = productRandomArray(&length);if(head == NULL)return -1;printf("=====================Table 大小设置为 3 ==========================\n");printf("====== 实验发现在大多数情况下FIFO 和 LRU 的命中率是一样的 ========\n");printf("======================实验数据是随机生成的========================\n");for(int i=0;i<length;i++)printf("%d ",head[i]);//fifofifo(head,length);//lrulru(head, length);//optopt(head, length);getchar();getchar();return 0;}
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