操作系统实验三（请求页式存储管理）

#include<bits/stdc++.h> using namespace std; int address[256]; int page[256]; int p=256; int pagesize; int kind; int link[32]; void init() { int m=0,m1=0,m2=0,i=0; srand(time(0)); while(i<p) { m = rand() % 32767; address[i] = m + 1; ++i; m1 = rand() % (m + 1); address[i] = m1; ++i; address[i] = m1 + 1; ++i; if (m1 < 32765) { m2 = rand() % (32767 - (m1 + 2)) + m1 + 2; address[i] = m2; ++i; } } for(int i=0;i<p;i++) { cout<<"address["<<std::left<<setw(3)<<i<<"]:"<<std::left<<setw(10)<<address[i]; if(i%4==3) cout<<endl; } cout<<"============================================================================"<<endl; } void LRU(int n) { int flag=0; int location; int key; int count=0; for(int i=0;i<n;i++) { link[i]=0; } for(int i=0; i<p; i++) { for(int j=n-1; j>=0; j--) { if(page[i]==link[j]) { flag=1; location=j; key=link[location]; } } if(flag==0) { count++; for(int j=n-1; j>=0; j--) { link[n-j-1]=link[n-j]; } link[n-1]=page[i]; } else { for(int j=n-1; j>=location; j--) { link[n-j+location-1]=link[n-j+location]; } link[n-1]=key; } flag=0; } cout<<(1-((double)count/p))*100<<"%"<<endl; } void OPT(int n) { int flag=0; int count=0; int furthest=0; int COUT[n]; int countt=0; for(int i=0;i<n;i++) { link[i]=0; } for(int i=0; i<p; i++) { for(int j=n-1; j>=0; j--) { if(page[i]==link[j]) { flag=1; } } for(int j=0; j<n; j++) { COUT[j]=0; } for(int k=i+1; k<p; k++) { for(int j=n-1; j>=0; j--) { if(page[k]==link[j]) { if(COUT[j]==1) { break; } COUT[j]++; furthest=k; } } } if(flag==0) { int flag1=0; count++; for(int j=n-1; j>=0; j--) { if(link[j]==0) { countt++; link[j]=page[i]; break; } if(countt==n) { for(int e=n-1;e>=0;e--) { if(COUT[e]==0) { flag1=1; link[e]=page[i]; break; } } if(link[j]==page[furthest] && flag1==0) { link[j]=page[i]; break; } } } } flag=0; } cout<<(1-((double)count/p))*100<<"%"<<endl; } void FIFO(int n) { int flag=0; int count=0; for(int i=0;i<n;i++) { link[i]=0; } for(int i=0; i<p; i++) { for(int j=n-1; j>=0; j--) { if(page[i]==link[j]) { flag=1; } } if(flag==0) { count++; for(int j=n-1; j>=0; j--) { link[n-j-1]=link[n-j]; } link[n-1]=page[i]; } flag=0; } cout<<(1-((double)count/p))*100<<"%"<<endl; } void LFU(int n) { int flag=0; int location; int key; int count=0; int COUTT[n]; for(int i=0;i<n;i++) { link[i]=0; COUTT[i]=0; } for(int i=0; i<p; i++) { key=10000; for(int j=n-1; j>=0; j--) { if(page[i]==link[j]) { flag=1; COUTT[j]++; } } if(flag==0) { count++; for(int j=n-1; j>=0; j--) { if(COUTT[j]<=key) { key=COUTT[j]; location=j; } } link[location]=page[i]; COUTT[location]=1; } flag=0; } cout<<(1-((double)count/p))*100<<"%"<<endl; } void print() { cout<<"-------------- --------------"<<endl; if(kind==1) { cout<<"OPT"<<endl; } if(kind==2) { cout<<"LRU"<<endl; } if(kind==3) { cout<<"FIFO"<<endl; } if(kind==4) { cout<<"LFU"<<endl; } cout<<std::left<<setw(24)<<"page assigned"<<"pages_in/total references"<<endl; int pageassigned=32768/pagesize; int count=0; for(int i=4;i<=pageassigned;i+=2) { if(kind==1) { cout<<std::left<<setw(24)<<i; OPT(i); } if(kind==2) { cout<<std::left<<setw(24)<<i; LRU(i); } if(kind==3) { cout<<std::left<<setw(24)<<i; FIFO(i); } if(kind==4) { cout<<std::left<<setw(24)<<i; LFU(i); } } } int main() { init(); char str[5]; char *str1="OPT"; char *str2="LRU"; char *str3="FIFO"; char *str4="LFU"; while(1) { cout<<"THE Algorithm Is:"; cin>>str; cout<<"vmsize=32k pagezise(1024,2048,...,8192)="; cin>>pagesize; cout<<"PAGE NUMBER WITH SIZE "<<pagesize<<"k FOR EACH ADDRESS IS:"<<endl; for(int i=0; i<p; i++) { page[i]=address[i]/pagesize+1; cout<<"pageno["<<std::left<<setw(3)<<i<<"]:"<<std::left<<setw(10)<<page[i]; if(i%4==3) cout<<endl; } cout<<endl; if(strcmp(str,str1)==0) { kind=1; print(); } if(strcmp(str,str2)==0) { kind=2; print(); } if(strcmp(str,str3)==0) { kind=3; print(); } if(strcmp(str,str4)==0) { kind=4; print(); } } return 0; }