00.txt

操作系统中对于缺页断页程序的处理

 #include <string.h> 
#include <iostream.h> 
#include <math.h> 
void main() 
{ 
  struct aa 
  {  int yh; 
     int bz; 
     int ymh; 
     int xgbz; 
     int cpwz; 
  }
m[7]={{0,1,5,0,11},
      {1,1,8,0,12},
      {2,1,9,0,13},
      {3,1,1,0,21},
      {4,0,0,0,22},
      {5,0,0,0,23},
      {6,0,0,0,121}}; 
char a[10]; 
int b,c,j,i,k=0,p[4]={5,8,9,1}; 
cout<<"修改-modi 退出-quit"<<endl; 
cout<<"please input instruction:"<<endl; 
cin>>a; 
if(strcmp(a,"quit")==0)return; 
   cin>>b>>c; 
while(strcmp(a,"quit")!=0) 
{ 
  for(j=0;j<7;j++) 
  if(m[j].yh==b) 
  { 
   if(m[j].bz==1) 
   { 
    cout<<"address:"<<m[j].ymh*1024+c<<endl; 
    cout<<"page address:"<<m[j].cpwz<<endl; 
    if(strcmp(a,"modi")==0) 
    m[j].xgbz=1; 
   } 
   else 
   { 
    for(i=0;i<7;i++) 
     if(m[i].ymh==p[k]) 
  { 
      if(m[i].xgbz==1) 
      cout<<"第"<<m[i].yh<<"页修改过换出前需写入硬盘!"<<endl; 
      cout<<"page out:"<<m[i].yh<<endl; 
      m[i].bz=0; 
      m[i].ymh=0; 
      m[i].xgbz=0; 
  } 
     m[j].bz=1; 
     m[j].ymh=p[k]; 
     if(strcmp(a,"modi")==0) 
     m[j].xgbz=1; 
     cout<<"page in:"<<m[j].yh<<endl; 
     cout<<"address:"<<m[j].ymh*1024+c<<endl; 
     cout<<"page address:"<<m[j].cpwz<<endl; 
     k=(k+1)>4; 
   } 
  } 
  cin>>a; 
   if(strcmp(a,"quit")==0)return; 
   cin>>b>>c; 
} 
}