zhihuansuanfa.cpp

是操作系统的置换算法

#include<iostream>
using namespace std;
#define N 40
#define M 1024//与页表的零页冲突
void main()
{   int yesize,neicun,pagesize,jishu,ld,yehao,kuaihao,x;
    long jizhi;
	int flag=1,lru,a[8][8],page[N][2] ,memory[N],top=-1,n=0,s1,t1,s2,t2,s3,t3,i,j;
	char ch0,ch1,ch2,ch3;
	for(j=0;j<8;j++)
	    a[0][j]=1;
	   for(i=1;i<8;i++)
		 {
		         for(j=0;j<8;j++)
			       a[i][j]=rand()%2;
			   }
		  for(i=0;i<=7;i++)
		  {
			    for(j=0;j<=7;j++)
				cout<<a[i][j]<<" "; cout<<endl;
		  }
		  cout<<"Enter the yesize:"<<endl;
	            cin>>yesize;
	            for(i=0;i<yesize;i++)
		            for(j=0;j<2;j++)
			            page[i][j]=0;
          cout<<"Enter the memorysize:"<<endl;
	           cin>>neicun;
			   jishu=neicun;
               for(i=0;i<neicun;i++)
				   memory[i]=M;
	      cout<<"Enter the size(1/kb):"<<endl;
	           cin>>pagesize;
		       jizhi=pagesize*1024;
          cout<<"            ****************************************************"<<endl;
		  cout<<"            **                                                **"<<endl;
		  cout<<"            **            Enter the 'L' to LRU                **"<<endl;
		  cout<<"            **                                                **"<<endl;
		  cout<<"            **          if you want out please enter '#'      **"<<endl;
		  cout<<"            ****************************************************"<<endl;
		  cout<<">",cin>>ch0;
		  while((ch0=='L')&&(flag))
		  {
			  	cout<<"Enter the number (10):"<<endl;
		        cin>>ld;
				yehao=ld/jizhi;
				if(page[yehao][1]==0)
				{ 
					cout<<"                                         "<<endl;
					cout<<"不在内存,发生缺页中断"<<endl;
					cout<<"                                         "<<endl;
					if(jishu>0)
					{for(i=1;i<8;i++)
						{for(j=0;j<8;j++)
							{if(a[i][j]==0)
								{a[i][j]=1;break;}
								else if(a[i][j]!=0)
								{;}
							}
						}
						kuaihao=i*8+j;
                        jishu=jishu-1;
					    page[yehao][0]=kuaihao;
						page[yehao][1]=1;
					    top=top+1;
						memory[top]=yehao;
						cout<<"show the ye:"<<endl;
						cout<<"                       块号"<<"    标志位"<<"                    内存"<<endl;
						cout<<"                                                                     "<<endl;
						s1=yesize-1;//这里的s1是为输出页表的时候可以倒着输出而设定的
						t1=neicun-1;//这里的t1是为输出内存的时候可以倒着输出而设定的
						while(t1>=0)
						{cout<<"            "<<"第"<<s1<<"页       "<<page[s1][0]<<"         "<<page[s1][1]<<"             "<<"第"<<t1<<"块     "<<memory[t1]<<endl;
							s1--;	t1--;	}
						while((t1<0)&&(s1>=0))
						{
							cout<<"            "<<"第"<<s1<<"页       "<<page[s1][0]<<"         "<<page[s1][1]<<endl;
							s1--;
						}
						cout<<" Do you want go on yes is enter 'y',else 'n',please choose:"<<endl;
						cout<<"-";
						cin>>ch1;
						if(ch1=='Y')
						{flag=1;}
						else if(ch1=='N')
						{cout<<"Think you see you"<<endl;flag=0;}
						else if((ch1=='y')||(ch1=='n'))
						{cout<<"enter the big'Y'or'N'"<<endl;}
						else 
						{ cout<<"enter error please do it again"<<endl;}
					}
					else
					{
						cout<<"       发生缺页并发生置换    "<<endl;
						x=memory[0];
						page[yehao][0]=page[x][0];
						page[yehao][1]=1;
						page[x][0]=0;
						page[x][1]=0;
						for(i=0;i<neicun-1;i++)
						{
						    memory[i]=memory[i+1];
						}
						memory[neicun-1]=yehao;
						cout<<"此时页表为:"<<endl;
						cout<<"           "<<endl;
						cout<<"                       块号"<<"    标志位"<<"                    内存"<<endl;
						s2=yesize-1;//这里的s2是为输出页表的时候可以倒着输出而设定的
						t2=neicun-1;//这里的t2是为输出内存的时候可以倒着输出而设定的
						while(t2>=0)
						{cout<<"            "<<"第"<<s2<<"页       "<<page[s2][0]<<"         "<<page[s2][1]<<"             "<<"第"<<t2<<"块     "<<memory[t2]<<endl;
							s2--;t2--;}
						while((t2<0)&&(s2>=0))
						{
							cout<<"            "<<"第"<<s2<<"页       "<<page[s2][0]<<"         "<<page[s2][1]<<endl;
							s2--;
						}
						cout<<" Do you want go on yes is enter 'y',else 'n',please choose:"<<endl;
						cout<<"-";
						cin>>ch2;
						if(ch2=='Y')
						{flag=1;}
						else if(ch2=='N')
						{cout<<"欢迎使用本程序"<<endl;flag=0;}
					}
}
				else if(page[yehao][1]==1)
				{
					if(memory[neicun-1]==yehao)
					{;}
					else if ((memory[neicun-1]==M)&&(memory[neicun-2]==M))
					{;}
					else if ((memory[neicun-1]==M)&&(memory[neicun-3]==yehao))//不是3也不会错，只是内存不变而以!!!
					{memory[neicun-3]=memory[neicun-2];memory[neicun-2]=yehao;}
					else if(memory[neicun-1]!=yehao)
					{for(i=0;i<neicun-1;i++)
						{if(memory[i]==yehao)lru=i;break;}
						while(lru<neicun-1)
						{memory[lru]=memory[lru+1];lru++;}
						memory[neicun-1]=yehao;
					}
					    cout<<"该页在内存,发生命中"<<endl;
						cout<<"此时页表为:"<<endl;
						cout<<"                       块号"<<"    标志位"<<"                    内存"<<endl;
						s3=yesize-1;//这里的s3是为输出页表的时候可以倒着输出而设定的
						t3=neicun-1;//这里的t3是为输出内存的时候可以倒着输出而设定的
						while(t3>=0)
						{cout<<"            "<<"第"<<s3<<"页       "<<page[s3][0]<<"         "<<page[s3][1]<<"             "<<"第"<<t3<<"块     "<<memory[t3]<<endl;
							s3--;	t3--;}
						while((t3<0)&&(s3>=0))
						{cout<<"            "<<"第"<<s3<<"页       "<<page[s3][0]<<"         "<<page[s3][1]<<endl;
							s3--;}
						cout<<" Do you want go on yes is enter 'y',else 'n',please choose:"<<endl;
						cout<<"-";
						cin>>ch3;
						if(ch3=='Y')
						{flag=1;}
						else if(ch3=='N')
						{cout<<"欢迎使用本程序"<<endl;
						  flag=0;}
					}
				else if(yehao>6)
				{cout<<"!!!页号超出了了页表长度，发生越界中断"<<endl;}
               }	
		while(ch0=='#')
		  { cout<<"Thinks see you"<<endl; break;}
}//共167行