31.c

实现进程间通信,消息的创建、发送和接收,共享存储区的创建、附接和断接,实现储存管理

#define TRUE 1
#define FALSE 0
#define INVALID -1
#define NULL  0

#define  total_instruction  320     
#define  total_vp  32               
#define  clear_period  50           //clearperiod

//Define page struct
typedef struct                      
{
	int pn,pfn,counter,time;
}pl_type;
pl_type pl[total_vp];              

//Define control struct
struct pfc_struct{                  
	int pn,pfn;
	struct pfc_struct *next;
};

typedef struct pfc_struct pfc_type;

pfc_type pfc[total_vp],*freepf_head,*busypf_head,*busypf_tail;

int diseffect,  a[total_instruction];
int page[total_instruction],  offset[total_instruction];

int  initialize(int);
int  FIFO(int);
int  LRU(int);
int  LFU(int);
int  NUR(int);
int  OPT(int);

int main( )
{
  int s,i,j;
  srand(10*getpid());             
s=(float)319*rand( )/32767/32767/2+1;  
for(i=0;i<total_instruction;i+=4) //generate the instruction sequence
{
     if(s<0||s>319)
     {
       printf("When i==%d,Error,s==%d\n",i,s);
       exit(0);
     }
     a[i]=s;                            
     a[i+1]=a[i]+1;                     
     a[i+2]=(float)a[i]*rand( )/32767/32767/2; 
     a[i+3]=a[i+2]+1;                  

     s=(float)(318-a[i+2])*rand( )/32767/32767/2+a[i+2]+2;
     if((a[i+2]>318)||(s>319))
       printf("a[%d+2],a number which is :%d and s==%d\n",i,a[i+2],s);

}
for (i=0;i<total_instruction;i++) //turn the instruction sequence into page stream
{
     page[i]=a[i]/10;
     offset[i]=a[i]%10;
}
for(i=4;i<=32;i++) 
{
      printf("---%2d page frames---\n",i);
      FIFO(i);
      LRU(i);
      LFU(i);
      NUR(i);
      OPT(i);

}
   return 0;
}

//Initiate relevant data structure
int initialize(total_pf)  
//Quantity of memory page of user's process
int total_pf;                         
{int i;
diseffect=0;
for(i=0;i<total_vp;i++)
{
       pl[i].pn=i;
       pl[i].pfn=INVALID;       
       pl[i].counter=0;
       pl[i].time=-1;         
}
for(i=0;i<total_pf-1;i++)
{
       pfc[i].next=&pfc[i+1];
       pfc[i].pfn=i;
}   
pfc[total_pf-1].next=NULL;
pfc[total_pf-1].pfn=total_pf-1;
freepf_head=&pfc[0];        

return 0;
}

//FIFO arithmetic
int FIFO(total_pf) 
//Quantity of memory page of user's process
int total_pf;                    
{
     int i,j;
     pfc_type *p;
     initialize(total_pf);        
     busypf_head=busypf_tail=NULL; 
     for(i=0;i<total_instruction;i++)
   {
   if(pl[page[i]].pfn==INVALID)   
     {
      diseffect+=1;                  
      if(freepf_head==NULL)         
       {
         p=busypf_head->next;
         pl[busypf_head->pn].pfn=INVALID;
         freepf_head=busypf_head;  
         freepf_head->next=NULL;
         busypf_head=p;
       }
        p=freepf_head->next;        
        freepf_head->next=NULL;
        freepf_head->pn=page[i];
        pl[page[i]].pfn=freepf_head->pfn;

	if(busypf_tail==NULL)
        busypf_head=busypf_tail=freepf_head;
     else
    {
      busypf_tail->next=freepf_head;  
      busypf_tail=freepf_head;
     }
        freepf_head=p;
     }
}
printf("FIFO:%6.4f\n",1-(float)diseffect/320);

return 0;
}

//LRU arithmetic
int LRU (total_pf)      
int total_pf;
{
 int min,minj,i,j,present_time;
 initialize(total_pf);
 present_time=0;

for(i=0;i<total_instruction;i++)
  {
      if(pl[page[i]].pfn==INVALID)            
    {
         diseffect++;
         if(freepf_head==NULL)             
      
         min=32767;
         for(j=0;j<total_vp;j++)            
           if(min>pl[j].time&&pl[j].pfn!=INVALID)
                    {
		      min=pl[j].time;
		      minj=j;
		     }
          freepf_head=&pfc[pl[minj].pfn];   
          pl[minj].pfn=INVALID;
          pl[minj].time=-1;
          freepf_head->next=NULL;
      }
        pl[page[i]].pfn=freepf_head->pfn;   
        pl[page[i]].time=present_time;
	freepf_head=freepf_head->next;     
     }
    else
       pl[page[i]].time=present_time;        

    present_time++;
   }
printf("LRU:%6.4f\n",1-(float)diseffect/320);
return 0;
}

//NUR arithmetic
int NUR(total_pf)                 
int  total_pf;
{ int i,j,dp,cont_flag,old_dp;
pfc_type *t;
initialize(total_pf);
dp=0;
for(i=0;i<total_instruction;i++)
{ if (pl[page[i]].pfn==INVALID)         
     {diseffect++;
      if(freepf_head==NULL)               
         { cont_flag=TRUE;
           old_dp=dp;
           while(cont_flag)
             if(pl[dp].counter==0&&pl[dp].pfn!=INVALID)
                 cont_flag=FALSE;
             else
            {
	     dp++;
             if(dp==total_vp)
	        dp=0;
             if(dp==old_dp)
                for(j=0;j<total_vp;j++)
	           pl[j].counter=0;
             }
           freepf_head=&pfc[pl[dp].pfn];
           pl[dp].pfn=INVALID;
           freepf_head->next=NULL;
         }
           pl[page[i]].pfn=freepf_head->pfn;
           freepf_head=freepf_head->next;
      }
else
     pl[page[i]].counter=1;
     if(i%clear_period==0)
        for(j=0;j<total_vp;j++)
             pl[j].counter=0;
}
printf("NUR:%6.4f\n",1-(float)diseffect/320);

return 0;
}

//OPT arithmetic
int OPT(total_pf)       
int total_pf;
{int i,j, max,maxpage,d,dist[total_vp];
pfc_type *t;
initialize(total_pf);
for(i=0;i<total_instruction;i++)
{  
  if(pl[page[i]].pfn==INVALID)      
   {
      diseffect++;
      if(freepf_head==NULL)        
         {for(j=0;j<total_vp;j++)
               if(pl[j].pfn!=INVALID) dist[j]=32767;  
	       else dist[j]=0;
          d=1;
          for(j=i+1;j<total_instruction;j++)
            {
	     if(pl[page[j]].pfn!=INVALID)
             dist[page[j]]=d;
             d++;
             }
          max=-1;
          for(j=0;j<total_vp;j++)
          if(max<dist[j])
            {
	      max=dist[j];
	      maxpage=j;
	     }
           freepf_head=&pfc[pl[maxpage].pfn];
           freepf_head->next=NULL;
           pl[maxpage].pfn=INVALID;
          }
   pl[page[i]].pfn=freepf_head->pfn;
   freepf_head=freepf_head->next;
     }
}
printf("OPT:%6.4f\n",1-(float)diseffect/320);

return 0;
}

//LFU arithmetic
int  LFU(total_pf)        
int total_pf;
{
 int i,j,min,minpage;
 pfc_type *t;
 initialize(total_pf);
 for(i=0;i<total_instruction;i++)
    {  if(pl[page[i]].pfn==INVALID)      
        { diseffect++;
          if(freepf_head==NULL)         
           { min=32767;
            for(j=0;j<total_vp;j++)
              {if(min>pl[j].counter&&pl[j].pfn!=INVALID)
                  {
		   min=pl[j].counter;
	           minpage=j;
		  }
               pl[j].counter=0;
               }
            freepf_head=&pfc[pl[minpage].pfn];
            pl[minpage].pfn=INVALID;
            freepf_head->next=NULL;
            }
	   pl[page[i]].pfn=freepf_head->pfn;  
           pl[page[i]].counter++;
	   freepf_head=freepf_head->next;      
        }
	else
           pl[page[i]].counter++;

      }
printf("LFU:%6.4f\n",1-(float)diseffect/320);

return 0;
}