1.txt

进程调度程序

#define N 20
#include<stdio.h>
#include<conio.h>
typedef struct pcb
{
  char pname[N];
  int runtime;
  int arrivetime;
  char state;
  struct pcb *next;
}PCB;
PCB head_input;
PCB head_run;
PCB *pcb_input;
static char R='r',C='c';
unsigned long current;
void inputprocess();
int readyprocess();
int readydata();
int runprocess();
FILE *f;
int readyprocess()
{
   while(1)
   {
     if(readydata()==0)
        return 1;
     else
        runprocess();
   }
}
int readydata()
{
   if(head_input.next==NULL)
   {
      if(head_run.next==NULL)
         return 0;
      else
         return 1;
   }
   PCB *p1,*p2,*p3;
   p1=head_run.next;
   p2=&head_run;
   while(p1!=NULL)
   {
      p2=p1;
      p1=p2->next;
   }
   p1=p2;
   p3=head_input.next;
   p2=&head_input;
   while(p3!=NULL)
   {
      if(((unsigned long)p3->arrivetime<=current)&&(p3->state==R))
      {
         printf("Time slice is %8d(time%4d); Process %s start,\n",
            current,(current+500)/1000,p3->pname);
         fprintf(f,"Time slice is %8d(time%4d); Process %s start,\n",
            current,(current+500)/1000,p3->pname); 
         p2->next=p3->next;
         p3->next=p1->next;
         p1->next=p3;
         p3=p2;
      }
      p2=p3;
      p3=p3->next;
   }
   return 1;
}
int runprocess()
{
   PCB *p1,*p2;
   if(head_run.next==NULL)
   {
     current++;
     return 1;
   }
   else
   {
      p1=head_run.next;
      p2=&head_run;
      while(p1!=NULL)
      {
         p1->runtime--;
         current++;
         if(p1->runtime<=0)
         {
            printf("Time slice is %8d time%4d; Process %s end.\n",
                current,(current+500)/1000,p1->pname);
            fprintf(f,"Time slice is %8d time%4d; Process %s end.\n",
                current,(current+500)/1000,p1->pname);
            p1->state=C;
            p2->next=p1->next;
            delete p1;
            p1=NULL;
         }
         else
         {
           p2=p1;
           p1=p2->next;
         }
      }
      return 1;
   }
}
void inputprocess()
{
   PCB *p1,*p2;
   int num;
   unsigned long max=0;
   printf("How many process do you want to run:");
   fprintf(f,"How many process do you want to run:");
   scanf("%d",&num);
   fprintf(f,"%d\n",&num);
   p1=&head_input;
   p2=p1;
   p1->next=new PCB;
   p1=p1->next;
   for(int i=0;i<num;i++)
   {
      printf("No. %3d process input pname:",i+1);
      fprintf(f,"No. %3d process input pname:",i+1);
      scanf("%s",p1->pname);
      fprintf(f,"%s\n",p1->pname);
      printf("             runtime:");
      fprintf(f,"             runtime:");
      scanf("%d",&(p1->runtime));
      fprintf(f,"%d\n",&(p1->runtime));
      printf("             arrivetime:");
      fprintf(f,"             arrivetime:");
      scanf("%d",&(p1->arrivetime));
      fprintf(f,"%d\n",&(p1->arrivetime));
      p1->runtime=(p1->runtime)*1000;
      p1->arrivetime=(p1->arrivetime)*1000;
      p1->state=R;
      if((unsigned long)(p1->arrivetime)>max)
         max=p1->arrivetime;
      p1->next=new PCB;
      p2=p1;
      p1=p1->next;
   }
   delete p1;
   p1=NULL;
   p2->next=NULL;
}

void main()
{
   f=fopen("result.txt","w");
   printf("\ntime1=1000 time slice\n");
   fprintf(f,"\ntime1=1000 time slice\n");
   current=0;
   inputprocess();
   readyprocess();
   getch();
   fclose(f);
}