進程調度c模擬實現

#include "stdio.h"
#include "stdlib.h"
#include "string.h"
typedef struct node
{
   char name[10];  /*進程標識符*/
   int prio;   /*進程優先數*/
   int round;  /*進程時間輪轉時間片*/
   int cputime; /*進程占用CPU時間*/
   int needtime; /*進程到完成還要的時間*/
   int count;  /*計數器*/
   char state; /*進程的狀態*/
   struct node *next; /*鏈指針*/
}PCB;
PCB *finish,*ready,*tail,*run; /*隊列指針*/
int N; /*進程數*/
/*將就緒隊列中的第一個進程投入運行*/
firstin()
{
   run=ready;   /*就緒隊列頭指針賦值給運行頭指針*/
   run->state='R';   /*進程狀態變為運行態*/
   ready=ready->next;  /*就緒對列頭指針后移到下一進程*/
}
/*標題輸出函數*/
void prt1(char a)
{
   if(toupper(a)=='P') /*優先數法*/
      printf("  name     cputime  needtime  priority  state\n");
   else
      printf("  name     cputime  needtime   count   round     state\n");
}
/*進程PCB輸出*/
void prt2(char a,PCB *q)
{
   if(toupper(a)=='P')  /*優先數法的輸出*/
      printf("  %-10s%-10d%-10d%-10d %c\n",q->name,
       q->cputime,q->needtime,q->prio,q->state);
   else/*輪轉法的輸出*/
      printf("  %-10s%-10d%-10d%-10d%-10d %-c\n",q->name,
       q->cputime,q->needtime,q->count,q->round,q->state);
}
/*輸出函數*/
void prt(char algo)
{
   PCB *p;
   prt1(algo);  /*輸出標題*/
   if(run!=NULL) /*如果運行指針不空*/
      prt2(algo,run); /*輸出當前正在運行的PCB*/
   p=ready;  /*輸出就緒隊列PCB*/
   while(p!=NULL)
   {
      prt2(algo,p);
      p=p->next;
   }
   p=finish;  /*輸出完成隊列的PCB*/
   while(p!=NULL)
   {
      prt2(algo,p);
      p=p->next;
   }
   getch();  /*壓任意鍵繼續*/
}
/*優先數的插入算法*/
insert1(PCB *q)
{
   PCB *p1,*s,*r;
   int b;
   s=q;  /*待插入的PCB指針*/
   p1=ready; /*就緒隊列頭指針*/
   r=p1; /*r做p1的前驅指針*/
   b=1;
   while((p1!=NULL)&&b)  /*根據優先數確定插入位置*/
      if(p1->prio>=s->prio)
      {
     r=p1;
     p1=p1->next;
      }
      else
     b=0;
   if(r!=p1)  /*如果條件成立說明插入在r與p1之間*/
   {
      r->next=s;
      s->next=p1;
   }
   else
   {
      s->next=p1;  /*否則插入在就緒隊列的頭*/
      ready=s;
   }
}
/*輪轉法插入函數*/
insert2(PCB *p2)
{
   tail->next=p2;  /*將新的PCB插入在當前就緒隊列的尾*/
   tail=p2;
   p2->next=NULL;
}
/*優先數創建初始PCB信息*/
void create1(char alg)
{
   PCB *p;
   int i,time;
   char na[10];
   ready=NULL; /*就緒隊列頭指針*/
   finish=NULL;  /*完成隊列頭指針*/
   run=NULL; /*運行隊列指針*/
   printf("Enter name and time of process\n"); /*輸入進程標識和所需時間創建PCB*/
   for(i=1;i<=N;i++)
   {
      p=malloc(sizeof(PCB));
      scanf("%s",na);
      scanf("%d",&time);
      strcpy(p->name,na);
      p->cputime=0;
      p->needtime=time;
      p->state='w';
      p->prio=50-time;
      if(ready!=NULL) /*就緒隊列不空調用插入函數插入*/
     insert1(p);
      else
      {
     p->next=ready; /*創建就緒隊列的第一個PCB*/
     ready=p;
      }
   }
   clrscr();
   printf("          output of priority:\n");
   printf("************************************************\n");
   prt(alg);  /*輸出進程PCB信息*/
   run=ready; /*將就緒隊列的第一個進程投入運行*/
   ready=ready->next;
   run->state='R';
}
/*輪轉法創建進程PCB*/
void create2(char alg)
{
   PCB *p;
   int i,time;
   char na[10];
   ready=NULL;
   finish=NULL;
   run=NULL;
   printf("Enter name and time of round process\n");
   for(i=1;i<=N;i++)
   {
      p=malloc(sizeof(PCB));
      scanf("%s",na);
      scanf("%d",&time);
      strcpy(p->name,na);
      p->cputime=0;
      p->needtime=time;
      p->count=0; /*計數器*/
      p->state='w';
      p->round=2;  /*時間片*/
      if(ready!=NULL)
     insert2(p);
      else
      {
     p->next=ready;
     ready=p;
     tail=p;
      }
   }
   clrscr();
   printf("              output of round\n");
   printf("************************************************\n");
   prt(alg);   /*輸出進程PCB信息*/
   run=ready;  /*將就緒隊列的第一個進程投入運行*/
   ready=ready->next;
   run->state='R';
}
/*優先數調度算法*/
priority(char alg)
{
   while(run!=NULL)  /*當運行隊列不空時，有進程正在運行*/
   {
      run->cputime=run->cputime+1;
      run->needtime=run->needtime-1;
      run->prio=run->prio-3; /*每運行一次優先數降低3個單位*/
      if(run->needtime==0)  /*如所需時間為0將其插入完成隊列*/
      {
     run->next=finish;
     finish=run;
     run->state='F';  /*置狀態為完成態*/
     run=NULL;  /*運行隊列頭指針為空*/
     if(ready!=NULL) /*如就緒隊列不空*/
        firstin(); /*將就緒對列的第一個進程投入運行*/
      }
      else /*沒有運行完同時優先數不是最大，則將其變為就緒態插入到就緒隊列*/
     if((ready!=NULL)&&(run->prio<ready->prio))
     {
        run->state='W';
        insert1(run);
        firstin(); /*將就緒隊列的第一個進程投入運行*/
     }
      prt(alg); /*輸出進程PCB信息*/
   }
}
/*時間片輪轉法*/
roundrun(char alg)
{
   while(run!=NULL)
   {
      run->cputime=run->cputime+1;
      run->needtime=run->needtime-1;
      run->count=run->count+1;
      if(run->needtime==0)/*運行完將其變為完成態，插入完成隊列*/
      {
     run->next=finish;
     finish=run;
     run->state='F';
     run=NULL;
     if(ready!=NULL)
        firstin(); /*就緒對列不空，將第一個進程投入運行*/
      }
      else
     if(run->count==run->round)  /*如果時間片到*/
     {
        run->count=0;  /*計數器置0*/
        if(ready!=NULL) /*如就緒隊列不空*/
        {
           run->state='W'; /*將進程插入到就緒隊列中等待輪轉*/
           insert2(run);
           firstin(); /*將就緒對列的第一個進程投入運行*/
        }
     }
      prt(alg); /*輸出進程信息*/
   }
}
/*主函數*/
main()
{
   char algo;  /*算法標記*/
   clrscr();
   printf("type the algorithm:P/R(priority/roundrobin)\n");
   scanf("%c",&algo); /*輸入字符確定算法*/
   printf("Enter process number\n");
   scanf("%d",&N); /*輸入進程數*/
   if(algo=='P'||algo=='p')
   {
      create1(algo); /*優先數法*/
      priority(algo);
   }
   else
      if(algo=='R'||algo=='r')
      {
     create2(algo); /*輪轉法*/
     roundrun(algo);
      }
}