操作系统进程调度实验

最新推荐文章于 2023-04-01 16:01:20 发布

噫嘘嘻

最新推荐文章于 2023-04-01 16:01:20 发布

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CC 4.0 BY-SA版权

本文链接：https://blog.youkuaiyun.com/qq_40516237/article/details/85319997

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
typedef struct node{
   char name[20]; /*进程的名字*/
   int prio;    /*进程的优先级*/
   int round;    /*分配CPU的时间片*/
   int cputime;    /*CPU执行时间*/
   int needtime;     /*进程执行所需要的时间*/
   char state;    /*进程的状态，W--就绪态，R--执行态，F--完成态*/
   int count;    /*记录执行的次数*/
   struct node *next; /*链表指针*/
}PCB;
PCB *ready=NULL,*run=NULL,*finish=NULL; /*定义三个队列，就绪队列，执行队列和完成队列*/
int num;
void GetFirst(); /*从就绪队列取得第一个节点*/
void Output(); /*输出队列信息*/
void InsertPrio(PCB *in); /*创建优先级队列，规定优先数越小，优先级越高*/
void InsertTime(PCB *in); /*时间片队列*/
void InsertFinish(PCB *in); /*时间片队列*/
void PrioCreate(); /*优先级输入函数*/
void TimeCreate(); /*时间片输入函数*/
void Priority(); /*按照优先级调度*/
void RoundRun(); /*时间片轮转调度*/
int main(void)
{
   char chose;
   printf("请输入要创建的进程数目:\n");
   scanf("%d",&num);
   getchar();
   printf("输入进程的调度方法：(P/R)\n");
   scanf("%c",&chose);
   switch(chose)
   {
       case 'P':
       case 'p':
           PrioCreate();
           Priority();
       break;
       case 'R':
       case 'r':
           TimeCreate();
           RoundRun();
           break;
       default:break;
   }
   Output();
   return 0;
}
void GetFirst() /*取得第一个就绪队列节点*/
{
   run = ready;

   if(ready!=NULL){
       run ->state = 'R';
       ready = ready ->next;
       run ->next = NULL;
   }
}
void Output() /*输出队列信息*/
{
   PCB *p;
   /*p = ready;*/
   printf("进程名\t优先级\t时间片\tcpu时间\t需要时间\t进程状态\t计数器\n");
   p = ready;
   while(p!=NULL){
       printf("%s\t%d\t%d\t%d\t%d\t\t%c\t\t%d\n",p->name,p->prio,p->round,p->cputime,p->needtime,p->state,p->count);
       p = p->next;
   }
   p = finish;
   while(p!=NULL){
       printf("%s\t%d\t%d\t%d\t%d\t\t%c\t\t%d\n",p->name,p->prio,p->round,p->cputime,p->needtime,p->state,p->count);
       p = p->next;
   }
   p = run;
   while(p!=NULL){
       printf("%s\t%d\t%d\t%d\t%d\t\t%c\t\t%d\n",p->name,p->prio,p->round,p->cputime,p->needtime,p->state,p->count);
       p = p->next;
   }
}
void InsertPrio(PCB *in) /*创建优先级队列，规定优先数越小，优先级越低*/
{
   PCB *fst,*nxt;
   fst = nxt = ready;

   if(ready == NULL){ /*如果队列为空，则为第一个元素*/
       in->next = ready;
       ready = in;
   }
   else{ /*查到合适的位置进行插入*/
       if(in ->prio > fst ->prio){ /*比第一个还要大(大于等于)，则插入到队头*/
       in->next = ready;
       ready = in;
       }
       else{
       while(fst->next != NULL) /*移动指针查找第一个别它小的元素的位置进行插入*/
       {
       nxt = fst;
       fst = fst->next;
       }

           if(fst ->next == NULL) /*已经搜索到队尾，则其优先级数最小，将其插入到队尾即可*/
           {
           in ->next = fst ->next;
           fst ->next = in;
           }
           else /*插入到队列中*/
           {
           nxt = in;
           in ->next = fst;
           }
       }
   }
}
void InsertTime(PCB *in) /*将进程插入到就绪队列尾部*/
{
   PCB *fst;
   fst = ready;

   if(ready == NULL){
       in->next = ready;
       ready = in;
   }
   else{
       while(fst->next != NULL){
       fst = fst->next;
       }
       in ->next = fst ->next;
       fst ->next = in;
   }
}
void InsertFinish(PCB *in) /*将进程插入到完成队列尾部*/
{
   PCB *fst;
   fst = finish;

   if(finish == NULL){
       in->next = finish;
       finish = in;
   }
   else{
       while(fst->next != NULL)
       {
       fst = fst->next;
       }
       in ->next = fst ->next;
       fst ->next = in;
   }
}
void PrioCreate() /*优先级调度输入函数*/
{
   PCB *tmp;
   int i;

   printf("输入进程名字和进程所需时间：\n");
   for(i = 0;i < num; i++)
   {
       if((tmp = (PCB *)malloc(sizeof(PCB)))==NULL)
       {
           perror("malloc");
           exit(1);
       }
       scanf("%s",tmp->name);
       getchar(); /*吸收回车符号*/
       scanf("%d",&(tmp->needtime));
       tmp ->cputime = 0;
       tmp ->state ='W';
       tmp ->prio = 50 - tmp->needtime; /*设置其优先级，需要的时间越多，优先级越低*/
       tmp ->round = 0;
       tmp ->count = 0;
       InsertPrio(tmp); /*按照优先级从高到低，插入到就绪队列*/
   }
}
void TimeCreate() /*时间片输入函数*/
{
   PCB *tmp;
   int i;

   printf("输入进程名字和进程时间片所需时间：\n");
   for(i = 0;i < num; i++){
       if((tmp = (PCB *)malloc(sizeof(PCB)))==NULL)
       {
       perror("malloc");
       exit(1);
       }
       scanf("%s",tmp->name);
       getchar();
       scanf("%d",&(tmp->needtime));
       tmp ->cputime = 0;
       tmp ->state ='W';
       tmp ->prio = 0;
       tmp ->round = 2; /*假设每个进程所分配的时间片是2*/
       tmp ->count = 0;
       InsertTime(tmp);
   }
}
void Priority() /*按照优先级调度，每次执行一个时间片*/
{
   int flag = 1;

   GetFirst();
   while(run != NULL) /*当就绪队列不为空时，则调度进程如执行队列执行*/
   {
       Output(); /*输出每次调度过程中各个节点的状态*/
       while(flag)
       {
           run->prio -= 0; /*优先级减去三,若设为0则优先级不变*/
           run->cputime++; /*CPU时间片加一*/
           run->needtime--;/*进程执行完成的剩余时间减一*/
           if(run->needtime == 0)/*如果进程执行完毕，将进程状态置为F，将其插入到完成队列*/
           {
               run ->state = 'F';
               run->count++; /*进程执行的次数加一*/
               InsertFinish(run);
               flag = 0;
           }
           else /*将进程状态置为W，入就绪队列*/
           {
               run->state = 'W';
               run->count++; /*进程执行的次数加一*/
               InsertTime(run);
               flag = 0;
           }
       }
       flag = 1;
       GetFirst(); /*继续取就绪队列队头进程进入执行队列*/
   }
}
void RoundRun() /*时间片轮转调度算法*/
{
   int flag = 1;

   GetFirst();
   while(run != NULL)
   {
       Output();
       while(flag)
       {
           run->count++;
           run->cputime++;
           run->needtime--;
           if(run->needtime == 0) /*进程执行完毕*/
           {
               run ->state = 'F';
               InsertFinish(run);
               flag = 0;
           }
           else if(run->count == run->round)/*时间片用完*/
           {
               run->state = 'W';
               run->count = 0; /*计数器清零，为下次做准备*/
               InsertTime(run);
               flag = 0;
           }
       }
       flag = 1;
       GetFirst();
   }
}