#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轮数\tcpu时间\t需要时间\t进程状态\t计数器\n");
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，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比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 -= 3; /*优先级减去三*/
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();
}
}
