进程调度模拟实验--源代码
#include "stdio.h"
#include "stdlib.h"
#include "string.h"
typedef struct node /*创建PCB*/
{ char name[10]; /*进程标识*/
int prio; /*进程优先数*/
int cputime; /*进程占用CPU时间*/
int needtime; /*进程完成所需时间*/
int count; /*计数器*/
char state; /*进程的状态*/
struct node *next; /*链指针*/
}PCB;
PCB *finish,*ready,*tail,*run;
int N;
//************************************************************************* void firstin() /*创建就绪队列对头指针*/
{
run=ready;
run->state='R';
ready=ready->next;
}
//************************************************************************* void prt(char algo) /*演示进程调度*/
{
PCB *p;
printf(" 标识 占用CPU时间 完成所需时间 优先数 状态\n");
if(run!=NULL)
printf(" %-6s%-14d%-14d%-8d %c\n",run->name,
run->cputime,run->needtime,run->prio,run->state);
p=ready;
while(p!=NULL)
{ printf(" %-6s%-14d%-14d%-8d %c\n",p->name,
p->cputime,p->needtime,p->prio,p->state);
p=p->next;
}
p=finish;
while(p!=NULL)
{ printf(" %-6s%-14d%-14d%-8d %c\n",p->name,
p->cputime,p->needtime,p->prio,p->state);
p=p->next;
}
getchar();
}
//*************************************************************************
void insert(PCB *q)
{
PCB *p1,*s,*r;
int b;
s=q;
p1=ready;
r=p1;
b=1;
while((p1!=NULL)&&b)
if(p1->prio>=s->prio)
{
r=p1;
p1=p1->next;
}
else
b=0;
if(r!=p1)
{
r->next=s;
s->next=p1;
}
else
{
s->next=p1;
ready=s;
}
}
//************************************************************************* void create(char alg) /*创建各个进程*/
{
PCB *p;
int i,time;
char na[10];
ready=NULL;
finish=NULL;
run=NULL;
for(i=1;i
{
p=(PCB *)malloc(sizeof(PCB));
printf("输入进程的标识:\n");
scanf("%s",na);
printf("输入进程的时间(不要超过50):\n");
scanf("%d",&time);
strcpy(p->name,na);
p->cputime=0;
p->needtime=time;
p->state='w';
p->prio=50-time; /*假设优先级与耗时之和为50*/
if(ready!=NULL)
insert(p);
else
{
p->next=ready;
ready=p;
}
}
// clrscr();
printf(" 显示进程\n");
printf("************************************************\n");
prt(alg);
run=ready;
ready=ready->next;
run->state='R';
}
//************************************************************************* void priority(char alg) /*优先级算法调度*/
{
while(run!=NULL&&run->prio>=0)
{
run->cputime=run->cputime+1;
run->needtime=run->needtime-1;
run->prio=run->prio-3;
if(run->needtime==0)
{
run->next=finish;
finish=run;
run->state='F';
run=NULL;
if(ready!=NULL)
firstin();
}
else
if((ready!=NULL)&&(run->prioprio))
{
run->state='W';
insert(run);
firstin();
}
prt(alg);
}
}
//************************************************************************* void main()
{ char algo;
// clrscr();
loop: printf("输入进程的总数(不要超过10个):\n");
scanf("%d",&N);
if(N>10)
{printf("输入的数字太大，请重新输入.\n");
goto loop;}
create(algo);
priority(algo);
}