实验要求：编写并调试一个模拟的进程调度程序，采用“最高优先数优先”调度算法对五个进程进行调度

设计思想：
“最高优先数优先”调度算法的基本思想是把cpu分配给就绪队列中优先数最高的进程。采用动态优先数，即优先数在创建进程时给定一个初始值，当进程获得一次cpu后其优先数就减少1。

运行界面和过程如下：









源程序如下：
#include "stdio.h"
#define getpcb(type)(type*)malloc(sizeof(type))
#define NULL 0

struct pcb
{
char name[10];
char state;
int super;
int ntime;
int rtime;
struct pcb*link;
} *ready=NULL,*p;
typedef struct pcb PCB;

main()
{
int len,h=0;
char c;
input();
len=space();
while( (len!=0)&&(ready!=NULL) )
{
c=getchar();
h++;
printf("\nthe execute number:%d\n",h);
p=ready;
ready=p->link;
p->link=NULL;
p->state='R';
check();
running();
printf("\npress any key to continue...");
c=getchar();
}
printf("\n\n the process has been finished.\n");
c=getchar();
}

 

input ()
{
int i,num;
char k;
clrscr();
printf("\ninput process number?");
scanf("%d",&num);
for(i=0;i<num;i++)
{
printf("\ninput the process No.%d:\n",i);
p=getpcb(PCB);
printf("\nthe name of Process:");
scanf("%s",p->name);
printf("\nthe super of Process:");
scanf("%d",&p->super);
printf("\nthe time need:");
scanf("%d",&p->ntime);
printf("\n");
p->rtime=0;
p->state='W';
p->link=NULL;
sort();
}
}

int space()
{
int l=0;
PCB *pr=ready;
while(pr!=NULL)
{
l++;
pr=pr->link;

}
return(l);
}

check()
{
PCB *pr;
printf("\n***Now the process running is:%s",p->name);
disp(p);
pr=ready;
printf("\n***Now the ready quenue is:\n");
while(pr!=NULL)
{
disp(pr);
pr=pr->link;
}

}

disp(pr)
PCB *pr;
{
printf("\nqname\tstate\tsuper\tdtime\truntime\n");
printf("%s\t",pr->name);
printf("%c\t",pr->state);
printf("%d\t",pr->super);
printf("%d\t",pr->ntime);
printf("%d\t",pr->rtime);
printf("\n");
}

 

destory()
{
printf("\nprocess[%s] has finished:\n",p->name);
free(p);
}