#include"stdio.h"
#include"stdlib.h"
#include<iostream>
using namespace std;
#define ready 1
#define run 2
struct pcb
{
char name[10];
int priority; /*进程的优先级*/
int state; /*进程的状态:可以有运行和就绪*/
int needtime; /*进程需要运行的时间*/
int runtime;
int time; /*进程已运行的时间*/
struct pcb *next; /*指向下一个进程PCB的指针*/
};
typedef struct pcb PCB;
PCB *head=NULL;
void create() /*此函数用于创建进程队列*/
{
PCB *p, *q;
int n,i;
printf("请输入要创建的进程的数量:");
scanf("%d",&n);
head=(PCB *)malloc(sizeof(PCB));
p=head;
for(i=1;i<=n;i++)
{
q=(PCB*)malloc(sizeof(PCB));
p->next=q;
p=q;
printf("\n请输入 NO.%d 个进程的标识符:",i);
scanf("%s",&p->name);
printf("请输入进程的优先级:");
scanf("%d",&p->priority);
printf("请输入进程所需的时间:");
scanf("%d",&p->needtime);
p->state=ready;
p->runtime=0;
p->next=NULL;
}
}
void lunzhuan () /*时间片轮转*/
{
PCB *p,*q,*r;
int time;
printf("请输入时间片大小:\n ");
scanf("%d",&time);
for(p=head->next;p->next;p=p->next)
r=p;
while(head->next)
{
p=head->next; /*选出就绪队列的第一个进程*/
p->state=run;
printf("\n正在运行的进程是:\n"); /*输出该进程的信息*/
printf("%s\t",p->name);
printf("state: 运行\t");
printf("needtime: %d\t",p->needtime);
printf("runtime: %d\n",p->needtime);
q=head->next;
if(p->needtime-p->runtime<=p->time) /*时间片内，进程运行结束否*/
{
p->runtime=p->needtime;
printf("runtime:%d\n",p->runtime);
}
else
{
p->runtime=p->runtime+p->time;
printf("runtime:%d\n",p->runtime);
}
q=p->next;
if(q!=NULL) /*输出就绪队列中的进程信息*/
printf("就绪队列是:\n");
else
printf("就绪队列为空!\n");
while(q)
{
printf("%s\t",q->name);
printf("state: 就绪\t");
printf("needtime:%d\t",q->needtime);
printf("runtime:%d\t",q->runtime);
printf("\n");
q=q->next;
}
if(p->runtime==p->needtime)
{
delete(head,p);
}
else
{
head->next=p->next;
r->next=p;
r=p;
r->state=ready;
r->next=NULL;
}
}
}
void main()
{
cout<<"开始创建进程："<<endl;
create();
if(head==NULL || head->next==NULL)
printf("就绪队列没有进程，请先创建进程\n");
else
lunzhuan();
}