进程调度.cpp

编写一进程调度程序模拟程序（调度算法可以采用下面提示中的算法

#include "stdio.h"
#include "malloc.h"
#include "string.h"
#include "time.h"
#include <stdlib.h> 
#define NULL 0
struct process{
	char name[20];
	struct process *next;
	int time;
	int priority;
	char state; 
};

struct process *creatlist(struct process *l)
{
	struct process *p,*q;
	char s1[]="P1",s2[]="P2",s3[]="P3",s4[]="P4",s5[]="P5";
	int i;
 	l=(struct process*)malloc(sizeof(struct process));
	p=l;
	for(i=0;i<5;i++)
	{
		q=(struct process*)malloc(sizeof(struct process));
		p->next=q;
		p=q;
		if(i==4)
			p->next=NULL;
	}
	p=l;
	strcpy(p->next->name,s2);
	p->next->time=4;
	p->next->state='R';
	p->next->priority=5;//5
	p=p->next;
	strcpy(p->next->name,s4);
	p->next->time=2;
	p->next->state='R';
	p->next->priority=4;//4
	p=p->next;
	strcpy(p->next->name,s3);
	p->next->time=1;
	p->next->state='R';
	p->next->priority=3;//3
	p=p->next;
	strcpy(p->next->name,s5);
	p->next->time=4;
	p->next->state='R';
	p->next->priority=2;//2
	p=p->next;
	strcpy(p->next->name,s1);
	p->next->time=5;
	p->next->state='R';
	p->next->priority=1;//1
	return l;
}
void run(struct process *l)
{
	struct process *p,*q,*o;
	char control;
	int t=time(0),i,m,n=1;
	p=l->next;
	while(1)
	{
		if(time(0)==t+1)//每秒执行一次
		{
			
			/*手动控制逐步测试for(i=0;;i++)
			{
				scanf("%c",&control);
				if(control=='\n')
					break;
			}*/

			system("cls"); //刷屏
			t=time(0);
			printf("\n\n\n\n正在运行的程序:\n");
			printf("%s %d %d %c\n\n",p->name,p->time,p->priority,p->state);//打印正在运行的程序
			p->time--;
			p->priority--;
			if(p->priority<0)
				p->priority=0;
			q=p->next;//打印正在等待的程序
			printf("正在等待的程序:\n");
			while(q!=NULL)
			{
				printf("%s %d %d %c\n",q->name,q->time,q->priority,q->state);
				q=q->next;
			}	
			printf("\n\n\n系统时间片:\n");		
			for(m=0;m<n;m++)
			{	
				if(m%4==0)
					printf("\n");
				printf("_______ ");
			}
			if(p->time==0)//如果所需时间为0则将PCB移到队列尾.
			{
				p->state='E';
				q=o=p->next;
				while(o!=NULL)
				{
					q=o;
					o=q->next;
				}
				l->next=p->next;
				q->next=p;
				p->next=NULL;
			}
			else//否则调整PCB队列.
			{
				q=p;
				o=p->next;
				while(p->priority<=o->priority&&o!=NULL&&o->state!='E')
				{
					q=o;
					o=q->next;
				}
				if(o!=p->next)
				{
					l->next=p->next;
					if(o!=NULL)//插到队中
					{
						p->next=o;
						q->next=p;
					}
					else//插到队尾
					{
						q->next=p;
						p->next=NULL;
					}
				}
			}
			p=l->next;
			if(l->next->time==0)//所有程序所需运行时间为0,结束.
			{	
				system("cls"); 
				printf("\n\n\n\n正在运行的程序:\n\n\n");
				q=p;
				printf("正在等待的程序:\n");
				while(q!=NULL)
				{
					printf("%s %d %d %c\n",q->name,q->time,q->priority,q->state);
					q=q->next;
				}
				printf("\n\n系统时间片:\n");
				for(m=0;m<n;m++)
				{
					if(m%4==0)
						printf("\n");
					printf("_______ ");
				}
				break;
			}
			n++;
		}
	}
	printf("\n\n所有程序运行结束.\n\n");
}
void main()
{
	struct process *l=NULL;
	l=creatlist(l);
	run(l);
}