操作系统 之 处理机调度

实验2 处理机调度
一、实验要求
●了解引起处理机调度的原因
●分析先来先服务算法，给出代码注释
二、实验内容
进程调度算法的数据结构主要有：进程函数定义，建立进程函数，进程调度函数。

示例：
#include "stdio.h"
#include <malloc.h>
#define max 100
#define pfree 0 /*process end*/
#define running 1 /*process running status*/
#define aready 2 /*process aready status */
#define blocking 3 /*process aready blocking status*/
typedef struct node
{
char name;
int status;
int precendence;
int ax,bx,cx,dx;
int pc;
int psw;
struct node *next; /*pcb define*/
}pcb;
pcb *createprocess(pcb *head)
{
pcb *p,*q;
int a,b,c,d,m,n;
char ID;
int s;
q=NULL;
printf("\ninput the first seven status pcb:");
scanf("\n%c",&ID);
scanf("%d%d%d%d%d%d",&a,&b,&c,&d,&m,&n);
while(ID!='*')
{
p=(pcb*)malloc(sizeof(pcb));
p->name=ID;
p->ax=a;
p->bx=b;
p->cx=c;
p->dx=d;
p->pc=m;
p->psw=n;
p->precendence=pre;
p->status=aready;
if(head==NULL)
head=p;
else
q->next=p;
q=p;
printf("\ninput the next pcb: ");
scanf("\n%c",&ID);
scanf("%d%d%d%d%d%d",&a,&b,&c,&d,&m,&n);
}
if(q!=NULL)
q->next=NULL;
q=head;
while(q)
{
printf("\n peocess name. status.ax. bx. cx. dx. pc. psw.\n ");
printf("%10c%5d%8d%5d%5d%5d%5d%5d%5d",q->name,q->status,q->precende
nce,q->ax,q->bx,q->cx,q->dx,q->pc,q->psw);
q=q->next;
}
return head;/*createprocess end*/
}
void processfifo(pcb *head)
{
pcb *p;
p=head;
printf("\n the process use fifo method.\n");
printf("running the frist process:\n");
while(p!=NULL)
{
p->status=running;
printf("\nprocess name status. ax. bx. cx. dx. pc. psw.");
printf("\n%10c%5d%8d%5d%5d%5d%5d%5d",p->name,p->status,p->ax,p->bx,
p->cx,p->dx,p->pc,p->psw); /*check process running status */
p->status=0;
p=p->next;
}
printf("\ncheck weatherfer the process complete: ");
p=head;
while(p)
{
printf("\n%3c%3d",p->name,p->status);
p=p->next;
}
printf("\ngame is over!\n");
}
main()
{
pcb *head;
head=NULL;
head=createprocess(head);
processfifo(head);
}
三、实验报告
1．在源程序上写出注释。

2．画出程序流程图。

3．调试程序并写出运行结果。