模拟linux的进程创建
#include "iostream.h"#include "string.h"
#include "stdlib.h"
#define NUM 10
struct PCB{
int id; //进程标识符
char * name; //进程标识符
char *status; //进程状态
PCB *next; //当前队列指针
PCB * all_q_next; //总链指针
int prio; //进程优先级
}pcb[10];
PCB * ready_q_head=0;
PCB * all_q_head=0; //总链头指针
void insert_all(PCB *);
void insert_ready(PCB *);
int search(char * name) //查找有无同名PCB块
{
PCB * p;
p=(struct PCB *)malloc(sizeof(struct PCB));
p=all_q_head;
if(!p) //队列为空
return 1;
cout<<"a";
if (strcmp(p->name,name)&&(p!=0)) //名字不等
p=p->next;
if(!p) return 0; //有同名
return 1; //无同名
}
int pcbcreate()
{
PCB * pcb_addr;
int i;
int j;
char name[10];
cout<<"\ninput the process name you want to create:";
cin>>name；
pcb_addr=(struct PCB *)malloc(sizeof(struct PCB));
cout<<"bb";
if(!search(name))
{
cout<<"there has been this procss!\n";
exit(-1);
}
for(i=0; (i<NUM)&&(pcb[i].id!=-1);i++) ; //查找空闲pcb块
if (i==10) //无空闲pcb块存在
{
cout<<"there has no empty pcbs!";
exit(-1);
}
pcb_addr=&pcb[i] ; //pcb块的地址
if (!strcmp(name,"system"))
{ //如果是系统进程
pcb_addr->id=1;
strcpy(pcb_addr->status,"system");
pcb_addr->prio=-127;
}
else
{//如果是用户进程
pcb_addr->id=i;
pcb_addr->name=name;
strcpy(pcb_addr->status,"ready");
cout<<"\ninput the priority of your process:\n";
cin>>pcb_addr->prio;
}
insert_all(pcb_addr);
insert_ready(pcb_addr);
cout<<"create successfully!\n"
<<"the informationa of the process are as following:\n"
<<"id:"<<pcb_addr->id
<<"name:"<<pcb_addr->name
<<"priority:"<<pcb_addr->prio;
return 1;
}
void insert_all(PCB * q) //插入总链队列
{
PCB * p;
p=(struct PCB *)malloc(sizeof(struct PCB));
p=all_q_head;
while (p->all_q_next)
p=p->all_q_next;
p=q;
q->all_q_next=0;
}
void insert_ready(PCB *q)//按优先级从小到大插入就绪队列
{
PCB * p, *t ;
p=(struct PCB *)malloc(sizeof(struct PCB));
t=(struct PCB *)malloc(sizeof(struct PCB));
p=t=ready_q_head;
while (p->prio<q->prio)
{
t=p;
p=p->next;
}
t->next=q;
q->next=p;
}
void kill() //假设通过进程名来撤销进程
{
int idd;
PCB * p,*t;
p=(struct PCB *)malloc(sizeof(struct PCB));
t=(struct PCB *)malloc(sizeof(struct PCB));
cout<<"input the process id you want to kill";
cin>>idd;
p=ready_q_head;
while (p->id!=idd) //修改就绪队列指针队列
{
t=p;
p=p->next;
}
t->next=p->next;
p=all_q_head; //修改总链指针
while (p->id!=idd)
{
t=p;
p=p->all_q_next;
}
t=p->all_q_next;
delete p;
cout<<"kill the process sucessfully!";
}
void main()
{
for (int i=0; i<10; i++)
{
pcb[i].id=-1;
pcb[i].name=0;
pcb[i].next=0;
pcb[i].prio=127;
pcb[i].all_q_next=0;
pcb[i].status=0;
}
pcbcreate();
kill();
}
运行时出现调bug的，把main函数里面的赋值去掉就可以了，不知道为什么，麻烦哪位大虾帮忙看下啊，急啊！
