banner
李大仁博客

李大仁博客

天地虽大,但有一念向善,心存良知,虽凡夫俗子,皆可为圣贤。

操作系统,模拟进程管理之PCB块管理法,C语言实现

首先大家祝福平安夜快乐啊,今天要发布的代码是一款 C 语言编写的模拟操作系统管理进程的程序调试环境 TC,使用了 PCB 进行进程管理控制,建立三个基本的队列:等待、执行、阻塞进行模拟操作系统的进程管理,模拟进程的调度,模拟用户的创建、执行、阻塞、挂起、唤醒等操作

最近要准备准备操作系统考试,所以放一个程序跟大家分享

代码如下:

/*
*yctc cg
*/
#include "stdio.h"
#include "dos.h"
#include "stdlib.h"
#include "conio.h"
#define SEC 3
#define NULL 0
/* 定义结构体 */
typedef struct PCB
{
int PID;
int UID;
struct PCB * next;
}PCB;
PCB *really , *excute , *wait;
/*create queue header */
/*queue operation 入队 */
int enqueue(PCB *head , PCB *node)
{
PCB *p;
p = head;
if(p -> next == NULL)
{
head -> next = node;
return 1;
}
while(p)
{
if(p -> next == NULL)
{
p -> next = node;
return 1;
}
else p = p -> next;
}
}/*enquue*/
/*dequeue 出队列 */
PCB * dequeue(PCB *head)
{
PCB *p;
p = head;
if(p -> next == NULL)
{
return NULL;
}
else
{
p = p -> next;
head -> next = p -> next;
p -> next = NULL;
return p;
}
/*head to next*/
}/*dequeue*/

/*PCB operate*/
/* 新建进程 */
int create()
{
PCB *p;
p = (PCB*)malloc(sizeof(PCB));
p -> next = NULL;
printf("input PID and UID to a new processn");
scanf("%d %d",&p -> PID,&p -> UID);
if(enqueue(really , p))
printf("create a process: PID = %d UID = %dn", p -> PID , p -> UID);
else
printf("create Failedn");
}/*create*/

/* 执行 fexcute*/
int fexcute()
{
PCB *p = dequeue(really);
if(p == NULL)
{
printf("NO process in queue n");
return 0;
}
else
{
enqueue(excute , p);
printf("add a process into excute queue process: PID = %d UID= %d n" ,p->PID , p->UID);
return 1;
}
}/*excute*/

int suspend()
{
PCB *p = dequeue(excute);
if(p == NULL)
{
printf("NO process in queue n");
return 0;
}
else
{
enqueue(really , p);
printf("add a process into really queue process: PID = %d UID= %d n" ,p->PID , p->UID);
return 1;
}
}

int wake()
{
PCB *p = dequeue(wait);
if(p == NULL)
{
printf("NO process in queue n");
return 0;
}
else
{
enqueue(really , p);
printf("add a process into wait really process: PID = %d UID= %d n" ,p->PID , p->UID);
return 1;
}
}

int block()
{
PCB *p = dequeue(excute);
if(p == NULL)
{
printf("NO process in queue n");
return 0;
}
else
{
enqueue(wait , p);
printf("add a process into wait queue process: PID = %d UID= %d n" ,p->PID , p->UID);
return 1;
}
}/*block*/
/* 输出队列 outputqueue*/
int outputqueue(PCB *head)
{
PCB *p;
if(head -> next == NULL)
{/* 队列为空 */
printf("queue is null n");
return 1;
}
p = head -> next; /*node pointer*/
while(p)
{/* 打印 process id UID*/
printf("PID = %d UID = %d n" , p -> PID , p -> UID);
p = p -> next;
}
return 0;
}
/*output 输出 */
int output()
{
printf("REALLLY QUEUE");
outputqueue(really);
printf("EXCUTE QUEUE: n");
outputqueue(excute);
printf("WAIT QUEUE: n");
outputqueue(wait);
}/*output*/
/*init 初始化 */
int init()
{
PCB *p;
clrscr();
really = (PCB*)malloc(sizeof(PCB));
really -> next=NULL;
excute = (PCB*)malloc(sizeof(PCB));
excute -> next=NULL;
wait = (PCB*)malloc(sizeof(PCB));
wait -> next = NULL;
printf("____________PROCESS SECHUDLE__________n");
printf("now initing.....................n");
printf("input PID and UID as integer , 0 0 as overn");
while(1)
{
p = (PCB*)malloc(sizeof(PCB));
p -> next = NULL;
scanf("%d %d",&p -> PID , &p -> UID);
if(p -> PID == 0 && p -> UID == 0)
break;
else
{
if(enqueue(really , p))
{
printf("new process PID = %d UID = %d added!n",p -> PID , p -> UID);
}
else return 0;
}
}
return 1;
}/*init*/
/* 运行一个 process*/
int run()
{
PCB *p = excute;
int s = SEC;
if(excute -> next == NULL)
{
printf("no process in excute queue n");
return 0;
}
else
{
p = excute -> next;
printf("system will sleep %ds as process runningn",s);
sleep(3);/*sleep as process runing time*/
printf("process: PID = %d UID= %d excute successed..n" , p -> PID , p -> UID );
excute -> next = p -> next;
free(p);
}
}/*run*/
/* 离开 */
int leave()
{
PCB *p,*t;
while(really->next || excute->next || wait->next)
{
p = really -> next;
while(p)
{
t = p -> next;
free(p);
p = t;
}
really -> next = NULL;
p = wait -> next;
while(p)
{
t = p -> next;
free(p);
p = t;
}
wait -> next = NULL;
p = excute -> next;
while(p)
{
t = p -> next;
free(p);
p = t;
}
excute -> next = NULL;
}
exit(0);
}/*leace*/

int help()
{
printf("_____________________HELP MENU_____________________n");
printf("t-h HELP show help optionn");
printf("t-c CREATE create a new process , and put to really queuen");
printf("t-b BLOCK block a process in excute queuen");
printf("t-w WAKE wake a process in wait queuen");
printf("t-e EXCUTE excute a process in really queuen");
printf("t-s SUSPEND suspend a process in excute queuen");
printf("t-o OUTPUT output all processes in queuesn");
printf("t-r RUN excute a process in excute queuen");
printf("t-x EXIT exit this programn");
printf("___________________________________________________n");
printf("t type 'H' will show this menun");
}/*help*/

int main()
{
char COMMAND = NULL;
if( init() != 1)
{
printf("init falied ! n ");
getch();
exit(0);
}
else
{
printf("init...OKn");
output();
help();
}
while(1)
{
/* 当三队列都不空 执行调度 */
printf(">");
scanf("%c",&COMMAND);
switch(COMMAND)
{
case 'n': break;
case 'H':
case 'h': help(); break;
case 'C':
case 'c': create(); break;
case 'B':
case 'b': block(); break;
case 'W':
case 'w': wake(); break;
case 'S':
case 's': suspend(); break;
case 'E':
case 'e': fexcute(); break;
case 'O':
case 'o': output(); break;
case 'X':
case 'x': leave(); break;
case 'R':
case 'r': run(); break;
}
}
}/*main*/

Loading...
Ownership of this post data is guaranteed by blockchain and smart contracts to the creator alone.