新建 文本文档.txt

操作系统

操作系统，模拟进程管理之PCB块管理法，C语言实现
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

/*
*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 process\n");
	scanf("%d %d",&p -> PID,&p -> UID);
	if(enqueue(really , p))
  printf("create a process: PID = %d UID = %d\n", p -> PID , p -> UID);
	else
  printf("create Failed\n");
}/*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:\n");
  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 over\n");
  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 running\n",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 option\n");
  printf("\t-c CREATE create a new process , and put to really queue\n");
  printf("\t-b BLOCK block a process in excute queue\n");
  printf("\t-w WAKE wake a process in wait queue\n");
  printf("\t-e EXCUTE excute a process in really queue\n");
  printf("\t-s SUSPEND suspend a process in excute queue\n");
  printf("\t-o OUTPUT output all processes in queues\n");
  printf("\t-r RUN excute a process in excute queue\n");
  printf("\t-x EXIT exit this program\n");
  printf("___________________________________________________\n");
  printf("\t type 'H' will show this menu\n");
}/*help*/
int main()
{
  char COMMAND = NULL;
  if( init() != 1)
	{
	  printf("init falied ! \n ");
	  getch();
	  exit(0);
	}
  else
	{
	  printf("init...OK\n");
	  output();
	  help();
	}
  while(1