操作系统----进程管理（C语言）

一、进程管理

#include "conio.h"
#include "stdio.h"
#include "stdlib.h"

struct  PCB_type
{  
	int pid;      //进程名-----------------轮转时间片，当前队列指针
	int priority;    //进程优先数
	int cputime;   //进程所占用的CPU时间
	int state;     //进程的状态
};
struct PCB_type neicun[20],waicun[20];
int shumu=0,pid_l;

int create();
void run( );
void huanchu();
void kill( );
void clrscr();

void main()
{
    int n;
    char a;
    n=1;
    while(n==1)
    {
		clrscr();
		printf("\n********************************************");
		printf("\n*               进程演示系统               *");
		printf("\n********************************************");
		printf("\n     1.创建新的进程      2.查看运行进程     ");
		printf("\n     3.换出某个进程      4.杀死运行进程     ");
		printf("\n     5.退出系统                             ");
		printf("\n********************************************");
		printf("\n请选择（1～5）");
		a=getch();
		switch(a)
		{ case'1':
		create( );  /*自定义过程*/
		break;
	   		  case'2':
				  run( );  /* 自定义过程 */
				  break;
			  case'3':
				  huanchu();  /*自定义过程*/
				  break;
			  case'4':
				  kill( );   /*自定义过程*/
				  break;
			  case'5':
				  exit(0);  
			  default: n=0;
		}
	}
}
void clrscr()
{
	system("cls");
}

int create( )  /* 创建一个进程的示例（不完整的程序） */
{
	if(shumu>=20)
	{
		printf("\n内存已满，请先结束或换出进程\n");
	}
	else
	{
		printf("\n请输入新进程的pid\n");
		scanf("%d",&neicun[shumu+1].pid);
		printf("\n请输入新进程的优先级\n");
		scanf("%d",&neicun[shumu+1].priority);
		printf("\n请输入新进程的大小\n");
		scanf("%d",&neicun[shumu+1].cputime);
		neicun[shumu+1].state=1;
		shumu++;
	}
	return neicun[shumu].state;
}

void run( )/*查看运行进程*/
{         
	int rpid;
	printf("\n请输入进程的pid\n");
	scanf("%d",&rpid);  	
	if(rpid>0&&rpid<=20&&neicun[rpid].state==1)
    {
		printf("\n进程的pid是: %d\n",neicun[rpid].pid);
		printf("进程的优先级是: %d\n",neicun[rpid].priority);
		printf("进程的大小是:%d\n",neicun[rpid].cputime);
    }
	else
	{
		printf("\n所查看运行进程不存在\n");
	}
	printf("请按回车退出查看\n");
	rpid=getch();     //可避免运行结果快速显示消失
}
void huanchu()/*换出某个进程*/
{ 
	int pid1,pid2;
	char c;
	printf("\n请输入需要替换出的进程的pid\n");
	scanf("%d",&pid1);
	printf("\n请输入需要替换进的进程的pid\n");
	scanf("%d",&pid2);
	if(pid1>0&&pid1<=20&&neicun[pid1].state==1)
	{
		if(neicun[pid1].priority>neicun[pid2].priority)
		{
			waicun[20].pid=neicun[pid1].pid;
			waicun[20].priority=neicun[pid1].priority;
			waicun[20].cputime=neicun[pid1].cputime;
			
			neicun[pid1].pid=neicun[pid2].pid;
			neicun[pid1].priority=neicun[pid2].priority;
			neicun[pid1].cputime=neicun[pid2].cputime;
			
			neicun[pid2].pid=waicun[20].pid;
			neicun[pid2].priority=waicun[20].priority;
			neicun[pid2].cputime=waicun[20].cputime;
			
			
			printf("\n替换完成\n");
			printf("\n被替换进程的pid是: %d\n",waicun[20].pid);
			printf("被替换进程的优先级是: %d\n",waicun[20].priority);
			printf("被替换进程的大小是:%d\n",waicun[20].cputime);
		}
		else
		{
			printf("\n进程优先级较小");
		}
	}
	else
	{
		printf("所查看运行进程不存在\n");
	}
	printf("请按回车退出换出进程\n");
	c=getch();
	return;
}
void kill()/*杀死运行进程*/
{ 
    
	int kpid;
	printf("\n请输入进程的pid\n");
	scanf("%d",&kpid);
	if(kpid>0&&kpid<20&&neicun[kpid].state==1)
	{
		neicun[kpid].state=0;
	}
	return;
}
/*void tongxun( )//进程之间通信
{
int tpid1,tpid2;
int buffer;
char d;
printf("\n请输入通信源进程pid\n");
scanf("%d",&tpid1);
printf("\n请输入通信目的进程pid\n");
scanf("%d",&tpid2);
if(tpid1>0&&tpid1<20&&neicun[tpid1].live==1)
{
buffer=neicun[tpid1].msg;
neicun[tpid1].msg=neicun[tpid2].msg;
neicun[tpid2].msg=buffer;

		printf("\n源进程的消息是: %d\n",neicun[tpid1].msg);
		printf("\n目的进程的消息是: %d\n",neicun[tpid2].msg);
		}
		else
		{
		printf("\n所查看运行进程不存在\n");
		}
		printf("\n请按回车退出进程通信\n");
		d=getch();
		return;
}
*/