processmanager.c

进程调度模拟程序

#include <stdio.h>
#include <stdlib.h>
#include <conio.h>
#define GETPCB(type)	(type*)malloc(sizeof(type));

struct pcb
{
	char name[10];//process name
	char state;	  //process state: 
	int super;	  //process superior
	int ntime;	  //arrive time
	int rtime;	  // run time
	struct pcb* link;//pointer to next process
}*ready = NULL, *p;
typedef struct pcb PCB;

void sort()
{
	PCB *first, *second;
	int insert = 0;
	if( ready == NULL || p->super > ready->super )
	{
		p->link = ready;
		ready = p;
	}
	else
	{
		first = ready;
		second = first->link;
		while( second != NULL )
		{
			if( p->super > second->super )
			{
				p->link = second;
				first->link = p;
				second = NULL;
				insert = 1;
			}
			else
			{
				first = first->link;
				second = second->link;
			}
		}
		if( insert == 0 )
			first->link = p;
	}
}

int input()
{
	int i, num;
	//clrscr();
	printf( "\n 请输入想运行的进程数目：" );
	scanf( "%d", &num );
	for( i = 0; i < num; i++ )
	{
		printf( "\n 进程号 No.%d:\n", i );
		p = GETPCB( PCB );
		printf( "\n 输入进程名: " );
		scanf( "%s", p->name );
		printf( "\n 输入进程优先数: " );
		scanf( "%d", &p->super );
		printf( "\n 输入进程所要运行的时间: " );
		scanf( "%d", &p->ntime );
		printf( "\n" );
		p->rtime = 0;
		p->state = 'W';
		p->link = NULL;
		sort();
	}
	return num;
}

void disp( PCB * pr	)//进程显示函数
{
	printf( "\n qname  state  super  ndtime  runtime \n" );
	printf( "|%s\t", pr->name );
	printf( "|%c\t", pr->state );
	printf( "|%d\t", pr->super );
	printf( "|%d\t", pr->ntime );
	printf( "|%d\t", pr->rtime );
}

void check()//进程查看函数
{
	PCB* pr;
	printf( "\n **** 正在运行的程序是: %s", p->name );
	disp( p );

	printf( "\n **** 正在等待的程序是: " );
	pr = ready;
	while( pr != NULL )
	{
		disp( pr );
		pr = pr->link;
	}
}

void destroy()
{
	printf( "\n process[%s] finish\n", p->name );
	free( p );
}

void running()
{
	p->rtime++;
	if( p->rtime == p->ntime )
		destroy();
	else
	{
		p->super--;
		p->state = 'W';
		sort();
	}
}

int main()
{
	int num = 0;
	char ch;
	int processLength = input();
	
	while( processLength != 0  && ready != NULL )
	{
		num++;
		printf( "\n 第 %d 次运行\n", num );
		
		p = ready;
		ready = p->link;
		p->link = NULL;
		p->state = 'R';
		check();
		running();
		printf( "\n press any to continue..." );
		getch();
	}

	printf( "\n\n processes done" );
	ch = getchar();
	return 0;
}