clock.c

这是《自己动手写操作系统》的原文件和代码

/*++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
                               clock.c
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
                                                    Forrest Yu, 2005
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/

#include "type.h"
#include "const.h"
#include "protect.h"
#include "proto.h"
#include "string.h"
#include "proc.h"
#include "global.h"


/*======================================================================*
                           clock_handler
 *======================================================================*/
PUBLIC void clock_handler(int irq)
{
	disp_str("#");

	if (k_reenter != 0) {
		disp_str("!");
		return;
	}

	p_proc_ready++;

	if (p_proc_ready >= proc_table + NR_TASKS) {
		p_proc_ready = proc_table;
	}
}