##include "../param.h"#include "../systm.h"#include "../user.h"#include "../proc.h"#define	UMODE	0170000#define	SCHMAG	10/* * clock is called straight from * the real time clock interrupt. * * Functions: *	reprime clock *	copy *switches to display *	implement callouts *	maintain user/system times *	maintain date *	profile *	tout wakeup (sys sleep) *	lightning bolt wakeup (every 4 sec) *	alarm clock signals *	jab the scheduler */clock(dev, sp, r1, nps, r0, pc, ps){	register struct callo *p1, *p2;	register struct proc *pp;	/*	 * restart clock	 */	*lks = 0115;	/*	 * display register	 */	display();	/*	 * callouts	 * if none, just return	 * else update first non-zero time	 */	if(callout[0].c_func == 0)		goto out;	p2 = &callout[0];	while(p2->c_time<=0 && p2->c_func!=0)		p2++;	p2->c_time--;	/*	 * if ps is high, just return	 */	if((ps&0340) != 0)		goto out;	/*	 * callout	 */	spl5();	if(callout[0].c_time <= 0) {		p1 = &callout[0];		while(p1->c_func != 0 && p1->c_time <= 0) {			(*p1->c_func)(p1->c_arg);			p1++;		}		p2 = &callout[0];		while(p2->c_func = p1->c_func) {			p2->c_time = p1->c_time;			p2->c_arg = p1->c_arg;			p1++;			p2++;		}	}	/*	 * lightning bolt time-out	 * and time of day	 */out:	if((ps&UMODE) == UMODE) {		u.u_utime++;		if(u.u_prof[3])			incupc(pc, u.u_prof);	} else		u.u_stime++;	pp = u.u_procp;	if(++pp->p_cpu == 0)		pp->p_cpu--;	if(++lbolt >= HZ) {		if((ps&0340) != 0)			return;		lbolt =- HZ;		if(++time[1] == 0)			++time[0];		spl1();		if(time[1]==tout[1] && time[0]==tout[0])			wakeup(tout);		if((time[1]&03) == 0) {			runrun++;			wakeup(&lbolt);		}		for(pp = &proc[0]; pp < &proc[NPROC]; pp++)		if (pp->p_stat) {			if(pp->p_time != 127)				pp->p_time++;			if((pp->p_cpu & 0377) > SCHMAG)				pp->p_cpu =- SCHMAG; else				pp->p_cpu = 0;			if(pp->p_pri > PUSER)				setpri(pp);		}		if(runin!=0) {			runin = 0;			wakeup(&runin);		}		if((ps&UMODE) == UMODE) {			u.u_ar0 = &r0;			if(issig())				psig();			setpri(u.u_procp);		}	}}/* * timeout is called to arrange that * fun(arg) is called in tim/HZ seconds. * An entry is sorted into the callout * structure. The time in each structure * entry is the number of HZ's more * than the previous entry. * In this way, decrementing the * first entry has the effect of * updating all entries. */timeout(fun, arg, tim){	register struct callo *p1, *p2;	register t;	int s;	t = tim;	s = PS->integ;	p1 = &callout[0];	spl7();	while(p1->c_func != 0 && p1->c_time <= t) {		t =- p1->c_time;		p1++;	}	p1->c_time =- t;	p2 = p1;	while(p2->c_func != 0)		p2++;	while(p2 >= p1) {		(p2+1)->c_time = p2->c_time;		(p2+1)->c_func = p2->c_func;		(p2+1)->c_arg = p2->c_arg;		p2--;	}	p1->c_time = t;	p1->c_func = fun;	p1->c_arg = arg;	PS->integ = s;}