Subversion Repositories planix.SVN

Rev

Rev 2 | Details | Compare with Previous | Last modification | View Log | RSS feed

Rev Author Line No. Line
2 - 1 
#include	"u.h"
2 
#include	"../port/lib.h"
3 
#include	"mem.h"
4 
#include	"dat.h"
5 
#include	"fns.h"
6 
 
7 
static Alarms	alarms;
8 
static Rendez	alarmr;
9 
 
10 
void
11 
alarmkproc(void*)
12 
{
13 
	Proc *rp;
14 
	ulong now;
15 
 
16 
	for(;;){
17 
		now = MACHP(0)->ticks;
18 
		qlock(&alarms);
19 
		/*
20 
		 * the odd test of now vs. rp->alarm is to cope with
21 
		 * now wrapping around.
22 
		 */
23 
		while((rp = alarms.head) && (long)(now - rp->alarm) >= 0){
24 
			if(rp->alarm != 0L){
25 
				if(canqlock(&rp->debug)){
26 
					if(!waserror()){
27 
						postnote(rp, 0, "alarm", NUser);
28 
						poperror();
29 
					}
30 
					qunlock(&rp->debug);
31 
					rp->alarm = 0L;
32 
				}else
33 
					break;
34 
			}
35 
			alarms.head = rp->palarm;
36 
		}
37 
		qunlock(&alarms);
38 
 
39 
		sleep(&alarmr, return0, 0);
40 
	}
41 
}
42 
 
43 
/*
44 
 *  called every clock tick
45 
 */
46 
void
47 
checkalarms(void)
48 
{
49 
	Proc *p;
50 
	ulong now;
51 
 
52 
	p = alarms.head;
53 
	now = MACHP(0)->ticks;
54 
 
55 
	if(p && (long)(now - p->alarm) >= 0)
56 
		wakeup(&alarmr);
57 
}
58 
 
59 
ulong
60 
procalarm(ulong time)
61 
{
62 
	Proc **l, *f;
63 
	ulong when, old;
64 
 
65 
	if(up->alarm)
66 
		old = tk2ms(up->alarm - MACHP(0)->ticks);
67 
	else
68 
		old = 0;
69 
	if(time == 0) {
70 
		up->alarm = 0;
71 
		return old;
72 
	}
73 
	when = ms2tk(time)+MACHP(0)->ticks;
74 
	if(when == 0)		/* ticks have wrapped to 0? */
75 
		when = 1;	/* distinguish a wrapped alarm from no alarm */
76 
 
77 
	qlock(&alarms);
78 
	l = &alarms.head;
79 
	for(f = *l; f; f = f->palarm) {
80 
		if(up == f){
81 
			*l = f->palarm;
82 
			break;
83 
		}
84 
		l = &f->palarm;
85 
	}
86 
 
87 
	up->palarm = 0;
88 
	if(alarms.head) {
89 
		l = &alarms.head;
90 
		for(f = *l; f; f = f->palarm) {
91 
			if((long)(f->alarm - when) >= 0) {
92 
				up->palarm = f;
93 
				*l = up;
94 
				goto done;
95 
			}
96 
			l = &f->palarm;
97 
		}
98 
		*l = up;
99 
	}
100 
	else
101 
		alarms.head = up;
102 
done:
103 
	up->alarm = when;
104 
	qunlock(&alarms);
105 
 
106 
	return old;
107 
}