~kris/9p

9hist

ref: de17a90e0c6fbd9667749c1e51d677882397f851 9hist/carrera/clock.c -rw-r--r-- 1.9 KiB
de17a90e — David du Colombier Plan 9 from Bell Labs 1999-01-25 27 years ago
                                                                                
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
#include	"u.h"
#include	"../port/lib.h"
#include	"mem.h"
#include	"dat.h"
#include	"fns.h"
#include	"io.h"

#include	"ureg.h"

void (*kproftimer)(ulong);

typedef struct Clock0link Clock0link;
typedef struct Clock0link {
	void		(*clock)(void);
	Clock0link*	link;
} Clock0link;

static Clock0link *clock0link;
static Lock clock0lock;

void
addclock0link(void (*clock)(void))
{
	Clock0link *lp;

	if((lp = malloc(sizeof(Clock0link))) == 0){
		print("addclock0link: too many links\n");
		return;
	}
	ilock(&clock0lock);
	lp->clock = clock;
	lp->link = clock0link;
	clock0link = lp;
	iunlock(&clock0lock);
}

/*
 *  delay for l milliseconds more or less.  delayloop is set by
 *  clockinit() to match the actual CPU speed.
 */
void
delay(int l)
{
	ulong i, j;

	j = m->delayloop;
	while(l-- > 0)
		for(i=0; i < j; i++)
			;
}

void
clockinit(void)
{
	long x;

	m->delayloop = m->speed*100;
	do {
		x = rdcount();
		delay(10);
		x = rdcount() - x;
	} while(x < 0);

	/*
	 *  fix count
	 */
	m->delayloop = (m->delayloop*m->speed*1000*10)/x;
	if(m->delayloop == 0)
		m->delayloop = 1;

	wrcompare(rdcount()+(m->speed*1000000)/HZ);
}

void
clock(Ureg *ur)
{
	Clock0link *lp;

	wrcompare(rdcount()+(m->speed*1000000)/HZ);

	m->ticks++;
	if(m->proc)
		m->proc->pc = ur->pc;

	accounttime();

	if(kproftimer != nil)
		kproftimer(ur->pc);

	kmapinval();

	if((active.machs&(1<<m->machno)) == 0)
		return;

	if(active.exiting && (active.machs & (1<<m->machno))) {
		print("someone's exiting\n");
		exit(0);
	}

	checkalarms();
	if(m->machno == 0){
		lock(&clock0lock);
		for(lp = clock0link; lp; lp = lp->link)
			lp->clock();
		unlock(&clock0lock);
	}

	if(m->flushmmu){
		if(up)
			flushmmu();
		m->flushmmu = 0;
	}

	if(up == 0 || up->state != Running)
		return;

	if(anyready())
		sched();

	/* user profiling clock */
	if(ur->status & KUSER) {
		(*(ulong*)(USTKTOP-BY2WD)) += TK2MS(1);
		segclock(ur->pc);
	}
}

uvlong
fastticks(uvlong *hz)
{
	if(hz)
		*hz = HZ;
	return m->ticks;
}