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
|
/* libhw/generic/alarmclock.h - Device-independent alarmclock definitions
*
* Copyright (C) 2024-2025 Luke T. Shumaker <lukeshu@lukeshu.com>
* SPDX-License-Identifier: AGPL-3.0-or-later
*/
#ifndef _LIBHW_GENERIC_ALARMCLOCK_H_
#define _LIBHW_GENERIC_ALARMCLOCK_H_
#include <stdbool.h> /* for bool */
#include <stdint.h> /* for uint{n}_t and UINT{n}_C */
#include <libmisc/private.h>
#include <libobj/obj.h>
/* Useful constants ***********************************************************/
#define NS_PER_S UINT64_C(1000000000) /* needs at least log₂(10⁹) ≈ 29.9 bits */
#define US_PER_S UINT64_C(1000000) /* needs at least log₂(10⁶) ≈ 19.9 bits */
#define MS_PER_S UINT64_C(1000) /* needs at least log₂(10³) ≈ 9.9 bits */
/* Structs ********************************************************************/
struct alarmclock_trigger;
struct alarmclock_trigger {
BEGIN_PRIVATE(LIBHW_GENERIC_ALARMCLOCK_H)
void *alarmclock;
struct alarmclock_trigger *prev, *next;
uint64_t fire_at_ns;
void (*cb)(void *);
void *cb_arg;
END_PRIVATE(LIBHW_GENERIC_ALARMCLOCK_H)
};
/* Interface ******************************************************************/
#define alarmclock_LO_IFACE \
/** \
* (2⁶⁴-1 nanoseconds is more than 500 years; there is little \
* risk of this overflowing) \
*/ \
LO_FUNC(uint64_t, get_time_ns) \
\
/** \
* Returns true on error. \
* \
* Implementations may return an error if fire_at_ns is more \
* than UINT32_MAX µs (72 minutes) in the future. \
* \
* If fire_at_ns is in the past, then it will fire \
* immediately. \
*/ \
LO_FUNC(bool, add_trigger, struct alarmclock_trigger *trigger, \
uint64_t fire_at_ns, \
void (*cb)(void *), \
void *cb_arg) \
\
LO_FUNC(void, del_trigger, struct alarmclock_trigger *trigger)
LO_INTERFACE(alarmclock)
/* Utilities ******************************************************************/
void alarmclock_sleep_until_ns(lo_interface alarmclock clock, uint64_t abstime_ns);
static inline void alarmclock_sleep_for_ns(lo_interface alarmclock clock, uint64_t delta_ns) {
alarmclock_sleep_until_ns(clock, LO_CALL(clock, get_time_ns) + delta_ns);
}
static inline void alarmclock_sleep_for_us(lo_interface alarmclock clock, uint64_t delta_us) {
alarmclock_sleep_for_ns(clock, delta_us * (NS_PER_S/US_PER_S));
}
static inline void alarmclock_sleep_for_ms(lo_interface alarmclock clock, uint64_t delta_ms) {
alarmclock_sleep_for_ns(clock, delta_ms * (NS_PER_S/MS_PER_S));
}
static inline void alarmclock_sleep_for_s(lo_interface alarmclock clock, uint64_t delta_s) {
alarmclock_sleep_for_ns(clock, delta_s * NS_PER_S);
}
/* Globals ********************************************************************/
extern lo_interface alarmclock bootclock;
#define sleep_until_ns(t) alarmclock_sleep_until_ns(bootclock, t)
#define sleep_for_ns(t) alarmclock_sleep_for_ns(bootclock, t)
#define sleep_for_us(t) alarmclock_sleep_for_us(bootclock, t)
#define sleep_for_ms(t) alarmclock_sleep_for_ms(bootclock, t)
#define sleep_for_s(t) alarmclock_sleep_for_s(bootclock, t)
#endif /* _LIBHW_GENERIC_ALARMCLOCK_H_ */
|
