-
Notifications
You must be signed in to change notification settings - Fork 421
/
coap_time.c
98 lines (76 loc) · 2.41 KB
/
coap_time.c
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
/* coap_time.c -- Clock Handling
*
* Copyright (C) 2015 Olaf Bergmann <bergmann@tzi.org>
*
* This file is part of the CoAP library libcoap. Please see
* README for terms of use.
*/
#ifdef WITH_POSIX
#include <time.h>
#include <sys/time.h>
#include <unistd.h> /* _POSIX_TIMERS */
#include "coap_config.h"
#include "coap_time.h"
static coap_time_t coap_clock_offset = 0;
#if _POSIX_TIMERS && !defined(__APPLE__)
/* _POSIX_TIMERS is > 0 when clock_gettime() is available */
/* Use real-time clock for correct timestamps in coap_log(). */
#define COAP_CLOCK CLOCK_REALTIME
#endif
void
coap_clock_init(void) {
#ifdef COAP_CLOCK
struct timespec tv;
clock_gettime(COAP_CLOCK, &tv);
#else /* _POSIX_TIMERS */
struct timeval tv;
gettimeofday(&tv, NULL);
#endif /* not _POSIX_TIMERS */
coap_clock_offset = tv.tv_sec;
}
/* creates a Qx.frac from fval */
#define Q(frac,fval) ((coap_tick_t)(((1 << (frac)) * (fval))))
/* number of frac bits for sub-seconds */
#define FRAC 10
/* rounds val up and right shifts by frac positions */
#define SHR_FP(val,frac) (((val) + (1 << ((frac) - 1))) >> (frac))
void
coap_ticks(coap_tick_t *t) {
unsigned long tmp;
#ifdef COAP_CLOCK
struct timespec tv;
clock_gettime(COAP_CLOCK, &tv);
/* Possible errors are (see clock_gettime(2)):
* EFAULT tp points outside the accessible address space.
* EINVAL The clk_id specified is not supported on this system.
* Both cases should not be possible here.
*/
tmp = SHR_FP(tv.tv_nsec * Q(FRAC, (COAP_TICKS_PER_SECOND/1000000000.0)), FRAC);
#else /* _POSIX_TIMERS */
/* Fall back to gettimeofday() */
struct timeval tv;
gettimeofday(&tv, NULL);
/* Possible errors are (see gettimeofday(2)):
* EFAULT One of tv or tz pointed outside the accessible address space.
* EINVAL Timezone (or something else) is invalid.
* Both cases should not be possible here.
*/
tmp = SHR_FP(tv.tv_usec * Q(FRAC, (COAP_TICKS_PER_SECOND/1000000.0)), FRAC);
#endif /* not _POSIX_TIMERS */
/* Finally, convert temporary FP representation to multiple of
* COAP_TICKS_PER_SECOND */
*t = tmp + (tv.tv_sec - coap_clock_offset) * COAP_TICKS_PER_SECOND;
}
coap_time_t
coap_ticks_to_rt(coap_tick_t t) {
return coap_clock_offset + (t / COAP_TICKS_PER_SECOND);
}
#undef Q
#undef FRAC
#undef SHR_FP
#else /* WITH_POSIX */
/* make compilers happy that do not like empty modules */
static inline void dummy()
{
}
#endif /* not WITH_POSIX */