libcoap 4.3.2rc2

coap_time.c
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1/* coap_time.c -- Clock Handling
2 *
3 * Copyright (C) 2015,2023 Olaf Bergmann <bergmann@tzi.org>
4 *
5 * SPDX-License-Identifier: BSD-2-Clause
6 *
7 * This file is part of the CoAP library libcoap. Please see
8 * README for terms of use.
9 */
10
16#include "coap3/coap_internal.h"
17
18#ifdef HAVE_TIME_H
19#include <time.h>
20#ifdef HAVE_SYS_TIME_H
21#include <sys/time.h>
22#endif
23#ifdef HAVE_UNISTD_H
24#include <unistd.h> /* _POSIX_TIMERS */
25#endif
26#ifdef HAVE_WINSOCK2_H
27#include <winsock2.h>
28#include <stdint.h>
29#endif
30
31 static coap_tick_t coap_clock_offset = 0;
32
33#if _POSIX_TIMERS && !defined(__APPLE__)
34/* _POSIX_TIMERS is > 0 when clock_gettime() is available */
35
36/* Use real-time clock for correct timestamps in coap_log(). */
37#define COAP_CLOCK CLOCK_REALTIME
38#endif
39
40#if defined(HAVE_WINSOCK2_H) && !defined(__MINGW32__)
41 static int
42gettimeofday(struct timeval *tp, TIME_ZONE_INFORMATION *tzp) {
43 (void)tzp;
44 static const uint64_t s_tUnixEpoch = 116444736000000000Ui64;
45
46 FILETIME file_time;
47 ULARGE_INTEGER time;
48 uint64_t tUsSinceUnicEpoch;
49
50 GetSystemTimeAsFileTime(&file_time);
51 time.LowPart = file_time.dwLowDateTime;
52 time.HighPart = file_time.dwHighDateTime;
53 tUsSinceUnicEpoch = (time.QuadPart - s_tUnixEpoch) / 10;
54
55 tp->tv_sec = (long)(tUsSinceUnicEpoch / 1000000);
56 tp->tv_usec = (long)(tUsSinceUnicEpoch % 1000000);
57 return 0;
58}
59#endif /* HAVE_WINSOCK2_H && !__MINGW32__ */
60
61 void
62 coap_clock_init(void) {
63#ifdef COAP_CLOCK
64 struct timespec tv;
65 clock_gettime(COAP_CLOCK, &tv);
66#else /* _POSIX_TIMERS */
67 struct timeval tv;
68 gettimeofday(&tv, NULL);
69#endif /* not _POSIX_TIMERS */
70
71 coap_clock_offset = tv.tv_sec;
72}
73
74/* creates a Qx.frac from fval */
75#define Q(frac,fval) ((1 << (frac)) * (fval))
76
77/* number of frac bits for sub-seconds */
78#define FRAC 10
79
80/* rounds val up and right shifts by frac positions */
81#define SHR_FP(val,frac) (((coap_tick_t)((val) + (1 << ((frac) - 1)))) >> (frac))
82
83 void
84 coap_ticks(coap_tick_t *t) {
85 coap_tick_t tmp;
86
87#ifdef COAP_CLOCK
88 struct timespec tv;
89 clock_gettime(COAP_CLOCK, &tv);
90 /* Possible errors are (see clock_gettime(2)):
91 * EFAULT tp points outside the accessible address space.
92 * EINVAL The clk_id specified is not supported on this system.
93 * Both cases should not be possible here.
94 */
95
96 tmp = SHR_FP(tv.tv_nsec * Q(FRAC, (COAP_TICKS_PER_SECOND/1000000000.0)), FRAC);
97#else /* _POSIX_TIMERS */
98 /* Fall back to gettimeofday() */
99
100 struct timeval tv;
101 gettimeofday(&tv, NULL);
102 /* Possible errors are (see gettimeofday(2)):
103 * EFAULT One of tv or tz pointed outside the accessible address space.
104 * EINVAL Timezone (or something else) is invalid.
105 * Both cases should not be possible here.
106 */
107
108 tmp = SHR_FP(tv.tv_usec * Q(FRAC, (COAP_TICKS_PER_SECOND/1000000.0)), FRAC);
109#endif /* not _POSIX_TIMERS */
110
111 /* Finally, convert temporary FP representation to multiple of
112 * COAP_TICKS_PER_SECOND */
113 *t = tmp + (tv.tv_sec - coap_clock_offset) * COAP_TICKS_PER_SECOND;
114}
115
116 coap_time_t
117 coap_ticks_to_rt(coap_tick_t t) {
118 return coap_clock_offset + (t / COAP_TICKS_PER_SECOND);
119}
120
121uint64_t
122 coap_ticks_to_rt_us(coap_tick_t t) {
123 return (uint64_t)coap_clock_offset * 1000000 + (uint64_t)t * 1000000 / COAP_TICKS_PER_SECOND;
124}
125
126 coap_tick_t
127 coap_ticks_from_rt_us(uint64_t t) {
128 return (coap_tick_t)((t - (uint64_t)coap_clock_offset * 1000000) * COAP_TICKS_PER_SECOND / 1000000);
129}
130
131#undef Q
132#undef FRAC
133#undef SHR_FP
134
135#else /* HAVE_TIME_H */
136
137/* make compilers happy that do not like empty modules */
138 COAP_STATIC_INLINE void
139 dummy(void) {
140}
141
142#endif /* not HAVE_TIME_H */
coap_internal.h
Pulls together all the internal only header files.
SHR_FP
#define SHR_FP(val, frac)
Q
#define Q(frac, fval)
creates a Qx.frac from fval in coap_fixed_point_t
Definition: coap_net.c:92
dummy
COAP_STATIC_INLINE void dummy(void)
Definition: coap_time.c:139
coap_ticks_from_rt_us
coap_tick_t coap_ticks_from_rt_us(uint64_t t)
Helper function that converts POSIX wallclock time in us to coap ticks.
coap_time_t
time_t coap_time_t
CoAP time in seconds since epoch.
Definition: coap_time.h:149
coap_clock_init
void coap_clock_init(void)
Initializes the internal clock.
coap_tick_t
uint64_t coap_tick_t
This data type represents internal timer ticks with COAP_TICKS_PER_SECOND resolution.
Definition: coap_time.h:144
coap_ticks_to_rt
coap_time_t coap_ticks_to_rt(coap_tick_t t)
Helper function that converts coap ticks to wallclock time.
COAP_TICKS_PER_SECOND
#define COAP_TICKS_PER_SECOND
Use ms resolution on POSIX systems.
Definition: coap_time.h:159
coap_ticks_to_rt_us
uint64_t coap_ticks_to_rt_us(coap_tick_t t)
Helper function that converts coap ticks to POSIX wallclock time in us.
coap_ticks
void coap_ticks(coap_tick_t *)
Returns the current value of an internal tick counter.
COAP_STATIC_INLINE
#define COAP_STATIC_INLINE
Definition: libcoap.h:53