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1 /*
2  * coap_time.h -- Clock Handling
3  *
4  * Copyright (C) 2010-2019 Olaf Bergmann <bergmann@tzi.org>
5  *
6  * This file is part of the CoAP library libcoap. Please see README for terms
7  * of use.
8  */
9 
10 /**
11  * @file coap_time.h
12  * @brief Clock Handling
13  */
14 
15 #ifndef COAP_TIME_H_
16 #define COAP_TIME_H_
17 
18 /**
19  * @defgroup clock Clock Handling
20  * Default implementation of internal clock.
21  * @{
22  */
23 
24 #if defined(WITH_LWIP)
25 
26 #include <stdint.h>
27 #include <lwip/sys.h>
28 
29 /* lwIP provides ms in sys_now */
30 #define COAP_TICKS_PER_SECOND 1000
31 
32 typedef uint32_t coap_tick_t;
33 typedef uint32_t coap_time_t;
34 typedef int32_t coap_tick_diff_t;
35 
coap_ticks_impl(coap_tick_t * t)36 COAP_STATIC_INLINE void coap_ticks_impl(coap_tick_t *t) {
37   *t = sys_now();
38 }
39 
coap_clock_init_impl(void)40 COAP_STATIC_INLINE void coap_clock_init_impl(void) {
41 }
42 
43 #define coap_clock_init coap_clock_init_impl
44 #define coap_ticks coap_ticks_impl
45 
coap_ticks_to_rt(coap_tick_t t)46 COAP_STATIC_INLINE coap_time_t coap_ticks_to_rt(coap_tick_t t) {
47   return t / COAP_TICKS_PER_SECOND;
48 }
49 
coap_ticks_to_rt_us(coap_tick_t t)50 COAP_STATIC_INLINE uint64_t coap_ticks_to_rt_us(coap_tick_t t) {
51   return (uint64_t)t * 1000000 / COAP_TICKS_PER_SECOND;
52 }
53 
54 #elif defined(WITH_CONTIKI)
55 
56 #include "clock.h"
57 
58 typedef clock_time_t coap_tick_t;
59 typedef clock_time_t coap_time_t;
60 
61 /**
62  * This data type is used to represent the difference between two clock_tick_t
63  * values. This data type must have the same size in memory as coap_tick_t to
64  * allow wrapping.
65  */
66 typedef int coap_tick_diff_t;
67 
68 #define COAP_TICKS_PER_SECOND CLOCK_SECOND
69 
coap_clock_init(void)70 COAP_STATIC_INLINE void coap_clock_init(void) {
71   clock_init();
72 }
73 
coap_ticks(coap_tick_t * t)74 COAP_STATIC_INLINE void coap_ticks(coap_tick_t *t) {
75   *t = clock_time();
76 }
77 
coap_ticks_to_rt(coap_tick_t t)78 COAP_STATIC_INLINE coap_time_t coap_ticks_to_rt(coap_tick_t t) {
79   return t / COAP_TICKS_PER_SECOND;
80 }
81 
coap_ticks_to_rt_us(coap_tick_t t)82 COAP_STATIC_INLINE uint64_t coap_ticks_to_rt_us(coap_tick_t t) {
83   return (uint64_t)t * 1000000 / COAP_TICKS_PER_SECOND;
84 }
85 
86 #else
87 #include <stdint.h>
88 
89 /**
90  * This data type represents internal timer ticks with COAP_TICKS_PER_SECOND
91  * resolution.
92  */
93 typedef uint64_t coap_tick_t;
94 
95 /**
96  * CoAP time in seconds since epoch.
97  */
98 typedef time_t coap_time_t;
99 
100 /**
101  * This data type is used to represent the difference between two clock_tick_t
102  * values. This data type must have the same size in memory as coap_tick_t to
103  * allow wrapping.
104  */
105 typedef int64_t coap_tick_diff_t;
106 
107 /** Use ms resolution on POSIX systems */
108 #define COAP_TICKS_PER_SECOND ((coap_tick_t)(1000U))
109 
110 /**
111  * Initializes the internal clock.
112  */
113 void coap_clock_init(void);
114 
115 /**
116  * Sets @p t to the internal time with COAP_TICKS_PER_SECOND resolution.
117  */
118 void coap_ticks(coap_tick_t *t);
119 
120 /**
121  * Helper function that converts coap ticks to wallclock time. On POSIX, this
122  * function returns the number of seconds since the epoch. On other systems, it
123  * may be the calculated number of seconds since last reboot or so.
124  *
125  * @param t Internal system ticks.
126  *
127  * @return  The number of seconds that has passed since a specific reference
128  *          point (seconds since epoch on POSIX).
129  */
130 coap_time_t coap_ticks_to_rt(coap_tick_t t);
131 
132 /**
133 * Helper function that converts coap ticks to POSIX wallclock time in us.
134 *
135 * @param t Internal system ticks.
136 *
137 * @return  The number of seconds that has passed since a specific reference
138 *          point (seconds since epoch on POSIX).
139 */
140 uint64_t coap_ticks_to_rt_us(coap_tick_t t);
141 
142 /**
143 * Helper function that converts POSIX wallclock time in us to coap ticks.
144 *
145 * @param t POSIX time is us
146 *
147 * @return  coap ticks
148 */
149 coap_tick_t coap_ticks_from_rt_us(uint64_t t);
150 #endif
151 
152 /**
153  * Returns @c 1 if and only if @p a is less than @p b where less is defined on a
154  * signed data type.
155  */
coap_time_lt(coap_tick_t a,coap_tick_t b)156 COAP_STATIC_INLINE int coap_time_lt(coap_tick_t a, coap_tick_t b) {
157   return ((coap_tick_diff_t)(a - b)) < 0;
158 }
159 
160 /**
161  * Returns @c 1 if and only if @p a is less than or equal @p b where less is
162  * defined on a signed data type.
163  */
coap_time_le(coap_tick_t a,coap_tick_t b)164 COAP_STATIC_INLINE int coap_time_le(coap_tick_t a, coap_tick_t b) {
165   return a == b || coap_time_lt(a,b);
166 }
167 
168 /** @} */
169 
170 #endif /* COAP_TIME_H_ */
171