1 /*
2  * Copyright (C) 2005 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 //
18 // Timer functions.
19 //
20 
21 #ifndef _LIBS_UTILS_TIMERS_H
22 #define _LIBS_UTILS_TIMERS_H
23 
24 #include <stdint.h>
25 #include <sys/time.h>
26 #include <sys/types.h>
27 
28 // ------------------------------------------------------------------
29 // C API
30 
31 #ifdef __cplusplus
32 extern "C" {
33 #endif
34 
35 typedef int64_t nsecs_t;  // nano-seconds
36 
seconds_to_nanoseconds(nsecs_t secs)37 static inline nsecs_t seconds_to_nanoseconds(nsecs_t secs) {
38     return secs * 1000000000;
39 }
40 
milliseconds_to_nanoseconds(nsecs_t secs)41 static inline nsecs_t milliseconds_to_nanoseconds(nsecs_t secs) {
42     return secs * 1000000;
43 }
44 
microseconds_to_nanoseconds(nsecs_t secs)45 static inline nsecs_t microseconds_to_nanoseconds(nsecs_t secs) {
46     return secs * 1000;
47 }
48 
nanoseconds_to_seconds(nsecs_t secs)49 static inline nsecs_t nanoseconds_to_seconds(nsecs_t secs) {
50     return secs / 1000000000;
51 }
52 
nanoseconds_to_milliseconds(nsecs_t secs)53 static inline nsecs_t nanoseconds_to_milliseconds(nsecs_t secs) {
54     return secs / 1000000;
55 }
56 
nanoseconds_to_microseconds(nsecs_t secs)57 static inline nsecs_t nanoseconds_to_microseconds(nsecs_t secs) {
58     return secs / 1000;
59 }
60 
s2ns(nsecs_t v)61 static inline nsecs_t s2ns(nsecs_t v) {
62     return seconds_to_nanoseconds(v);
63 }
ms2ns(nsecs_t v)64 static inline nsecs_t ms2ns(nsecs_t v) {
65     return milliseconds_to_nanoseconds(v);
66 }
us2ns(nsecs_t v)67 static inline nsecs_t us2ns(nsecs_t v) {
68     return microseconds_to_nanoseconds(v);
69 }
ns2s(nsecs_t v)70 static inline nsecs_t ns2s(nsecs_t v) {
71     return nanoseconds_to_seconds(v);
72 }
ns2ms(nsecs_t v)73 static inline nsecs_t ns2ms(nsecs_t v) {
74     return nanoseconds_to_milliseconds(v);
75 }
ns2us(nsecs_t v)76 static inline nsecs_t ns2us(nsecs_t v) {
77     return nanoseconds_to_microseconds(v);
78 }
79 
seconds(nsecs_t v)80 static inline nsecs_t seconds(nsecs_t v) {
81     return s2ns(v);
82 }
milliseconds(nsecs_t v)83 static inline nsecs_t milliseconds(nsecs_t v) {
84     return ms2ns(v);
85 }
microseconds(nsecs_t v)86 static inline nsecs_t microseconds(nsecs_t v) {
87     return us2ns(v);
88 }
89 
90 enum {
91     SYSTEM_TIME_REALTIME = 0,   // system-wide realtime clock
92     SYSTEM_TIME_MONOTONIC = 1,  // monotonic time since unspecified starting point
93     SYSTEM_TIME_PROCESS = 2,    // high-resolution per-process clock
94     SYSTEM_TIME_THREAD = 3,     // high-resolution per-thread clock
95     SYSTEM_TIME_BOOTTIME = 4    // same as SYSTEM_TIME_MONOTONIC, but including CPU suspend time
96 };
97 
98 // return the system-time according to the specified clock
99 #ifdef __cplusplus
100 nsecs_t systemTime(int clock = SYSTEM_TIME_MONOTONIC);
101 #else
102 nsecs_t systemTime(int clock);
103 #endif  // def __cplusplus
104 
105 /**
106  * Returns the number of milliseconds to wait between the reference time and the timeout time.
107  * If the timeout is in the past relative to the reference time, returns 0.
108  * If the timeout is more than INT_MAX milliseconds in the future relative to the reference time,
109  * such as when timeoutTime == LLONG_MAX, returns -1 to indicate an infinite timeout delay.
110  * Otherwise, returns the difference between the reference time and timeout time
111  * rounded up to the next millisecond.
112  */
113 int toMillisecondTimeoutDelay(nsecs_t referenceTime, nsecs_t timeoutTime);
114 
115 #ifdef __cplusplus
116 }  // extern "C"
117 #endif
118 
119 #endif  // _LIBS_UTILS_TIMERS_H
120