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 #ifndef _LIBS_UTILS_TIMERS_H
21 #define _LIBS_UTILS_TIMERS_H
22 
23 #include <stdint.h>
24 #include <sys/types.h>
25 #include <sys/time.h>
26 
27 #include <utils/Compat.h>
28 
29 // ------------------------------------------------------------------
30 // C API
31 
32 #ifdef __cplusplus
33 extern "C" {
34 #endif
35 
36 typedef int64_t nsecs_t;       // nano-seconds
37 
seconds_to_nanoseconds(nsecs_t secs)38 static CONSTEXPR inline nsecs_t seconds_to_nanoseconds(nsecs_t secs)
39 {
40     return secs*1000000000;
41 }
42 
milliseconds_to_nanoseconds(nsecs_t secs)43 static CONSTEXPR inline nsecs_t milliseconds_to_nanoseconds(nsecs_t secs)
44 {
45     return secs*1000000;
46 }
47 
microseconds_to_nanoseconds(nsecs_t secs)48 static CONSTEXPR inline nsecs_t microseconds_to_nanoseconds(nsecs_t secs)
49 {
50     return secs*1000;
51 }
52 
nanoseconds_to_seconds(nsecs_t secs)53 static CONSTEXPR inline nsecs_t nanoseconds_to_seconds(nsecs_t secs)
54 {
55     return secs/1000000000;
56 }
57 
nanoseconds_to_milliseconds(nsecs_t secs)58 static CONSTEXPR inline nsecs_t nanoseconds_to_milliseconds(nsecs_t secs)
59 {
60     return secs/1000000;
61 }
62 
nanoseconds_to_microseconds(nsecs_t secs)63 static CONSTEXPR inline nsecs_t nanoseconds_to_microseconds(nsecs_t secs)
64 {
65     return secs/1000;
66 }
67 
s2ns(nsecs_t v)68 static CONSTEXPR inline nsecs_t s2ns(nsecs_t v)  {return seconds_to_nanoseconds(v);}
ms2ns(nsecs_t v)69 static CONSTEXPR inline nsecs_t ms2ns(nsecs_t v) {return milliseconds_to_nanoseconds(v);}
us2ns(nsecs_t v)70 static CONSTEXPR inline nsecs_t us2ns(nsecs_t v) {return microseconds_to_nanoseconds(v);}
ns2s(nsecs_t v)71 static CONSTEXPR inline nsecs_t ns2s(nsecs_t v)  {return nanoseconds_to_seconds(v);}
ns2ms(nsecs_t v)72 static CONSTEXPR inline nsecs_t ns2ms(nsecs_t v) {return nanoseconds_to_milliseconds(v);}
ns2us(nsecs_t v)73 static CONSTEXPR inline nsecs_t ns2us(nsecs_t v) {return nanoseconds_to_microseconds(v);}
74 
seconds(nsecs_t v)75 static CONSTEXPR inline nsecs_t seconds(nsecs_t v)      { return s2ns(v); }
milliseconds(nsecs_t v)76 static CONSTEXPR inline nsecs_t milliseconds(nsecs_t v) { return ms2ns(v); }
microseconds(nsecs_t v)77 static CONSTEXPR inline nsecs_t microseconds(nsecs_t v) { return us2ns(v); }
78 
79 enum {
80     SYSTEM_TIME_REALTIME = 0,  // system-wide realtime clock
81     SYSTEM_TIME_MONOTONIC = 1, // monotonic time since unspecified starting point
82     SYSTEM_TIME_PROCESS = 2,   // high-resolution per-process clock
83     SYSTEM_TIME_THREAD = 3,    // high-resolution per-thread clock
84     SYSTEM_TIME_BOOTTIME = 4   // same as SYSTEM_TIME_MONOTONIC, but including CPU suspend time
85 };
86 
87 // return the system-time according to the specified clock
88 #ifdef __cplusplus
89 nsecs_t systemTime(int clock = SYSTEM_TIME_MONOTONIC);
90 #else
91 nsecs_t systemTime(int clock);
92 #endif // def __cplusplus
93 
94 /**
95  * Returns the number of milliseconds to wait between the reference time and the timeout time.
96  * If the timeout is in the past relative to the reference time, returns 0.
97  * If the timeout is more than INT_MAX milliseconds in the future relative to the reference time,
98  * such as when timeoutTime == LLONG_MAX, returns -1 to indicate an infinite timeout delay.
99  * Otherwise, returns the difference between the reference time and timeout time
100  * rounded up to the next millisecond.
101  */
102 int toMillisecondTimeoutDelay(nsecs_t referenceTime, nsecs_t timeoutTime);
103 
104 #ifdef __cplusplus
105 } // extern "C"
106 #endif
107 
108 #endif // _LIBS_UTILS_TIMERS_H
109