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// ------------------------------------------------------------------
28// C API
29
30#ifdef __cplusplus
31extern "C" {
32#endif
33
34typedef int64_t nsecs_t;       // nano-seconds
35
36static inline nsecs_t seconds_to_nanoseconds(nsecs_t secs)
37{
38    return secs*1000000000;
39}
40
41static inline nsecs_t milliseconds_to_nanoseconds(nsecs_t secs)
42{
43    return secs*1000000;
44}
45
46static inline nsecs_t microseconds_to_nanoseconds(nsecs_t secs)
47{
48    return secs*1000;
49}
50
51static inline nsecs_t nanoseconds_to_seconds(nsecs_t secs)
52{
53    return secs/1000000000;
54}
55
56static inline nsecs_t nanoseconds_to_milliseconds(nsecs_t secs)
57{
58    return secs/1000000;
59}
60
61static inline nsecs_t nanoseconds_to_microseconds(nsecs_t secs)
62{
63    return secs/1000;
64}
65
66static inline nsecs_t s2ns(nsecs_t v)  {return seconds_to_nanoseconds(v);}
67static inline nsecs_t ms2ns(nsecs_t v) {return milliseconds_to_nanoseconds(v);}
68static inline nsecs_t us2ns(nsecs_t v) {return microseconds_to_nanoseconds(v);}
69static inline nsecs_t ns2s(nsecs_t v)  {return nanoseconds_to_seconds(v);}
70static inline nsecs_t ns2ms(nsecs_t v) {return nanoseconds_to_milliseconds(v);}
71static inline nsecs_t ns2us(nsecs_t v) {return nanoseconds_to_microseconds(v);}
72
73static inline nsecs_t seconds(nsecs_t v)      { return s2ns(v); }
74static inline nsecs_t milliseconds(nsecs_t v) { return ms2ns(v); }
75static inline nsecs_t microseconds(nsecs_t v) { return us2ns(v); }
76
77enum {
78    SYSTEM_TIME_REALTIME = 0,  // system-wide realtime clock
79    SYSTEM_TIME_MONOTONIC = 1, // monotonic time since unspecified starting point
80    SYSTEM_TIME_PROCESS = 2,   // high-resolution per-process clock
81    SYSTEM_TIME_THREAD = 3,    // high-resolution per-thread clock
82    SYSTEM_TIME_BOOTTIME = 4   // same as SYSTEM_TIME_MONOTONIC, but including CPU suspend time
83};
84
85// return the system-time according to the specified clock
86#ifdef __cplusplus
87nsecs_t systemTime(int clock = SYSTEM_TIME_MONOTONIC);
88#else
89nsecs_t systemTime(int clock);
90#endif // def __cplusplus
91
92/**
93 * Returns the number of milliseconds to wait between the reference time and the timeout time.
94 * If the timeout is in the past relative to the reference time, returns 0.
95 * If the timeout is more than INT_MAX milliseconds in the future relative to the reference time,
96 * such as when timeoutTime == LLONG_MAX, returns -1 to indicate an infinite timeout delay.
97 * Otherwise, returns the difference between the reference time and timeout time
98 * rounded up to the next millisecond.
99 */
100int toMillisecondTimeoutDelay(nsecs_t referenceTime, nsecs_t timeoutTime);
101
102#ifdef __cplusplus
103} // extern "C"
104#endif
105
106// ------------------------------------------------------------------
107// C++ API
108
109#ifdef __cplusplus
110
111namespace android {
112/*
113 * Time the duration of something.
114 *
115 * Includes some timeval manipulation functions.
116 */
117class DurationTimer {
118public:
119    DurationTimer() {}
120    ~DurationTimer() {}
121
122    // Start the timer.
123    void start();
124    // Stop the timer.
125    void stop();
126    // Get the duration in microseconds.
127    long long durationUsecs() const;
128
129    // Subtract two timevals.  Returns the difference (ptv1-ptv2) in
130    // microseconds.
131    static long long subtractTimevals(const struct timeval* ptv1,
132        const struct timeval* ptv2);
133
134    // Add the specified amount of time to the timeval.
135    static void addToTimeval(struct timeval* ptv, long usec);
136
137private:
138    struct timeval  mStartWhen;
139    struct timeval  mStopWhen;
140};
141
142}; // android
143#endif // def __cplusplus
144
145#endif // _LIBS_UTILS_TIMERS_H
146