summaryrefslogtreecommitdiffhomepage
path: root/compat/timer.cpp
blob: a3d91af4cbdae01dd80b5c3a15083998902d50f6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
/* Copyright (c) 2014-2015, Stanislaw Halik <sthalik@misaki.pl>

 * Permission to use, copy, modify, and/or distribute this
 * software for any purpose with or without fee is hereby granted,
 * provided that the above copyright notice and this permission
 * notice appear in all copies.
 */

#include <cassert>

#include "timer.hpp"
#include <cmath>

Timer::Timer()
{
    start();
}

void Timer::start()
{
    gettime(&state);
}

// common

void Timer::gettime(timespec* state)
{
#if defined(_WIN32) || defined(__MACH__)
    otr_clock_gettime(state);
#elif defined CLOCK_MONOTONIC
    const int res = clock_gettime(CLOCK_MONOTONIC, state);
    assert(res == 0 && "must support CLOCK_MONOTONIC");
#else
#   error "timer query method not known"
#endif
}

// nanoseconds

long long Timer::elapsed_nsecs() const
{
    timespec cur{};
    gettime(&cur);
    return conv_nsecs(cur);
}

long long Timer::conv_nsecs(const timespec& cur) const
{
    return (cur.tv_sec - state.tv_sec) * 1000000000LL + (cur.tv_nsec - state.tv_nsec);
}

// microseconds

double Timer::elapsed_usecs() const
{
    timespec cur{};
    gettime(&cur);
    const long long nsecs = conv_nsecs(cur);
    return nsecs * 1e-3;
}

// milliseconds

double Timer::elapsed_ms() const
{
    return elapsed_usecs() / 1000.;
}

double Timer::elapsed_seconds() const
{
    return double(elapsed_nsecs() * 1e-9L);
}

// --
// platform-specific code starts here
// --

#if defined _WIN32
LARGE_INTEGER Timer::otr_get_clock_frequency()
{
    LARGE_INTEGER freq{};
    (void) QueryPerformanceFrequency(&freq);
    return freq;
}

void Timer::otr_clock_gettime(timespec* ts)
{
    static const LARGE_INTEGER freq = otr_get_clock_frequency();

    LARGE_INTEGER d;

    (void) QueryPerformanceCounter(&d);

    using ll = long long;
    const ll part = ll(std::roundl((d.QuadPart * 1000000000.L) / ll(freq.QuadPart)));
    using t_s = decltype(ts->tv_sec);
    using t_ns = decltype(ts->tv_nsec);

    ts->tv_sec = t_s(part / 1000000000);
    ts->tv_nsec = t_ns(part % 1000000000);
}

#elif defined __MACH__
mach_timebase_info_data_t Timer::otr_get_mach_frequency()
{
    mach_timebase_info_data_t timebase_info;
    (void) mach_timebase_info(&timebase_info);
    return timebase_info;
}

void Timer::otr_clock_gettime(timespec* ts)
{
    static const mach_timebase_info_data_t timebase_info = otr_get_mach_frequency();
    uint64_t state, nsec;
    state = mach_absolute_time();
    nsec = state * timebase_info.numer / timebase_info.denom;
    ts->tv_sec = nsec / 1000000000L;
    ts->tv_nsec = nsec % 1000000000L;
}

#endif