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
122
123
124
125
126
127
128
129
|
// -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
// vi: set et ts=4 sw=2 sts=2:
// SPDX-FileCopyrightInfo: Copyright © DUNE Project contributors, see file LICENSE.md in module root
// SPDX-License-Identifier: LicenseRef-GPL-2.0-only-with-DUNE-exception
#ifndef DUNE_TIMER_HH
#define DUNE_TIMER_HH
#include <chrono>
namespace Dune {
/** @addtogroup Common
@{
*/
/*! \file
\brief A simple timing class.
*/
/** \brief A simple stop watch
This class reports the elapsed real time, i.e. time elapsed
after Timer::reset(). It does not measure the time spent computing,
i.e. time spend in concurrent threads is not added up while
time measurements include the time elapsed while sleeping.
The class is basically a wrapper around std::chrono::high_resolution_clock::now().
*/
class Timer
{
using Clock = std::chrono::high_resolution_clock;
using Units = std::chrono::duration<double>; // seconds stored as double
public:
/** \brief A new timer, create and reset
*
* \param startImmediately If true (default) the timer starts counting immediately
*/
Timer (bool startImmediately=true) noexcept
{
isRunning_ = startImmediately;
reset();
}
//! Reset timer while keeping the running/stopped state
void reset() noexcept
{
sumElapsed_ = std::chrono::seconds{0};
storedLastElapsed_ = std::chrono::seconds{0};
cstart = Clock::now();
}
//! Start the timer and continue measurement if it is not running. Otherwise do nothing.
void start() noexcept
{
if (not (isRunning_))
{
cstart = Clock::now();
isRunning_ = true;
}
}
//! Get elapsed user-time from last reset until now/last stop in seconds.
double elapsed () const noexcept
{
return durationCast(rawElapsed());
}
//! Get elapsed user-time from last start until now/last stop in seconds.
double lastElapsed () const noexcept
{
return durationCast(rawLastElapsed());
}
//! Stop the timer and return elapsed().
double stop() noexcept
{
if (isRunning_)
{
// update storedLastElapsed_ and sumElapsed_ and stop timer
storedLastElapsed_ = rawLastElapsed();
sumElapsed_ += storedLastElapsed_;
isRunning_ = false;
}
return elapsed();
}
private:
bool isRunning_;
Clock::duration sumElapsed_;
Clock::duration storedLastElapsed_;
Clock::duration rawElapsed () const noexcept
{
// if timer is running add the time elapsed since last start to sum
if (isRunning_)
return sumElapsed_ + rawLastElapsed();
return sumElapsed_;
}
//! Get elapsed user-time from last start until now/last stop in seconds.
Clock::duration rawLastElapsed () const noexcept
{
// if timer is running return the current value
if (isRunning_)
return Clock::now() - cstart;
// if timer is not running return stored value from last run
return storedLastElapsed_;
}
double durationCast(Clock::duration duration) const noexcept {
return std::chrono::duration_cast<Units>(duration).count();
}
Clock::time_point cstart;
}; // end class Timer
/** @} end documentation */
} // end namespace
#endif
|
