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
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
|
/*=============================================================================
Copyright (c) 2005-2007 Hartmut Kaiser
2007, 2009 Tim Blechmann
Distributed under the Boost Software License, Version 1.0.
(See accompanying file LICENSE_1_0.txt or copy at
http://www.boost.org/LICENSE_1_0.txt)
=============================================================================*/
#if !defined(BOOST_HIGH_RESOLUTION_TIMER_HPP)
#define BOOST_HIGH_RESOLUTION_TIMER_HPP
#include <boost/config.hpp>
#include <boost/throw_exception.hpp>
#if _POSIX_C_SOURCE >= 199309L
#include "time.h"
#include <stdexcept>
#include <limits>
namespace boost {
class high_resolution_timer
{
public:
high_resolution_timer()
{
restart();
}
void restart()
{
int status = clock_gettime(CLOCK_REALTIME, &start_time);
if (status == -1)
boost::throw_exception(std::runtime_error("Couldn't initialize start_time"));
}
double elapsed() const // return elapsed time in seconds
{
struct timespec now;
int status = clock_gettime(CLOCK_REALTIME, &now);
if (status == -1)
boost::throw_exception(std::runtime_error("Couldn't get current time"));
struct timespec diff;
double ret_sec = double(now.tv_sec - start_time.tv_sec);
double ret_nsec = double(now.tv_nsec - start_time.tv_nsec);
while (ret_nsec < 0)
{
ret_sec -= 1.0;
ret_nsec += 1e9;
}
double ret = ret_sec + ret_nsec / 1e9;
return ret;
}
double elapsed_max() const // return estimated maximum value for elapsed()
{
return double((std::numeric_limits<double>::max)());
}
double elapsed_min() const // return minimum value for elapsed()
{
return 0.0;
}
private:
struct timespec start_time;
};
} // namespace boost
#elif defined(__APPLE__)
#import <mach/mach_time.h>
namespace boost {
class high_resolution_timer
{
public:
high_resolution_timer(void)
{
mach_timebase_info_data_t info;
kern_return_t err = mach_timebase_info(&info);
if (err)
throw std::runtime_error("cannot create mach timebase info");
conversion_factor = (double)info.numer/(double)info.denom;
restart();
}
void restart()
{
start = mach_absolute_time();
}
double elapsed() const // return elapsed time in seconds
{
uint64_t now = mach_absolute_time();
double duration = double(now - start) * conversion_factor;
return duration
}
double elapsed_max() const // return estimated maximum value for elapsed()
{
return double((std::numeric_limits<double>::max)());
}
double elapsed_min() const // return minimum value for elapsed()
{
return 0.0;
}
private:
uint64_t start;
double conversion_factor;
};
} // namespace boost
#elif defined(BOOST_WINDOWS)
#include <stdexcept>
#include <limits>
#include <windows.h>
namespace boost {
///////////////////////////////////////////////////////////////////////////////
//
// high_resolution_timer
// A timer object measures elapsed time.
// CAUTION: Windows only!
//
///////////////////////////////////////////////////////////////////////////////
class high_resolution_timer
{
public:
high_resolution_timer()
{
start_time.QuadPart = 0;
frequency.QuadPart = 0;
if (!QueryPerformanceFrequency(&frequency))
boost::throw_exception(std::runtime_error("Couldn't acquire frequency"));
restart();
}
void restart()
{
if (!QueryPerformanceCounter(&start_time))
boost::throw_exception(std::runtime_error("Couldn't initialize start_time"));
}
double elapsed() const // return elapsed time in seconds
{
LARGE_INTEGER now;
if (!QueryPerformanceCounter(&now))
boost::throw_exception(std::runtime_error("Couldn't get current time"));
return double(now.QuadPart - start_time.QuadPart) / frequency.QuadPart;
}
double elapsed_max() const // return estimated maximum value for elapsed()
{
return (double((std::numeric_limits<LONGLONG>::max)())
- double(start_time.QuadPart)) / double(frequency.QuadPart);
}
double elapsed_min() const // return minimum value for elapsed()
{
return 1.0 / frequency.QuadPart;
}
private:
LARGE_INTEGER start_time;
LARGE_INTEGER frequency;
};
} // namespace boost
#else
// For other platforms, simply fall back to boost::timer
#include <boost/timer.hpp>
#include <boost/throw_exception.hpp>
namespace boost {
typedef boost::timer high_resolution_timer;
}
#endif
#endif // !defined(BOOST_HIGH_RESOLUTION_TIMER_HPP)
|
