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
|
/************************************************************************
*
* Copyright (C) 2009-2023 IRCAD France
* Copyright (C) 2012-2021 IHU Strasbourg
*
* This file is part of Sight.
*
* Sight is free software: you can redistribute it and/or modify it under
* the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Sight is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with Sight. If not, see <https://www.gnu.org/licenses/>.
*
***********************************************************************/
#pragma once
#include <algorithm>
#include <cstddef>
#include <limits>
#include <thread>
#include <vector>
namespace sight::data::thread
{
class region_threader
{
public:
region_threader() :
m_nb_thread((std::thread::hardware_concurrency() > 1) ? std::thread::hardware_concurrency() : 1)
{
}
region_threader(std::size_t _nb_thread, bool _capped = true) :
m_nb_thread(std::min(_capped ? std::thread::hardware_concurrency() : std::numeric_limits<std::size_t>::max(),
(_nb_thread > 1) ? _nb_thread : 1))
{
}
//------------------------------------------------------------------------------
template<typename T>
void operator()(T _func, const std::ptrdiff_t _data_size)
{
std::vector<std::thread> threads;
const std::ptrdiff_t step = (_data_size / static_cast<std::ptrdiff_t>(m_nb_thread)) + 1;
if(m_nb_thread > 1)
{
std::ptrdiff_t region_begin = 0;
std::size_t thread_id = 0;
for( ; region_begin < _data_size ; region_begin += step, ++thread_id)
{
threads.push_back(
std::thread(
_func,
region_begin,
std::min(_data_size, region_begin + step),
thread_id
)
);
}
for(auto& thread : threads)
{
thread.join();
}
threads.clear();
}
else
{
_func(0, _data_size, 0);
}
}
//------------------------------------------------------------------------------
[[nodiscard]] std::size_t number_of_thread() const
{
return m_nb_thread;
}
protected:
const std::size_t m_nb_thread;
};
} // namespace sight::data::thread
|
