Libosmium  2.16.0
Fast and flexible C++ library for working with OpenStreetMap data
pool.hpp
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1 #ifndef OSMIUM_THREAD_POOL_HPP
2 #define OSMIUM_THREAD_POOL_HPP
3 
4 /*
5 
6 This file is part of Osmium (https://osmcode.org/libosmium).
7 
8 Copyright 2013-2021 Jochen Topf <jochen@topf.org> and others (see README).
9 
10 Boost Software License - Version 1.0 - August 17th, 2003
11 
12 Permission is hereby granted, free of charge, to any person or organization
13 obtaining a copy of the software and accompanying documentation covered by
14 this license (the "Software") to use, reproduce, display, distribute,
15 execute, and transmit the Software, and to prepare derivative works of the
16 Software, and to permit third-parties to whom the Software is furnished to
17 do so, all subject to the following:
18 
19 The copyright notices in the Software and this entire statement, including
20 the above license grant, this restriction and the following disclaimer,
21 must be included in all copies of the Software, in whole or in part, and
22 all derivative works of the Software, unless such copies or derivative
23 works are solely in the form of machine-executable object code generated by
24 a source language processor.
25 
26 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
27 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
28 FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
29 SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
30 FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
31 ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
32 DEALINGS IN THE SOFTWARE.
33 
34 */
35 
37 #include <osmium/thread/queue.hpp>
38 #include <osmium/thread/util.hpp>
39 #include <osmium/util/config.hpp>
40 
41 #include <cstddef>
42 #include <future>
43 #include <thread>
44 #include <type_traits>
45 #include <utility>
46 #include <vector>
47 
48 namespace osmium {
49 
53  namespace thread {
54 
55  namespace detail {
56 
57  // Maximum number of allowed pool threads (just to keep the user
58  // from setting something silly).
59  enum {
60  max_pool_threads = 32
61  };
62 
63  inline int get_pool_size(int num_threads, int user_setting, unsigned hardware_concurrency) {
64  if (num_threads == 0) {
65  num_threads = user_setting ? user_setting : -2;
66  }
67 
68  if (num_threads < 0) {
69  num_threads += int(hardware_concurrency);
70  }
71 
72  if (num_threads < 1) {
73  num_threads = 1;
74  } else if (num_threads > max_pool_threads) {
75  num_threads = max_pool_threads;
76  }
77 
78  return num_threads;
79  }
80 
81  inline std::size_t get_work_queue_size() noexcept {
82  return osmium::config::get_max_queue_size("WORK", 10);
83  }
84 
85  } // namespace detail
86 
90  class Pool {
91 
96  class thread_joiner {
97 
98  std::vector<std::thread>& m_threads;
99 
100  public:
101 
102  explicit thread_joiner(std::vector<std::thread>& threads) :
103  m_threads(threads) {
104  }
105 
106  thread_joiner(const thread_joiner&) = delete;
107  thread_joiner& operator=(const thread_joiner&) = delete;
108 
109  thread_joiner(thread_joiner&&) = delete;
111 
113  for (auto& thread : m_threads) {
114  if (thread.joinable()) {
115  thread.join();
116  }
117  }
118  }
119 
120  }; // class thread_joiner
121 
123  std::vector<std::thread> m_threads{};
126 
127  void worker_thread() {
128  osmium::thread::set_thread_name("_osmium_worker");
129  while (true) {
130  function_wrapper task;
131  m_work_queue.wait_and_pop(task);
132  if (task && task()) {
133  // The called tasks returns true only when the
134  // worker thread should shut down.
135  return;
136  }
137  }
138  }
139 
140  public:
141 
142  enum {
144  };
145 
146  enum {
148  };
149 
165  explicit Pool(int num_threads = default_num_threads, std::size_t max_queue_size = default_queue_size) :
166  m_work_queue(max_queue_size > 0 ? max_queue_size : detail::get_work_queue_size(), "work"),
168  m_num_threads(detail::get_pool_size(num_threads, osmium::config::get_pool_threads(), std::thread::hardware_concurrency())) {
169 
170  try {
171  for (int i = 0; i < m_num_threads; ++i) {
172  m_threads.emplace_back(&Pool::worker_thread, this);
173  }
174  } catch (...) {
176  throw;
177  }
178  }
179 
186  static Pool& default_instance() {
187  static Pool pool{};
188  return pool;
189  }
190 
192  for (int i = 0; i < m_num_threads; ++i) {
193  // The special function wrapper makes a worker shut down.
195  }
196  }
197 
198  Pool(const Pool&) = delete;
199  Pool& operator=(const Pool&) = delete;
200 
201  Pool(Pool&&) = delete;
202  Pool& operator=(Pool&&) = delete;
203 
204  ~Pool() {
206  }
207 
208  int num_threads() const noexcept {
209  return m_num_threads;
210  }
211 
212  std::size_t queue_size() const {
213  return m_work_queue.size();
214  }
215 
216  bool queue_empty() const {
217  return m_work_queue.empty();
218  }
219 
220  template <typename TFunction>
221  std::future<typename std::result_of<TFunction()>::type> submit(TFunction&& func) {
222  using result_type = typename std::result_of<TFunction()>::type;
223 
224  std::packaged_task<result_type()> task{std::forward<TFunction>(func)};
225  std::future<result_type> future_result{task.get_future()};
226  m_work_queue.push(std::move(task));
227 
228  return future_result;
229  }
230 
231  }; // class Pool
232 
233  } // namespace thread
234 
235 } // namespace osmium
236 
237 #endif // OSMIUM_THREAD_POOL_HPP
osmium::thread::Pool
Definition: pool.hpp:90
osmium::thread::Pool::queue_empty
bool queue_empty() const
Definition: pool.hpp:216
config.hpp
osmium::thread::Pool::~Pool
~Pool()
Definition: pool.hpp:204
osmium::thread::function_wrapper
Definition: function_wrapper.hpp:48
detail
Definition: attr.hpp:342
osmium::thread::Pool::submit
std::future< typename std::result_of< TFunction()>::type > submit(TFunction &&func)
Definition: pool.hpp:221
osmium::thread::set_thread_name
void set_thread_name(const char *name) noexcept
Definition: util.hpp:76
osmium::config::get_max_queue_size
std::size_t get_max_queue_size(const char *queue_name, const std::size_t default_value) noexcept
Definition: config.hpp:83
function_wrapper.hpp
osmium::thread::Pool::default_instance
static Pool & default_instance()
Definition: pool.hpp:186
osmium::thread::Pool::operator=
Pool & operator=(const Pool &)=delete
osmium::thread::Pool::default_queue_size
@ default_queue_size
Definition: pool.hpp:147
osmium::thread::Pool::m_work_queue
osmium::thread::Queue< function_wrapper > m_work_queue
Definition: pool.hpp:122
osmium
Namespace for everything in the Osmium library.
Definition: assembler.hpp:53
osmium::thread::Queue
Definition: queue.hpp:57
osmium::thread::Pool::queue_size
std::size_t queue_size() const
Definition: pool.hpp:212
osmium::thread::Pool::worker_thread
void worker_thread()
Definition: pool.hpp:127
queue.hpp
util.hpp
osmium::thread::Pool::num_threads
int num_threads() const noexcept
Definition: pool.hpp:208
osmium::thread::Pool::shutdown_all_workers
void shutdown_all_workers()
Definition: pool.hpp:191
osmium::thread::Pool::m_joiner
thread_joiner m_joiner
Definition: pool.hpp:124
osmium::config::get_pool_threads
int get_pool_threads() noexcept
Definition: config.hpp:62
std
Definition: location.hpp:551
osmium::thread::Pool::thread_joiner::m_threads
std::vector< std::thread > & m_threads
Definition: pool.hpp:98
osmium::thread::Pool::m_num_threads
int m_num_threads
Definition: pool.hpp:125
osmium::thread::Pool::thread_joiner::thread_joiner
thread_joiner(std::vector< std::thread > &threads)
Definition: pool.hpp:102
osmium::thread::Pool::thread_joiner::~thread_joiner
~thread_joiner()
Definition: pool.hpp:112
osmium::thread::Pool::m_threads
std::vector< std::thread > m_threads
Definition: pool.hpp:123
osmium::thread::Pool::Pool
Pool(int num_threads=default_num_threads, std::size_t max_queue_size=default_queue_size)
Definition: pool.hpp:165
osmium::thread::Pool::thread_joiner::operator=
thread_joiner & operator=(const thread_joiner &)=delete
osmium::thread::Pool::thread_joiner
Definition: pool.hpp:96
osmium::osm_entity_bits::type
type
Definition: entity_bits.hpp:63
osmium::thread::Pool::default_num_threads
@ default_num_threads
Definition: pool.hpp:143