pool.hpp
Go to the documentation of this file.
#ifndef OSMIUM_THREAD_POOL_HPP
#define OSMIUM_THREAD_POOL_HPP
/*
This file is part of Osmium (http://osmcode.org/libosmium).
Copyright 2013-2016 Jochen Topf <jochen@topf.org> and others (see README).
Boost Software License - Version 1.0 - August 17th, 2003
Permission is hereby granted, free of charge, to any person or organization
obtaining a copy of the software and accompanying documentation covered by
this license (the "Software") to use, reproduce, display, distribute,
execute, and transmit the Software, and to prepare derivative works of the
Software, and to permit third-parties to whom the Software is furnished to
do so, all subject to the following:
The copyright notices in the Software and this entire statement, including
the above license grant, this restriction and the following disclaimer,
must be included in all copies of the Software, in whole or in part, and
all derivative works of the Software, unless such copies or derivative
works are solely in the form of machine-executable object code generated by
a source language processor.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
DEALINGS IN THE SOFTWARE.
*/
#include <algorithm>
#include <atomic>
#include <cstddef>
#include <cstdlib>
#include <future>
#include <thread>
#include <type_traits>
#include <vector>
#include <osmium/thread/function_wrapper.hpp>
#include <osmium/thread/queue.hpp>
#include <osmium/thread/util.hpp>
#include <osmium/util/config.hpp>
namespace osmium {
namespace thread {
namespace detail {
// Maximum number of allowed pool threads (just to keep the user
// from setting something silly).
constexpr const int max_pool_threads = 256;
inline int get_pool_size(int num_threads, int user_setting, unsigned hardware_concurrency) {
if (num_threads == 0) {
num_threads = user_setting ? user_setting : -2;
}
if (num_threads < 0) {
num_threads += hardware_concurrency;
}
if (num_threads < 1) {
num_threads = 1;
} else if (num_threads > max_pool_threads) {
num_threads = max_pool_threads;
}
return num_threads;
}
} // namespace detail
class Pool {
class thread_joiner {
std::vector<std::thread>& m_threads;
public:
explicit thread_joiner(std::vector<std::thread>& threads) :
m_threads(threads) {
}
~thread_joiner() {
for (auto& thread : m_threads) {
if (thread.joinable()) {
thread.join();
}
}
}
}; // class thread_joiner
osmium::thread::Queue<function_wrapper> m_work_queue;
std::vector<std::thread> m_threads;
thread_joiner m_joiner;
int m_num_threads;
void worker_thread() {
osmium::thread::set_thread_name("_osmium_worker");
while (true) {
function_wrapper task;
m_work_queue.wait_and_pop_with_timeout(task);
if (task) {
if (task()) {
// The called tasks returns true only when the
// worker thread should shut down.
return;
}
}
}
}
explicit Pool(int num_threads, size_t max_queue_size) :
m_work_queue(max_queue_size, "work"),
m_threads(),
m_joiner(m_threads),
m_num_threads(detail::get_pool_size(num_threads, osmium::config::get_pool_threads(), std::thread::hardware_concurrency())) {
try {
for (int i = 0; i < m_num_threads; ++i) {
m_threads.push_back(std::thread(&Pool::worker_thread, this));
}
} catch (...) {
shutdown_all_workers();
throw;
}
}
public:
static constexpr int default_num_threads = 0;
static constexpr size_t max_work_queue_size = 10;
static Pool& instance() {
static Pool pool(default_num_threads, max_work_queue_size);
return pool;
}
void shutdown_all_workers() {
for (int i = 0; i < m_num_threads; ++i) {
// The special function wrapper makes a worker shut down.
m_work_queue.push(function_wrapper{0});
}
}
~Pool() {
shutdown_all_workers();
m_work_queue.shutdown();
}
size_t queue_size() const {
return m_work_queue.size();
}
bool queue_empty() const {
return m_work_queue.empty();
}
template <typename TFunction>
std::future<typename std::result_of<TFunction()>::type> submit(TFunction&& func) {
typedef typename std::result_of<TFunction()>::type result_type;
std::packaged_task<result_type()> task(std::forward<TFunction>(func));
std::future<result_type> future_result(task.get_future());
m_work_queue.push(std::move(task));
return future_result;
}
}; // class Pool
} // namespace thread
} // namespace osmium
#endif // OSMIUM_THREAD_POOL_HPP
osmium::thread::Pool::Pool
Pool(int num_threads, size_t max_queue_size)
Definition: pool.hpp:144
osmium::osm_entity_bits::type
type
Definition: entity_bits.hpp:60
util.hpp
osmium::thread::Queue::size
size_t size() const
Definition: queue.hpp:188
osmium::thread::Queue::empty
bool empty() const
Definition: queue.hpp:183
osmium::thread::Queue
Definition: queue.hpp:56
osmium::thread::set_thread_name
void set_thread_name(const char *name) noexcept
Definition: util.hpp:74
osmium::thread::Pool::~Pool
~Pool()
Definition: pool.hpp:177
std
Definition: reader_iterator.hpp:39
config.hpp
osmium::thread::Pool::thread_joiner::m_threads
std::vector< std::thread > & m_threads
Definition: pool.hpp:94
osmium::thread::Queue::shutdown
void shutdown()
Definition: queue.hpp:144
osmium::thread::Pool::submit
std::future< typename std::result_of< TFunction()>::type > submit(TFunction &&func)
Definition: pool.hpp:191
osmium::thread::Pool::worker_thread
void worker_thread()
Definition: pool.hpp:117
osmium::thread::Pool::instance
static Pool & instance()
Definition: pool.hpp:165
osmium
Namespace for everything in the Osmium library.
Definition: assembler.hpp:59
detail
Definition: attr.hpp:298
osmium::thread::Queue::wait_and_pop_with_timeout
void wait_and_pop_with_timeout(T &value)
Definition: queue.hpp:160
osmium::config::get_pool_threads
int get_pool_threads()
Definition: config.hpp:47
osmium::thread::function_wrapper
Definition: function_wrapper.hpp:48
osmium::thread::Pool::m_threads
std::vector< std::thread > m_threads
Definition: pool.hpp:113
osmium::thread::Pool
Definition: pool.hpp:86
function_wrapper.hpp
osmium::thread::Pool::m_work_queue
osmium::thread::Queue< function_wrapper > m_work_queue
Definition: pool.hpp:112
osmium::thread::Pool::thread_joiner::thread_joiner
thread_joiner(std::vector< std::thread > &threads)
Definition: pool.hpp:98
osmium::thread::Pool::m_num_threads
int m_num_threads
Definition: pool.hpp:115
osmium::thread::Pool::thread_joiner
Definition: pool.hpp:92
osmium::thread::Pool::thread_joiner::~thread_joiner
~thread_joiner()
Definition: pool.hpp:102
osmium::thread::Queue::push
void push(T value)
Definition: queue.hpp:122
osmium::thread::Pool::shutdown_all_workers
void shutdown_all_workers()
Definition: pool.hpp:170
osmium::thread::Pool::queue_empty
bool queue_empty() const
Definition: pool.hpp:186
osmium::thread::Pool::m_joiner
thread_joiner m_joiner
Definition: pool.hpp:114
osmium::thread::Pool::queue_size
size_t queue_size() const
Definition: pool.hpp:182
queue.hpp