Files
columnlynx/include/asio/impl/thread_pool.ipp
2025-11-06 15:51:56 +01:00

146 lines
3.0 KiB
C++

//
// impl/thread_pool.ipp
// ~~~~~~~~~~~~~~~~~~~~
//
// Copyright (c) 2003-2025 Christopher M. Kohlhoff (chris at kohlhoff dot com)
//
// 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)
//
#ifndef ASIO_IMPL_THREAD_POOL_IPP
#define ASIO_IMPL_THREAD_POOL_IPP
#if defined(_MSC_VER) && (_MSC_VER >= 1200)
# pragma once
#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
#include "asio/detail/config.hpp"
#include <stdexcept>
#include "asio/thread_pool.hpp"
#include "asio/detail/throw_exception.hpp"
#include "asio/detail/push_options.hpp"
namespace asio {
struct thread_pool::thread_function
{
detail::scheduler* scheduler_;
void operator()()
{
#if !defined(ASIO_NO_EXCEPTIONS)
try
{
#endif// !defined(ASIO_NO_EXCEPTIONS)
asio::error_code ec;
scheduler_->run(ec);
#if !defined(ASIO_NO_EXCEPTIONS)
}
catch (...)
{
std::terminate();
}
#endif// !defined(ASIO_NO_EXCEPTIONS)
}
};
#if !defined(ASIO_NO_TS_EXECUTORS)
long thread_pool::default_thread_pool_size()
{
std::size_t num_threads = detail::thread::hardware_concurrency() * 2;
num_threads = num_threads == 0 ? 2 : num_threads;
return static_cast<long>(num_threads);
}
thread_pool::thread_pool()
: scheduler_(asio::make_service<detail::scheduler>(*this, false)),
threads_(allocator<void>(*this)),
num_threads_(default_thread_pool_size()),
joinable_(true)
{
start();
}
#endif // !defined(ASIO_NO_TS_EXECUTORS)
long thread_pool::clamp_thread_pool_size(std::size_t n)
{
if (n > 0x7FFFFFFF)
{
std::out_of_range ex("thread pool size");
asio::detail::throw_exception(ex);
}
return static_cast<long>(n & 0x7FFFFFFF);
}
thread_pool::thread_pool(std::size_t num_threads)
: execution_context(config_from_concurrency_hint(num_threads == 1 ? 1 : 0)),
scheduler_(asio::make_service<detail::scheduler>(*this, false)),
threads_(allocator<void>(*this)),
num_threads_(clamp_thread_pool_size(num_threads)),
joinable_(true)
{
start();
}
thread_pool::thread_pool(std::size_t num_threads,
const execution_context::service_maker& initial_services)
: execution_context(initial_services),
scheduler_(asio::make_service<detail::scheduler>(*this, false)),
threads_(allocator<void>(*this)),
num_threads_(clamp_thread_pool_size(num_threads)),
joinable_(true)
{
start();
}
thread_pool::~thread_pool()
{
stop();
join();
shutdown();
}
void thread_pool::start()
{
scheduler_.work_started();
thread_function f = { &scheduler_ };
threads_.create_threads(f, static_cast<std::size_t>(num_threads_));
}
void thread_pool::stop()
{
scheduler_.stop();
}
void thread_pool::attach()
{
++num_threads_;
thread_function f = { &scheduler_ };
f();
}
void thread_pool::join()
{
if (joinable_)
{
joinable_ = false;
scheduler_.work_finished();
threads_.join();
}
}
void thread_pool::wait()
{
join();
}
} // namespace asio
#include "asio/detail/pop_options.hpp"
#endif // ASIO_IMPL_THREAD_POOL_IPP