doc/html/boost_asio/example/http/server2/io_service_pool.cpp
//
// io_service_pool.cpp
// ~~~~~~~~~~~~~~~~~~~
//
// Copyright (c) 2003-2010 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)
//
#include "server.hpp"
#include <stdexcept>
#include <boost/thread.hpp>
#include <boost/bind.hpp>
#include <boost/shared_ptr.hpp>
namespace http {
namespace server2 {
io_service_pool::io_service_pool(std::size_t pool_size)
: next_io_service_(0)
{
if (pool_size == 0)
throw std::runtime_error("io_service_pool size is 0");
// Give all the io_services work to do so that their run() functions will not
// exit until they are explicitly stopped.
for (std::size_t i = 0; i < pool_size; ++i)
{
io_service_ptr io_service(new boost::asio::io_service);
work_ptr work(new boost::asio::io_service::work(*io_service));
io_services_.push_back(io_service);
work_.push_back(work);
}
}
void io_service_pool::run()
{
// Create a pool of threads to run all of the io_services.
std::vector<boost::shared_ptr<boost::thread> > threads;
for (std::size_t i = 0; i < io_services_.size(); ++i)
{
boost::shared_ptr<boost::thread> thread(new boost::thread(
boost::bind(&boost::asio::io_service::run, io_services_[i])));
threads.push_back(thread);
}
// Wait for all threads in the pool to exit.
for (std::size_t i = 0; i < threads.size(); ++i)
threads[i]->join();
}
void io_service_pool::stop()
{
// Explicitly stop all io_services.
for (std::size_t i = 0; i < io_services_.size(); ++i)
io_services_[i]->stop();
}
boost::asio::io_service& io_service_pool::get_io_service()
{
// Use a round-robin scheme to choose the next io_service to use.
boost::asio::io_service& io_service = *io_services_[next_io_service_];
++next_io_service_;
if (next_io_service_ == io_services_.size())
next_io_service_ = 0;
return io_service;
}
} // namespace server2
} // namespace http