Thread Pool with Boost
#include <iostream>
#include <thread>
#include <future>
#include <utility>
#include <chrono>
#include <boost/thread.hpp>
#include <boost/bind.hpp>
#include <boost/asio.hpp>
class ThreadPool {
public:
explicit ThreadPool(size_t size) : work_(io_service_) {
for (size_t i = 0; i < size; ++i) {
workers_.create_thread(
boost::bind(&boost::asio::io_service::run, &io_service_));
}
}
~ThreadPool() {
std::cout << "~ThreadPool" << std::endl;
io_service_.stop();
workers_.join_all();
}
template<class F>
void Enqueue(F f) {
io_service_.post(f);
}
private:
boost::thread_group workers_;
boost::asio::io_service io_service_;
boost::asio::io_service::work work_;
};
boost::mutex io_mutex;
void count(int id)
{
for (int i = 0; i < 10; i++)
{
boost::mutex::scoped_lock lock(io_mutex);
std::cout << id << ":" << i << std::endl;
}
}
void test_thread()
{
boost::thread thrd1(boost::bind(&count, 1));
boost::thread thrd2(boost::bind(&count, 2));
thrd1.join();
thrd2.join();
}
void print(int i)
{
boost::mutex::scoped_lock lock(io_mutex);
std::cout << "print() #" << boost::this_thread::get_id() << std::endl;
std::cout << "hello " << i << std::endl;
boost::this_thread::sleep(boost::posix_time::seconds(1));
std::cout << "world " << i << std::endl;
}
void test_thread_pool()
{
ThreadPool pool(4);
for (int i = 0; i < 8; ++i) {
pool.Enqueue(boost::bind(&print, i));
}
}
void do_task(std::promise<int> &promiseObj) {
boost::mutex::scoped_lock lock(io_mutex);
std::cout << "Inside thread: " << std::this_thread::get_id() << std::endl;
std::cout << "Inside thread: sleep 2 seconds... " << std::endl;
std::this_thread::sleep_for(std::chrono::seconds(2));
promiseObj.set_value(35);
}
void test_future()
{
std::promise<int> promiseObj;
std::future<int> futureObj = promiseObj.get_future();
std::cout << "create thread..." << std::endl;
std::thread th(do_task, std::ref(promiseObj));
std::cout << "futureObj.get() block main thread." << std::endl;
std::cout << futureObj.get() << std::endl;
th.join();
std::cout << "after join" << std::endl;
}
int main(int argc, char* argv[])
{
test_future();
return 0;
}
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