Sample how to create a boost threadpool in a class

threadpool.cpp

#include <boost/asio/io_service.hpp>
#include <boost/bind.hpp>
#include <boost/thread/thread.hpp>
#include <boost/make_shared.hpp>
#include <iostream>


class Bla{
public:
	void callback(std::string msg){
		std::cout << msg << std::endl;
		usleep(1000000);
	}
	Bla(){
		/*
		 * This will start the io_service_ processing loop. All tasks
		 * assigned with io_service_->post() will start executing.
		 */
		io_service_ = boost::make_shared<boost::asio::io_service>();
		work_ = boost::make_shared<boost::asio::io_service::work>(*io_service_);
		/*
		 * This will add 2 threads to the thread pool. (You could just put it in a for loop)
		 */
		std::size_t my_thread_count = 2;
		for (std::size_t i = 0; i < my_thread_count; ++i){
			threadpool_.create_thread(boost::bind(&boost::asio::io_service::run, io_service_));
		}
	};
	void run(){
		/*
		 * This will assign tasks to the thread pool.
		 * More about boost::bind: "http://www.boost.org/doc/libs/1_54_0/libs/bind/bind.html#with_functions"
		 */
		io_service_->post(boost::bind(&Bla::callback,this, "Hello World!"));
		io_service_->post(boost::bind(&Bla::callback,this, "./cache"));
		io_service_->post(boost::bind(&Bla::callback,this, "twitter,gmail,facebook,tumblr,reddit"));

	};
	void stop(){
		/*
		 * This will stop the io_service_ processing loop. Any tasks
		 * you add behind this point will not execute.
		 */
		io_service_->stop();
		/*
		 * Will wait till all the threads in the thread pool are finished with
		 * their assigned tasks and 'join' them. Just assume the threads inside
		 * the threadpool_ will be destroyed by this method.
		 */
		threadpool_.join_all();
	};
private:
	/*
	 * Create an asio::io_service and a thread_group (through pool in essence)
	 */
	boost::shared_ptr<boost::asio::io_service> io_service_;
	boost::shared_ptr<boost::asio::io_service::work> work_;
	boost::thread_group threadpool_;

};
int main(int argc, char **argv){
	Bla b;
	b.callback("test");
	b.run();

	usleep(3000000);
	b.stop();
	return 0;
}