如何在C ++中使用boost来创build线程池？

如何在C ++中使用boost来创build线程池，以及如何将任务分配给线程池？

Answer 1

这个过程非常简单。 首先创build一个asio :: io_service和一个thread_group。 使用链接到io_service的线程填充thread_group。 使用boost :: bind函数将任务分配给线程。

要停止线程（通常在退出程序时），停止io_service并join所有线程。

你应该只需要这些标题：

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

这里是一个例子：

 /* * Create an asio::io_service and a thread_group (through pool in essence) */ boost::asio::io_service ioService; boost::thread_group threadpool; /* * This will start the ioService processing loop. All tasks * assigned with ioService.post() will start executing. */ boost::asio::io_service::work work(ioService); /* * This will add 2 threads to the thread pool. (You could just put it in a for loop) */ threadpool.create_thread( boost::bind(&boost::asio::io_service::run, &ioService) ); threadpool.create_thread( boost::bind(&boost::asio::io_service::run, &ioService) ); /* * 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" */ ioService.post(boost::bind(myTask, "Hello World!")); ioService.post(boost::bind(clearCache, "./cache")); ioService.post(boost::bind(getSocialUpdates, "twitter,gmail,facebook,tumblr,reddit")); /* * This will stop the ioService processing loop. Any tasks * you add behind this point will not execute. */ ioService.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(); 

来源： 食谱<Asio

Answer 2

我知道你喜欢代码。

我的版本

 namespace bamthread { typedef std::unique_ptr<boost::asio::io_service::work> asio_worker; struct ThreadPool { ThreadPool(size_t threads) :service(), working(new asio_worker::element_type(service)) { while(threads--) { auto worker = boost::bind(&boost::asio::io_service::run, &(this->service)); g.add_thread(new boost::thread(worker)); } } template<class F> void enqueue(F f){ service.post(f); } ~ThreadPool() { working.reset(); //allow run() to exit g.join_all(); service.stop(); } private: boost::asio::io_service service; //< the io_service we are wrapping asio_worker working; boost::thread_group g; //< need to keep track of threads so we can join them }; } 

一块代码使用它：

 { bamthread::ThreadPool tp(n_threads); BOOST_FOREACH(int y, boost::irange(starty, endy, step)){ int im_x = 0; BOOST_FOREACH(int x, boost::irange(startx, endx, step)){ tp.enqueue (boost::bind(&camera_view_depth::threaded_intersection, this, intersections, intersected, im_x, im_y, _faces, x, y)); ++im_x; } ++im_y; } }