Question

In this blog I found a pretty neat example on how to create a simple thread pool using boost::asio. I basically want to use it like this:

#include <thread>
#include <functional>
#include <boost/asio.hpp>

int main ( int argc, char* argv[] ) {
    asio::io_service io_service;
    asio::io_service::work work(io_service);

    std::vector<std::thread> threadPool;

    for(size_t t = 0; t < std::thread::hardware_concurrency(); t++){
        threadPool.push_back(thread(std::bind(&asio::io_service::run, &io_service)));
    }

    io_service.post(std::bind(an_expensive_calculation, 42));
    io_service.post(std::bind(a_long_running_task, 123));

    //Do some things with the main thread

    io_service.stop();
    for(std::thread& t : threadPool) {
        t.join();
    }
}

Boost::asio is, as far as I know, mainly made for network IO. However, I mainly want to use it for general purpose functions. Concurrency issues would be adressed using asio::io_service::strand.

So my question: Is it a good idea to create a thread pool like this, even if my program does not use network IO? Are there any obvious performance losses compared to other thread pool implementations? If so, are there better implementations that are also as neat?

Answer 1

Boost.Asio is not solely for network programming, see the reference documentation. It has extensive support for things like

• time based operations (deadline_timer)
• signal handling
• platform specific operations such as posix streams and Windows handles

I’ve used it for other purposes in several applications as well. One example being a thread pool to service potentially long running blocking database operations while providing an asynchronous interface for the application. Boost.Asio really is a very powerful library. Using it for a general purpose thread pool as you propose can work just fine.