#include <cstdlib>
#include <iostream>

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

namespace asio = boost::asio;


void f( int i ) {
  // do actually nothing...

    int j = i*2;
    j = j/4;

}

int main(int argc, char *argv[]) {


  for( std::size_t concurrency=1; concurrency<9; ++concurrency ) {
    //std::size_t const concurrency = 3;
    std::cout << "Concurrency = " << concurrency << std::endl;

    asio::io_service io_service( concurrency );

    boost::timer t;

    double jobsize = 10000000;
    for( int i = 0; i < int(jobsize); ++i ) {
        io_service.post( boost::bind( &f, i ) );
    }

    double a(  t.elapsed()  );
    std::cout << "Finished posting after:   " << a << std::endl;

    std::vector< boost::shared_ptr<boost::thread> > threads;
    for( std::size_t i=0; i<(concurrency-1); ++i ) {
        threads.push_back( boost::shared_ptr<boost::thread>(new boost::thread( boost::bind( &asio::io_service::run, &io_service))) );
    }
    for( std::size_t i=0; i<(concurrency-1); ++i ) {
        threads[i]->join();
    }
    io_service.run();

    double b( t.elapsed()  );
    std::cout << "Finished execution after: " << b << " " << t.elapsed() << std::endl;
    std::cout << "Execs / sec:              " << jobsize << "/" << (b-a) << "=" << (jobsize/(b-a)) << std::endl;


  }

  return EXIT_SUCCESS;
}