text: 
  //          Copyright Oliver Kowalke 2014.
  // Distributed under the Boost Software License, Version 1.0.
  //    (See accompanying file LICENSE_1_0.txt or copy at
  //          http://www.boost.org/LICENSE_1_0.txt)
  
  #include <cstdlib>
  #include <iostream>
  #include <stdexcept>
  
  #include <boost/chrono.hpp>
  #include <boost/coroutine2/all.hpp>
  #include <boost/cstdint.hpp>
  #include <boost/program_options.hpp>
  
  #include "../bind_processor.hpp"
  #include "../clock.hpp"
  #include "../cycle.hpp"
  
  typedef boost::coroutines2::segmented_stack           stack_allocator;
  typedef boost::coroutines2::coroutine< void >   coro_type;
  
  boost::uint64_t jobs = 1000;
  
  void fn( coro_type::push_type & c)
  { while ( true) c(); }
  
  duration_type measure_time( duration_type overhead)
  {
      stack_allocator stack_alloc;
  
      time_point_type start( clock_type::now() );
      for ( std::size_t i = 0; i < jobs; ++i) {
          coro_type::pull_type c( stack_alloc, fn);
      }
      duration_type total = clock_type::now() - start;
      total -= overhead_clock(); // overhead of measurement
      total /= jobs;  // loops
  
      return total;
  }
  
  # ifdef BOOST_CONTEXT_CYCLE
  cycle_type measure_cycles( cycle_type overhead)
  {
      stack_allocator stack_alloc;
  
      cycle_type start( cycles() );
      for ( std::size_t i = 0; i < jobs; ++i) {
          coro_type::pull_type c( stack_alloc, fn);
      }
      cycle_type total = cycles() - start;
      total -= overhead; // overhead of measurement
      total /= jobs;  // loops
  
      return total;
  }
  # endif
  
  int main( int argc, char * argv[])
  {
      try
      {
          bool bind = false;
          boost::program_options::options_description desc("allowed options");
          desc.add_options()
              ("help", "help message")
              ("bind,b", boost::program_options::value< bool >( & bind), "bind thread to CPU")
              ("jobs,j", boost::program_options::value< boost::uint64_t >( & jobs), "jobs to run");
  
          boost::program_options::variables_map vm;
          boost::program_options::store(
                  boost::program_options::parse_command_line(
                      argc,
                      argv,
                      desc),
                  vm);
          boost::program_options::notify( vm);
  
          if ( vm.count("help") ) {
              std::cout << desc << std::endl;
              return EXIT_SUCCESS;
          }
  
          if ( bind) bind_to_processor( 0);
  
          duration_type overhead_c = overhead_clock();
          std::cout << "overhead " << overhead_c.count() << " nano seconds" << std::endl;
          boost::uint64_t res = measure_time( overhead_c).count();
          std::cout << "average of " << res << " nano seconds" << std::endl;
  #ifdef BOOST_CONTEXT_CYCLE
          cycle_type overhead_y = overhead_cycle();
          std::cout << "overhead " << overhead_y << " cpu cycles" << std::endl;
          res = measure_cycles( overhead_y);
          std::cout << "average of " << res << " cpu cycles" << std::endl;
  #endif
  
          return EXIT_SUCCESS;
      }
      catch ( std::exception const& e)
      { std::cerr << "exception: " << e.what() << std::endl; }
      catch (...)
      { std::cerr << "unhandled exception" << std::endl; }
      return EXIT_FAILURE;
  }
  