ceph/src/boost/libs/fiber/performance/fiber/overhead_detach.cpp

   1
   2 //          Copyright Oliver Kowalke 2009.
   3 // Distributed under the Boost Software License, Version 1.0.
   4 //    (See accompanying file LICENSE_1_0.txt or copy at
   5 //          http://www.boost.org/LICENSE_1_0.txt)
   6
   7 #include <cstdlib>
   8 #include <iostream>
   9 #include <stdexcept>
  10
  11 #include <boost/cstdint.hpp>
  12 #include <boost/fiber/all.hpp>
  13 #include <boost/preprocessor.hpp>
  14
  15 #include "../clock.hpp"
  16
  17 #ifndef JOBS
  18 #define JOBS BOOST_PP_LIMIT_REPEAT
  19 #endif
  20
  21 #define CREATE(z, n, _) \
  22     boost::fibers::fiber BOOST_PP_CAT(f,n) (worker);
  23
  24 #define DETACH(z, n, _) \
  25     BOOST_PP_CAT(f,n) .detach();
  26
  27 void worker() {}
  28
  29 duration_type measure( duration_type overhead) {
  30     boost::fibers::fiber( worker).join();
  31     BOOST_PP_REPEAT_FROM_TO(1, JOBS, CREATE, _)
  32     time_point_type start( clock_type::now() );
  33     BOOST_PP_REPEAT_FROM_TO(1, JOBS, DETACH, _);
  34     duration_type result = clock_type::now() - start;
  35     result -= overhead;
  36     result /= JOBS;  // joined fibers
  37     return result;
  38 }
  39
  40 int main( int argc, char * argv[]) {
  41     try {
  42         duration_type overhead = overhead_clock();
  43         boost::uint64_t res = measure( overhead).count();
  44         std::cout << "average of " << res << " nano seconds" << std::endl;
  45         return EXIT_SUCCESS;
  46     } catch ( std::exception const& e) {
  47         std::cerr << "exception: " << e.what() << std::endl;
  48     } catch (...) {
  49         std::cerr << "unhandled exception" << std::endl;
  50     }
  51     return EXIT_FAILURE;
  52 }