ceph/src/boost/libs/context/performance/winfiber/performance.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 <cstddef>
   8 #include <cstdlib>
   9 #include <iostream>
  10 #include <stdexcept>
  11
  12 #include <windows.h>
  13
  14 #include <boost/chrono.hpp>
  15 #include <boost/cstdint.hpp>
  16 #include <boost/program_options.hpp>
  17
  18 #include "../bind_processor.hpp"
  19 #include "../clock.hpp"
  20 #include "../cycle.hpp"
  21 #include "../../example/simple_stack_allocator.hpp"
  22
  23 typedef boost::context::simple_stack_allocator<
  24             8 * 1024 * 1024, 64 * 1024, 8 * 1024
  25         >                                       stack_allocator;
  26
  27 boost::uint64_t jobs = 1000;
  28 LPVOID fc, fm;
  29
  30 VOID __stdcall fn( LPVOID)
  31 { while ( true) ::SwitchToFiber( fm); }
  32
  33 duration_type measure_time()
  34 {
  35     // cache warum-up
  36     ::SwitchToFiber( fc);
  37
  38     time_point_type start( clock_type::now() );
  39     for ( std::size_t i = 0; i < jobs; ++i) {
  40         ::SwitchToFiber( fc);
  41     }
  42     duration_type total = clock_type::now() - start;
  43     total -= overhead_clock(); // overhead of measurement
  44     total /= jobs;  // loops
  45     total /= 2;  // 2x jump_fcontext
  46
  47     return total;
  48 }
  49
  50 #ifdef BOOST_CONTEXT_CYCLE
  51 cycle_type measure_cycles()
  52 {
  53     // cache warum-up
  54     ::SwitchToFiber( fc);
  55
  56     cycle_type start( cycles() );
  57     for ( std::size_t i = 0; i < jobs; ++i) {
  58         ::SwitchToFiber( fc);
  59     }
  60     cycle_type total = cycles() - start;
  61     total -= overhead_cycle(); // overhead of measurement
  62     total /= jobs;  // loops
  63     total /= 2;  // 2x jump_fcontext
  64
  65     return total;
  66 }
  67 #endif
  68
  69 int main( int argc, char * argv[])
  70 {
  71     try
  72     {
  73         bind_to_processor( 0);
  74
  75         boost::program_options::options_description desc("allowed options");
  76         desc.add_options()
  77             ("help", "help message")
  78             ("jobs,j", boost::program_options::value< boost::uint64_t >( & jobs), "jobs to run");
  79
  80         boost::program_options::variables_map vm;
  81         boost::program_options::store(
  82                 boost::program_options::parse_command_line(
  83                     argc,
  84                     argv,
  85                     desc),
  86                 vm);
  87         boost::program_options::notify( vm);
  88
  89         if ( vm.count("help") ) {
  90             std::cout << desc << std::endl;
  91             return EXIT_SUCCESS;
  92         }
  93
  94         fm = ::ConvertThreadToFiber( 0);
  95         fc = ::CreateFiber( stack_allocator::default_stacksize(), fn, 0);
  96
  97         boost::uint64_t res = measure_time().count();
  98         std::cout << "average of " << res << " nano seconds" << std::endl;
  99 #ifdef BOOST_CONTEXT_CYCLE
 100         res = measure_cycles();
 101         std::cout << "average of " << res << " cpu cycles" << std::endl;
 102 #endif
 103
 104         return EXIT_SUCCESS;
 105     }
 106     catch ( std::exception const& e)
 107     { std::cerr << "exception: " << e.what() << std::endl; }
 108     catch (...)
 109     { std::cerr << "unhandled exception" << std::endl; }
 110     return EXIT_FAILURE;
 111 }