ceph/src/boost/libs/coroutine2/performance/performance_switch.cpp

   1
   2 //          Copyright Oliver Kowalke 2014.
   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 #include <string>
  11
  12 #include <boost/chrono.hpp>
  13 #include <boost/coroutine2/all.hpp>
  14 #include <boost/cstdint.hpp>
  15 #include <boost/program_options.hpp>
  16
  17 #include "bind_processor.hpp"
  18 #include "clock.hpp"
  19 #include "cycle.hpp"
  20
  21 boost::uint64_t jobs = 1000;
  22
  23 struct X
  24 {
  25     std::string str;
  26
  27     X( std::string const& str_) :
  28         str( str_)
  29     {}
  30 };
  31
  32 const X x("abc");
  33
  34 void fn_void( boost::coroutines2::coroutine< void >::push_type & c)
  35 { while ( true) c(); }
  36
  37 void fn_int( boost::coroutines2::coroutine< int >::push_type & c)
  38 { while ( true) c( 7); }
  39
  40 void fn_x( boost::coroutines2::coroutine< X >::push_type & c)
  41 {
  42     while ( true) c( x);
  43 }
  44
  45 duration_type measure_time_void( duration_type overhead)
  46 {
  47     boost::coroutines2::coroutine< void >::pull_type c( fn_void);
  48
  49     time_point_type start( clock_type::now() );
  50     for ( std::size_t i = 0; i < jobs; ++i) {
  51         c();
  52     }
  53     duration_type total = clock_type::now() - start;
  54     total -= overhead_clock(); // overhead of measurement
  55     total /= jobs;  // loops
  56     total /= 2;  // 2x jump_fcontext
  57
  58     return total;
  59 }
  60
  61 duration_type measure_time_int( duration_type overhead)
  62 {
  63     boost::coroutines2::coroutine< int >::pull_type c( fn_int);
  64
  65     time_point_type start( clock_type::now() );
  66     for ( std::size_t i = 0; i < jobs; ++i) {
  67         c();
  68     }
  69     duration_type total = clock_type::now() - start;
  70     total -= overhead_clock(); // overhead of measurement
  71     total /= jobs;  // loops
  72     total /= 2;  // 2x jump_fcontext
  73
  74     return total;
  75 }
  76
  77 duration_type measure_time_x( duration_type overhead)
  78 {
  79     boost::coroutines2::coroutine< X >::pull_type c( fn_x);
  80
  81     time_point_type start( clock_type::now() );
  82     for ( std::size_t i = 0; i < jobs; ++i) {
  83         c();
  84     }
  85     duration_type total = clock_type::now() - start;
  86     total -= overhead_clock(); // overhead of measurement
  87     total /= jobs;  // loops
  88     total /= 2;  // 2x jump_fcontext
  89
  90     return total;
  91 }
  92
  93 # ifdef BOOST_CONTEXT_CYCLE
  94 cycle_type measure_cycles_void( cycle_type overhead)
  95 {
  96     boost::coroutines2::coroutine< void >::pull_type c( fn_void);
  97
  98     cycle_type start( cycles() );
  99     for ( std::size_t i = 0; i < jobs; ++i) {
 100         c();
 101     }
 102     cycle_type total = cycles() - start;
 103     total -= overhead; // overhead of measurement
 104     total /= jobs;  // loops
 105     total /= 2;  // 2x jump_fcontext
 106
 107     return total;
 108 }
 109
 110 cycle_type measure_cycles_int( cycle_type overhead)
 111 {
 112     boost::coroutines2::coroutine< int >::pull_type c( fn_int);
 113
 114     cycle_type start( cycles() );
 115     for ( std::size_t i = 0; i < jobs; ++i) {
 116         c();
 117     }
 118     cycle_type total = cycles() - start;
 119     total -= overhead; // overhead of measurement
 120     total /= jobs;  // loops
 121     total /= 2;  // 2x jump_fcontext
 122
 123     return total;
 124 }
 125
 126 cycle_type measure_cycles_x( cycle_type overhead)
 127 {
 128     boost::coroutines2::coroutine< X >::pull_type c( fn_x);
 129
 130     cycle_type start( cycles() );
 131     for ( std::size_t i = 0; i < jobs; ++i) {
 132         c();
 133     }
 134     cycle_type total = cycles() - start;
 135     total -= overhead; // overhead of measurement
 136     total /= jobs;  // loops
 137     total /= 2;  // 2x jump_fcontext
 138
 139     return total;
 140 }
 141 # endif
 142
 143 int main( int argc, char * argv[])
 144 {
 145     try
 146     {
 147         bool bind = false;
 148         boost::program_options::options_description desc("allowed options");
 149         desc.add_options()
 150             ("help", "help message")
 151             ("bind,b", boost::program_options::value< bool >( & bind), "bind thread to CPU")
 152             ("jobs,j", boost::program_options::value< boost::uint64_t >( & jobs), "jobs to run");
 153
 154         boost::program_options::variables_map vm;
 155         boost::program_options::store(
 156                 boost::program_options::parse_command_line(
 157                     argc,
 158                     argv,
 159                     desc),
 160                 vm);
 161         boost::program_options::notify( vm);
 162
 163         if ( vm.count("help") ) {
 164             std::cout << desc << std::endl;
 165             return EXIT_SUCCESS;
 166         }
 167
 168         if ( bind) bind_to_processor( 0);
 169
 170         duration_type overhead_c = overhead_clock();
 171         boost::uint64_t res = measure_time_void( overhead_c).count();
 172         std::cout << "void: average of " << res << " nano seconds" << std::endl;
 173         res = measure_time_int( overhead_c).count();
 174         std::cout << "int: average of " << res << " nano seconds" << std::endl;
 175         res = measure_time_x( overhead_c).count();
 176         std::cout << "X: average of " << res << " nano seconds" << std::endl;
 177 #ifdef BOOST_CONTEXT_CYCLE
 178         cycle_type overhead_y = overhead_cycle();
 179         res = measure_cycles_void( overhead_y);
 180         std::cout << "void: average of " << res << " cpu cycles" << std::endl;
 181         res = measure_cycles_int( overhead_y);
 182         std::cout << "int: average of " << res << " cpu cycles" << std::endl;
 183         res = measure_cycles_x( overhead_y);
 184         std::cout << "X: average of " << res << " cpu cycles" << std::endl;
 185 #endif
 186
 187         return EXIT_SUCCESS;
 188     }
 189     catch ( std::exception const& e)
 190     { std::cerr << "exception: " << e.what() << std::endl; }
 191     catch (...)
 192     { std::cerr << "unhandled exception" << std::endl; }
 193     return EXIT_FAILURE;
 194 }