ceph/src/boost/libs/coroutine/performance/asymmetric/performance_create_standard.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/chrono.hpp>
  12 #include <boost/coroutine/all.hpp>
  13 #include <boost/cstdint.hpp>
  14 #include <boost/program_options.hpp>
  15
  16 #include "../bind_processor.hpp"
  17 #include "../clock.hpp"
  18 #include "../cycle.hpp"
  19
  20 typedef boost::coroutines::standard_stack_allocator         stack_allocator;
  21 typedef boost::coroutines::asymmetric_coroutine< void >     coro_type;
  22
  23 boost::coroutines::flag_fpu_t preserve_fpu = boost::coroutines::fpu_not_preserved;
  24 boost::coroutines::flag_unwind_t unwind_stack = boost::coroutines::stack_unwind;
  25 boost::uint64_t jobs = 1000;
  26
  27 void fn( coro_type::push_type & c)
  28 { while ( true) c(); }
  29
  30 duration_type measure_time( duration_type overhead)
  31 {
  32     stack_allocator stack_alloc;
  33
  34     time_point_type start( clock_type::now() );
  35     for ( std::size_t i = 0; i < jobs; ++i) {
  36         coro_type::pull_type c( fn,
  37             boost::coroutines::attributes( unwind_stack, preserve_fpu), stack_alloc);
  38     }
  39     duration_type total = clock_type::now() - start;
  40     total -= overhead_clock(); // overhead of measurement
  41     total /= jobs;  // loops
  42
  43     return total;
  44 }
  45
  46 # ifdef BOOST_CONTEXT_CYCLE
  47 cycle_type measure_cycles( cycle_type overhead)
  48 {
  49     stack_allocator stack_alloc;
  50
  51     cycle_type start( cycles() );
  52     for ( std::size_t i = 0; i < jobs; ++i) {
  53         coro_type::pull_type c( fn,
  54             boost::coroutines::attributes( unwind_stack, preserve_fpu), stack_alloc);
  55     }
  56     cycle_type total = cycles() - start;
  57     total -= overhead; // overhead of measurement
  58     total /= jobs;  // loops
  59
  60     return total;
  61 }
  62 # endif
  63
  64 int main( int argc, char * argv[])
  65 {
  66     try
  67     {
  68         bool preserve = false, unwind = true, bind = false;
  69         boost::program_options::options_description desc("allowed options");
  70         desc.add_options()
  71             ("help", "help message")
  72             ("bind,b", boost::program_options::value< bool >( & bind), "bind thread to CPU")
  73             ("fpu,f", boost::program_options::value< bool >( & preserve), "preserve FPU registers")
  74             ("unwind,u", boost::program_options::value< bool >( & unwind), "unwind coroutine-stack")
  75             ("jobs,j", boost::program_options::value< boost::uint64_t >( & jobs), "jobs to run");
  76
  77         boost::program_options::variables_map vm;
  78         boost::program_options::store(
  79                 boost::program_options::parse_command_line(
  80                     argc,
  81                     argv,
  82                     desc),
  83                 vm);
  84         boost::program_options::notify( vm);
  85
  86         if ( vm.count("help") ) {
  87             std::cout << desc << std::endl;
  88             return EXIT_SUCCESS;
  89         }
  90
  91         if ( preserve) preserve_fpu = boost::coroutines::fpu_preserved;
  92         if ( ! unwind) unwind_stack = boost::coroutines::no_stack_unwind;
  93         if ( bind) bind_to_processor( 0);
  94
  95         duration_type overhead_c = overhead_clock();
  96         std::cout << "overhead " << overhead_c.count() << " nano seconds" << std::endl;
  97         boost::uint64_t res = measure_time( overhead_c).count();
  98         std::cout << "average of " << res << " nano seconds" << std::endl;
  99 #ifdef BOOST_CONTEXT_CYCLE
 100         cycle_type overhead_y = overhead_cycle();
 101         std::cout << "overhead " << overhead_y << " cpu cycles" << std::endl;
 102         res = measure_cycles( overhead_y);
 103         std::cout << "average of " << res << " cpu cycles" << std::endl;
 104 #endif
 105
 106         return EXIT_SUCCESS;
 107     }
 108     catch ( std::exception const& e)
 109     { std::cerr << "exception: " << e.what() << std::endl; }
 110     catch (...)
 111     { std::cerr << "unhandled exception" << std::endl; }
 112     return EXIT_FAILURE;
 113 }