| |
| // Copyright Oliver Kowalke 2009. |
| // 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 <cstddef> |
| #include <cstdlib> |
| #include <iostream> |
| #include <stdexcept> |
| |
| #include <boost/cstdint.hpp> |
| #include <boost/program_options.hpp> |
| |
| #include <ucontext.h> |
| |
| #include "../bind_processor.hpp" |
| #include "../clock.hpp" |
| #include "../cycle.hpp" |
| #include "../../example/simple_stack_allocator.hpp" |
| |
| typedef boost::context::simple_stack_allocator< |
| 8 * 1024 * 1024, 64 * 1024, 8 * 1024 |
| > stack_allocator; |
| |
| boost::uint64_t jobs = 1000; |
| ucontext_t uc, ucm; |
| |
| static void fn() |
| { while ( true) ::swapcontext( & uc, & ucm); } |
| |
| duration_type measure_time() |
| { |
| // cache warum-up |
| ::swapcontext( & ucm, & uc); |
| |
| time_point_type start( clock_type::now() ); |
| for ( std::size_t i = 0; i < jobs; ++i) { |
| ::swapcontext( & ucm, & uc); |
| } |
| duration_type total = clock_type::now() - start; |
| total -= overhead_clock(); // overhead of measurement |
| total /= jobs; // loops |
| total /= 2; // 2x jump_fcontext |
| |
| return total; |
| } |
| |
| #ifdef BOOST_CONTEXT_CYCLE |
| cycle_type measure_cycles() |
| { |
| // cache warum-up |
| ::swapcontext( & ucm, & uc); |
| |
| cycle_type start( cycles() ); |
| for ( std::size_t i = 0; i < jobs; ++i) { |
| ::swapcontext( & ucm, & uc); |
| } |
| cycle_type total = cycles() - start; |
| total -= overhead_cycle(); // overhead of measurement |
| total /= jobs; // loops |
| total /= 2; // 2x jump_fcontext |
| |
| return total; |
| } |
| #endif |
| |
| int main( int argc, char * argv[]) |
| { |
| try |
| { |
| bind_to_processor( 0); |
| |
| boost::program_options::options_description desc("allowed options"); |
| desc.add_options() |
| ("help", "help message") |
| ("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; |
| } |
| |
| stack_allocator stack_alloc; |
| ::getcontext( & uc); |
| uc.uc_stack.ss_sp = stack_alloc.allocate( stack_allocator::default_stacksize() ); |
| uc.uc_stack.ss_size = stack_allocator::default_stacksize(); |
| ::makecontext( & uc, fn, 7); |
| |
| boost::uint64_t res = measure_time().count(); |
| std::cout << "average of " << res << " nano seconds" << std::endl; |
| #ifdef BOOST_CONTEXT_CYCLE |
| res = measure_cycles(); |
| 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; |
| } |