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fiber/performance/fiber/overhead_join.cpp
Oliver Kowalke 2f19be6d67 use C++11
2014-12-27 19:07:42 +01:00

103 lines
2.8 KiB
C++

// 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 <cstdlib>
#include <iostream>
#include <stdexcept>
#include <string>
#include <boost/fiber/all.hpp>
#include <boost/preprocessor.hpp>
#include <boost/program_options.hpp>
#include "../clock.hpp"
#include "../preallocated_stack_allocator.hpp"
#ifndef JOBS
#define JOBS BOOST_PP_LIMIT_REPEAT
#endif
#define JOIN(z, n, _) \
boost::fibers::fiber( stack_alloc, worker).join();
bool prealloc = false;
bool preserve = false;
void worker() {}
template< typename StackAllocator >
duration_type measure( duration_type overhead, StackAllocator const& stack_alloc)
{
boost::fibers::fiber( stack_alloc, worker).join();
time_point_type start( clock_type::now() );
BOOST_PP_REPEAT_FROM_TO(1, JOBS, JOIN, _)
duration_type total = clock_type::now() - start;
total -= overhead_clock(); // overhead of measurement
total /= JOBS; // loops
return total;
}
duration_type measure_standard( duration_type overhead)
{
boost::fibers::fixedsize stack_alloc;
return measure( overhead, stack_alloc);
}
duration_type measure_prealloc( duration_type overhead)
{
preallocated_stack_allocator stack_alloc( JOBS + 1);
return measure( overhead, stack_alloc);
}
int main( int argc, char * argv[])
{
try
{
boost::program_options::options_description desc("allowed options");
desc.add_options()
("help", "help message")
("preserve", boost::program_options::value< bool >( & preserve), "preserve FPU")
("prealloc", boost::program_options::value< bool >( & prealloc), "use preallocated stack");
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;
}
boost::fibers::preserve_fpu( preserve);
duration_type overhead = overhead_clock();
std::cout << "overhead " << overhead.count() << " nano seconds" << std::endl;
boost::uint64_t res =
prealloc
? measure_prealloc( overhead).count()
: measure_standard( overhead).count();
std::cout << "average of " << res << " nano seconds" << std::endl;
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;
}