libs/fiber/performance/fiber/overhead_yield.cpp
// 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 <boost/cstdint.hpp>
#include <boost/fiber/all.hpp>
#include <boost/preprocessor.hpp>
#include "../clock.hpp"
#ifndef JOBS
#define JOBS BOOST_PP_LIMIT_REPEAT
#endif
#define CREATE(z, n, _) \
boost::fibers::fiber BOOST_PP_CAT(f,n) ( \
[&total,&overhead](){ \
time_point_type start( clock_type::now() ); \
boost::this_fiber::yield(); \
duration_type diff = clock_type::now() - start; \
diff -= overhead; \
total += diff; \
});
#define JOIN(z, n, _) \
BOOST_PP_CAT(f,n) .join();
void worker() {}
duration_type measure( duration_type overhead) {
boost::fibers::fiber( worker).join();
duration_type total = duration_type::zero();
BOOST_PP_REPEAT_FROM_TO(1, JOBS, CREATE, _)
BOOST_PP_REPEAT_FROM_TO(1, JOBS, JOIN, _);
total /= JOBS; // JOBS switches for return from this_fiber::yield()
total /= JOBS; // measurement of JOBS fibers
return total;
}
int main( int argc, char * argv[]) {
try {
duration_type overhead = overhead_clock();
boost::uint64_t res = measure( 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;
}