int main( int argc, char * argv[])
{
try
{
bool preserve = false, bind = false;
boost::program_options::options_description desc("allowed options");
desc.add_options()
("help", "help message")
("bind,b", boost::program_options::value< bool >( & bind), "bind thread to CPU")
("fpu,f", boost::program_options::value< bool >( & preserve), "preserve FPU registers")
("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;
}
if ( preserve) preserve_fpu = boost::coroutines::fpu_preserved;
if ( bind) bind_to_processor( 0);
duration_type overhead_c = overhead_clock();
std::cout << "overhead " << overhead_c.count() << " nano seconds" << std::endl;
boost::uint64_t res = measure_time_void( overhead_c).count();
std::cout << "void: average of " << res << " nano seconds" << std::endl;
res = measure_time_int( overhead_c).count();
std::cout << "int: average of " << res << " nano seconds" << std::endl;
res = measure_time_x( overhead_c).count();
std::cout << "X: average of " << res << " nano seconds" << std::endl;
#ifdef BOOST_CONTEXT_CYCLE
cycle_type overhead_y = overhead_cycle();
std::cout << "overhead " << overhead_y << " cpu cycles" << std::endl;
res = measure_cycles_void( overhead_y);
std::cout << "void: average of " << res << " cpu cycles" << std::endl;
res = measure_cycles_int( overhead_y);
std::cout << "int: average of " << res << " cpu cycles" << std::endl;
res = measure_cycles_x( overhead_y);
std::cout << "X: 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;
}
cycle_type measure_cycles_fc() {
// cache warum-up
boost::context::jump_fcontext( & fcm, fc, 7, preserve_fpu);
cycle_type start( cycles() );
for ( std::size_t i = 0; i < jobs; ++i) {
boost::context::jump_fcontext( & fcm, fc, 7, preserve_fpu);
}
cycle_type total = cycles() - start;
total -= overhead_cycle(); // overhead of measurement
total /= jobs; // loops
total /= 2; // 2x jump_fcontext
return total;
}
cycle_type measure_cycles_ec() {
boost::context::execution_context ctx( boost::context::execution_context::current() );
// cache warum-up
boost::context::fixedsize_stack alloc;
boost::context::execution_context ectx( std::allocator_arg, alloc, bar);
ectx( & ctx);
cycle_type start( cycles() );
for ( std::size_t i = 0; i < jobs; ++i) {
ectx( & ctx);
}
cycle_type total = cycles() - start;
total -= overhead_cycle(); // overhead of measurement
total /= jobs; // loops
total /= 2; // 2x jump_fcontext
return total;
}
cycle_type measure_cycles_fc() {
stack_allocator stack_alloc;
boost::context::detail::fcontext_t ctx = boost::context::detail::make_fcontext(
stack_alloc.allocate( stack_allocator::default_stacksize() ),
stack_allocator::default_stacksize(),
foo);
// cache warum-up
boost::context::detail::transfer_t t = boost::context::detail::jump_fcontext( ctx, 0);
cycle_type start( cycles() );
for ( std::size_t i = 0; i < jobs; ++i) {
t = boost::context::detail::jump_fcontext( t.fctx, 0);
}
cycle_type total = cycles() - start;
total -= overhead_cycle(); // overhead of measurement
total /= jobs; // loops
total /= 2; // 2x jump_fcontext
return total;
}
