start_time = sg4::Engine::get_clock();
sg4::CommPtr c1 = sg4::Comm::sendto_async(hosts[0], hosts[4], 1.0);
sg4::CommPtr c2 = sg4::Comm::sendto_async(hosts[0], hosts[4], 1.0);
start_time = sg4::Engine::get_clock();
sg4::CommPtr c1 = sg4::Comm::sendto_async(hosts[0], hosts[4], 1.0);
sg4::CommPtr c2 = sg4::Comm::sendto_async(hosts[0], hosts[4], 1.0);