simgrid::kernel::activity::ExecImpl::on_creation.connect([](simgrid::kernel::activity::ExecImplPtr activity){
if (activity->host_ != nullptr) { // We only run on one host
simgrid::s4u::Host* host = activity->host_;
simgrid::kernel::activity::ExecImpl::on_creation.connect([](simgrid::kernel::activity::ExecImplPtr activity){
if (activity->host_ != nullptr) { // We only run on one host
simgrid::s4u::Host* host = activity->host_;