simgrid::kernel::activity::SleepImpl* synchro = new simgrid::kernel::activity::SleepImpl();
synchro->host = host;
synchro->surf_sleep = host->pimpl_cpu->sleep(duration);
simgrid::kernel::activity::SleepImpl* synchro = new simgrid::kernel::activity::SleepImpl();
synchro->host = host;
synchro->surf_sleep = host->pimpl_cpu->sleep(duration);