THROW3(system_error,EINVAL,"invalid select: nb fds: %d, timeout: %d.%d",
max_fds, (int)tout.tv_sec,(int) tout.tv_usec);
case ENOMEM:
THROW3(system_error,EINVAL,"invalid select: nb fds: %d, timeout: %d.%d",
max_fds, (int)tout.tv_sec,(int) tout.tv_usec);
case ENOMEM: