pollution: fds
pollution: nfds
pollution: timeout
int poll(struct pollfd *fds, nfds_t nfds, int timeout); 

pollution: fds
pollution: nfds
pollution: tmo_p
pollution: sigmask
int ppoll(struct pollfd *fds, nfds_t nfds, const struct timespec *tmo_p, const sigset_t *sigmask);