pollfds = realloc(pollfds, n * sizeof *pollfds); return pollfds == 0 ? -1 : 0;
if (n == 0) return 0; pollfds = malloc(n * sizeof *pollfds); if (pollfds == 0) return -1; num_pollfds = n; return 0;
int init_pollfds(size_t n){	pollfds = realloc(pollfds, n * sizeof *pollfds);	return pollfds == 0 ? -1 : 0;}