pselect
extern int pselect(int numBits, struct fd_set *readBits, struct fd_set *writeBits,
n = pselect(srecv + 1, &rfds, NULL, NULL, &timeout, NULL);
n = pselect(srecv + 1, &rfds, NULL, NULL, &timeout, NULL);
static int pselect(int, void *, void *, void *,
n = pselect(s + 1, &dsmask, NULL, NULL, &timeout, NULL);