ASR_WANT_READ
fds[0].events = (ar->ar_cond == ASR_WANT_READ) ? POLLIN:POLLOUT;
ar->ar_cond = ASR_WANT_READ;
ar->ar_cond = ASR_WANT_READ;
ar->ar_cond = ASR_WANT_READ;
ar.ar_cond == ASR_WANT_READ ? EV_READ : EV_WRITE,