+/*
+ * Entrypoints for poll-loop based asynch io:
+ */
+
+struct pollfd;
+/* In case your system doesn't have it or you forgot to include
+ * <sys/poll.h>, to stop the following declarations from causing
+ * problems. If your system doesn't have poll then the following
+ * entrypoints will not be defined in libadns. Sorry !
+ */
+
+int adns_beforepoll(adns_state ads, struct pollfd *fds, int *nfds_io, int *timeout_io,
+ const struct timeval *now);
+/* Finds out which fd's adns is interested in, and when it would like
+ * to be able to time things out. This is in a form suitable for use
+ * with poll(2).
+ *
+ * On entry, usually fds should point to at least *nfds_io structs.
+ * adns will fill up to that many structs will information for poll,
+ * and record in *nfds_io how many structs it filled. If it wants to
+ * listen for more structs then *nfds_io will be set to the number
+ * required and _beforepoll will return ERANGE.
+ *
+ * You may call _beforepoll with fds==0 and *nfds_io 0, in which case
+ * adns will fill in the number of fds that it might be interested in
+ * in *nfds_io, and always return either 0 (if it is not interested in
+ * any fds) or ERANGE (if it is).
+ *
+ * NOTE that (unless timeout_io is 0) adns may acquire additional fds
+ * from one call to the next, so you must put adns_beforepoll in a
+ * loop, rather than assuming that the second call (with the buffer
+ * size requested by the first) will not return ERANGE.
+ *
+ * adns only ever sets POLLIN, POLLOUT and POLLPRI in its pollfd
+ * structs, and only ever looks at those bits. POLLPRI is required to
+ * detect TCP Urgent Data (which should not be used by a DNS server)
+ * so that adns can know that the TCP stream is now useless.
+ *
+ * In any case, *timeout_io should be a timeout value as for poll(2),
+ * which adns will modify downwards as required. If the caller does
+ * not plan to block then *timeout_io should be 0 on entry, or
+ * alternatively, timeout_io may be 0. (Alternatively, the caller may
+ * use _beforeselect with timeout_io==0 to find out about file
+ * descriptors, and use _firsttimeout is used to find out when adns
+ * might want to time something out.)
+ *
+ * adns_beforepoll will return 0 on success, and will not fail for any
+ * reason other than the fds buffer being too small (ERANGE).
+ *
+ * This call will never actually do any I/O, or change the fds that
+ * adns is using or the timeouts it wants; and in any case it won't
+ * block.
+ */
+
+#define ADNS_POLLFDS_RECOMMENDED 2
+/* If you allocate an fds buf with at least RECOMMENDED entries then
+ * you are unlikely to need to enlarge it. You are recommended to do
+ * so if it's convenient. However, you must be prepared for adns to
+ * require more space than this.
+ */
+
+void adns_afterpoll(adns_state ads, const struct pollfd *fds, int nfds,
+ const struct timeval *now);
+/* Gives adns flow-of-control for a bit; intended for use after
+ * poll(2). fds and nfds should be the results from poll(). pollfd
+ * structs mentioning fds not belonging to adns will be ignored.
+ */
+
+
+adns_status adns_rr_info(adns_rrtype type,
+ const char **rrtname_r, const char **fmtname_r,
+ int *len_r,
+ const void *datap, char **data_r);
+/* Gets information in human-readable (but non-i18n) form
+ * for eg debugging purposes. type must be specified,
+ * and the official name of the corresponding RR type will
+ * be returned in *rrtname_r, and information about the processing
+ * style in *fmtname_r. The length of the table entry in an answer
+ * for that type will be returned in in *len_r.
+ * Any or all of rrtname_r, fmtname_r and len_r may be 0.
+ * If fmtname_r is non-null then *fmtname_r may be
+ * null on return, indicating that no special processing is
+ * involved.
+ *
+ * data_r be must be non-null iff datap is. In this case
+ * *data_r will be set to point to a human-readable text
+ * string representing the RR data. The text will have
+ * been obtained from malloc() and must be freed by the caller.
+ *
+ * Usually this routine will succeed. Possible errors include:
+ * adns_s_nomemory
+ * adns_s_rrtypeunknown
+ * adns_s_invaliddata (*datap contained garbage)
+ * If an error occurs then no memory has been allocated,
+ * and *rrtname_r, *fmtname_r, *len_r and *data_r are undefined.
+ */
+
+const char *adns_strerror(adns_status st);
+const char *adns_errabbrev(adns_status st);
+/* Like strerror but for adns_status values. adns_errabbrev returns
+ * the abbreviation of the error - eg, for adns_s_timeout it returns
+ * "timeout". You MUST NOT call these functions with status values
+ * not returned by the same adns library.
+ */
+
+#ifdef __cplusplus
+} /* end of extern "C" */
+#endif