2 /* Copyright 1998 by the Massachusetts Institute of Technology.
4 * Permission to use, copy, modify, and distribute this
5 * software and its documentation for any purpose and without
6 * fee is hereby granted, provided that the above copyright
7 * notice appear in all copies and that both that copyright
8 * notice and this permission notice appear in supporting
9 * documentation, and that the name of M.I.T. not be used in
10 * advertising or publicity pertaining to distribution of the
11 * software without specific, written prior permission.
12 * M.I.T. makes no representations about the suitability of
13 * this software for any purpose. It is provided "as is"
14 * without express or implied warranty.
17 #include "ares_setup.h"
19 #ifdef HAVE_SYS_TIME_H
26 #include "ares_private.h"
28 /* WARNING: Beware that this is linear in the number of outstanding
29 * requests! You are probably far better off just calling ares_process()
30 * once per second, rather than calling ares_timeout() to figure out
31 * when to next call ares_process().
33 struct timeval *ares_timeout(ares_channel channel, struct timeval *maxtv,
34 struct timeval *tvbuf)
37 struct list_node* list_head;
38 struct list_node* list_node;
40 struct timeval nextstop;
41 long offset, min_offset;
43 /* No queries, no timeout (and no fetch of the current time). */
44 if (ares__is_list_empty(&(channel->all_queries)))
47 /* Find the minimum timeout for the current set of queries. */
51 list_head = &(channel->all_queries);
52 for (list_node = list_head->next; list_node != list_head;
53 list_node = list_node->next)
55 query = list_node->data;
56 if (query->timeout.tv_sec == 0)
58 offset = ares__timeoffset(&now, &query->timeout);
61 if (min_offset == -1 || offset < min_offset)
65 /* If we found a minimum timeout and it's sooner than the one specified in
66 * maxtv (if any), return it. Otherwise go with maxtv.
70 nextstop.tv_sec = min_offset/1000;
71 nextstop.tv_usec = (min_offset%1000)*1000;
73 if (!maxtv || ares__timedout(maxtv, &nextstop))