| 1 | /* Copyright 1998 by the Massachusetts Institute of Technology. |
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| 2 | * |
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| 3 | * Permission to use, copy, modify, and distribute this |
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| 4 | * software and its documentation for any purpose and without |
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| 5 | * fee is hereby granted, provided that the above copyright |
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| 6 | * notice appear in all copies and that both that copyright |
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| 7 | * notice and this permission notice appear in supporting |
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| 8 | * documentation, and that the name of M.I.T. not be used in |
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| 9 | * advertising or publicity pertaining to distribution of the |
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| 10 | * software without specific, written prior permission. |
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| 11 | * M.I.T. makes no representations about the suitability of |
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| 12 | * this software for any purpose. It is provided "as is" |
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| 13 | * without express or implied warranty. |
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| 14 | */ |
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| 15 | |
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| 16 | static const char rcsid[] = "$Id: ares_timeout.c,v 1.1 1998-08-13 18:06:35 ghudson Exp $"; |
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| 17 | |
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| 18 | #include <sys/types.h> |
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| 19 | #include <sys/time.h> |
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| 20 | #include <time.h> |
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| 21 | #include "ares.h" |
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| 22 | #include "ares_private.h" |
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| 23 | |
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| 24 | struct timeval *ares_timeout(ares_channel channel, struct timeval *maxtv, |
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| 25 | struct timeval *tvbuf) |
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| 26 | { |
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| 27 | struct query *query; |
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| 28 | time_t now; |
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| 29 | int offset, min_offset; |
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| 30 | |
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| 31 | /* No queries, no timeout (and no fetch of the current time). */ |
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| 32 | if (!channel->queries) |
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| 33 | return maxtv; |
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| 34 | |
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| 35 | /* Find the minimum timeout for the current set of queries. */ |
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| 36 | time(&now); |
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| 37 | min_offset = -1; |
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| 38 | for (query = channel->queries; query; query = query->next) |
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| 39 | { |
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| 40 | if (query->timeout == 0) |
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| 41 | continue; |
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| 42 | offset = query->timeout - now; |
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| 43 | if (offset < 0) |
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| 44 | offset = 0; |
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| 45 | if (min_offset == -1 || offset < min_offset) |
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| 46 | min_offset = offset; |
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| 47 | } |
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| 48 | |
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| 49 | /* If we found a minimum timeout and it's sooner than the one |
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| 50 | * specified in maxtv (if any), return it. Otherwise go with |
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| 51 | * maxtv. |
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| 52 | */ |
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| 53 | if (min_offset != -1 && (!maxtv || min_offset <= maxtv->tv_sec)) |
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| 54 | { |
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| 55 | tvbuf->tv_sec = min_offset; |
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| 56 | tvbuf->tv_usec = 0; |
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| 57 | return tvbuf; |
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| 58 | } |
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| 59 | else |
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| 60 | return maxtv; |
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| 61 | } |
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