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1 | /* Convert double to timespec. |
2 | ||
ba318903 | 3 | Copyright (C) 2011-2014 Free Software Foundation, Inc. |
c8fff863 PE |
4 | |
5 | This program is free software: you can redistribute it and/or modify | |
6 | it under the terms of the GNU General Public License as published by | |
7 | the Free Software Foundation; either version 3 of the License, or | |
8 | (at your option) any later version. | |
9 | ||
10 | This program is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | GNU General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU General Public License | |
16 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ | |
17 | ||
18 | /* written by Paul Eggert */ | |
19 | ||
20 | /* Convert the double value SEC to a struct timespec. Round toward | |
21 | positive infinity. On overflow, return an extremal value. */ | |
22 | ||
23 | #include <config.h> | |
24 | ||
25 | #include "timespec.h" | |
26 | ||
27 | #include "intprops.h" | |
28 | ||
29 | struct timespec | |
30 | dtotimespec (double sec) | |
31 | { | |
c8fff863 PE |
32 | double min_representable = TYPE_MINIMUM (time_t); |
33 | double max_representable = | |
230fe2a5 PE |
34 | ((TYPE_MAXIMUM (time_t) * (double) TIMESPEC_RESOLUTION |
35 | + (TIMESPEC_RESOLUTION - 1)) | |
36 | / TIMESPEC_RESOLUTION); | |
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37 | |
38 | if (! (min_representable < sec)) | |
230fe2a5 | 39 | return make_timespec (TYPE_MINIMUM (time_t), 0); |
c8fff863 | 40 | else if (! (sec < max_representable)) |
230fe2a5 | 41 | return make_timespec (TYPE_MAXIMUM (time_t), TIMESPEC_RESOLUTION - 1); |
c8fff863 PE |
42 | else |
43 | { | |
44 | time_t s = sec; | |
230fe2a5 | 45 | double frac = TIMESPEC_RESOLUTION * (sec - s); |
c8fff863 PE |
46 | long ns = frac; |
47 | ns += ns < frac; | |
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48 | s += ns / TIMESPEC_RESOLUTION; |
49 | ns %= TIMESPEC_RESOLUTION; | |
c8fff863 PE |
50 | |
51 | if (ns < 0) | |
52 | { | |
53 | s--; | |
230fe2a5 | 54 | ns += TIMESPEC_RESOLUTION; |
c8fff863 PE |
55 | } |
56 | ||
230fe2a5 | 57 | return make_timespec (s, ns); |
c8fff863 | 58 | } |
c8fff863 | 59 | } |