Mercurial > hg > octave-kai > gnulib-hg
annotate lib/dtotimespec.c @ 17476:6057744acd2c default tip master
autoupdate
| author | Karl Berry <karl@freefriends.org> |
|---|---|
| date | Fri, 16 Aug 2013 06:32:22 -0700 |
| parents | e542fd46ad6f |
| children |
| rev | line source |
|---|---|
| 15332 | 1 /* Convert double to timespec. |
| 2 | |
|
17249
e542fd46ad6f
maint: update all copyright year number ranges
Eric Blake <eblake@redhat.com>
parents:
16201
diff
changeset
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3 Copyright (C) 2011-2013 Free Software Foundation, Inc. |
| 15332 | 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 { | |
| 32 enum { BILLION = 1000 * 1000 * 1000 }; | |
| 33 double min_representable = TYPE_MINIMUM (time_t); | |
| 34 double max_representable = | |
| 35 ((TYPE_MAXIMUM (time_t) * (double) BILLION + (BILLION - 1)) | |
| 36 / BILLION); | |
| 37 struct timespec r; | |
| 38 | |
| 39 if (! (min_representable < sec)) | |
| 40 { | |
| 41 r.tv_sec = TYPE_MINIMUM (time_t); | |
| 42 r.tv_nsec = 0; | |
| 43 } | |
| 44 else if (! (sec < max_representable)) | |
| 45 { | |
| 46 r.tv_sec = TYPE_MAXIMUM (time_t); | |
| 47 r.tv_nsec = BILLION - 1; | |
| 48 } | |
| 49 else | |
| 50 { | |
| 51 time_t s = sec; | |
| 52 double frac = BILLION * (sec - s); | |
| 53 long ns = frac; | |
| 54 ns += ns < frac; | |
| 55 s += ns / BILLION; | |
| 56 ns %= BILLION; | |
| 57 | |
| 58 if (ns < 0) | |
| 59 { | |
| 60 s--; | |
| 61 ns += BILLION; | |
| 62 } | |
| 63 | |
| 64 r.tv_sec = s; | |
| 65 r.tv_nsec = ns; | |
| 66 } | |
| 67 | |
| 68 return r; | |
| 69 } |