1 /* Convert double to timespec.
3 Copyright (C) 2011-2013 Free Software Foundation, Inc.
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.
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.
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/>. */
18 /* written by Paul Eggert */
20 /* Convert the double value SEC to a struct timespec. Round toward
21 positive infinity. On overflow, return an extremal value. */
30 dtotimespec (double sec)
32 double min_representable = TYPE_MINIMUM (time_t);
33 double max_representable =
34 ((TYPE_MAXIMUM (time_t) * (double) TIMESPEC_RESOLUTION
35 + (TIMESPEC_RESOLUTION - 1))
36 / TIMESPEC_RESOLUTION);
38 if (! (min_representable < sec))
39 return make_timespec (TYPE_MINIMUM (time_t), 0);
40 else if (! (sec < max_representable))
41 return make_timespec (TYPE_MAXIMUM (time_t), TIMESPEC_RESOLUTION - 1);
45 double frac = TIMESPEC_RESOLUTION * (sec - s);
48 s += ns / TIMESPEC_RESOLUTION;
49 ns %= TIMESPEC_RESOLUTION;
54 ns += TIMESPEC_RESOLUTION;
57 return make_timespec (s, ns);