1/* Convert double to timespec.
2 Copyright (C) 2011-2023 Free Software Foundation, Inc.
3 This file is part of the GNU C Library and is also part of gnulib.
4 Patches to this file should be submitted to both projects.
5
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
10
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
15
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, see
18 <https://www.gnu.org/licenses/>. */
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 <support/timespec.h>
24#include <intprops.h>
25
26struct timespec
27dtotimespec (double sec)
28{
29 if (sec <= TYPE_MINIMUM (time_t))
30 return make_timespec (TYPE_MINIMUM (time_t), 0);
31 else if (sec >= 1.0 + TYPE_MAXIMUM (time_t))
32 return make_timespec (TYPE_MAXIMUM (time_t), TIMESPEC_HZ - 1);
33 else
34 {
35 time_t s = sec;
36 double frac = TIMESPEC_HZ * (sec - s);
37 long ns = frac;
38 ns += ns < frac;
39 s += ns / TIMESPEC_HZ;
40 ns %= TIMESPEC_HZ;
41
42 if (ns < 0)
43 {
44 s--;
45 ns += TIMESPEC_HZ;
46 }
47
48 return make_timespec (s, ns);
49 }
50}
51