1 /* Convert double to timespec. 2 3 Copyright (C) 2011-2021 Free Software Foundation, Inc. 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 <https://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 if (! (TYPE_MINIMUM (time_t) < sec)) 33 return make_timespec (TYPE_MINIMUM (time_t), 0); 34 else if (! (sec < 1.0 + TYPE_MAXIMUM (time_t))) 35 return make_timespec (TYPE_MAXIMUM (time_t), TIMESPEC_HZ - 1); 36 else 37 { 38 time_t s = sec; 39 double frac = TIMESPEC_HZ * (sec - s); 40 long ns = frac; 41 ns += ns < frac; 42 s += ns / TIMESPEC_HZ; 43 ns %= TIMESPEC_HZ; 44 45 if (ns < 0) 46 { 47 s--; 48 ns += TIMESPEC_HZ; 49 } 50 51 return make_timespec (s, ns); 52 } 53 }