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Diffstat (limited to 'support/dtotimespec.c')
-rw-r--r-- | support/dtotimespec.c | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/support/dtotimespec.c b/support/dtotimespec.c new file mode 100644 index 0000000..cde5b4d --- /dev/null +++ b/support/dtotimespec.c @@ -0,0 +1,50 @@ +/* Convert double to timespec. + Copyright (C) 2011-2023 Free Software Foundation, Inc. + This file is part of the GNU C Library and is also part of gnulib. + Patches to this file should be submitted to both projects. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +/* Convert the double value SEC to a struct timespec. Round toward + positive infinity. On overflow, return an extremal value. */ + +#include <support/timespec.h> +#include <intprops.h> + +struct timespec +dtotimespec (double sec) +{ + if (sec <= TYPE_MINIMUM (time_t)) + return make_timespec (TYPE_MINIMUM (time_t), 0); + else if (sec >= 1.0 + TYPE_MAXIMUM (time_t)) + return make_timespec (TYPE_MAXIMUM (time_t), TIMESPEC_HZ - 1); + else + { + time_t s = sec; + double frac = TIMESPEC_HZ * (sec - s); + long ns = frac; + ns += ns < frac; + s += ns / TIMESPEC_HZ; + ns %= TIMESPEC_HZ; + + if (ns < 0) + { + s--; + ns += TIMESPEC_HZ; + } + + return make_timespec (s, ns); + } +} |