mirror of
https://gitlab.com/sortix/sortix.git
synced 2023-02-13 20:55:38 -05:00
60 lines
1.9 KiB
C++
60 lines
1.9 KiB
C++
/*******************************************************************************
|
|
|
|
Copyright(C) Jonas 'Sortie' Termansen 2013.
|
|
|
|
This file is part of the Sortix C Library.
|
|
|
|
The Sortix 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 3 of the License, or (at your
|
|
option) any later version.
|
|
|
|
The Sortix 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 Sortix C Library. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
timespec.cpp
|
|
Utility functions for manipulation of struct timespec.
|
|
|
|
*******************************************************************************/
|
|
|
|
#include <timespec.h>
|
|
|
|
static const long NANOSECONDS_PER_SECOND = 1000000000L;
|
|
|
|
// TODO: The C modulo operator doesn't do exactly what we desire.
|
|
static long proper_modulo(long a, long b)
|
|
{
|
|
if ( 0 <= a )
|
|
return a % b;
|
|
long tmp = - (unsigned long) a % b;
|
|
return tmp ? tmp : 0;
|
|
}
|
|
|
|
extern "C" struct timespec timespec_canonalize(struct timespec t)
|
|
{
|
|
t.tv_sec += t.tv_nsec / NANOSECONDS_PER_SECOND;
|
|
t.tv_nsec = proper_modulo(t.tv_nsec, NANOSECONDS_PER_SECOND);
|
|
return t;
|
|
}
|
|
|
|
extern "C" struct timespec timespec_add(struct timespec a, struct timespec b)
|
|
{
|
|
struct timespec ret;
|
|
a = timespec_canonalize(a);
|
|
b = timespec_canonalize(b);
|
|
ret.tv_sec = a.tv_sec + b.tv_sec;
|
|
ret.tv_nsec = a.tv_nsec + b.tv_nsec;
|
|
return timespec_canonalize(ret);
|
|
}
|
|
|
|
extern "C" struct timespec timespec_sub(struct timespec a, struct timespec b)
|
|
{
|
|
a = timespec_canonalize(a);
|
|
b = timespec_canonalize(b);
|
|
return timespec_add(a, timespec_neg(b));
|
|
}
|