mirror of
https://git.savannah.gnu.org/git/emacs.git
synced 2024-12-12 09:28:24 +00:00
66 lines
1.6 KiB
C
66 lines
1.6 KiB
C
/* Add two struct timespec values.
|
|
|
|
Copyright (C) 2011-2020 Free Software Foundation, Inc.
|
|
|
|
This program is free software: you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 3 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program 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 General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program. If not, see <https://www.gnu.org/licenses/>. */
|
|
|
|
/* Written by Paul Eggert. */
|
|
|
|
/* Return the sum of two timespec values A and B. On overflow, return
|
|
an extremal value. This assumes 0 <= tv_nsec < TIMESPEC_HZ. */
|
|
|
|
#include <config.h>
|
|
#include "timespec.h"
|
|
|
|
#include "intprops.h"
|
|
|
|
struct timespec
|
|
timespec_add (struct timespec a, struct timespec b)
|
|
{
|
|
time_t rs = a.tv_sec;
|
|
time_t bs = b.tv_sec;
|
|
int ns = a.tv_nsec + b.tv_nsec;
|
|
int nsd = ns - TIMESPEC_HZ;
|
|
int rns = ns;
|
|
|
|
if (0 <= nsd)
|
|
{
|
|
rns = nsd;
|
|
time_t bs1;
|
|
if (!INT_ADD_WRAPV (bs, 1, &bs1))
|
|
bs = bs1;
|
|
else if (rs < 0)
|
|
rs++;
|
|
else
|
|
goto high_overflow;
|
|
}
|
|
|
|
if (INT_ADD_WRAPV (rs, bs, &rs))
|
|
{
|
|
if (bs < 0)
|
|
{
|
|
rs = TYPE_MINIMUM (time_t);
|
|
rns = 0;
|
|
}
|
|
else
|
|
{
|
|
high_overflow:
|
|
rs = TYPE_MAXIMUM (time_t);
|
|
rns = TIMESPEC_HZ - 1;
|
|
}
|
|
}
|
|
|
|
return make_timespec (rs, rns);
|
|
}
|