mirror of
https://git.savannah.gnu.org/git/emacs.git
synced 2024-12-27 10:54:40 +00:00
72 lines
1.7 KiB
C
72 lines
1.7 KiB
C
|
/* Add two struct timespec values.
|
||
|
|
|
||
|
|
Copyright (C) 2011-2012 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 <http://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 <= 999999999. */
|
||
|
|
|
||
|
|
#include <config.h>
|
||
|
|
#include "timespec.h"
|
||
|
|
|
||
|
|
#include "intprops.h"
|
||
|
|
|
||
|
|
struct timespec
|
||
|
|
timespec_add (struct timespec a, struct timespec b)
|
||
|
|
{
|
||
|
|
struct timespec r;
|
||
|
|
time_t rs = a.tv_sec;
|
||
|
|
time_t bs = b.tv_sec;
|
||
|
|
int ns = a.tv_nsec + b.tv_nsec;
|
||
|
|
int nsd = ns - 1000000000;
|
||
|
|
int rns = ns;
|
||
|
|
|
||
|
|
if (0 <= nsd)
|
||
|
|
{
|
||
|
|
rns = nsd;
|
||
|
|
if (rs == TYPE_MAXIMUM (time_t))
|
||
|
|
{
|
||
|
|
if (0 <= bs)
|
||
|
|
goto high_overflow;
|
||
|
|
bs++;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
rs++;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (INT_ADD_OVERFLOW (rs, bs))
|
||
|
|
{
|
||
|
|
if (rs < 0)
|
||
|
|
{
|
||
|
|
rs = TYPE_MINIMUM (time_t);
|
||
|
|
rns = 0;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
high_overflow:
|
||
|
|
rs = TYPE_MAXIMUM (time_t);
|
||
|
|
rns = 999999999;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
else
|
||
|
|
rs += bs;
|
||
|
|
|
||
|
|
r.tv_sec = rs;
|
||
|
|
r.tv_nsec = rns;
|
||
|
|
return r;
|
||
|
|
}
|