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-rw-r--r--gnulib-tests/timespec-add.c66
1 files changed, 66 insertions, 0 deletions
diff --git a/gnulib-tests/timespec-add.c b/gnulib-tests/timespec-add.c
new file mode 100644
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+++ b/gnulib-tests/timespec-add.c
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+/* Add two struct timespec values.
+
+ Copyright (C) 2011-2023 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 <stdckdint.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 (!ckd_add (&bs1, bs, 1))
+ bs = bs1;
+ else if (rs < 0)
+ rs++;
+ else
+ goto high_overflow;
+ }
+
+ if (ckd_add (&rs, rs, bs))
+ {
+ 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);
+}