summaryrefslogtreecommitdiffstats
path: root/gnulib-tests/timespec-add.c
diff options
context:
space:
mode:
Diffstat (limited to 'gnulib-tests/timespec-add.c')
-rw-r--r--gnulib-tests/timespec-add.c65
1 files changed, 65 insertions, 0 deletions
diff --git a/gnulib-tests/timespec-add.c b/gnulib-tests/timespec-add.c
new file mode 100644
index 0000000..0f270e5
--- /dev/null
+++ b/gnulib-tests/timespec-add.c
@@ -0,0 +1,65 @@
+/* Add two struct timespec values.
+
+ Copyright (C) 2011-2022 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);
+}