diff options
Diffstat (limited to 'gnulib-tests/timespec-add.c')
-rw-r--r-- | gnulib-tests/timespec-add.c | 65 |
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); +} |