time/tst-timespec_getres.c

   1 /* Basic tests for timespec_getres.
   2    Copyright (C) 2021-2023 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <time.h>
  20 #include <support/check.h>
  21
  22 static int
  23 do_test (void)
  24 {
  25   {
  26     struct timespec ts;
  27     TEST_COMPARE (timespec_getres (&ts, 0), 0);
  28     TEST_COMPARE (timespec_getres (NULL, 0), 0);
  29   }
  30
  31   {
  32     struct timespec ts;
  33     TEST_COMPARE (timespec_getres (&ts, TIME_UTC), TIME_UTC);
  34     /* Expect all supported systems to support TIME_UTC with
  35        resolution better than one second.  */
  36     TEST_VERIFY (ts.tv_sec == 0);
  37     TEST_VERIFY (ts.tv_nsec > 0);
  38     TEST_VERIFY (ts.tv_nsec < 1000000000);
  39     TEST_COMPARE (timespec_getres (NULL, TIME_UTC), TIME_UTC);
  40     /* Expect the resolution to be the same as that reported for
  41        CLOCK_REALTIME with clock_getres.  */
  42     struct timespec cts;
  43     TEST_COMPARE (clock_getres (CLOCK_REALTIME, &cts), 0);
  44     TEST_COMPARE (ts.tv_sec, cts.tv_sec);
  45     TEST_COMPARE (ts.tv_nsec, cts.tv_nsec);
  46   }
  47
  48   return 0;
  49 }
  50
  51 #include <support/test-driver.c>