time/tst-clock2.c

   1 /* Test setting the monotonic clock.
   2    Copyright (C) 2007-2024 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 <errno.h>
  20 #include <support/check.h>
  21 #include <time.h>
  22 #include <unistd.h>
  23
  24 int
  25 do_test (void)
  26 {
  27 #if defined CLOCK_MONOTONIC && defined _POSIX_MONOTONIC_CLOCK
  28   if (sysconf (_SC_MONOTONIC_CLOCK) <= 0)
  29     FAIL_UNSUPPORTED ("_SC_MONOTONIC_CLOCK not supported");
  30
  31   struct timespec ts;
  32   TEST_COMPARE (clock_gettime (CLOCK_MONOTONIC, &ts), 0);
  33
  34   /* Setting the monotonic clock must fail.  */
  35   TEST_VERIFY (clock_settime (CLOCK_MONOTONIC, &ts) == -1);
  36   TEST_VERIFY (errno == EINVAL || errno == EPERM);
  37
  38   return 0;
  39 #else
  40   return EXIT_UNSUPPORTED;
  41 #endif
  42 }
  43
  44 #include <support/test-driver.c>