posix/tst-nanosleep.c

   1 /* Copyright (C) 2003-2023 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <errno.h>
  19 #include <stdio.h>
  20 #include <unistd.h>
  21 #include <sys/time.h>
  22 #include <time.h>
  23
  24
  25 /* Test that nanosleep() does sleep.  */
  26 static int
  27 do_test (void)
  28 {
  29   /* Current time.  */
  30   struct timeval tv1;
  31   (void) gettimeofday (&tv1, NULL);
  32
  33   struct timespec ts;
  34   ts.tv_sec = 1;
  35   ts.tv_nsec = 0;
  36   TEMP_FAILURE_RETRY (nanosleep (&ts, &ts));
  37
  38   /* At least one second must have passed.  */
  39   struct timeval tv2;
  40   (void) gettimeofday (&tv2, NULL);
  41
  42   tv2.tv_sec -= tv1.tv_sec;
  43   tv2.tv_usec -= tv1.tv_usec;
  44   if (tv2.tv_usec < 0)
  45     --tv2.tv_sec;
  46
  47   if (tv2.tv_sec < 1)
  48     {
  49       puts ("nanosleep didn't sleep long enough");
  50       return 1;
  51     }
  52
  53   return 0;
  54 }
  55
  56 #define TEST_FUNCTION do_test ()
  57 #include "../test-skeleton.c"