nptl/tst-call-once.c

   1 /* C11 threads call_once test.
   2    Copyright (C) 2018-2019 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    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <threads.h>
  20 #include <stdio.h>
  21 #include <unistd.h>
  22
  23 #include <support/check.h>
  24
  25 /* Flag that controls the first thread access.  */
  26 static once_flag flag = ONCE_FLAG_INIT;
  27
  28 static int value = 0;
  29
  30 static void
  31 do_once (void)
  32 {
  33   value++;
  34 }
  35
  36 static int
  37 func (void* data)
  38 {
  39   call_once (&flag, do_once);
  40   thrd_exit (thrd_success);
  41 }
  42
  43 #define N 20
  44
  45 int
  46 do_test (void)
  47 {
  48   thrd_t ids[N];
  49
  50   for (int i = 0; i < N; ++i)
  51     {
  52       if (thrd_create (&ids[i], func, NULL) != thrd_success)
  53         FAIL_EXIT1 ("thrd_create failed");
  54     }
  55
  56   /* Join threads.  */
  57   for (int i = 0; i < N; ++i)
  58     {
  59       if (thrd_join (ids[i], NULL) != thrd_success)
  60         FAIL_EXIT1 ("thrd_join failed");
  61     }
  62
  63   return (value != 1);
  64 }
  65
  66 #include <support/test-driver.c>