glibc/nptl/tst-call-once.c

/* C11 threads call_once test.
   Copyright (C) 2018-2019 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <http://www.gnu.org/licenses/>.  */

#include <threads.h>
#include <stdio.h>
#include <unistd.h>

#include <support/check.h>

/* Flag that controls the first thread access.  */
static once_flag flag = ONCE_FLAG_INIT;

static int value = 0;

static void
do_once (void)
{
  value++;
}

static int
func (void* data)
{
  call_once (&flag, do_once);
  thrd_exit (thrd_success);
}

#define N 20

int
do_test (void)
{
  thrd_t ids[N];

  for (int i = 0; i < N; ++i)
    {
      if (thrd_create (&ids[i], func, NULL) != thrd_success)
	FAIL_EXIT1 ("thrd_create failed");
    }

  /* Join threads.  */
  for (int i = 0; i < N; ++i)
    {
      if (thrd_join (ids[i], NULL) != thrd_success)
	FAIL_EXIT1 ("thrd_join failed");
    }

  return (value != 1);
}

#include <support/test-driver.c>