1/*
2 * pthread_once.c
3 *
4 * Description:
5 * This translation unit implements miscellaneous thread functions.
6 *
7 * --------------------------------------------------------------------------
8 *
9 *      Pthreads-win32 - POSIX Threads Library for Win32
10 *      Copyright(C) 1998 John E. Bossom
11 *      Copyright(C) 1999,2005 Pthreads-win32 contributors
12 *
13 *      Contact Email: rpj@callisto.canberra.edu.au
14 *
15 *      The current list of contributors is contained
16 *      in the file CONTRIBUTORS included with the source
17 *      code distribution. The list can also be seen at the
18 *      following World Wide Web location:
19 *      http://sources.redhat.com/pthreads-win32/contributors.html
20 *
21 *      This library is free software; you can redistribute it and/or
22 *      modify it under the terms of the GNU Lesser General Public
23 *      License as published by the Free Software Foundation; either
24 *      version 2 of the License, or (at your option) any later version.
25 *
26 *      This library is distributed in the hope that it will be useful,
27 *      but WITHOUT ANY WARRANTY; without even the implied warranty of
28 *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
29 *      Lesser General Public License for more details.
30 *
31 *      You should have received a copy of the GNU Lesser General Public
32 *      License along with this library in the file COPYING.LIB;
33 *      if not, write to the Free Software Foundation, Inc.,
34 *      59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
35 */
36
37#include "pthread.h"
38#include "implement.h"
39
40int
41pthread_once (pthread_once_t * once_control, void (PTW32_CDECL *init_routine) (void))
42{
43  if (once_control == NULL || init_routine == NULL)
44    {
45      return EINVAL;
46    }
47
48  if ((PTW32_INTERLOCKED_LONG)PTW32_FALSE ==
49      (PTW32_INTERLOCKED_LONG)PTW32_INTERLOCKED_EXCHANGE_ADD_LONG((PTW32_INTERLOCKED_LONGPTR)&once_control->done,
50                                                                  (PTW32_INTERLOCKED_LONG)0)) /* MBR fence */
51    {
52      ptw32_mcs_local_node_t node;
53
54      ptw32_mcs_lock_acquire((ptw32_mcs_lock_t *)&once_control->lock, &node);
55
56      if (!once_control->done)
57	{
58
59#if defined(_MSC_VER) && _MSC_VER < 1400
60#pragma inline_depth(0)
61#endif
62
63	  pthread_cleanup_push(ptw32_mcs_lock_release, &node);
64	  (*init_routine)();
65	  pthread_cleanup_pop(0);
66
67#if defined(_MSC_VER) && _MSC_VER < 1400
68#pragma inline_depth()
69#endif
70
71	  once_control->done = PTW32_TRUE;
72	}
73
74	ptw32_mcs_lock_release(&node);
75    }
76
77  return 0;
78
79}				/* pthread_once */
80