native_client_sdk/src/libraries/third_party/pthreads-win32/pthread_once.c

   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
  40 int
  41 pthread_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 */