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/*
* pthread_once.c
*
* Description:
* This translation unit implements miscellaneous thread functions.
*
* --------------------------------------------------------------------------
*
* Pthreads-win32 - POSIX Threads Library for Win32
* Copyright(C) 1998 John E. Bossom
* Copyright(C) 1999,2005 Pthreads-win32 contributors
*
* Contact Email: rpj@callisto.canberra.edu.au
*
* The current list of contributors is contained
* in the file CONTRIBUTORS included with the source
* code distribution. The list can also be seen at the
* following World Wide Web location:
* http://sources.redhat.com/pthreads-win32/contributors.html
*
* This 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 of the License, or (at your option) any later version.
*
* This 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 this library in the file COPYING.LIB;
* if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#include "pthread.h"
#include "implement.h"
static void PTW32_CDECL
ptw32_once_on_init_cancel (void * arg)
{
/* when the initting thread is cancelled we have to release the lock */
ptw32_mcs_local_node_t *node = (ptw32_mcs_local_node_t *)arg;
ptw32_mcs_lock_release(node);
}
int
pthread_once (pthread_once_t * once_control, void (*init_routine) (void))
{
if (once_control == NULL || init_routine == NULL)
{
return EINVAL;
}
if (!InterlockedExchangeAdd((LPLONG)&once_control->done, 0)) /* MBR fence */
{
ptw32_mcs_local_node_t node;
ptw32_mcs_lock_acquire((ptw32_mcs_lock_t *)&once_control->lock, &node);
if (!once_control->done)
{
#ifdef _MSC_VER
#pragma inline_depth(0)
#endif
pthread_cleanup_push(ptw32_once_on_init_cancel, (void *)&node);
(*init_routine)();
pthread_cleanup_pop(0);
#ifdef _MSC_VER
#pragma inline_depth()
#endif
once_control->done = PTW32_TRUE;
}
ptw32_mcs_lock_release(&node);
}
return 0;
} /* pthread_once */
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