| /* |
| * 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 */ |