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glibc  2.9
pthread_rwlock_trywrlock.c
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00001 /* Copyright (C) 2002, 2003, 2007 Free Software Foundation, Inc.
00002    This file is part of the GNU C Library.
00003    Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
00004 
00005    The GNU C Library is free software; you can redistribute it and/or
00006    modify it under the terms of the GNU Lesser General Public
00007    License as published by the Free Software Foundation; either
00008    version 2.1 of the License, or (at your option) any later version.
00009 
00010    The GNU C Library is distributed in the hope that it will be useful,
00011    but WITHOUT ANY WARRANTY; without even the implied warranty of
00012    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00013    Lesser General Public License for more details.
00014 
00015    You should have received a copy of the GNU Lesser General Public
00016    License along with the GNU C Library; if not, write to the Free
00017    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
00018    02111-1307 USA.  */
00019 
00020 #include <errno.h>
00021 #include "pthreadP.h"
00022 #include <lowlevellock.h>
00023 
00024 
00025 int
00026 __pthread_rwlock_trywrlock (rwlock)
00027      pthread_rwlock_t *rwlock;
00028 {
00029   int result = EBUSY;
00030 
00031   lll_lock (rwlock->__data.__lock, rwlock->__data.__shared);
00032 
00033   if (rwlock->__data.__writer == 0 && rwlock->__data.__nr_readers == 0)
00034     {
00035       rwlock->__data.__writer = THREAD_GETMEM (THREAD_SELF, tid);
00036       result = 0;
00037     }
00038 
00039   lll_unlock (rwlock->__data.__lock, rwlock->__data.__shared);
00040 
00041   return result;
00042 }
00043 strong_alias (__pthread_rwlock_trywrlock, pthread_rwlock_trywrlock)