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- /* Copyright (C) 2002, 2007 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
- Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
- The GNU C 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 2.1 of the License, or (at your option) any later version.
- The GNU C 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 the GNU C Library; if not, see
- <http://www.gnu.org/licenses/>. */
- #include <errno.h>
- #include "pthreadP.h"
- #include <lowlevellock.h>
- int
- __pthread_rwlock_tryrdlock (
- pthread_rwlock_t *rwlock)
- {
- int result = EBUSY;
- lll_lock (rwlock->__data.__lock, rwlock->__data.__shared);
- if (rwlock->__data.__writer == 0
- && (rwlock->__data.__nr_writers_queued == 0
- || PTHREAD_RWLOCK_PREFER_READER_P (rwlock)))
- {
- if (__builtin_expect (++rwlock->__data.__nr_readers == 0, 0))
- {
- --rwlock->__data.__nr_readers;
- result = EAGAIN;
- }
- else
- result = 0;
- }
- lll_unlock (rwlock->__data.__lock, rwlock->__data.__shared);
- return result;
- }
- strong_alias (__pthread_rwlock_tryrdlock, pthread_rwlock_tryrdlock)
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