1/* Copyright (C) 2002-2016 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <http://www.gnu.org/licenses/>. */
18
19#include <errno.h>
20#include "pthreadP.h"
21#include <lowlevellock.h>
22#include <elide.h>
23
24
25int
26__pthread_rwlock_trywrlock (pthread_rwlock_t *rwlock)
27{
28 int result = EBUSY;
29
30 if (ELIDE_TRYLOCK (rwlock->__data.__rwelision,
31 rwlock->__data.__lock == 0
32 && rwlock->__data.__nr_readers == 0
33 && rwlock->__data.__writer, 1))
34 return 0;
35
36 lll_lock (rwlock->__data.__lock, rwlock->__data.__shared);
37
38 if (rwlock->__data.__writer == 0 && rwlock->__data.__nr_readers == 0)
39 {
40 rwlock->__data.__writer = THREAD_GETMEM (THREAD_SELF, tid);
41 result = 0;
42 }
43
44 lll_unlock (rwlock->__data.__lock, rwlock->__data.__shared);
45
46 return result;
47}
48strong_alias (__pthread_rwlock_trywrlock, pthread_rwlock_trywrlock)
49