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 | |
25 | int |
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 | } |
48 | strong_alias (__pthread_rwlock_trywrlock, pthread_rwlock_trywrlock) |
49 | |