]>
Commit | Line | Data |
---|---|---|
33574c17 ST |
1 | /* Try to acquire a rwlock for writing. Generic version. |
2 | Copyright (C) 2002-2018 Free Software Foundation, Inc. | |
3 | This file is part of the GNU C Library. | |
4 | ||
5 | The GNU C Library is free software; you can redistribute it and/or | |
ad2b41bf ST |
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. | |
33574c17 ST |
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 | |
ad2b41bf | 13 | Lesser General Public License for more details. |
33574c17 | 14 | |
ad2b41bf ST |
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/>. */ | |
33574c17 ST |
18 | |
19 | #include <pthread.h> | |
20 | #include <assert.h> | |
21 | ||
22 | #include <pt-internal.h> | |
23 | ||
24 | /* Try to acquire RWLOCK for writing. */ | |
25 | int | |
26 | pthread_rwlock_trywrlock (struct __pthread_rwlock *rwlock) | |
27 | { | |
28 | __pthread_spin_lock (&rwlock->__lock); | |
29 | if (__pthread_spin_trylock (&rwlock->__held) == 0) | |
30 | /* Successfully acquired the lock. */ | |
31 | { | |
32 | assert (rwlock->__readerqueue == 0); | |
33 | assert (rwlock->__writerqueue == 0); | |
34 | assert (rwlock->__readers == 0); | |
35 | ||
36 | __pthread_spin_unlock (&rwlock->__lock); | |
37 | return 0; | |
38 | } | |
39 | ||
40 | /* The lock is busy. */ | |
41 | ||
42 | __pthread_spin_unlock (&rwlock->__lock); | |
43 | ||
44 | return EBUSY; | |
45 | } |