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 <pthread-errnos.h> |
20 | #include <sysdep.h> |
21 | |
22 | |
23 | #ifdef UP |
24 | # define LOCK |
25 | #else |
26 | # define LOCK lock |
27 | #endif |
28 | |
29 | ENTRY(pthread_spin_trylock) |
30 | movl $1, %eax |
31 | xorl %ecx, %ecx |
32 | LOCK |
33 | cmpxchgl %ecx, (%rdi) |
34 | movl $EBUSY, %eax |
35 | cmovel %ecx, %eax |
36 | retq |
37 | END(pthread_spin_trylock) |
38 | |