summaryrefslogtreecommitdiff
path: root/libpthread/nptl/sysdeps/x86_64/pthread_spin_trylock.S
blob: 2bf8711b7c6051711812dd892a1d07bc1a514dd1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
/* Copyright (C) 2002, 2003 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 <pthread-errnos.h>


#ifdef UP
# define LOCK
#else
# define LOCK lock
#endif

	.globl	pthread_spin_trylock
	.type	pthread_spin_trylock,@function
	.align	16
pthread_spin_trylock:
	movl	$1, %eax
	xorl	%ecx, %ecx
	LOCK
	cmpxchgl %ecx, (%rdi)
	movl	$EBUSY, %eax
	cmovel	%ecx, %eax
	retq
	.size	pthread_spin_trylock,.-pthread_spin_trylock