aboutsummaryrefslogtreecommitdiff
blob: 1893a347379ba5671629367337c5e7002116147d (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
40
41
42
43
44
45
46
47
/* Copyright (C) 2002-2014 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 <sysdep.h>
#include <lowlevellock.h>
#include <shlib-compat.h>
#include <pthread-errnos.h>

	.text

	.globl	sem_trywait
	.type	sem_trywait,@function
	.align	16
sem_trywait:
	movl	(%rdi), %eax
2:	testl	%eax, %eax
	jz	1f

	leal	-1(%rax), %edx
	LOCK
	cmpxchgl %edx, (%rdi)
	jne	2b

	xorl	%eax, %eax
	retq

1:
	movq	errno@gottpoff(%rip), %rdx
	movl	$EAGAIN, %fs:(%rdx)
	orl	$-1, %eax
	retq
	.size	sem_trywait,.-sem_trywait