about summary refs log tree commit diff
path: root/nptl/sysdeps/unix/sysv/linux/i386/i486/lowlevellock.S
blob: f27fe2bc1f71c07c30c4daedc9282605922896d2 (plain) (blame)
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
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
/* 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, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#include <sysdep.h>
#include <pthread-errnos.h>

	.text

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

#define SYS_gettimeofday	__NR_gettimeofday
#define SYS_futex		240
#define FUTEX_WAIT		0
#define FUTEX_WAKE		1


	.globl	__lll_lock_wait
	.type	__lll_lock_wait,@function
	.hidden	__lll_lock_wait
	.align	16
__lll_lock_wait:
	pushl	%esi
	pushl	%ebx
	pushl	%edx

	movl	%ecx, %ebx
	xorl	%esi, %esi	/* No timeout.  */
	xorl	%ecx, %ecx	/* movl $FUTEX_WAIT, %ecx */
1:
	leal	-1(%eax), %edx	/* account for the preceeded xadd.  */
	movl	$SYS_futex, %eax
	ENTER_KERNEL

	orl	$-1, %eax	/* Load -1.  */
	LOCK
	xaddl	%eax, (%ebx)
	jne,pn	1b

	movl	$-1, (%ebx)

	popl	%edx
	popl	%ebx
	popl	%esi
	ret
	.size	__lll_lock_wait,.-__lll_lock_wait


#ifdef NOT_IN_libc
	.globl	lll_unlock_wake_cb
	.type	lll_unlock_wake_cb,@function
	.hidden	lll_unlock_wake_cb
	.align	16
lll_unlock_wake_cb:
	pushl	%ebx
	pushl	%ecx
	pushl	%edx

	movl	20(%esp), %ebx
	LOCK
	addl	$1, (%ebx)
	jng	1f

	popl	%edx
	popl	%ecx
	popl	%ebx
	ret
	.size	lll_unlock_wake_cb,.-lll_unlock_wake_cb
#endif


	.globl	__lll_unlock_wake
	.type	__lll_unlock_wake,@function
	.hidden	__lll_unlock_wake
	.align	16
__lll_unlock_wake:
	pushl	%ebx
	pushl	%ecx
	pushl	%edx

	movl	%eax, %ebx
1:	movl	$FUTEX_WAKE, %ecx
	movl	$1, %edx	/* Wake one thread.  */
	movl	$SYS_futex, %eax
	movl	%edx, (%ebx)	/* Stores '$1'.  */
	ENTER_KERNEL

	popl	%edx
	popl	%ecx
	popl	%ebx
	ret
	.size	__lll_unlock_wake,.-__lll_unlock_wake


#ifdef NOT_IN_libc
	.globl	__lll_timedwait_tid
	.type	__lll_timedwait_tid,@function
	.hidden	__lll_timedwait_tid
	.align	16
__lll_timedwait_tid:
	pushl	%edi
	pushl	%esi
	pushl	%ebx
	pushl	%ebp

	movl	%eax, %ebp
	movl	%edx, %edi
	subl	$8, %esp

	/* Get current time.  */
2:	movl	%esp, %ebx
	xorl	%ecx, %ecx
	movl	$SYS_gettimeofday, %eax
	ENTER_KERNEL

	/* Compute relative timeout.  */
	movl	4(%esp), %eax
	movl	$1000, %edx
	mul	%edx		/* Milli seconds to nano seconds.  */
	movl	(%edi), %ecx
	movl	4(%edi), %edx
	subl	(%esp), %ecx
	subl	%eax, %edx
	jns	5f
	addl	$1000000000, %edx
	subl	$1, %ecx
5:	testl	%ecx, %ecx
	js	6f		/* Time is already up.  */

	movl	%ecx, (%esp)	/* Store relative timeout.  */
	movl	%edx, 4(%esp)

	movl	(%ebp), %edx
	testl	%edx, %edx
	jz	4f

	movl	%esp, %esi
	xorl	%ecx, %ecx	/* movl $FUTEX_WAIT, %ecx */
	movl	%ebp, %ebx
	movl	$SYS_futex, %eax
	ENTER_KERNEL

	cmpl	$0, (%ebx)
	jne	1f
4:	xorl	%eax, %eax

3:	addl	$8, %esp
	popl	%ebp
	popl	%ebx
	popl	%esi
	popl	%edi
	ret

1:	cmpl	$-ETIMEDOUT, %eax
	jne	2b
6:	movl	$ETIMEDOUT, %eax
	jmp	3b
	.size	__lll_timedwait_tid,.-__lll_timedwait_tid
#endif