summaryrefslogtreecommitdiff
path: root/nptl/sysdeps/unix/sysv/linux/i386/i486/lowlevelrobustlock.S
blob: 73d8bc4cccef85ecd00812c2638737e33c213b43 (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
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
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
/* Copyright (C) 2002, 2003, 2004, 2006 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>
#include <lowlevelrobustlock.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
#define FUTEX_WAITERS		0x80000000
#define FUTEX_OWNER_DIED	0x40000000


	.globl	__lll_robust_mutex_lock_wait
	.type	__lll_robust_mutex_lock_wait,@function
	.hidden	__lll_robust_mutex_lock_wait
	.align	16
__lll_robust_mutex_lock_wait:
	cfi_startproc
	pushl	%edx
	cfi_adjust_cfa_offset(4)
	pushl	%ebx
	cfi_adjust_cfa_offset(4)
	pushl	%esi
	cfi_adjust_cfa_offset(4)
	cfi_offset(%edx, -8)
	cfi_offset(%ebx, -12)
	cfi_offset(%esi, -16)

	movl	%ecx, %ebx
	xorl	%esi, %esi	/* No timeout.  */
	xorl	%ecx, %ecx	/* movl $FUTEX_WAIT, %ecx */

4:	movl	%eax, %edx
	orl	$FUTEX_WAITERS, %edx

	testl	$FUTEX_OWNER_DIED, %eax
	jnz	3f

	cmpl	%edx, %eax	/* NB:	 %edx == 2 */
	je	1f

	LOCK
	cmpxchgl %edx, (%ebx)
	jnz	2f

1:	movl	$SYS_futex, %eax
	ENTER_KERNEL

	movl	(%ebx), %eax

2:	test	%eax, %eax
	jne	4b

	movl	%gs:TID, %edx
	orl	$FUTEX_WAITERS, %edx
	LOCK
	cmpxchgl %edx, (%ebx)
	jnz	4b
	/* NB:	 %eax == 0 */

3:	popl	%esi
	cfi_adjust_cfa_offset(-4)
	cfi_restore(%esi)
	popl	%ebx
	cfi_adjust_cfa_offset(-4)
	cfi_restore(%ebx)
	popl	%edx
	cfi_adjust_cfa_offset(-4)
	cfi_restore(%edx)
	ret
	cfi_endproc
	.size	__lll_robust_mutex_lock_wait,.-__lll_robust_mutex_lock_wait


	.globl	__lll_robust_mutex_timedlock_wait
	.type	__lll_robust_mutex_timedlock_wait,@function
	.hidden	__lll_robust_mutex_timedlock_wait
	.align	16
__lll_robust_mutex_timedlock_wait:
	cfi_startproc
	/* Check for a valid timeout value.  */
	cmpl	$1000000000, 4(%edx)
	jae	3f

	pushl	%edi
	cfi_adjust_cfa_offset(4)
	pushl	%esi
	cfi_adjust_cfa_offset(4)
	pushl	%ebx
	cfi_adjust_cfa_offset(4)
	pushl	%ebp
	cfi_adjust_cfa_offset(4)
	cfi_offset(%edi, -8)
	cfi_offset(%esi, -12)
	cfi_offset(%ebx, -16)
	cfi_offset(%ebp, -20)

	/* Stack frame for the timespec and timeval structs.  */
	subl	$12, %esp
	cfi_adjust_cfa_offset(12)

	movl	%ecx, %ebp
	movl	%edx, %edi

1:	movl	%eax, 8(%esp)

	/* Get current time.  */
	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	4f
	addl	$1000000000, %edx
	subl	$1, %ecx
4:	testl	%ecx, %ecx
	js	8f		/* Time is already up.  */

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

	movl	%ebp, %ebx

	movl	8(%esp), %edx
	movl	%edx, %eax
	orl	$FUTEX_WAITERS, %edx

	testl	$FUTEX_OWNER_DIED, %eax
	jnz	6f

	cmpl	%eax, %edx
	je	2f

	LOCK
	cmpxchgl %edx, (%ebx)
	movl	$0, %ecx	/* Must use mov to avoid changing cc.  */
	jnz	5f

2:
	/* Futex call.  */
	movl	%esp, %esi
	xorl	%ecx, %ecx	/* movl $FUTEX_WAIT, %ecx */
	movl	$SYS_futex, %eax
	ENTER_KERNEL
	movl	%eax, %ecx

	movl	(%ebx), %eax

5:	testl	%eax, %eax
	jne	7f

	movl	%gs:TID, %edx
	orl	$FUTEX_WAITERS, %edx
	LOCK
	cmpxchgl %edx, (%ebx)
	jnz	7f

6:	addl	$12, %esp
	cfi_adjust_cfa_offset(-12)
	popl	%ebp
	cfi_adjust_cfa_offset(-4)
	cfi_restore(%ebp)
	popl	%ebx
	cfi_adjust_cfa_offset(-4)
	cfi_restore(%ebx)
	popl	%esi
	cfi_adjust_cfa_offset(-4)
	cfi_restore(%esi)
	popl	%edi
	cfi_adjust_cfa_offset(-4)
	cfi_restore(%edi)
	ret

3:	movl	$EINVAL, %eax
	ret

	cfi_adjust_cfa_offset(28)
	cfi_offset(%edi, -8)
	cfi_offset(%esi, -12)
	cfi_offset(%ebx, -16)
	cfi_offset(%ebp, -20)
	/* Check whether the time expired.  */
7:	cmpl	$-ETIMEDOUT, %ecx
	jne	1b

8:	movl	$ETIMEDOUT, %eax
	jmp	6b
	cfi_endproc
	.size	__lll_robust_mutex_timedlock_wait,.-__lll_robust_mutex_timedlock_wait