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
|
/* Copyright (C) 2002, 2003, 2005, 2007 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 <lowlevelrwlock.h>
#include <pthread-errnos.h>
#include <kernel-features.h>
#define SYS_futex 202
#define FUTEX_WAIT 0
#define FUTEX_WAKE 1
#define FUTEX_PRIVATE_FLAG 128
/* For the calculation see asm/vsyscall.h. */
#define VSYSCALL_ADDR_vgettimeofday 0xffffffffff600000
#ifndef UP
# define LOCK lock
#else
# define LOCK
#endif
.text
.globl pthread_rwlock_timedwrlock
.type pthread_rwlock_timedwrlock,@function
.align 16
pthread_rwlock_timedwrlock:
pushq %r12
pushq %r13
pushq %r14
subq $16, %rsp
movq %rdi, %r12
movq %rsi, %r13
/* Get the lock. */
movl $1, %esi
xorl %eax, %eax
LOCK
#if MUTEX == 0
cmpxchgl %esi, (%rdi)
#else
cmpxchgl %esi, MUTEX(%rdi)
#endif
jnz 1f
2: movl WRITER(%r12), %eax
testl %eax, %eax
jne 14f
cmpl $0, NR_READERS(%r12)
je 5f
/* Check the value of the timeout parameter. */
3: cmpq $1000000000, 8(%r13)
jae 19f
incl WRITERS_QUEUED(%r12)
je 4f
movl WRITERS_WAKEUP(%r12), %r14d
LOCK
#if MUTEX == 0
decl (%r12)
#else
decl MUTEX(%r12)
#endif
jne 10f
/* Get current time. */
11: movq %rsp, %rdi
xorl %esi, %esi
movq $VSYSCALL_ADDR_vgettimeofday, %rax
callq *%rax
/* Compute relative timeout. */
movq 8(%rsp), %rax
movl $1000, %edi
mul %rdi /* Milli seconds to nano seconds. */
movq (%r13), %rcx
movq 8(%r13), %rdi
subq (%rsp), %rcx
subq %rax, %rdi
jns 15f
addq $1000000000, %rdi
decq %rcx
15: testq %rcx, %rcx
js 16f /* Time is already up. */
/* Futex call. */
movq %rcx, (%rsp) /* Store relative timeout. */
movq %rdi, 8(%rsp)
#ifdef __ASSUME_PRIVATE_FUTEX
movl $FUTEX_PRIVATE_FLAG|FUTEX_WAIT, %esi
xorl PSHARED(%rdi), %esi
#else
# if FUTEX_WAIT == 0
movl PSHARED(%r12), %esi
# else
movl $FUTEX_WAIT, %esi
orl PSHARED(%r12), %esi
# endif
xorl %fs:PRIVATE_FUTEX, %esi
#endif
movq %rsp, %r10
movl %r14d, %edx
leaq WRITERS_WAKEUP(%r12), %rdi
movl $SYS_futex, %eax
syscall
movq %rax, %rdx
17:
/* Reget the lock. */
movl $1, %esi
xorl %eax, %eax
LOCK
#if MUTEX == 0
cmpxchgl %esi, (%r12)
#else
cmpxchgl %esi, MUTEX(%r12)
#endif
jnz 12f
13: decl WRITERS_QUEUED(%r12)
cmpq $-ETIMEDOUT, %rdx
jne 2b
18: movl $ETIMEDOUT, %edx
jmp 9f
5: xorl %edx, %edx
movl %fs:TID, %eax
movl %eax, WRITER(%r12)
9: LOCK
#if MUTEX == 0
decl (%r12)
#else
decl MUTEX(%r12)
#endif
jne 6f
7: movq %rdx, %rax
addq $16, %rsp
popq %r14
popq %r13
popq %r12
retq
1:
#if MUTEX != 0
addq $MUTEX, %rdi
#endif
callq __lll_mutex_lock_wait
jmp 2b
14: cmpl %fs:TID, %eax
jne 3b
20: movl $EDEADLK, %edx
jmp 9b
6:
#if MUTEX == 0
movq %r12, %rdi
#else
leal MUTEX(%r12), %rdi
#endif
callq __lll_mutex_unlock_wake
jmp 7b
/* Overflow. */
4: decl WRITERS_QUEUED(%r12)
movl $EAGAIN, %edx
jmp 9b
10:
#if MUTEX == 0
movq %r12, %rdi
#else
leaq MUTEX(%r12), %rdi
#endif
callq __lll_mutex_unlock_wake
jmp 11b
12:
#if MUTEX == 0
movq %r12, %rdi
#else
leaq MUTEX(%r12), %rdi
#endif
callq __lll_mutex_lock_wait
jmp 13b
16: movq $-ETIMEDOUT, %rdx
jmp 17b
19: movl $EINVAL, %edx
jmp 9b
.size pthread_rwlock_timedwrlock,.-pthread_rwlock_timedwrlock
|