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
|
/* 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 <shlib-compat.h>
#include <lowlevellock.h>
#include <lowlevelcond.h>
#include <kernel-features.h>
#include <pthread-pi-defines.h>
#include <pthread-errnos.h>
#include <stap-probe.h>
.text
/* int pthread_cond_signal (pthread_cond_t *cond) */
.globl __pthread_cond_signal
.type __pthread_cond_signal, @function
.align 16
__pthread_cond_signal:
cfi_startproc
pushl %ebx
cfi_adjust_cfa_offset(4)
cfi_rel_offset(%ebx, 0)
pushl %edi
cfi_adjust_cfa_offset(4)
cfi_rel_offset(%edi, 0)
cfi_remember_state
movl 12(%esp), %edi
LIBC_PROBE (cond_signal, 1, %edi)
/* Get internal lock. */
movl $1, %edx
xorl %eax, %eax
LOCK
#if cond_lock == 0
cmpxchgl %edx, (%edi)
#else
cmpxchgl %edx, cond_lock(%edi)
#endif
jnz 1f
2: leal cond_futex(%edi), %ebx
movl total_seq+4(%edi), %eax
movl total_seq(%edi), %ecx
cmpl wakeup_seq+4(%edi), %eax
#if cond_lock != 0
/* Must use leal to preserve the flags. */
leal cond_lock(%edi), %edi
#endif
ja 3f
jb 4f
cmpl wakeup_seq-cond_futex(%ebx), %ecx
jbe 4f
/* Bump the wakeup number. */
3: addl $1, wakeup_seq-cond_futex(%ebx)
adcl $0, wakeup_seq-cond_futex+4(%ebx)
addl $1, (%ebx)
/* Wake up one thread. */
pushl %esi
cfi_adjust_cfa_offset(4)
cfi_rel_offset(%esi, 0)
pushl %ebp
cfi_adjust_cfa_offset(4)
cfi_rel_offset(%ebp, 0)
#if FUTEX_PRIVATE_FLAG > 255
xorl %ecx, %ecx
#endif
cmpl $-1, dep_mutex-cond_futex(%ebx)
sete %cl
je 8f
movl dep_mutex-cond_futex(%ebx), %edx
/* Requeue to a non-robust PI mutex if the PI bit is set and
the robust bit is not set. */
movl MUTEX_KIND(%edx), %eax
andl $(ROBUST_BIT|PI_BIT), %eax
cmpl $PI_BIT, %eax
je 9f
8: subl $1, %ecx
#ifdef __ASSUME_PRIVATE_FUTEX
andl $FUTEX_PRIVATE_FLAG, %ecx
#else
andl %gs:PRIVATE_FUTEX, %ecx
#endif
addl $FUTEX_WAKE_OP, %ecx
movl $SYS_futex, %eax
movl $1, %edx
movl $1, %esi
movl $FUTEX_OP_CLEAR_WAKE_IF_GT_ONE, %ebp
/* FIXME: Until Ingo fixes 4G/4G vDSO, 6 arg syscalls are broken for
sysenter.
ENTER_KERNEL */
int $0x80
popl %ebp
cfi_adjust_cfa_offset(-4)
cfi_restore(%ebp)
popl %esi
cfi_adjust_cfa_offset(-4)
cfi_restore(%esi)
/* For any kind of error, we try again with WAKE.
The general test also covers running on old kernels. */
cmpl $-4095, %eax
jae 7f
6: xorl %eax, %eax
popl %edi
cfi_adjust_cfa_offset(-4)
cfi_restore(%edi)
popl %ebx
cfi_adjust_cfa_offset(-4)
cfi_restore(%ebx)
ret
cfi_restore_state
9: movl $(FUTEX_CMP_REQUEUE_PI|FUTEX_PRIVATE_FLAG), %ecx
movl $SYS_futex, %eax
movl $1, %edx
xorl %esi, %esi
movl dep_mutex-cond_futex(%ebx), %edi
movl (%ebx), %ebp
/* FIXME: Until Ingo fixes 4G/4G vDSO, 6 arg syscalls are broken for
sysenter.
ENTER_KERNEL */
int $0x80
popl %ebp
popl %esi
leal -cond_futex(%ebx), %edi
/* For any kind of error, we try again with WAKE.
The general test also covers running on old kernels. */
cmpl $-4095, %eax
jb 4f
7:
#ifdef __ASSUME_PRIVATE_FUTEX
andl $FUTEX_PRIVATE_FLAG, %ecx
#else
andl %gs:PRIVATE_FUTEX, %ecx
#endif
orl $FUTEX_WAKE, %ecx
movl $SYS_futex, %eax
/* %edx should be 1 already from $FUTEX_WAKE_OP syscall.
movl $1, %edx */
ENTER_KERNEL
/* Unlock. Note that at this point %edi always points to
cond_lock. */
4: LOCK
subl $1, (%edi)
je 6b
/* Unlock in loop requires wakeup. */
5: movl %edi, %eax
#if (LLL_SHARED-LLL_PRIVATE) > 255
xorl %ecx, %ecx
#endif
cmpl $-1, dep_mutex-cond_futex(%ebx)
setne %cl
subl $1, %ecx
andl $(LLL_SHARED-LLL_PRIVATE), %ecx
#if LLL_PRIVATE != 0
addl $LLL_PRIVATE, %ecx
#endif
call __lll_unlock_wake
jmp 6b
/* Initial locking failed. */
1:
#if cond_lock == 0
movl %edi, %edx
#else
leal cond_lock(%edi), %edx
#endif
#if (LLL_SHARED-LLL_PRIVATE) > 255
xorl %ecx, %ecx
#endif
cmpl $-1, dep_mutex(%edi)
setne %cl
subl $1, %ecx
andl $(LLL_SHARED-LLL_PRIVATE), %ecx
#if LLL_PRIVATE != 0
addl $LLL_PRIVATE, %ecx
#endif
call __lll_lock_wait
jmp 2b
cfi_endproc
.size __pthread_cond_signal, .-__pthread_cond_signal
versioned_symbol (libpthread, __pthread_cond_signal, pthread_cond_signal,
GLIBC_2_3_2)
|
