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
|
/* 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>
#ifndef UP
# define LOCK lock
#else
# define LOCK
#endif
#define SYS_futex 240
#define FUTEX_WAKE 1
.comm __fork_generation, 4, 4
.text
.globl __pthread_once
.type __pthread_once,@function
.align 16
__pthread_once:
movl 4(%esp), %ecx
testl $2, (%ecx)
jz 1f
xorl %eax, %eax
ret
1: pushl %ebx
pushl %esi
movl %ecx, %ebx
xorl %esi, %esi
/* Not yet initialized or initialization in progress.
Get the fork generation counter now. */
6: movl (%ebx), %eax
#ifdef PIC
call __i686.get_pc_thunk.cx
addl $_GLOBAL_OFFSET_TABLE_, %ecx
#endif
5: movl %eax, %edx
testl $2, %eax
jnz 4f
andl $3, %edx
#ifdef PIC
orl __fork_generation@GOTOFF(%ecx), %edx
#else
orl __fork_generation, %edx
#endif
orl $1, %edx
LOCK
cmpxchgl %edx, (%ebx)
jnz 5b
/* Check whether another thread already runs the initializer. */
testl $1, %eax
jz 3f /* No -> do it. */
/* Check whether the initializer execution was interrupted
by a fork. */
xorl %edx, %eax
testl $0xfffffffc, %eax
jnz 3f /* Different for generation -> run initializer. */
/* Somebody else got here first. Wait. */
movl %esi, %ecx /* movl $FUTEX_WAIT, %ecx */
movl $SYS_futex, %eax
ENTER_KERNEL
jmp 6b
3: /* Call the initializer function after setting up the
cancellation handler. */
subl $16, %esp
/* Push the cleanup handler. */
#ifdef PIC
leal clear_once_control@GOTOFF(%ecx), %eax
#else
leal clear_once_control, %eax
#endif
movl %esp, %edx
pushl %ebx
pushl %eax
pushl %edx
call __pthread_cleanup_push /* Note: no @PLT. */
movl 44(%esp), %eax
call *%eax
/* Pop the cleanup handler. This code depends on the once
handler and _pthread_cleanup_push not touch the content
of the stack. Otherwise the first parameter would have
to be reloaded. */
movl $0, 4(%esp)
call __pthread_cleanup_pop /* Note: no @PLT. */
addl $28, %esp
/* Sucessful run of the initializer. Signal that we are done. */
LOCK
incl (%ebx)
/* Wake up all other threads. */
movl $0x7fffffff, %edx
movl $FUTEX_WAKE, %ecx
movl $SYS_futex, %eax
ENTER_KERNEL
4: popl %esi
popl %ebx
xorl %eax, %eax
ret
.size __pthread_once,.-__pthread_once
.globl __pthread_once_internal
__pthread_once_internal = __pthread_once
.globl pthread_once
pthread_once = __pthread_once
.type clear_once_control,@function
.align 16
clear_once_control:
pushl %esi
pushl %ebx
movl 12(%esp), %ebx
movl $0, (%ebx)
xorl %esi, %esi
movl $0x7fffffff, %edx
movl $FUTEX_WAKE, %ecx
movl $SYS_futex, %eax
ENTER_KERNEL
popl %ebx
popl %esi
ret
.size clear_once_control,.-clear_once_control
#ifdef PIC
.section .gnu.linkonce.t.__i686.get_pc_thunk.cx,"ax",@progbits
.globl __i686.get_pc_thunk.cx
.hidden __i686.get_pc_thunk.cx
.type __i686.get_pc_thunk.cx,@function
__i686.get_pc_thunk.cx:
movl (%esp), %ecx;
ret
.size __i686.get_pc_thunk.cx,.-__i686.get_pc_thunk.cx
#endif
|
GitWeb