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9a1d9254 | 1 | /* Copyright (C) 2002, 2003, 2007, 2012 Free Software Foundation, Inc. |
76a50749 UD |
2 | This file is part of the GNU C Library. |
3 | Contributed by Ulrich Drepper <drepper@redhat.com>, 2002. | |
4 | ||
5 | The GNU C Library is free software; you can redistribute it and/or | |
6 | modify it under the terms of the GNU Lesser General Public | |
7 | License as published by the Free Software Foundation; either | |
8 | version 2.1 of the License, or (at your option) any later version. | |
9 | ||
10 | The GNU C Library is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | Lesser General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU Lesser General Public | |
59ba27a6 PE |
16 | License along with the GNU C Library; if not, see |
17 | <http://www.gnu.org/licenses/>. */ | |
76a50749 | 18 | |
3a4d1e1e | 19 | #include <unwindbuf.h> |
76a50749 | 20 | #include <sysdep.h> |
5a8075b1 | 21 | #include <kernel-features.h> |
e51deae7 | 22 | #include <lowlevellock.h> |
5a8075b1 | 23 | |
76a50749 | 24 | |
76a50749 UD |
25 | .comm __fork_generation, 4, 4 |
26 | ||
27 | .text | |
28 | ||
29 | ||
30 | .globl __pthread_once | |
31 | .type __pthread_once,@function | |
32 | .align 16 | |
3a4d1e1e | 33 | cfi_startproc |
76a50749 UD |
34 | __pthread_once: |
35 | movl 4(%esp), %ecx | |
36 | testl $2, (%ecx) | |
37 | jz 1f | |
38 | xorl %eax, %eax | |
39 | ret | |
40 | ||
41 | 1: pushl %ebx | |
3a4d1e1e UD |
42 | cfi_adjust_cfa_offset (4) |
43 | cfi_rel_offset (3, 0) | |
76a50749 | 44 | pushl %esi |
3a4d1e1e UD |
45 | cfi_adjust_cfa_offset (4) |
46 | cfi_rel_offset (6, 0) | |
76a50749 UD |
47 | movl %ecx, %ebx |
48 | xorl %esi, %esi | |
49 | ||
50 | /* Not yet initialized or initialization in progress. | |
51 | Get the fork generation counter now. */ | |
52 | 6: movl (%ebx), %eax | |
53 | #ifdef PIC | |
9a1d9254 | 54 | LOAD_PIC_REG(cx) |
76a50749 UD |
55 | #endif |
56 | ||
57 | 5: movl %eax, %edx | |
58 | ||
59 | testl $2, %eax | |
60 | jnz 4f | |
61 | ||
62 | andl $3, %edx | |
63 | #ifdef PIC | |
64 | orl __fork_generation@GOTOFF(%ecx), %edx | |
65 | #else | |
66 | orl __fork_generation, %edx | |
67 | #endif | |
68 | orl $1, %edx | |
69 | ||
70 | LOCK | |
71 | cmpxchgl %edx, (%ebx) | |
72 | jnz 5b | |
73 | ||
74 | /* Check whether another thread already runs the initializer. */ | |
75 | testl $1, %eax | |
76 | jz 3f /* No -> do it. */ | |
77 | ||
78 | /* Check whether the initializer execution was interrupted | |
79 | by a fork. */ | |
80 | xorl %edx, %eax | |
81 | testl $0xfffffffc, %eax | |
82 | jnz 3f /* Different for generation -> run initializer. */ | |
83 | ||
84 | /* Somebody else got here first. Wait. */ | |
5a8075b1 UD |
85 | #ifdef __ASSUME_PRIVATE_FUTEX |
86 | movl $FUTEX_WAIT|FUTEX_PRIVATE_FLAG, %ecx | |
87 | #else | |
88 | # if FUTEX_WAIT == 0 | |
89 | movl %gs:PRIVATE_FUTEX, %ecx | |
90 | # else | |
91 | movl $FUTEX_WAIT, %ecx | |
92 | orl %gs:PRIVATE_FUTEX, %ecx | |
93 | # endif | |
94 | #endif | |
76a50749 | 95 | movl $SYS_futex, %eax |
097eca29 | 96 | ENTER_KERNEL |
76a50749 UD |
97 | jmp 6b |
98 | ||
99 | 3: /* Call the initializer function after setting up the | |
3a4d1e1e UD |
100 | cancellation handler. Note that it is not possible here |
101 | to use the unwind-based cleanup handling. This would require | |
102 | that the user-provided function and all the code it calls | |
103 | is compiled with exceptions. Unfortunately this cannot be | |
104 | guaranteed. */ | |
105 | subl $UNWINDBUFSIZE+8, %esp | |
106 | cfi_adjust_cfa_offset (UNWINDBUFSIZE+8) | |
107 | movl %ecx, %ebx /* PIC register value. */ | |
108 | ||
109 | leal 8+UWJMPBUF(%esp), %eax | |
76a50749 | 110 | movl $0, 4(%esp) |
3a4d1e1e UD |
111 | movl %eax, (%esp) |
112 | call __sigsetjmp@PLT | |
e9a7bbab | 113 | testl %eax, %eax |
3a4d1e1e | 114 | jne 7f |
76a50749 | 115 | |
3a4d1e1e | 116 | leal 8(%esp), %eax |
da0c02ee | 117 | call HIDDEN_JUMPTARGET(__pthread_register_cancel) |
3a4d1e1e UD |
118 | |
119 | /* Call the user-provided initialization function. */ | |
120 | call *24+UNWINDBUFSIZE(%esp) | |
121 | ||
122 | /* Pop the cleanup handler. */ | |
123 | leal 8(%esp), %eax | |
da0c02ee | 124 | call HIDDEN_JUMPTARGET(__pthread_unregister_cancel) |
3a4d1e1e UD |
125 | addl $UNWINDBUFSIZE+8, %esp |
126 | cfi_adjust_cfa_offset (-UNWINDBUFSIZE-8) | |
76a50749 UD |
127 | |
128 | /* Sucessful run of the initializer. Signal that we are done. */ | |
3a4d1e1e | 129 | movl 12(%esp), %ebx |
76a50749 | 130 | LOCK |
ccf1d573 | 131 | addl $1, (%ebx) |
76a50749 UD |
132 | |
133 | /* Wake up all other threads. */ | |
134 | movl $0x7fffffff, %edx | |
5a8075b1 UD |
135 | #ifdef __ASSUME_PRIVATE_FUTEX |
136 | movl $FUTEX_WAKE|FUTEX_PRIVATE_FLAG, %ecx | |
137 | #else | |
76a50749 | 138 | movl $FUTEX_WAKE, %ecx |
5a8075b1 UD |
139 | orl %gs:PRIVATE_FUTEX, %ecx |
140 | #endif | |
76a50749 | 141 | movl $SYS_futex, %eax |
097eca29 | 142 | ENTER_KERNEL |
76a50749 UD |
143 | |
144 | 4: popl %esi | |
3a4d1e1e UD |
145 | cfi_adjust_cfa_offset (-4) |
146 | cfi_restore (6) | |
76a50749 | 147 | popl %ebx |
3a4d1e1e UD |
148 | cfi_adjust_cfa_offset (-4) |
149 | cfi_restore (3) | |
76a50749 UD |
150 | xorl %eax, %eax |
151 | ret | |
152 | ||
3a4d1e1e UD |
153 | 7: /* __sigsetjmp returned for the second time. */ |
154 | movl 20+UNWINDBUFSIZE(%esp), %ebx | |
155 | cfi_adjust_cfa_offset (UNWINDBUFSIZE+16) | |
156 | cfi_offset (3, -8) | |
157 | cfi_offset (6, -12) | |
defd1870 | 158 | movl $0, (%ebx) |
76a50749 | 159 | |
76a50749 | 160 | movl $0x7fffffff, %edx |
5a8075b1 UD |
161 | #ifdef __ASSUME_PRIVATE_FUTEX |
162 | movl $FUTEX_WAKE|FUTEX_PRIVATE_FLAG, %ecx | |
163 | #else | |
76a50749 | 164 | movl $FUTEX_WAKE, %ecx |
5a8075b1 UD |
165 | orl %gs:PRIVATE_FUTEX, %ecx |
166 | #endif | |
76a50749 | 167 | movl $SYS_futex, %eax |
097eca29 | 168 | ENTER_KERNEL |
76a50749 | 169 | |
3a4d1e1e | 170 | leal 8(%esp), %eax |
da0c02ee | 171 | call HIDDEN_JUMPTARGET (__pthread_unwind_next) |
3a4d1e1e UD |
172 | /* NOTREACHED */ |
173 | hlt | |
174 | cfi_endproc | |
175 | .size __pthread_once,.-__pthread_once | |
176 | ||
177 | .globl __pthread_once_internal | |
178 | __pthread_once_internal = __pthread_once | |
179 | ||
180 | .globl pthread_once | |
181 | pthread_once = __pthread_once |