1 /* Copyright (C) 2002, 2003, 2007 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
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.
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.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <http://www.gnu.org/licenses/>. */
19 #include <unwindbuf.h>
21 #include <bits/kernel-features.h>
22 #include <lowlevellock.h>
26 .comm __fork_generation, 4, 4
32 .type __pthread_once,@function
33 .protected __pthread_once
44 cfi_adjust_cfa_offset (4)
47 cfi_adjust_cfa_offset (4)
52 /* Not yet initialized or initialization in progress.
53 Get the fork generation counter now. */
56 call __x86.get_pc_thunk.cx
57 addl $_GLOBAL_OFFSET_TABLE_, %ecx
67 orl __fork_generation@GOTOFF(%ecx), %edx
69 orl __fork_generation, %edx
77 /* Check whether another thread already runs the initializer. */
79 jz 3f /* No -> do it. */
81 /* Check whether the initializer execution was interrupted
84 testl $0xfffffffc, %eax
85 jnz 3f /* Different for generation -> run initializer. */
87 /* Somebody else got here first. Wait. */
88 #ifdef __ASSUME_PRIVATE_FUTEX
89 movl $FUTEX_WAIT|FUTEX_PRIVATE_FLAG, %ecx
92 movl %gs:PRIVATE_FUTEX, %ecx
94 movl $FUTEX_WAIT, %ecx
95 orl %gs:PRIVATE_FUTEX, %ecx
102 3: /* Call the initializer function after setting up the
103 cancellation handler. Note that it is not possible here
104 to use the unwind-based cleanup handling. This would require
105 that the user-provided function and all the code it calls
106 is compiled with exceptions. Unfortunately this cannot be
108 subl $UNWINDBUFSIZE+8, %esp
109 cfi_adjust_cfa_offset (UNWINDBUFSIZE+8)
110 movl %ecx, %ebx /* PIC register value. */
112 leal 8+UWJMPBUF(%esp), %eax
120 call HIDDEN_JUMPTARGET(__pthread_register_cancel)
122 /* Call the user-provided initialization function. */
123 call *24+UNWINDBUFSIZE(%esp)
125 /* Pop the cleanup handler. */
127 call HIDDEN_JUMPTARGET(__pthread_unregister_cancel)
128 addl $UNWINDBUFSIZE+8, %esp
129 cfi_adjust_cfa_offset (-UNWINDBUFSIZE-8)
131 /* Sucessful run of the initializer. Signal that we are done. */
136 /* Wake up all other threads. */
137 movl $0x7fffffff, %edx
138 #ifdef __ASSUME_PRIVATE_FUTEX
139 movl $FUTEX_WAKE|FUTEX_PRIVATE_FLAG, %ecx
141 movl $FUTEX_WAKE, %ecx
142 orl %gs:PRIVATE_FUTEX, %ecx
144 movl $SYS_futex, %eax
148 cfi_adjust_cfa_offset (-4)
151 cfi_adjust_cfa_offset (-4)
156 7: /* __sigsetjmp returned for the second time. */
157 movl 20+UNWINDBUFSIZE(%esp), %ebx
158 cfi_adjust_cfa_offset (UNWINDBUFSIZE+16)
163 movl $0x7fffffff, %edx
164 #ifdef __ASSUME_PRIVATE_FUTEX
165 movl $FUTEX_WAKE|FUTEX_PRIVATE_FLAG, %ecx
167 movl $FUTEX_WAKE, %ecx
168 orl %gs:PRIVATE_FUTEX, %ecx
170 movl $SYS_futex, %eax
174 call HIDDEN_JUMPTARGET (__pthread_unwind_next)
178 .size __pthread_once,.-__pthread_once
180 .globl __pthread_once_internal
181 __pthread_once_internal = __pthread_once
184 pthread_once = __pthread_once
188 .section .gnu.linkonce.t.__x86.get_pc_thunk.cx,"ax",@progbits
189 .globl __x86.get_pc_thunk.cx
190 .hidden __x86.get_pc_thunk.cx
191 .type __x86.get_pc_thunk.cx,@function
192 __x86.get_pc_thunk.cx:
195 .size __x86.get_pc_thunk.cx,.-__x86.get_pc_thunk.cx