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, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
20 #include <unwindbuf.h>
22 #include <bits/kernel-features.h>
23 #include <lowlevellock.h>
27 .comm __fork_generation, 4, 4
33 .type __pthread_once,@function
34 .protected __pthread_once
45 cfi_adjust_cfa_offset (4)
48 cfi_adjust_cfa_offset (4)
53 /* Not yet initialized or initialization in progress.
54 Get the fork generation counter now. */
57 call __x86.get_pc_thunk.cx
58 addl $_GLOBAL_OFFSET_TABLE_, %ecx
68 orl __fork_generation@GOTOFF(%ecx), %edx
70 orl __fork_generation, %edx
78 /* Check whether another thread already runs the initializer. */
80 jz 3f /* No -> do it. */
82 /* Check whether the initializer execution was interrupted
85 testl $0xfffffffc, %eax
86 jnz 3f /* Different for generation -> run initializer. */
88 /* Somebody else got here first. Wait. */
89 #ifdef __ASSUME_PRIVATE_FUTEX
90 movl $FUTEX_WAIT|FUTEX_PRIVATE_FLAG, %ecx
93 movl %gs:PRIVATE_FUTEX, %ecx
95 movl $FUTEX_WAIT, %ecx
96 orl %gs:PRIVATE_FUTEX, %ecx
103 3: /* Call the initializer function after setting up the
104 cancellation handler. Note that it is not possible here
105 to use the unwind-based cleanup handling. This would require
106 that the user-provided function and all the code it calls
107 is compiled with exceptions. Unfortunately this cannot be
109 subl $UNWINDBUFSIZE+8, %esp
110 cfi_adjust_cfa_offset (UNWINDBUFSIZE+8)
111 movl %ecx, %ebx /* PIC register value. */
113 leal 8+UWJMPBUF(%esp), %eax
121 call HIDDEN_JUMPTARGET(__pthread_register_cancel)
123 /* Call the user-provided initialization function. */
124 call *24+UNWINDBUFSIZE(%esp)
126 /* Pop the cleanup handler. */
128 call HIDDEN_JUMPTARGET(__pthread_unregister_cancel)
129 addl $UNWINDBUFSIZE+8, %esp
130 cfi_adjust_cfa_offset (-UNWINDBUFSIZE-8)
132 /* Sucessful run of the initializer. Signal that we are done. */
137 /* Wake up all other threads. */
138 movl $0x7fffffff, %edx
139 #ifdef __ASSUME_PRIVATE_FUTEX
140 movl $FUTEX_WAKE|FUTEX_PRIVATE_FLAG, %ecx
142 movl $FUTEX_WAKE, %ecx
143 orl %gs:PRIVATE_FUTEX, %ecx
145 movl $SYS_futex, %eax
149 cfi_adjust_cfa_offset (-4)
152 cfi_adjust_cfa_offset (-4)
157 7: /* __sigsetjmp returned for the second time. */
158 movl 20+UNWINDBUFSIZE(%esp), %ebx
159 cfi_adjust_cfa_offset (UNWINDBUFSIZE+16)
164 movl $0x7fffffff, %edx
165 #ifdef __ASSUME_PRIVATE_FUTEX
166 movl $FUTEX_WAKE|FUTEX_PRIVATE_FLAG, %ecx
168 movl $FUTEX_WAKE, %ecx
169 orl %gs:PRIVATE_FUTEX, %ecx
171 movl $SYS_futex, %eax
175 call HIDDEN_JUMPTARGET (__pthread_unwind_next)
179 .size __pthread_once,.-__pthread_once
181 .globl __pthread_once_internal
182 __pthread_once_internal = __pthread_once
185 pthread_once = __pthread_once
189 .section .gnu.linkonce.t.__x86.get_pc_thunk.cx,"ax",@progbits
190 .globl __x86.get_pc_thunk.cx
191 .hidden __x86.get_pc_thunk.cx
192 .type __x86.get_pc_thunk.cx,@function
193 __x86.get_pc_thunk.cx:
196 .size __x86.get_pc_thunk.cx,.-__x86.get_pc_thunk.cx