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/* Copyright (C) 2002 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
int $0x80
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 _GI_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 _GI_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
int $0x80
4: popl %esi
popl %ebx
xorl %eax, %eax
ret
.size __pthread_once,.-__pthread_once
.globl pthread_once
pthread_once = __pthread_once
.type clear_once_control,@function
.align 16
clear_once_control:
pushl %esi
pushl %ebx
movl 4(%esp), %eax
movl $0, (%eax)
xorl %esi, %esi
movl $0x7fffffff, %edx
movl $FUTEX_WAKE, %ecx
movl $SYS_futex, %eax
int $0x80
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
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