mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-03 10:21:05 +00:00
179 lines
4.2 KiB
ArmAsm
179 lines
4.2 KiB
ArmAsm
/* Copyright (C) 2002-2012 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, see
|
|
<http://www.gnu.org/licenses/>. */
|
|
|
|
#include <unwindbuf.h>
|
|
#include <sysdep.h>
|
|
#include <kernel-features.h>
|
|
#include <lowlevellock.h>
|
|
|
|
|
|
.comm __fork_generation, 4, 4
|
|
|
|
.text
|
|
|
|
|
|
.globl __pthread_once
|
|
.type __pthread_once,@function
|
|
.align 16
|
|
cfi_startproc
|
|
__pthread_once:
|
|
movl 4(%esp), %ecx
|
|
testl $2, (%ecx)
|
|
jz 1f
|
|
xorl %eax, %eax
|
|
ret
|
|
|
|
1: pushl %ebx
|
|
cfi_adjust_cfa_offset (4)
|
|
cfi_rel_offset (3, 0)
|
|
pushl %esi
|
|
cfi_adjust_cfa_offset (4)
|
|
cfi_rel_offset (6, 0)
|
|
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
|
|
LOAD_PIC_REG(cx)
|
|
#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. */
|
|
#ifdef __ASSUME_PRIVATE_FUTEX
|
|
movl $FUTEX_WAIT|FUTEX_PRIVATE_FLAG, %ecx
|
|
#else
|
|
# if FUTEX_WAIT == 0
|
|
movl %gs:PRIVATE_FUTEX, %ecx
|
|
# else
|
|
movl $FUTEX_WAIT, %ecx
|
|
orl %gs:PRIVATE_FUTEX, %ecx
|
|
# endif
|
|
#endif
|
|
movl $SYS_futex, %eax
|
|
ENTER_KERNEL
|
|
jmp 6b
|
|
|
|
3: /* Call the initializer function after setting up the
|
|
cancellation handler. Note that it is not possible here
|
|
to use the unwind-based cleanup handling. This would require
|
|
that the user-provided function and all the code it calls
|
|
is compiled with exceptions. Unfortunately this cannot be
|
|
guaranteed. */
|
|
subl $UNWINDBUFSIZE+8, %esp
|
|
cfi_adjust_cfa_offset (UNWINDBUFSIZE+8)
|
|
movl %ecx, %ebx /* PIC register value. */
|
|
|
|
leal 8+UWJMPBUF(%esp), %eax
|
|
movl $0, 4(%esp)
|
|
movl %eax, (%esp)
|
|
call __sigsetjmp@PLT
|
|
testl %eax, %eax
|
|
jne 7f
|
|
|
|
leal 8(%esp), %eax
|
|
call HIDDEN_JUMPTARGET(__pthread_register_cancel)
|
|
|
|
/* Call the user-provided initialization function. */
|
|
call *24+UNWINDBUFSIZE(%esp)
|
|
|
|
/* Pop the cleanup handler. */
|
|
leal 8(%esp), %eax
|
|
call HIDDEN_JUMPTARGET(__pthread_unregister_cancel)
|
|
addl $UNWINDBUFSIZE+8, %esp
|
|
cfi_adjust_cfa_offset (-UNWINDBUFSIZE-8)
|
|
|
|
/* Sucessful run of the initializer. Signal that we are done. */
|
|
movl 12(%esp), %ebx
|
|
LOCK
|
|
addl $1, (%ebx)
|
|
|
|
/* Wake up all other threads. */
|
|
movl $0x7fffffff, %edx
|
|
#ifdef __ASSUME_PRIVATE_FUTEX
|
|
movl $FUTEX_WAKE|FUTEX_PRIVATE_FLAG, %ecx
|
|
#else
|
|
movl $FUTEX_WAKE, %ecx
|
|
orl %gs:PRIVATE_FUTEX, %ecx
|
|
#endif
|
|
movl $SYS_futex, %eax
|
|
ENTER_KERNEL
|
|
|
|
4: popl %esi
|
|
cfi_adjust_cfa_offset (-4)
|
|
cfi_restore (6)
|
|
popl %ebx
|
|
cfi_adjust_cfa_offset (-4)
|
|
cfi_restore (3)
|
|
xorl %eax, %eax
|
|
ret
|
|
|
|
7: /* __sigsetjmp returned for the second time. */
|
|
movl 20+UNWINDBUFSIZE(%esp), %ebx
|
|
cfi_adjust_cfa_offset (UNWINDBUFSIZE+16)
|
|
cfi_offset (3, -8)
|
|
cfi_offset (6, -12)
|
|
movl $0, (%ebx)
|
|
|
|
movl $0x7fffffff, %edx
|
|
#ifdef __ASSUME_PRIVATE_FUTEX
|
|
movl $FUTEX_WAKE|FUTEX_PRIVATE_FLAG, %ecx
|
|
#else
|
|
movl $FUTEX_WAKE, %ecx
|
|
orl %gs:PRIVATE_FUTEX, %ecx
|
|
#endif
|
|
movl $SYS_futex, %eax
|
|
ENTER_KERNEL
|
|
|
|
leal 8(%esp), %eax
|
|
call HIDDEN_JUMPTARGET (__pthread_unwind_next)
|
|
/* NOTREACHED */
|
|
hlt
|
|
cfi_endproc
|
|
.size __pthread_once,.-__pthread_once
|
|
|
|
hidden_def (__pthread_once)
|
|
strong_alias (__pthread_once, pthread_once)
|