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/* Copyright (C) 2002, 2003, 2005, 2007 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 <kernel-features.h>
#include <tcb-offsets.h>
#ifndef UP
# define LOCK lock
#else
# define LOCK
#endif
#define SYS_futex 202
#define FUTEX_WAIT 0
#define FUTEX_WAKE 1
#define FUTEX_PRIVATE_FLAG 128
.comm __fork_generation, 4, 4
.text
.globl __pthread_once
.type __pthread_once,@function
.align 16
__pthread_once:
.LSTARTCODE:
testl $2, (%rdi)
jz 1f
xorl %eax, %eax
retq
/* Preserve the function pointer. */
1: pushq %rsi
.Lpush_rsi:
xorq %r10, %r10
/* Not yet initialized or initialization in progress.
Get the fork generation counter now. */
6: movl (%rdi), %eax
5: movl %eax, %edx
testl $2, %eax
jnz 4f
andl $3, %edx
orl __fork_generation(%rip), %edx
orl $1, %edx
LOCK
cmpxchgl %edx, (%rdi)
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, %esi
#else
# if FUTEX_WAIT == 0
movl %fs:PRIVATE_FUTEX, %esi
# else
movl $FUTEX_WAIT, %esi
orl %fs:PRIVATE_FUTEX, %esi
# endif
#endif
movl $SYS_futex, %eax
syscall
jmp 6b
/* Preserve the pointer to the control variable. */
3: pushq %rdi
.Lpush_rdi:
pushq %rdi
.Lpush_rdi2:
.LcleanupSTART:
callq *16(%rsp)
.LcleanupEND:
/* Get the control variable address back. */
popq %rdi
.Lpop_rdi:
/* Sucessful run of the initializer. Signal that we are done. */
LOCK
incl (%rdi)
addq $8, %rsp
.Ladd1:
/* Wake up all other threads. */
movl $0x7fffffff, %edx
#ifdef __ASSUME_PRIVATE_FUTEX
movl $FUTEX_WAKE|FUTEX_PRIVATE_FLAG, %esi
#else
movl $FUTEX_WAKE, %esi
orl %fs:PRIVATE_FUTEX, %esi
#endif
movl $SYS_futex, %eax
syscall
4: addq $8, %rsp
.Ladd2:
xorl %eax, %eax
retq
.size __pthread_once,.-__pthread_once
.globl __pthread_once_internal
__pthread_once_internal = __pthread_once
.globl pthread_once
pthread_once = __pthread_once
.type clear_once_control,@function
.align 16
clear_once_control:
movq (%rsp), %rdi
movq %rax, %r8
movl $0, (%rdi)
movl $0x7fffffff, %edx
#ifdef __ASSUME_PRIVATE_FUTEX
movl $FUTEX_WAKE|FUTEX_PRIVATE_FLAG, %esi
#else
movl $FUTEX_WAKE, %esi
orl %fs:PRIVATE_FUTEX, %esi
#endif
movl $SYS_futex, %eax
syscall
movq %r8, %rdi
.LcallUR:
call _Unwind_Resume@PLT
hlt
.LENDCODE:
.size clear_once_control,.-clear_once_control
.section .gcc_except_table,"a",@progbits
.LexceptSTART:
.byte 0xff # @LPStart format (omit)
.byte 0xff # @TType format (omit)
.byte 0x01 # call-site format
# DW_EH_PE_uleb128
.uleb128 .Lcstend-.Lcstbegin
.Lcstbegin:
.uleb128 .LcleanupSTART-.LSTARTCODE
.uleb128 .LcleanupEND-.LcleanupSTART
.uleb128 clear_once_control-.LSTARTCODE
.uleb128 0
.uleb128 .LcallUR-.LSTARTCODE
.uleb128 .LENDCODE-.LcallUR
.uleb128 0
.uleb128 0
.Lcstend:
.section .eh_frame,"a",@progbits
.LSTARTFRAME:
.long .LENDCIE-.LSTARTCIE # Length of the CIE.
.LSTARTCIE:
.long 0 # CIE ID.
.byte 1 # Version number.
#ifdef SHARED
.string "zPLR" # NUL-terminated augmentation
# string.
#else
.string "zPL" # NUL-terminated augmentation
# string.
#endif
.uleb128 1 # Code alignment factor.
.sleb128 -8 # Data alignment factor.
.byte 16 # Return address register
# column.
#ifdef SHARED
.uleb128 7 # Augmentation value length.
.byte 0x9b # Personality: DW_EH_PE_pcrel
# + DW_EH_PE_sdata4
# + DW_EH_PE_indirect
.long DW.ref.__gcc_personality_v0-.
.byte 0x1b # LSDA Encoding: DW_EH_PE_pcrel
# + DW_EH_PE_sdata4.
.byte 0x1b # FDE Encoding: DW_EH_PE_pcrel
# + DW_EH_PE_sdata4.
#else
.uleb128 10 # Augmentation value length.
.byte 0x0 # Personality: absolute
.quad __gcc_personality_v0
.byte 0x0 # LSDA Encoding: absolute
#endif
.byte 0x0c # DW_CFA_def_cfa
.uleb128 7
.uleb128 8
.byte 0x90 # DW_CFA_offset, column 0x10
.uleb128 1
.align 8
.LENDCIE:
.long .LENDFDE-.LSTARTFDE # Length of the FDE.
.LSTARTFDE:
.long .LSTARTFDE-.LSTARTFRAME # CIE pointer.
#ifdef SHARED
.long .LSTARTCODE-. # PC-relative start address
# of the code.
.long .LENDCODE-.LSTARTCODE # Length of the code.
.uleb128 4 # Augmentation size
.long .LexceptSTART-.
#else
.quad .LSTARTCODE # Start address of the code.
.quad .LENDCODE-.LSTARTCODE # Length of the code.
.uleb128 8 # Augmentation size
.quad .LexceptSTART
#endif
.byte 4 # DW_CFA_advance_loc4
.long .Lpush_rsi-.LSTARTCODE
.byte 14 # DW_CFA_def_cfa_offset
.uleb128 16
.byte 4 # DW_CFA_advance_loc4
.long .Lpush_rdi-.Lpush_rsi
.byte 14 # DW_CFA_def_cfa_offset
.uleb128 24
.byte 4 # DW_CFA_advance_loc4
.long .Lpush_rdi2-.Lpush_rdi
.byte 14 # DW_CFA_def_cfa_offset
.uleb128 32
.byte 4 # DW_CFA_advance_loc4
.long .Lpop_rdi-.Lpush_rdi2
.byte 14 # DW_CFA_def_cfa_offset
.uleb128 24
.byte 4 # DW_CFA_advance_loc4
.long .Ladd1-.Lpop_rdi
.byte 14 # DW_CFA_def_cfa_offset
.uleb128 16
.byte 4 # DW_CFA_advance_loc4
.long .Ladd2-.Ladd1
.byte 14 # DW_CFA_def_cfa_offset
.uleb128 8
.byte 4 # DW_CFA_advance_loc4
.long clear_once_control-.Ladd2
.byte 14 # DW_CFA_def_cfa_offset
.uleb128 32
#if 0
.byte 4 # DW_CFA_advance_loc4
.long .Lpop_rdi3-clear_once_control
.byte 14 # DW_CFA_def_cfa_offset
.uleb128 16
#endif
.align 8
.LENDFDE:
#ifdef SHARED
.hidden DW.ref.__gcc_personality_v0
.weak DW.ref.__gcc_personality_v0
.section .gnu.linkonce.d.DW.ref.__gcc_personality_v0,"aw",@progbits
.align 8
.type DW.ref.__gcc_personality_v0, @object
.size DW.ref.__gcc_personality_v0, 8
DW.ref.__gcc_personality_v0:
.quad __gcc_personality_v0
#endif
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