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/* Copyright (C) 2003-2014 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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>
#include "lowlevel-atomic.h"
.comm __fork_generation, 4, 4
.text
.globl __pthread_once
.type __pthread_once,@function
.align 5
cfi_startproc
__pthread_once:
mov.l @r4, r0
tst #2, r0
bt 1f
rts
mov #0, r0
1:
mov.l r12, @-r15
cfi_adjust_cfa_offset (4)
cfi_rel_offset (r12, 0)
mov.l r9, @-r15
cfi_adjust_cfa_offset (4)
cfi_rel_offset (r9, 0)
mov.l r8, @-r15
cfi_adjust_cfa_offset (4)
cfi_rel_offset (r8, 0)
sts.l pr, @-r15
cfi_adjust_cfa_offset (4)
cfi_rel_offset (pr, 0)
mov r5, r8
mov r4, r9
/* Not yet initialized or initialization in progress.
Get the fork generation counter now. */
6:
mov.l @r4, r1
mova .Lgot, r0
mov.l .Lgot, r12
add r0, r12
5:
mov r1, r0
tst #2, r0
bf 4f
and #3, r0
mov.l .Lfgen, r2
#ifdef PIC
add r12, r2
#endif
mov.l @r2, r3
or r3, r0
or #1, r0
mov r0, r3
mov r1, r5
CMPXCHG (r5, @r4, r3, r2)
bf 5b
/* Check whether another thread already runs the initializer. */
mov r2, r0
tst #1, r0
bt 3f /* No -> do it. */
/* Check whether the initializer execution was interrupted
by a fork. */
xor r3, r0
mov #-4, r1 /* -4 = 0xfffffffc */
tst r1, r0
bf 3f /* Different for generation -> run initializer. */
/* Somebody else got here first. Wait. */
#ifdef __ASSUME_PRIVATE_FUTEX
mov #(FUTEX_PRIVATE_FLAG|FUTEX_WAIT), r5
extu.b r5, r5
#else
stc gbr, r1
mov.w .Lpfoff, r2
add r2, r1
mov.l @r1, r5
# if FUTEX_WAIT != 0
mov #FUTEX_WAIT, r0
or r0, r5
# endif
#endif
mov r3, r6
mov #0, r7
mov #SYS_futex, r3
extu.b r3, r3
trapa #0x14
SYSCALL_INST_PAD
bra 6b
nop
.align 2
.Lgot:
.long _GLOBAL_OFFSET_TABLE_
#ifdef PIC
.Lfgen:
.long __fork_generation@GOTOFF
#else
.Lfgen:
.long __fork_generation
#endif
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. */
add #-UNWINDBUFSIZE, r15
cfi_adjust_cfa_offset (UNWINDBUFSIZE)
mov.l .Lsigsetjmp, r1
mov #UWJMPBUF, r4
add r15, r4
bsrf r1
mov #0, r5
.Lsigsetjmp0:
tst r0, r0
bf 7f
mov.l .Lcpush, r1
bsrf r1
mov r15, r4
.Lcpush0:
/* Call the user-provided initialization function. */
jsr @r8
nop
/* Pop the cleanup handler. */
mov.l .Lcpop, r1
bsrf r1
mov r15, r4
.Lcpop0:
add #UNWINDBUFSIZE, r15
cfi_adjust_cfa_offset (-UNWINDBUFSIZE)
/* Sucessful run of the initializer. Signal that we are done. */
INC (@r9, r2)
/* Wake up all other threads. */
mov r9, r4
#ifdef __ASSUME_PRIVATE_FUTEX
mov #(FUTEX_PRIVATE_FLAG|FUTEX_WAKE), r5
extu.b r5, r5
#else
stc gbr, r1
mov.w .Lpfoff, r2
add r2, r1
mov.l @r1, r5
mov #FUTEX_WAKE, r0
or r0, r5
#endif
mov #-1, r6
shlr r6 /* r6 = 0x7fffffff */
mov #0, r7
mov #SYS_futex, r3
extu.b r3, r3
trapa #0x14
SYSCALL_INST_PAD
4:
lds.l @r15+, pr
cfi_adjust_cfa_offset (-4)
cfi_restore (pr)
mov.l @r15+, r8
cfi_adjust_cfa_offset (-4)
cfi_restore (r8)
mov.l @r15+, r9
cfi_adjust_cfa_offset (-4)
cfi_restore (r9)
mov.l @r15+, r12
cfi_adjust_cfa_offset (-4)
cfi_restore (r12)
rts
mov #0, r0
7:
/* __sigsetjmp returned for the second time. */
cfi_adjust_cfa_offset (UNWINDBUFSIZE+16)
cfi_offset (r12, -4)
cfi_offset (r9, -8)
cfi_offset (r8, -12)
cfi_offset (pr, -16)
mov #0, r7
mov.l r7, @r9
mov r9, r4
#ifdef __ASSUME_PRIVATE_FUTEX
mov #(FUTEX_PRIVATE_FLAG|FUTEX_WAKE), r5
#else
stc gbr, r1
mov.w .Lpfoff, r2
add r2, r1
mov.l @r1, r5
mov #FUTEX_WAKE, r0
or r0, r5
#endif
extu.b r5, r5
mov #-1, r6
shlr r6 /* r6 = 0x7fffffff */
mov #SYS_futex, r3
extu.b r3, r3
trapa #0x14
SYSCALL_INST_PAD
mov.l .Lunext, r1
bsrf r1
mov r15, r4
.Lunext0:
/* NOTREACHED */
sleep
cfi_endproc
#ifndef __ASSUME_PRIVATE_FUTEX
.Lpfoff:
.word PRIVATE_FUTEX - TLS_PRE_TCB_SIZE
#endif
.align 2
.Lsigsetjmp:
.long __sigsetjmp@PLT-(.Lsigsetjmp0-.)
.Lcpush:
.long HIDDEN_JUMPTARGET(__pthread_register_cancel)-.Lcpush0
.Lcpop:
.long HIDDEN_JUMPTARGET(__pthread_unregister_cancel)-.Lcpop0
.Lunext:
.long HIDDEN_JUMPTARGET(__pthread_unwind_next)-.Lunext0
.size __pthread_once,.-__pthread_once
hidden_def (__pthread_once)
strong_alias (__pthread_once, pthread_once)
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