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/* Copyright (C) 2002, 2003, 2005, 2007, 2009 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>
#include <lowlevellock.h>
#include <lowlevelrwlock.h>
#include <pthread-errnos.h>
#include <kernel-features.h>
.text
.globl __pthread_rwlock_wrlock
.type __pthread_rwlock_wrlock,@function
.align 16
__pthread_rwlock_wrlock:
cfi_startproc
movq NRW_WORD(%rdi), %rax
.Lagain:
movq $(NRW_WW_MASK|NRW_WL|NRW_RC_MASK), %rdx
testq %rdx, %rax
jnz .Lwait
// XXX Probably make AR a don't-care for !WP. Unconditionally set it
movq $(NRW_AR|NRW_WL), %rdx
movq $NRW_WL, %rcx
testq $NRW_WP, %rax
cmovz %rcx, %rdx
orq %rax, %rdx
LOCK
cmpxchgq %rdx, NRW_WORD(%rdi)
jnz .Lagain
movl %fs:TID, %eax
movl %eax, WRITER(%rdi)
xorl %eax, %eax
ret
.Lwait: movq $NRW_WL, %rcx
testq %rcx, %rax
jz 1f
movl %fs:TID, %eax
cmpl %eax, WRITER(%rdi)
je .Ldeadlk
1: leaq NRW_WORD+4(%rdi), %rdi
movq $NRW_WW, %rdx
movq $NRW_WW_MASK, %rcx
addq %rax, %rdx
testq %rcx, %rdx
jz .Lovfl
LOCK
cmpxchgq %rdx, -4(%rdi)
jnz .Lagain
xorq %r10, %r10
movl $NRW_W_WAKEUP, %r9d
.Lwait2:
movl $(FUTEX_WAIT_BITSET|FUTEX_PRIVATE_FLAG), %esi
movl $__NR_futex, %eax
xorl PSHARED-(NRW_WORD+4)(%rdi), %esi
syscall
movq -4(%rdi), %rax
.Lagain2:
movq $(NRW_WL|NRW_RC_MASK), %rdx
movq $(NRW_WL|NRW_AR), %rcx
testq %rdx, %rax
movq $NRW_AR, %rsi
setz %cl
andq %rax, %rcx
cmpq %rsi, %rcx
sete %cl
orb %dl, %cl
jz .Lwait2
movq $-NRW_WW, %rdx
addq %rax, %rdx
xorl %ecx, %ecx
testq $NRW_WP, %rax
cmovz %rcx, %rsi
orq %rsi, %rdx
LOCK
cmpxchgq %rdx, -4(%rdi)
jnz .Lagain2
movl %fs:TID, %eax
movl %eax, WRITER(%rdi)
xorl %eax, %eax
ret
.Lovfl: movl $EAGAIN, %eax
ret
.Ldeadlk:
movl $EDEADLK, %eax
ret
#if 0
xorq %r10, %r10
/* Get the lock. */
movl $1, %esi
xorl %eax, %eax
LOCK
#if MUTEX == 0
cmpxchgl %esi, (%rdi)
#else
cmpxchgl %esi, MUTEX(%rdi)
#endif
jnz 1f
2: movl WRITER(%rdi), %eax
testl %eax, %eax
jne 14f
cmpl $0, NR_READERS(%rdi)
je 5f
3: incl WRITERS_QUEUED(%rdi)
je 4f
movl WRITERS_WAKEUP(%rdi), %edx
LOCK
#if MUTEX == 0
decl (%rdi)
#else
decl MUTEX(%rdi)
#endif
jne 10f
11:
#ifdef __ASSUME_PRIVATE_FUTEX
movl $FUTEX_PRIVATE_FLAG|FUTEX_WAIT, %esi
xorl PSHARED(%rdi), %esi
#else
# if FUTEX_WAIT == 0
movl PSHARED(%rdi), %esi
# else
movl $FUTEX_WAIT, %esi
orl PSHARED(%rdi), %esi
# endif
xorl %fs:PRIVATE_FUTEX, %esi
#endif
addq $WRITERS_WAKEUP, %rdi
movl $SYS_futex, %eax
syscall
subq $WRITERS_WAKEUP, %rdi
/* Reget the lock. */
movl $1, %esi
xorl %eax, %eax
LOCK
#if MUTEX == 0
cmpxchgl %esi, (%rdi)
#else
cmpxchgl %esi, MUTEX(%rdi)
#endif
jnz 12f
13: decl WRITERS_QUEUED(%rdi)
jmp 2b
5: xorl %edx, %edx
movl %fs:TID, %eax
movl %eax, WRITER(%rdi)
9: LOCK
#if MUTEX == 0
decl (%rdi)
#else
decl MUTEX(%rdi)
#endif
jne 6f
7:
movq %rdx, %rax
retq
1: movl PSHARED(%rdi), %esi
#if MUTEX != 0
addq $MUTEX, %rdi
#endif
callq __lll_lock_wait
#if MUTEX != 0
subq $MUTEX, %rdi
#endif
jmp 2b
14: cmpl %fs:TID, %eax
jne 3b
movl $EDEADLK, %edx
jmp 9b
6: movl PSHARED(%rdi), %esi
#if MUTEX != 0
addq $MUTEX, %rdi
#endif
callq __lll_unlock_wake
jmp 7b
4: decl WRITERS_QUEUED(%rdi)
movl $EAGAIN, %edx
jmp 9b
10: movl PSHARED(%rdi), %esi
#if MUTEX != 0
addq $MUTEX, %rdi
#endif
callq __lll_unlock_wake
#if MUTEX != 0
subq $MUTEX, %rdi
#endif
jmp 11b
12: movl PSHARED(%rdi), %esi
#if MUTEX != 0
addq $MUTEX, %rdi
#endif
callq __lll_lock_wait
#if MUTEX != 0
subq $MUTEX, %rdi
#endif
jmp 13b
#endif
cfi_endproc
.size __pthread_rwlock_wrlock,.-__pthread_rwlock_wrlock
.globl pthread_rwlock_wrlock
pthread_rwlock_wrlock = __pthread_rwlock_wrlock
.globl __pthread_rwlock_wrlock_internal
__pthread_rwlock_wrlock_internal = __pthread_rwlock_wrlock
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