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/* Copyright (C) 2002-2014 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 <sysdep.h>
#include <lowlevellock.h>
#include <lowlevelrwlock.h>
#include <pthread-errnos.h>
#include <kernel-features.h>
#include <stap-probe.h>
.text
.globl __pthread_rwlock_wrlock
.type __pthread_rwlock_wrlock,@function
.align 16
__pthread_rwlock_wrlock:
cfi_startproc
LIBC_PROBE (wrlock_entry, 1, %rdi)
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
cfi_endproc
.size __pthread_rwlock_wrlock,.-__pthread_rwlock_wrlock
strong_alias (__pthread_rwlock_wrlock, pthread_rwlock_wrlock)
hidden_def (__pthread_rwlock_wrlock)
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