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/* Copyright (C) 2002, 2003, 2004, 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 <sysdep.h>
#include <lowlevelrwlock.h>
#include <pthread-errnos.h>
#define SYS_futex 202
#define FUTEX_WAIT 0
#define FUTEX_WAKE 1
/* For the calculation see asm/vsyscall.h. */
#define VSYSCALL_ADDR_vgettimeofday 0xffffffffff600000
#ifndef UP
# define LOCK lock
#else
# define LOCK
#endif
.text
.globl pthread_rwlock_timedrdlock
.type pthread_rwlock_timedrdlock,@function
.align 16
pthread_rwlock_timedrdlock:
pushq %r12
pushq %r13
pushq %r14
subq $16, %rsp
movq %rdi, %r12
movq %rsi, %r13
/* 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(%r12), %eax
testl %eax, %eax
jne 14f
cmpl $0, WRITERS_QUEUED(%r12)
je 5f
cmpl $0, FLAGS(%r12)
je 5f
/* Check the value of the timeout parameter. */
3: cmpq $1000000000, 8(%r13)
jae 19f
incl READERS_QUEUED(%r12)
je 4f
movl READERS_WAKEUP(%r12), %r14d
/* Unlock. */
LOCK
#if MUTEX == 0
decl (%r12)
#else
decl MUTEX(%r12)
#endif
jne 10f
/* Get current time. */
11: movq %rsp, %rdi
xorl %esi, %esi
movq $VSYSCALL_ADDR_vgettimeofday, %rax
callq *%rax
/* Compute relative timeout. */
movq 8(%rsp), %rax
movl $1000, %edi
mul %rdi /* Milli seconds to nano seconds. */
movq (%r13), %rcx
movq 8(%r13), %rdi
subq (%rsp), %rcx
subq %rax, %rdi
jns 15f
addq $1000000000, %rdi
decq %rcx
15: testq %rcx, %rcx
js 16f /* Time is already up. */
/* Futex call. */
movq %rcx, (%rsp) /* Store relative timeout. */
movq %rdi, 8(%rsp)
#if __ASSUME_PRIVATE_FUTEX
movl $FUTEX_PRIVATE_FLAG|FUTEX_WAIT, %esi
xorl PSHARED(%rdi), %esi
#else
# if FUTEX_WAIT == 0
movl PSHARED(%r12), %esi
# else
movl $FUTEX_WAIT, %esi
orl PSHARED(%r12), %esi
# endif
xorl %fs:PRIVATE_FUTEX, %esi
#endif
movq %rsp, %r10
movl %r14d, %edx
leaq READERS_WAKEUP(%r12), %rdi
movl $SYS_futex, %eax
syscall
movq %rax, %rdx
17:
/* Reget the lock. */
movl $1, %esi
xorl %eax, %eax
LOCK
#if MUTEX == 0
cmpxchgl %esi, (%r12)
#else
cmpxchgl %esi, MUTEX(%r12)
#endif
jnz 12f
13: decl READERS_QUEUED(%r12)
cmpq $-ETIMEDOUT, %rdx
jne 2b
18: movl $ETIMEDOUT, %edx
jmp 9f
5: xorl %edx, %edx
incl NR_READERS(%r12)
je 8f
9: LOCK
#if MUTEX == 0
decl (%r12)
#else
decl MUTEX(%r12)
#endif
jne 6f
7: movq %rdx, %rax
addq $16, %rsp
popq %r14
popq %r13
popq %r12
retq
1:
#if MUTEX != 0
addq $MUTEX, %rdi
#endif
callq __lll_mutex_lock_wait
jmp 2b
14: cmpl %fs:TID, %eax
jne 3b
movl $EDEADLK, %edx
jmp 9b
6:
#if MUTEX == 0
movq %r12, %rdi
#else
leal MUTEX(%r12), %rdi
#endif
callq __lll_mutex_unlock_wake
jmp 7b
/* Overflow. */
8: decl NR_READERS(%r12)
movl $EAGAIN, %edx
jmp 9b
/* Overflow. */
4: decl READERS_QUEUED(%r12)
movl $EAGAIN, %edx
jmp 9b
10:
#if MUTEX == 0
movq %r12, %rdi
#else
leaq MUTEX(%r12), %rdi
#endif
callq __lll_mutex_unlock_wake
jmp 11b
12:
#if MUTEX == 0
movq %r12, %rdi
#else
leaq MUTEX(%r12), %rdi
#endif
callq __lll_mutex_lock_wait
jmp 13b
16: movq $-ETIMEDOUT, %rdx
jmp 17b
19: movl $EINVAL, %edx
jmp 9b
.size pthread_rwlock_timedrdlock,.-pthread_rwlock_timedrdlock
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