[glibc.git] / nptl / sysdeps / unix / sysv / linux / x86_64 / pthread_rwlock_unlock.S

/* Copyright (C) 2002, 2003 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>


#define SYS_futex		202
#define FUTEX_WAIT		0
#define FUTEX_WAKE		1

#ifndef UP
# define LOCK lock
#else
# define LOCK
#endif


	.text

	.globl	__pthread_rwlock_unlock
	.type	__pthread_rwlock_unlock,@function
	.align	16
__pthread_rwlock_unlock:
	/* 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:	cmpq	$0, WRITER(%rdi)
	jne	5f
	decl	NR_READERS(%rdi)
	jnz	6f

5:	movq	$0, WRITER(%rdi)

	movq	$1, %rsi
	leaq	WRITERS_WAKEUP(%rdi), %r10
	movq	%rsi, %rdx
	cmpl	$0, WRITERS_QUEUED(%rdi)
	jne	0f

	/* If also no readers waiting nothing to do.  */
	cmpl	$0, READERS_QUEUED(%rdi)
	je	6f

	movl	$0x7fffffff, %edx
	leaq	READERS_WAKEUP(%rdi), %r10

0:	incl	(%r10)
	LOCK
#if MUTEX == 0
	decl	(%rdi)
#else
	decl	MUTEX(%rdi)
#endif
	jne	7f

8:	movq	$SYS_futex, %rax
	movq	%r10, %rdi
	syscall

	xorq	%rax, %rax
	retq

	.align	16
6:	LOCK
#if MUTEX == 0
	decl	(%rdi)
#else
	decl	MUTEX(%rdi)
#endif
	jne	3f

4:	xorq	%rax, %rax
	retq

1:
#if MUTEX != 0
	addq	$MUTEX, %rdi
#endif
	callq	__lll_mutex_lock_wait
#if MUTEX != 0
	subq	$MUTEX, %rdi
#endif
	jmp	2b

3:
#if MUTEX != 0
	addq	$MUTEX, %rdi
#endif
	callq	__lll_mutex_unlock_wake
	jmp	4b

7:
#if MUTEX != 0
	addq	$MUTEX, %rdi
#endif
	callq	__lll_mutex_unlock_wake
	jmp	8b

	.size	__pthread_rwlock_unlock,.-__pthread_rwlock_unlock

	.globl	pthread_rwlock_unlock
pthread_rwlock_unlock = __pthread_rwlock_unlock

	.globl	__pthread_rwlock_unlock_internal
__pthread_rwlock_unlock_internal = __pthread_rwlock_unlock
Commit	Line	Data
da49194d UD	1	/* Copyright (C) 2002, 2003 Free Software Foundation, Inc.
	2	This file is part of the GNU C Library.
	3	Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
	4
	5	The GNU C Library is free software; you can redistribute it and/or
	6	modify it under the terms of the GNU Lesser General Public
	7	License as published by the Free Software Foundation; either
	8	version 2.1 of the License, or (at your option) any later version.
	9
	10	The GNU C Library is distributed in the hope that it will be useful,
	11	but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	13	Lesser General Public License for more details.
	14
	15	You should have received a copy of the GNU Lesser General Public
	16	License along with the GNU C Library; if not, write to the Free
	17	Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
	18	02111-1307 USA. */
	19
	20	#include <sysdep.h>
	21	#include <lowlevelrwlock.h>
	22
	23
46a32546	24	#define SYS_futex 202
da49194d UD	25	#define FUTEX_WAIT 0
	26	#define FUTEX_WAKE 1
	27
	28	#ifndef UP
	29	# define LOCK lock
	30	#else
	31	# define LOCK
	32	#endif
	33
	34
	35	.text
	36
	37	.globl __pthread_rwlock_unlock
	38	.type __pthread_rwlock_unlock,@function
	39	.align 16
	40	__pthread_rwlock_unlock:
	41	/* Get the lock. */
	42	movl $1, %esi
3a226d33	43	xorl %eax, %eax
da49194d UD	44	LOCK
da49194d UD	45	#if MUTEX == 0
3a226d33	46	cmpxchgl %esi, (%rdi)
da49194d	47	#else
3a226d33	48	cmpxchgl %esi, MUTEX(%rdi)
da49194d	49	#endif
3a226d33	50	jnz 1f
da49194d UD	51
	52	2: cmpq $0, WRITER(%rdi)
	53	jne 5f
	54	decl NR_READERS(%rdi)
	55	jnz 6f
	56
	57	5: movq $0, WRITER(%rdi)
	58
	59	movq $1, %rsi
46a32546	60	leaq WRITERS_WAKEUP(%rdi), %r10
da49194d UD	61	movq %rsi, %rdx
	62	cmpl $0, WRITERS_QUEUED(%rdi)
	63	jne 0f
	64
	65	/* If also no readers waiting nothing to do. */
	66	cmpl $0, READERS_QUEUED(%rdi)
	67	je 6f
	68
46a32546 UD	69	movl $0x7fffffff, %edx
46a32546 UD	70	leaq READERS_WAKEUP(%rdi), %r10
da49194d	71
46a32546	72	0: incl (%r10)
da49194d UD	73	LOCK
	74	#if MUTEX == 0
	75	decl (%rdi)
	76	#else
	77	decl MUTEX(%rdi)
	78	#endif
	79	jne 7f
	80
	81	8: movq $SYS_futex, %rax
46a32546	82	movq %r10, %rdi
da49194d UD	83	syscall
	84
	85	xorq %rax, %rax
	86	retq
	87
	88	.align 16
	89	6: LOCK
	90	#if MUTEX == 0
	91	decl (%rdi)
	92	#else
	93	decl MUTEX(%rdi)
	94	#endif
	95	jne 3f
	96
	97	4: xorq %rax, %rax
	98	retq
	99
	100	1:
	101	#if MUTEX != 0
	102	addq $MUTEX, %rdi
	103	#endif
92ed3daf	104	callq __lll_mutex_lock_wait
da49194d UD	105	#if MUTEX != 0
	106	subq $MUTEX, %rdi
	107	#endif
	108	jmp 2b
	109
	110	3:
	111	#if MUTEX != 0
	112	addq $MUTEX, %rdi
	113	#endif
92ed3daf	114	callq __lll_mutex_unlock_wake
da49194d UD	115	jmp 4b
	116
	117	7:
	118	#if MUTEX != 0
	119	addq $MUTEX, %rdi
	120	#endif
92ed3daf	121	callq __lll_mutex_unlock_wake
da49194d UD	122	jmp 8b
	123
	124	.size __pthread_rwlock_unlock,.-__pthread_rwlock_unlock
	125
	126	.globl pthread_rwlock_unlock
	127	pthread_rwlock_unlock = __pthread_rwlock_unlock
	128
	129	.globl __pthread_rwlock_unlock_internal
	130	__pthread_rwlock_unlock_internal = __pthread_rwlock_unlock