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

/* Copyright (C) 2002-2005, 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, see
   <http://www.gnu.org/licenses/>.  */

#include <sysdep.h>
#include <shlib-compat.h>
#include <lowlevellock.h>
#include <lowlevelcond.h>
#include <pthread-pi-defines.h>
#include <kernel-features.h>
#include <pthread-errnos.h>


	.text

	/* int pthread_cond_signal (pthread_cond_t *cond) */
	.globl	__pthread_cond_signal
	.type	__pthread_cond_signal, @function
	.align	16
__pthread_cond_signal:

	/* Get internal lock.  */
	movq	%rdi, %r8
	movl	$1, %esi
	xorl	%eax, %eax
	LOCK
#if cond_lock == 0
	cmpxchgl %esi, (%rdi)
#else
	cmpxchgl %esi, cond_lock(%rdi)
#endif
	jnz	1f

2:	addq	$cond_futex, %rdi
	movq	total_seq(%r8), %rcx
	cmpq	wakeup_seq(%r8), %rcx
	jbe	4f

	/* Bump the wakeup number.  */
	addq	$1, wakeup_seq(%r8)
	addl	$1, (%rdi)

	/* Wake up one thread.  */
	cmpq	$-1, dep_mutex(%r8)
	movl	$FUTEX_WAKE_OP, %esi
	movl	$1, %edx
	movl	$SYS_futex, %eax
	je	8f

	/* Get the address of the mutex used.  */
	movq    dep_mutex(%r8), %rcx
	movl	MUTEX_KIND(%rcx), %r11d
	andl	$(ROBUST_BIT|PI_BIT), %r11d
	cmpl	$PI_BIT, %r11d
	je	9f

#ifdef __ASSUME_PRIVATE_FUTEX
	movl	$(FUTEX_WAKE_OP|FUTEX_PRIVATE_FLAG), %esi
#else
	orl	%fs:PRIVATE_FUTEX, %esi
#endif

8:	movl	$1, %r10d
#if cond_lock != 0
	addq	$cond_lock, %r8
#endif
	movl	$FUTEX_OP_CLEAR_WAKE_IF_GT_ONE, %r9d
	syscall
#if cond_lock != 0
	subq	$cond_lock, %r8
#endif
	/* For any kind of error, we try again with WAKE.
	   The general test also covers running on old kernels.  */
	cmpq	$-4095, %rax
	jae	7f

	xorl	%eax, %eax
	retq

	/* Wake up one thread and requeue none in the PI Mutex case.  */
9:	movl	$(FUTEX_CMP_REQUEUE_PI|FUTEX_PRIVATE_FLAG), %esi
	movq	%rcx, %r8
	xorq	%r10, %r10
	movl	(%rdi), %r9d	// XXX Can this be right?
	syscall

	leaq	-cond_futex(%rdi), %r8

	/* For any kind of error, we try again with WAKE.
	   The general test also covers running on old kernels.  */
	cmpq	$-4095, %rax
	jb	4f

7:
#ifdef __ASSUME_PRIVATE_FUTEX
	andl	$FUTEX_PRIVATE_FLAG, %esi
#else
	andl	%fs:PRIVATE_FUTEX, %esi
#endif
	orl	$FUTEX_WAKE, %esi
	movl	$SYS_futex, %eax
	/* %rdx should be 1 already from $FUTEX_WAKE_OP syscall.
	movl	$1, %edx  */
	syscall

	/* Unlock.  */
4:	LOCK
#if cond_lock == 0
	decl	(%r8)
#else
	decl	cond_lock(%r8)
#endif
	jne	5f

6:	xorl	%eax, %eax
	retq

	/* Initial locking failed.  */
1:
#if cond_lock != 0
	addq	$cond_lock, %rdi
#endif
	cmpq	$-1, dep_mutex-cond_lock(%rdi)
	movl	$LLL_PRIVATE, %eax
	movl	$LLL_SHARED, %esi
	cmovne	%eax, %esi
	callq	__lll_lock_wait
#if cond_lock != 0
	subq	$cond_lock, %rdi
#endif
	jmp	2b

	/* Unlock in loop requires wakeup.  */
5:
	movq	%r8, %rdi
#if cond_lock != 0
	addq	$cond_lock, %rdi
#endif
	cmpq	$-1, dep_mutex-cond_lock(%rdi)
	movl	$LLL_PRIVATE, %eax
	movl	$LLL_SHARED, %esi
	cmovne	%eax, %esi
	callq	__lll_unlock_wake
	jmp	6b
	.size	__pthread_cond_signal, .-__pthread_cond_signal
versioned_symbol (libpthread, __pthread_cond_signal, pthread_cond_signal,
		  GLIBC_2_3_2)
Commit	Line	Data
42e69bcf	1	/* Copyright (C) 2002-2005, 2007, 2009 Free Software Foundation, Inc.
d0aacb47 UD	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
59ba27a6 PE	16	License along with the GNU C Library; if not, see
59ba27a6 PE	17	<http://www.gnu.org/licenses/>. */
d0aacb47 UD	18
	19	#include <sysdep.h>
	20	#include <shlib-compat.h>
e51deae7	21	#include <lowlevellock.h>
d0aacb47	22	#include <lowlevelcond.h>
42e69bcf	23	#include <pthread-pi-defines.h>
69431c9a	24	#include <kernel-features.h>
e51deae7	25	#include <pthread-errnos.h>
d0aacb47 UD	26
	27
	28	.text
	29
	30	/* int pthread_cond_signal (pthread_cond_t cond) /
	31	.globl __pthread_cond_signal
	32	.type __pthread_cond_signal, @function
	33	.align 16
	34	__pthread_cond_signal:
	35
	36	/* Get internal lock. */
7661d9f7	37	movq %rdi, %r8
d0aacb47	38	movl $1, %esi
3a226d33	39	xorl %eax, %eax
d0aacb47 UD	40	LOCK
d0aacb47 UD	41	#if cond_lock == 0
3a226d33	42	cmpxchgl %esi, (%rdi)
d0aacb47	43	#else
3a226d33	44	cmpxchgl %esi, cond_lock(%rdi)
d0aacb47	45	#endif
3a226d33	46	jnz 1f
d0aacb47	47
75fccede	48	2: addq $cond_futex, %rdi
69431c9a	49	movq total_seq(%r8), %rcx
75fccede	50	cmpq wakeup_seq(%r8), %rcx
d0aacb47 UD	51	jbe 4f
	52
	53	/* Bump the wakeup number. */
75fccede UD	54	addq $1, wakeup_seq(%r8)
75fccede UD	55	addl $1, (%rdi)
d0aacb47 UD	56
d0aacb47 UD	57	/* Wake up one thread. */
5bd8a249	58	cmpq $-1, dep_mutex(%r8)
42e69bcf	59	movl $FUTEX_WAKE_OP, %esi
ee618985	60	movl $1, %edx
42e69bcf UD	61	movl $SYS_futex, %eax
	62	je 8f
	63
	64	/* Get the address of the mutex used. */
	65	movq dep_mutex(%r8), %rcx
ec492239 AS	66	movl MUTEX_KIND(%rcx), %r11d
	67	andl $(ROBUST_BIT\|PI_BIT), %r11d
	68	cmpl $PI_BIT, %r11d
b0948ffd	69	je 9f
42e69bcf	70
5bd8a249	71	#ifdef __ASSUME_PRIVATE_FUTEX
5bd8a249	72	movl $(FUTEX_WAKE_OP\|FUTEX_PRIVATE_FLAG), %esi
5bd8a249	73	#else
42e69bcf	74	orl %fs:PRIVATE_FUTEX, %esi
5bd8a249	75	#endif
42e69bcf UD	76
42e69bcf UD	77	8: movl $1, %r10d
a3615024 UD	78	#if cond_lock != 0
	79	addq $cond_lock, %r8
	80	#endif
	81	movl $FUTEX_OP_CLEAR_WAKE_IF_GT_ONE, %r9d
	82	syscall
	83	#if cond_lock != 0
	84	subq $cond_lock, %r8
	85	#endif
	86	/* For any kind of error, we try again with WAKE.
	87	The general test also covers running on old kernels. */
	88	cmpq $-4095, %rax
	89	jae 7f
	90
	91	xorl %eax, %eax
	92	retq
	93
42e69bcf UD	94	/* Wake up one thread and requeue none in the PI Mutex case. */
	95	9: movl $(FUTEX_CMP_REQUEUE_PI\|FUTEX_PRIVATE_FLAG), %esi
	96	movq %rcx, %r8
	97	xorq %r10, %r10
	98	movl (%rdi), %r9d // XXX Can this be right?
	99	syscall
	100
	101	leaq -cond_futex(%rdi), %r8
	102
	103	/* For any kind of error, we try again with WAKE.
	104	The general test also covers running on old kernels. */
	105	cmpq $-4095, %rax
	106	jb 4f
	107
	108	7:
	109	#ifdef __ASSUME_PRIVATE_FUTEX
	110	andl $FUTEX_PRIVATE_FLAG, %esi
	111	#else
	112	andl %fs:PRIVATE_FUTEX, %esi
	113	#endif
	114	orl $FUTEX_WAKE, %esi
a3615024 UD	115	movl $SYS_futex, %eax
	116	/* %rdx should be 1 already from $FUTEX_WAKE_OP syscall.
	117	movl $1, %edx */
d0aacb47 UD	118	syscall
	119
	120	/* Unlock. */
	121	4: LOCK
7661d9f7 UD	122	#if cond_lock == 0
	123	decl (%r8)
	124	#else
69431c9a	125	decl cond_lock(%r8)
7661d9f7	126	#endif
d0aacb47 UD	127	jne 5f
	128
	129	6: xorl %eax, %eax
	130	retq
	131
	132	/* Initial locking failed. */
	133	1:
	134	#if cond_lock != 0
	135	addq $cond_lock, %rdi
	136	#endif
5bd8a249 UD	137	cmpq $-1, dep_mutex-cond_lock(%rdi)
5bd8a249 UD	138	movl $LLL_PRIVATE, %eax
e51deae7	139	movl $LLL_SHARED, %esi
5bd8a249	140	cmovne %eax, %esi
e51deae7	141	callq __lll_lock_wait
d0aacb47 UD	142	#if cond_lock != 0
	143	subq $cond_lock, %rdi
	144	#endif
	145	jmp 2b
	146
7661d9f7	147	/* Unlock in loop requires wakeup. */
69431c9a	148	5:
69431c9a	149	movq %r8, %rdi
5bd8a249 UD	150	#if cond_lock != 0
	151	addq $cond_lock, %rdi
	152	#endif
	153	cmpq $-1, dep_mutex-cond_lock(%rdi)
	154	movl $LLL_PRIVATE, %eax
e51deae7	155	movl $LLL_SHARED, %esi
5bd8a249	156	cmovne %eax, %esi
e51deae7	157	callq __lll_unlock_wake
d0aacb47 UD	158	jmp 6b
	159	.size __pthread_cond_signal, .-__pthread_cond_signal
	160	versioned_symbol (libpthread, __pthread_cond_signal, pthread_cond_signal,
	161	GLIBC_2_3_2)