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

/* Copyright (C) 2002-2016 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>
#include <stap-probe.h>


	.text

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

	LIBC_PROBE (cond_signal, 1, %rdi)

	/* 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.  */
	LP_OP(cmp) $-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.  */
	mov     dep_mutex(%r8), %RCX_LP
	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
	LP_OP(cmp) $-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
	LP_OP(cmp) $-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
f7a9f785	1	/* Copyright (C) 2002-2016 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>
5acf7263	26	#include <stap-probe.h>
d0aacb47 UD	27
	28
	29	.text
	30
	31	/* int pthread_cond_signal (pthread_cond_t cond) /
	32	.globl __pthread_cond_signal
	33	.type __pthread_cond_signal, @function
	34	.align 16
	35	__pthread_cond_signal:
	36
5acf7263 RM	37	LIBC_PROBE (cond_signal, 1, %rdi)
5acf7263 RM	38
d0aacb47	39	/* Get internal lock. */
7661d9f7	40	movq %rdi, %r8
d0aacb47	41	movl $1, %esi
3a226d33	42	xorl %eax, %eax
d0aacb47 UD	43	LOCK
d0aacb47 UD	44	#if cond_lock == 0
3a226d33	45	cmpxchgl %esi, (%rdi)
d0aacb47	46	#else
3a226d33	47	cmpxchgl %esi, cond_lock(%rdi)
d0aacb47	48	#endif
3a226d33	49	jnz 1f
d0aacb47	50
75fccede	51	2: addq $cond_futex, %rdi
69431c9a	52	movq total_seq(%r8), %rcx
75fccede	53	cmpq wakeup_seq(%r8), %rcx
d0aacb47 UD	54	jbe 4f
	55
	56	/* Bump the wakeup number. */
75fccede UD	57	addq $1, wakeup_seq(%r8)
75fccede UD	58	addl $1, (%rdi)
d0aacb47 UD	59
d0aacb47 UD	60	/* Wake up one thread. */
d9754f55	61	LP_OP(cmp) $-1, dep_mutex(%r8)
42e69bcf	62	movl $FUTEX_WAKE_OP, %esi
ee618985	63	movl $1, %edx
42e69bcf UD	64	movl $SYS_futex, %eax
	65	je 8f
	66
	67	/* Get the address of the mutex used. */
d9754f55	68	mov dep_mutex(%r8), %RCX_LP
ec492239 AS	69	movl MUTEX_KIND(%rcx), %r11d
	70	andl $(ROBUST_BIT\|PI_BIT), %r11d
	71	cmpl $PI_BIT, %r11d
b0948ffd	72	je 9f
42e69bcf	73
5bd8a249	74	#ifdef __ASSUME_PRIVATE_FUTEX
5bd8a249	75	movl $(FUTEX_WAKE_OP\|FUTEX_PRIVATE_FLAG), %esi
5bd8a249	76	#else
42e69bcf	77	orl %fs:PRIVATE_FUTEX, %esi
5bd8a249	78	#endif
42e69bcf UD	79
42e69bcf UD	80	8: movl $1, %r10d
a3615024 UD	81	#if cond_lock != 0
	82	addq $cond_lock, %r8
	83	#endif
	84	movl $FUTEX_OP_CLEAR_WAKE_IF_GT_ONE, %r9d
	85	syscall
	86	#if cond_lock != 0
	87	subq $cond_lock, %r8
	88	#endif
	89	/* For any kind of error, we try again with WAKE.
	90	The general test also covers running on old kernels. */
	91	cmpq $-4095, %rax
	92	jae 7f
	93
	94	xorl %eax, %eax
	95	retq
	96
42e69bcf UD	97	/* Wake up one thread and requeue none in the PI Mutex case. */
	98	9: movl $(FUTEX_CMP_REQUEUE_PI\|FUTEX_PRIVATE_FLAG), %esi
	99	movq %rcx, %r8
	100	xorq %r10, %r10
	101	movl (%rdi), %r9d // XXX Can this be right?
	102	syscall
	103
	104	leaq -cond_futex(%rdi), %r8
	105
	106	/* For any kind of error, we try again with WAKE.
	107	The general test also covers running on old kernels. */
	108	cmpq $-4095, %rax
	109	jb 4f
	110
	111	7:
	112	#ifdef __ASSUME_PRIVATE_FUTEX
	113	andl $FUTEX_PRIVATE_FLAG, %esi
	114	#else
	115	andl %fs:PRIVATE_FUTEX, %esi
	116	#endif
	117	orl $FUTEX_WAKE, %esi
a3615024 UD	118	movl $SYS_futex, %eax
	119	/* %rdx should be 1 already from $FUTEX_WAKE_OP syscall.
	120	movl $1, %edx */
d0aacb47 UD	121	syscall
	122
	123	/* Unlock. */
	124	4: LOCK
7661d9f7 UD	125	#if cond_lock == 0
	126	decl (%r8)
	127	#else
69431c9a	128	decl cond_lock(%r8)
7661d9f7	129	#endif
d0aacb47 UD	130	jne 5f
	131
	132	6: xorl %eax, %eax
	133	retq
	134
	135	/* Initial locking failed. */
	136	1:
	137	#if cond_lock != 0
	138	addq $cond_lock, %rdi
	139	#endif
d9754f55	140	LP_OP(cmp) $-1, dep_mutex-cond_lock(%rdi)
5bd8a249	141	movl $LLL_PRIVATE, %eax
e51deae7	142	movl $LLL_SHARED, %esi
5bd8a249	143	cmovne %eax, %esi
e51deae7	144	callq __lll_lock_wait
d0aacb47 UD	145	#if cond_lock != 0
	146	subq $cond_lock, %rdi
	147	#endif
	148	jmp 2b
	149
7661d9f7	150	/* Unlock in loop requires wakeup. */
69431c9a	151	5:
69431c9a	152	movq %r8, %rdi
5bd8a249 UD	153	#if cond_lock != 0
	154	addq $cond_lock, %rdi
	155	#endif
d9754f55	156	LP_OP(cmp) $-1, dep_mutex-cond_lock(%rdi)
5bd8a249	157	movl $LLL_PRIVATE, %eax
e51deae7	158	movl $LLL_SHARED, %esi
5bd8a249	159	cmovne %eax, %esi
e51deae7	160	callq __lll_unlock_wake
d0aacb47 UD	161	jmp 6b
	162	.size __pthread_cond_signal, .-__pthread_cond_signal
	163	versioned_symbol (libpthread, __pthread_cond_signal, pthread_cond_signal,
	164	GLIBC_2_3_2)