about summary refs log tree commit diff
path: root/nptl/sysdeps/unix/sysv/linux/i386/i486/pthread_cond_signal.S
blob: 807d2f5015a0e3d5bb752de5a99ea3577eef1efb (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
/* 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 <shlib-compat.h>
#include <lowlevelcond.h>

#ifdef UP
# define LOCK
#else
# define LOCK lock
#endif

#define SYS_futex		240
#define FUTEX_WAIT		0
#define FUTEX_WAKE		1


	.text

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

	pushl	%ebx

	movl	8(%esp), %ebx

	/* Get internal lock.  */
	movl	$1, %eax
	LOCK
#if cond_lock == 0
	xaddl	%eax, (%ebx)
#else
	xaddl	%eax, cond_lock(%ebx)
#endif
	testl	%eax, %eax
	jne	1f

2:	addl	$wakeup_seq, %ebx
	movl	total_seq+4-wakeup_seq(%ebx), %eax
	movl	total_seq-wakeup_seq(%ebx), %ecx
	cmpl	4(%ebx), %eax
	ja	3f
	jb	4f
	cmpl	(%ebx), %ecx
	jbe	4f

	/* Bump the wakeup number.  */
3:	addl	$1, (%ebx)
	adcl	$0, 4(%ebx)

	/* Wake up one thread.  */
	movl	$FUTEX_WAKE, %ecx
	movl	$SYS_futex, %eax
	movl	%ecx, %edx	/* movl $1, %edx */
	ENTER_KERNEL

	/* Unlock.  */
4:	LOCK
	decl	cond_lock-wakeup_seq(%ebx)
	jne	5f

6:	xorl	%eax, %eax
	popl	%ebx
	ret

	/* Initial locking failed.  */
1:
#if cond_lock == 0
	movl	%ebx, %ecx
#else
	leal	cond_lock(%ebx), %ecx
#endif
	call	__lll_mutex_lock_wait
	jmp	2b

	/* Unlock in loop requires waekup.  */
5:
	leal	cond_lock-wakeup_seq(%ebx), %eax
	call	__lll_mutex_unlock_wake
	jmp	6b
	.size	__pthread_cond_signal, .-__pthread_cond_signal
versioned_symbol (libpthread, __pthread_cond_signal, pthread_cond_signal,
		  GLIBC_2_3_2)