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
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
|
/* 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 <shlib-compat.h>
#include <lowlevellock.h>
#include <lowlevelcond.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 $1, %edx
#ifdef __ASSUME_PRIVATE_FUTEX
movl $FUTEX_WAKE_OP, %eax
movl $(FUTEX_WAKE_OP|FUTEX_PRIVATE_FLAG), %esi
cmove %eax, %esi
#else
movl $0, %eax
movl %fs:PRIVATE_FUTEX, %esi
cmove %eax, %esi
orl $FUTEX_WAKE_OP, %esi
#endif
movl $1, %r10d
movl $SYS_futex, %eax
#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
7: /* %esi should be either FUTEX_WAKE_OP or
FUTEX_WAKE_OP|FUTEX_PRIVATE_FLAG from the previous syscall. */
xorl $(FUTEX_WAKE | FUTEX_WAKE_OP), %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)
|