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
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
|
/* Linuxthreads - a simple clone()-based implementation of Posix */
/* threads for Linux. */
/* Copyright (C) 1996 Xavier Leroy (Xavier.Leroy@inria.fr) */
/* */
/* This program is free software; you can redistribute it and/or */
/* modify it under the terms of the GNU Library General Public License */
/* as published by the Free Software Foundation; either version 2 */
/* of the License, or (at your option) any later version. */
/* */
/* This program 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 Library General Public License for more details. */
/* Mutexes */
#include <errno.h>
#include <sched.h>
#include <stddef.h>
#include "pthread.h"
#include "internals.h"
#include "spinlock.h"
#include "queue.h"
#include "restart.h"
int __pthread_mutex_init(pthread_mutex_t * mutex,
const pthread_mutexattr_t * mutex_attr)
{
__pthread_init_lock(&mutex->__m_lock);
mutex->__m_kind =
mutex_attr == NULL ? PTHREAD_MUTEX_FAST_NP : mutex_attr->__mutexkind;
mutex->__m_count = 0;
mutex->__m_owner = NULL;
return 0;
}
strong_alias (__pthread_mutex_init, pthread_mutex_init)
int __pthread_mutex_destroy(pthread_mutex_t * mutex)
{
if (mutex->__m_lock.__status != 0) return EBUSY;
return 0;
}
strong_alias (__pthread_mutex_destroy, pthread_mutex_destroy)
int __pthread_mutex_trylock(pthread_mutex_t * mutex)
{
pthread_descr self;
int retcode;
switch(mutex->__m_kind) {
case PTHREAD_MUTEX_FAST_NP:
retcode = __pthread_trylock(&mutex->__m_lock);
return retcode;
case PTHREAD_MUTEX_RECURSIVE_NP:
self = thread_self();
if (mutex->__m_owner == self) {
mutex->__m_count++;
return 0;
}
retcode = __pthread_trylock(&mutex->__m_lock);
if (retcode == 0) {
mutex->__m_owner = self;
mutex->__m_count = 0;
}
return retcode;
case PTHREAD_MUTEX_ERRORCHECK_NP:
retcode = __pthread_trylock(&mutex->__m_lock);
if (retcode == 0) {
mutex->__m_owner = thread_self();
}
return retcode;
default:
return EINVAL;
}
}
strong_alias (__pthread_mutex_trylock, pthread_mutex_trylock)
int __pthread_mutex_lock(pthread_mutex_t * mutex)
{
pthread_descr self;
switch(mutex->__m_kind) {
case PTHREAD_MUTEX_FAST_NP:
__pthread_lock(&mutex->__m_lock, NULL);
return 0;
case PTHREAD_MUTEX_RECURSIVE_NP:
self = thread_self();
if (mutex->__m_owner == self) {
mutex->__m_count++;
return 0;
}
__pthread_lock(&mutex->__m_lock, self);
mutex->__m_owner = self;
mutex->__m_count = 0;
return 0;
case PTHREAD_MUTEX_ERRORCHECK_NP:
self = thread_self();
if (mutex->__m_owner == self) return EDEADLK;
__pthread_lock(&mutex->__m_lock, self);
mutex->__m_owner = self;
return 0;
default:
return EINVAL;
}
}
strong_alias (__pthread_mutex_lock, pthread_mutex_lock)
int __pthread_mutex_unlock(pthread_mutex_t * mutex)
{
switch (mutex->__m_kind) {
case PTHREAD_MUTEX_FAST_NP:
__pthread_unlock(&mutex->__m_lock);
return 0;
case PTHREAD_MUTEX_RECURSIVE_NP:
if (mutex->__m_count > 0) {
mutex->__m_count--;
return 0;
}
mutex->__m_owner = NULL;
__pthread_unlock(&mutex->__m_lock);
return 0;
case PTHREAD_MUTEX_ERRORCHECK_NP:
if (mutex->__m_owner != thread_self() || mutex->__m_lock.__status == 0)
return EPERM;
mutex->__m_owner = NULL;
__pthread_unlock(&mutex->__m_lock);
return 0;
default:
return EINVAL;
}
}
strong_alias (__pthread_mutex_unlock, pthread_mutex_unlock)
int __pthread_mutexattr_init(pthread_mutexattr_t *attr)
{
attr->__mutexkind = PTHREAD_MUTEX_FAST_NP;
return 0;
}
strong_alias (__pthread_mutexattr_init, pthread_mutexattr_init)
int __pthread_mutexattr_destroy(pthread_mutexattr_t *attr)
{
return 0;
}
strong_alias (__pthread_mutexattr_destroy, pthread_mutexattr_destroy)
int __pthread_mutexattr_settype(pthread_mutexattr_t *attr, int kind)
{
if (kind != PTHREAD_MUTEX_FAST_NP
&& kind != PTHREAD_MUTEX_RECURSIVE_NP
&& kind != PTHREAD_MUTEX_ERRORCHECK_NP)
return EINVAL;
attr->__mutexkind = kind;
return 0;
}
weak_alias (__pthread_mutexattr_settype, pthread_mutexattr_settype)
strong_alias ( __pthread_mutexattr_settype, __pthread_mutexattr_setkind_np)
weak_alias (__pthread_mutexattr_setkind_np, pthread_mutexattr_setkind_np)
int __pthread_mutexattr_gettype(const pthread_mutexattr_t *attr, int *kind)
{
*kind = attr->__mutexkind;
return 0;
}
weak_alias (__pthread_mutexattr_gettype, pthread_mutexattr_gettype)
strong_alias (__pthread_mutexattr_gettype, __pthread_mutexattr_getkind_np)
weak_alias (__pthread_mutexattr_getkind_np, pthread_mutexattr_getkind_np)
/* Once-only execution */
static pthread_mutex_t once_masterlock = PTHREAD_MUTEX_INITIALIZER;
static pthread_cond_t once_finished = PTHREAD_COND_INITIALIZER;
enum { NEVER = 0, IN_PROGRESS = 1, DONE = 2 };
int __pthread_once(pthread_once_t * once_control, void (*init_routine)(void))
{
/* Test without locking first for speed */
if (*once_control == DONE) return 0;
/* Lock and test again */
pthread_mutex_lock(&once_masterlock);
/* If init_routine is being called from another routine, wait until
it completes. */
while (*once_control == IN_PROGRESS) {
pthread_cond_wait(&once_finished, &once_masterlock);
}
/* Here *once_control is stable and either NEVER or DONE. */
if (*once_control == NEVER) {
*once_control = IN_PROGRESS;
pthread_mutex_unlock(&once_masterlock);
init_routine();
pthread_mutex_lock(&once_masterlock);
*once_control = DONE;
pthread_cond_broadcast(&once_finished);
}
pthread_mutex_unlock(&once_masterlock);
return 0;
}
strong_alias (__pthread_once, pthread_once)
|
