1 /* Linuxthreads - a simple clone()-based implementation of Posix */
2 /* threads for Linux. */
3 /* Copyright (C) 1996 Xavier Leroy (Xavier.Leroy@inria.fr) */
5 /* This program is free software; you can redistribute it and/or */
6 /* modify it under the terms of the GNU Library General Public License */
7 /* as published by the Free Software Foundation; either version 2 */
8 /* of the License, or (at your option) any later version. */
10 /* This program 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 */
13 /* GNU Library General Public License for more details. */
21 #include "internals.h"
26 int __pthread_mutex_init(pthread_mutex_t * mutex,
27 const pthread_mutexattr_t * mutex_attr)
29 __pthread_init_lock(&mutex->__m_lock);
31 mutex_attr == NULL ? PTHREAD_MUTEX_FAST_NP : mutex_attr->__mutexkind;
33 mutex->__m_owner = NULL;
36 strong_alias (__pthread_mutex_init, pthread_mutex_init)
38 int __pthread_mutex_destroy(pthread_mutex_t * mutex)
40 if (mutex->__m_lock.__status != 0) return EBUSY;
43 strong_alias (__pthread_mutex_destroy, pthread_mutex_destroy)
45 int __pthread_mutex_trylock(pthread_mutex_t * mutex)
50 switch(mutex->__m_kind) {
51 case PTHREAD_MUTEX_FAST_NP:
52 retcode = __pthread_trylock(&mutex->__m_lock);
54 case PTHREAD_MUTEX_RECURSIVE_NP:
56 if (mutex->__m_owner == self) {
60 retcode = __pthread_trylock(&mutex->__m_lock);
62 mutex->__m_owner = self;
66 case PTHREAD_MUTEX_ERRORCHECK_NP:
67 retcode = __pthread_trylock(&mutex->__m_lock);
69 mutex->__m_owner = thread_self();
76 strong_alias (__pthread_mutex_trylock, pthread_mutex_trylock)
78 int __pthread_mutex_lock(pthread_mutex_t * mutex)
82 switch(mutex->__m_kind) {
83 case PTHREAD_MUTEX_FAST_NP:
84 __pthread_lock(&mutex->__m_lock, NULL);
86 case PTHREAD_MUTEX_RECURSIVE_NP:
88 if (mutex->__m_owner == self) {
92 __pthread_lock(&mutex->__m_lock, self);
93 mutex->__m_owner = self;
96 case PTHREAD_MUTEX_ERRORCHECK_NP:
98 if (mutex->__m_owner == self) return EDEADLK;
99 __pthread_lock(&mutex->__m_lock, self);
100 mutex->__m_owner = self;
106 strong_alias (__pthread_mutex_lock, pthread_mutex_lock)
108 int __pthread_mutex_unlock(pthread_mutex_t * mutex)
110 switch (mutex->__m_kind) {
111 case PTHREAD_MUTEX_FAST_NP:
112 __pthread_unlock(&mutex->__m_lock);
114 case PTHREAD_MUTEX_RECURSIVE_NP:
115 if (mutex->__m_count > 0) {
119 mutex->__m_owner = NULL;
120 __pthread_unlock(&mutex->__m_lock);
122 case PTHREAD_MUTEX_ERRORCHECK_NP:
123 if (mutex->__m_owner != thread_self() || mutex->__m_lock.__status == 0)
125 mutex->__m_owner = NULL;
126 __pthread_unlock(&mutex->__m_lock);
132 strong_alias (__pthread_mutex_unlock, pthread_mutex_unlock)
134 int __pthread_mutexattr_init(pthread_mutexattr_t *attr)
136 attr->__mutexkind = PTHREAD_MUTEX_FAST_NP;
139 strong_alias (__pthread_mutexattr_init, pthread_mutexattr_init)
141 int __pthread_mutexattr_destroy(pthread_mutexattr_t *attr)
145 strong_alias (__pthread_mutexattr_destroy, pthread_mutexattr_destroy)
147 int __pthread_mutexattr_settype(pthread_mutexattr_t *attr, int kind)
149 if (kind != PTHREAD_MUTEX_FAST_NP
150 && kind != PTHREAD_MUTEX_RECURSIVE_NP
151 && kind != PTHREAD_MUTEX_ERRORCHECK_NP)
153 attr->__mutexkind = kind;
156 weak_alias (__pthread_mutexattr_settype, pthread_mutexattr_settype)
157 strong_alias ( __pthread_mutexattr_settype, __pthread_mutexattr_setkind_np)
158 weak_alias (__pthread_mutexattr_setkind_np, pthread_mutexattr_setkind_np)
160 int __pthread_mutexattr_gettype(const pthread_mutexattr_t *attr, int *kind)
162 *kind = attr->__mutexkind;
165 weak_alias (__pthread_mutexattr_gettype, pthread_mutexattr_gettype)
166 strong_alias (__pthread_mutexattr_gettype, __pthread_mutexattr_getkind_np)
167 weak_alias (__pthread_mutexattr_getkind_np, pthread_mutexattr_getkind_np)
169 /* Once-only execution */
171 static pthread_mutex_t once_masterlock = PTHREAD_MUTEX_INITIALIZER;
172 static pthread_cond_t once_finished = PTHREAD_COND_INITIALIZER;
174 enum { NEVER = 0, IN_PROGRESS = 1, DONE = 2 };
176 /* If a thread is canceled while calling the init_routine out of
177 pthread once, this handler will reset the once_control variable
178 to the NEVER state. */
180 static void pthread_once_cancelhandler(void *arg)
182 pthread_once_t *once_control = arg;
184 pthread_mutex_lock(&once_masterlock);
185 *once_control = NEVER;
186 pthread_mutex_unlock(&once_masterlock);
187 pthread_cond_broadcast(&once_finished);
190 int __pthread_once(pthread_once_t * once_control, void (*init_routine)(void))
192 /* flag for doing the condition broadcast outside of mutex */
195 /* Test without locking first for speed */
196 if (*once_control == DONE) return 0;
197 /* Lock and test again */
201 pthread_mutex_lock(&once_masterlock);
202 /* If init_routine is being called from another routine, wait until
204 while (*once_control == IN_PROGRESS) {
205 pthread_cond_wait(&once_finished, &once_masterlock);
207 /* Here *once_control is stable and either NEVER or DONE. */
208 if (*once_control == NEVER) {
209 *once_control = IN_PROGRESS;
210 pthread_mutex_unlock(&once_masterlock);
211 pthread_cleanup_push(pthread_once_cancelhandler, once_control);
213 pthread_cleanup_pop(0);
214 pthread_mutex_lock(&once_masterlock);
215 *once_control = DONE;
218 pthread_mutex_unlock(&once_masterlock);
221 pthread_cond_broadcast(&once_finished);
225 strong_alias (__pthread_once, pthread_once)