1 /*
2  * Copyright (c) 1995 John Birrell <jb@cimlogic.com.au>.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by John Birrell.
16  * 4. Neither the name of the author nor the names of any co-contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  * $DragonFly: src/lib/libthread_xu/thread/thr_spec.c,v 1.5 2006/04/06 13:03:09 davidxu Exp $
33  */
34 
35 #include "namespace.h"
36 #include <machine/tls.h>
37 
38 #include <signal.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include <errno.h>
42 #include <pthread.h>
43 #include "un-namespace.h"
44 
45 #include "thr_private.h"
46 
47 struct pthread_key _thread_keytable[PTHREAD_KEYS_MAX];
48 umtx_t	_keytable_lock;
49 
50 int
51 _pthread_key_create(pthread_key_t *key, void (*destructor) (void *))
52 {
53 	struct pthread *curthread = tls_get_curthread();
54 	int i;
55 
56 	/* Lock the key table: */
57 	THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
58 	for (i = 0; i < PTHREAD_KEYS_MAX; i++) {
59 
60 		if (_thread_keytable[i].allocated == 0) {
61 			_thread_keytable[i].allocated = 1;
62 			_thread_keytable[i].destructor = destructor;
63 			_thread_keytable[i].seqno++;
64 
65 			/* Unlock the key table: */
66 			THR_LOCK_RELEASE(curthread, &_keytable_lock);
67 			*key = i;
68 			return (0);
69 		}
70 
71 	}
72 	/* Unlock the key table: */
73 	THR_LOCK_RELEASE(curthread, &_keytable_lock);
74 	return (EAGAIN);
75 }
76 
77 int
78 _pthread_key_delete(pthread_key_t key)
79 {
80 	struct pthread *curthread = tls_get_curthread();
81 	int ret = 0;
82 
83 	if ((unsigned int)key < PTHREAD_KEYS_MAX) {
84 		/* Lock the key table: */
85 		THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
86 
87 		if (_thread_keytable[key].allocated)
88 			_thread_keytable[key].allocated = 0;
89 		else
90 			ret = EINVAL;
91 
92 		/* Unlock the key table: */
93 		THR_LOCK_RELEASE(curthread, &_keytable_lock);
94 	} else
95 		ret = EINVAL;
96 	return (ret);
97 }
98 
99 void
100 _thread_cleanupspecific(void)
101 {
102 	struct pthread	*curthread = tls_get_curthread();
103 	void		(*destructor)( void *);
104 	const void	*data = NULL;
105 	int		key;
106 	int		i;
107 
108 	if (curthread->specific == NULL)
109 		return;
110 
111 	/* Lock the key table: */
112 	THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
113 	for (i = 0; (i < PTHREAD_DESTRUCTOR_ITERATIONS) &&
114 	    (curthread->specific_data_count > 0); i++) {
115 		for (key = 0; (key < PTHREAD_KEYS_MAX) &&
116 		    (curthread->specific_data_count > 0); key++) {
117 			destructor = NULL;
118 
119 			if (_thread_keytable[key].allocated &&
120 			    (curthread->specific[key].data != NULL)) {
121 				if (curthread->specific[key].seqno ==
122 				    _thread_keytable[key].seqno) {
123 					data =
124 					    curthread->specific[key].data;
125 					destructor = _thread_keytable[key].destructor;
126 				}
127 				curthread->specific[key].data = NULL;
128 				curthread->specific_data_count--;
129 			}
130 
131 			/*
132 			 * If there is a destructore, call it
133 			 * with the key table entry unlocked:
134 			 */
135 			if (destructor != NULL) {
136 				/*
137 				 * Don't hold the lock while calling the
138 				 * destructor:
139 				 */
140 				THR_LOCK_RELEASE(curthread, &_keytable_lock);
141 				destructor(__DECONST(void *, data));
142 				THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
143 			}
144 		}
145 	}
146 	THR_LOCK_RELEASE(curthread, &_keytable_lock);
147 	free(curthread->specific);
148 	curthread->specific = NULL;
149 	if (curthread->specific_data_count > 0)
150 		stderr_debug("Thread %p has exited with leftover "
151 		    "thread-specific data after %d destructor iterations\n",
152 		    curthread, PTHREAD_DESTRUCTOR_ITERATIONS);
153 }
154 
155 static inline struct pthread_specific_elem *
156 pthread_key_allocate_data(void)
157 {
158 	struct pthread_specific_elem *new_data;
159 
160 	new_data = (struct pthread_specific_elem *)
161 	    malloc(sizeof(struct pthread_specific_elem) * PTHREAD_KEYS_MAX);
162 	if (new_data != NULL) {
163 		memset((void *) new_data, 0,
164 		    sizeof(struct pthread_specific_elem) * PTHREAD_KEYS_MAX);
165 	}
166 	return (new_data);
167 }
168 
169 int
170 _pthread_setspecific(pthread_key_t key, const void *value)
171 {
172 	struct pthread	*pthread;
173 	int		ret = 0;
174 
175 	/* Point to the running thread: */
176 	pthread = tls_get_curthread();
177 
178 	if ((pthread->specific) ||
179 	    (pthread->specific = pthread_key_allocate_data())) {
180 		if ((unsigned int)key < PTHREAD_KEYS_MAX) {
181 			if (_thread_keytable[key].allocated) {
182 				if (pthread->specific[key].data == NULL) {
183 					if (value != NULL)
184 						pthread->specific_data_count++;
185 				} else if (value == NULL)
186 					pthread->specific_data_count--;
187 				pthread->specific[key].data = value;
188 				pthread->specific[key].seqno =
189 				    _thread_keytable[key].seqno;
190 				ret = 0;
191 			} else
192 				ret = EINVAL;
193 		} else
194 			ret = EINVAL;
195 	} else
196 		ret = ENOMEM;
197 	return (ret);
198 }
199 
200 void *
201 _pthread_getspecific(pthread_key_t key)
202 {
203 	struct pthread	*pthread;
204 	const void	*data;
205 
206 	/* Point to the running thread: */
207 	pthread = tls_get_curthread();
208 
209 	/* Check if there is specific data: */
210 	if (pthread->specific != NULL && (unsigned int)key < PTHREAD_KEYS_MAX) {
211 		/* Check if this key has been used before: */
212 		if (_thread_keytable[key].allocated &&
213 		    (pthread->specific[key].seqno == _thread_keytable[key].seqno)) {
214 			/* Return the value: */
215 			data = pthread->specific[key].data;
216 		} else {
217 			/*
218 			 * This key has not been used before, so return NULL
219 			 * instead:
220 			 */
221 			data = NULL;
222 		}
223 	} else
224 		/* No specific data has been created, so just return NULL: */
225 		data = NULL;
226 	return __DECONST(void *, data);
227 }
228 
229 __strong_reference(_pthread_key_create, pthread_key_create);
230 __strong_reference(_pthread_key_delete, pthread_key_delete);
231 __strong_reference(_pthread_getspecific, pthread_getspecific);
232 __strong_reference(_pthread_setspecific, pthread_setspecific);
233 
234