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. Neither the name of the author nor the names of any co-contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 */
30
31 #include "namespace.h"
32 #include <machine/tls.h>
33 #include <signal.h>
34 #include <stdlib.h>
35 #include <string.h>
36 #include <errno.h>
37 #include <pthread.h>
38 #include "un-namespace.h"
39
40 #include "thr_private.h"
41
42 struct pthread_key _thread_keytable[PTHREAD_KEYS_MAX];
43 umtx_t _keytable_lock;
44 static size_t _pthread_specific_bytes;
45
46 int
_pthread_key_create(pthread_key_t * key,void (* destructor)(void *))47 _pthread_key_create(pthread_key_t *key, void (*destructor) (void *))
48 {
49 pthread_t curthread;
50 int i;
51
52 /* User program might be preparing to call pthread_create() */
53 _thr_check_init();
54
55 curthread = tls_get_curthread();
56
57 /* Lock the key table: */
58 THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
59 for (i = 1; i < PTHREAD_KEYS_MAX; i++) {
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
_pthread_key_delete(pthread_key_t key)78 _pthread_key_delete(pthread_key_t key)
79 {
80 pthread_t 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
_thread_cleanupspecific(void)100 _thread_cleanupspecific(void)
101 {
102 pthread_t 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 = curthread->specific[key].data;
124 destructor = _thread_keytable[key].destructor;
125 }
126 curthread->specific[key].data = NULL;
127 curthread->specific_data_count--;
128 } else if (curthread->specific[key].data != NULL) {
129 /*
130 * This can happen if the key is deleted via
131 * pthread_key_delete without first setting the value
132 * to NULL in all threads. POSIX says that the
133 * destructor is not invoked in this case.
134 */
135 curthread->specific[key].data = NULL;
136 curthread->specific_data_count--;
137 }
138
139 /*
140 * If there is a destructor, call it
141 * with the key table entry unlocked:
142 */
143 if (destructor != NULL) {
144 /*
145 * Don't hold the lock while calling the
146 * destructor:
147 */
148 THR_LOCK_RELEASE(curthread, &_keytable_lock);
149 destructor(__DECONST(void *, data));
150 THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
151 }
152 }
153 }
154 THR_LOCK_RELEASE(curthread, &_keytable_lock);
155
156 munmap(curthread->specific, _pthread_specific_bytes);
157 curthread->specific = NULL;
158
159 if (curthread->specific_data_count > 0) {
160 stderr_debug("Thread %p has exited with leftover "
161 "thread-specific data after %d destructor "
162 "iterations\n",
163 curthread, PTHREAD_DESTRUCTOR_ITERATIONS);
164 }
165 }
166
167 static inline struct pthread_specific_elem *
pthread_key_allocate_data(void)168 pthread_key_allocate_data(void)
169 {
170 struct pthread_specific_elem *new_data;
171 size_t bytes;
172 size_t pgmask;
173
174 bytes = _pthread_specific_bytes;
175 if (bytes == 0) {
176 pgmask = getpagesize() - 1;
177 bytes = sizeof(struct pthread_specific_elem) * PTHREAD_KEYS_MAX;
178 bytes = (bytes + pgmask) & ~pgmask;
179 _pthread_specific_bytes = bytes;
180 }
181 new_data = mmap(NULL, bytes, PROT_READ | PROT_WRITE,
182 MAP_ANON | MAP_PRIVATE, -1, 0);
183 if (new_data == MAP_FAILED)
184 new_data = NULL;
185
186 return (new_data);
187 }
188
189 int
_pthread_setspecific(pthread_key_t key,const void * value)190 _pthread_setspecific(pthread_key_t key, const void *value)
191 {
192 pthread_t pthread;
193 int ret = 0;
194
195 /* Point to the running thread: */
196 pthread = tls_get_curthread();
197
198 if (pthread->specific ||
199 (pthread->specific = pthread_key_allocate_data()) != NULL) {
200 if ((unsigned int)key < PTHREAD_KEYS_MAX) {
201 if (_thread_keytable[key].allocated) {
202 if (pthread->specific[key].data == NULL) {
203 if (value != NULL)
204 pthread->specific_data_count++;
205 } else if (value == NULL)
206 pthread->specific_data_count--;
207 pthread->specific[key].data = value;
208 pthread->specific[key].seqno =
209 _thread_keytable[key].seqno;
210 ret = 0;
211 } else {
212 ret = EINVAL;
213 }
214 } else {
215 ret = EINVAL;
216 }
217 } else {
218 ret = ENOMEM;
219 }
220 return (ret);
221 }
222
223 void *
_pthread_getspecific(pthread_key_t key)224 _pthread_getspecific(pthread_key_t key)
225 {
226 pthread_t pthread;
227 const void *data;
228
229 /* Point to the running thread: */
230 pthread = tls_get_curthread();
231
232 /* Check if there is specific data: */
233 if (pthread->specific != NULL && (unsigned int)key < PTHREAD_KEYS_MAX) {
234 /* Check if this key has been used before: */
235 if (_thread_keytable[key].allocated &&
236 (pthread->specific[key].seqno == _thread_keytable[key].seqno)) {
237 /* Return the value: */
238 data = pthread->specific[key].data;
239 } else {
240 /*
241 * This key has not been used before, so return NULL
242 * instead.
243 */
244 data = NULL;
245 }
246 } else
247 /* No specific data has been created, so just return NULL: */
248 data = NULL;
249 return __DECONST(void *, data);
250 }
251
252 __strong_reference(_pthread_key_create, pthread_key_create);
253 __strong_reference(_pthread_key_delete, pthread_key_delete);
254 __strong_reference(_pthread_getspecific, pthread_getspecific);
255 __strong_reference(_pthread_setspecific, pthread_setspecific);
256