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 * $FreeBSD: src/lib/libpthread/thread/thr_spec.c,v 1.22 2004/07/13 22:49:58 davidxu Exp $ 33 * $DragonFly: src/lib/libthread_xu/thread/thr_spec.c,v 1.4 2006/04/05 12:12:23 davidxu Exp $ 34 */ 35 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 "thr_private.h" 44 45 struct pthread_key _thread_keytable[PTHREAD_KEYS_MAX]; 46 umtx_t _keytable_lock; 47 48 int 49 _pthread_key_create(pthread_key_t *key, void (*destructor) (void *)) 50 { 51 struct pthread *curthread = tls_get_curthread(); 52 int i; 53 54 /* Lock the key table: */ 55 THR_LOCK_ACQUIRE(curthread, &_keytable_lock); 56 for (i = 0; i < PTHREAD_KEYS_MAX; i++) { 57 58 if (_thread_keytable[i].allocated == 0) { 59 _thread_keytable[i].allocated = 1; 60 _thread_keytable[i].destructor = destructor; 61 _thread_keytable[i].seqno++; 62 63 /* Unlock the key table: */ 64 THR_LOCK_RELEASE(curthread, &_keytable_lock); 65 *key = i; 66 return (0); 67 } 68 69 } 70 /* Unlock the key table: */ 71 THR_LOCK_RELEASE(curthread, &_keytable_lock); 72 return (EAGAIN); 73 } 74 75 int 76 _pthread_key_delete(pthread_key_t key) 77 { 78 struct pthread *curthread = tls_get_curthread(); 79 int ret = 0; 80 81 if ((unsigned int)key < PTHREAD_KEYS_MAX) { 82 /* Lock the key table: */ 83 THR_LOCK_ACQUIRE(curthread, &_keytable_lock); 84 85 if (_thread_keytable[key].allocated) 86 _thread_keytable[key].allocated = 0; 87 else 88 ret = EINVAL; 89 90 /* Unlock the key table: */ 91 THR_LOCK_RELEASE(curthread, &_keytable_lock); 92 } else 93 ret = EINVAL; 94 return (ret); 95 } 96 97 void 98 _thread_cleanupspecific(void) 99 { 100 struct pthread *curthread = tls_get_curthread(); 101 void (*destructor)( void *); 102 void *data = NULL; 103 int key; 104 int i; 105 106 if (curthread->specific == NULL) 107 return; 108 109 /* Lock the key table: */ 110 THR_LOCK_ACQUIRE(curthread, &_keytable_lock); 111 for (i = 0; (i < PTHREAD_DESTRUCTOR_ITERATIONS) && 112 (curthread->specific_data_count > 0); i++) { 113 for (key = 0; (key < PTHREAD_KEYS_MAX) && 114 (curthread->specific_data_count > 0); key++) { 115 destructor = NULL; 116 117 if (_thread_keytable[key].allocated && 118 (curthread->specific[key].data != NULL)) { 119 if (curthread->specific[key].seqno == 120 _thread_keytable[key].seqno) { 121 data = (void *) 122 curthread->specific[key].data; 123 destructor = _thread_keytable[key].destructor; 124 } 125 curthread->specific[key].data = NULL; 126 curthread->specific_data_count--; 127 } 128 129 /* 130 * If there is a destructore, call it 131 * with the key table entry unlocked: 132 */ 133 if (destructor != NULL) { 134 /* 135 * Don't hold the lock while calling the 136 * destructor: 137 */ 138 THR_LOCK_RELEASE(curthread, &_keytable_lock); 139 destructor(data); 140 THR_LOCK_ACQUIRE(curthread, &_keytable_lock); 141 } 142 } 143 } 144 THR_LOCK_RELEASE(curthread, &_keytable_lock); 145 free(curthread->specific); 146 curthread->specific = NULL; 147 if (curthread->specific_data_count > 0) 148 stderr_debug("Thread %p has exited with leftover " 149 "thread-specific data after %d destructor iterations\n", 150 curthread, PTHREAD_DESTRUCTOR_ITERATIONS); 151 } 152 153 static inline struct pthread_specific_elem * 154 pthread_key_allocate_data(void) 155 { 156 struct pthread_specific_elem *new_data; 157 158 new_data = (struct pthread_specific_elem *) 159 malloc(sizeof(struct pthread_specific_elem) * PTHREAD_KEYS_MAX); 160 if (new_data != NULL) { 161 memset((void *) new_data, 0, 162 sizeof(struct pthread_specific_elem) * PTHREAD_KEYS_MAX); 163 } 164 return (new_data); 165 } 166 167 int 168 _pthread_setspecific(pthread_key_t key, const void *value) 169 { 170 struct pthread *pthread; 171 int ret = 0; 172 173 /* Point to the running thread: */ 174 pthread = tls_get_curthread(); 175 176 if ((pthread->specific) || 177 (pthread->specific = pthread_key_allocate_data())) { 178 if ((unsigned int)key < PTHREAD_KEYS_MAX) { 179 if (_thread_keytable[key].allocated) { 180 if (pthread->specific[key].data == NULL) { 181 if (value != NULL) 182 pthread->specific_data_count++; 183 } else if (value == NULL) 184 pthread->specific_data_count--; 185 pthread->specific[key].data = value; 186 pthread->specific[key].seqno = 187 _thread_keytable[key].seqno; 188 ret = 0; 189 } else 190 ret = EINVAL; 191 } else 192 ret = EINVAL; 193 } else 194 ret = ENOMEM; 195 return (ret); 196 } 197 198 void * 199 _pthread_getspecific(pthread_key_t key) 200 { 201 struct pthread *pthread; 202 void *data; 203 204 /* Point to the running thread: */ 205 pthread = tls_get_curthread(); 206 207 /* Check if there is specific data: */ 208 if (pthread->specific != NULL && (unsigned int)key < PTHREAD_KEYS_MAX) { 209 /* Check if this key has been used before: */ 210 if (_thread_keytable[key].allocated && 211 (pthread->specific[key].seqno == _thread_keytable[key].seqno)) { 212 /* Return the value: */ 213 data = (void *) pthread->specific[key].data; 214 } else { 215 /* 216 * This key has not been used before, so return NULL 217 * instead: 218 */ 219 data = NULL; 220 } 221 } else 222 /* No specific data has been created, so just return NULL: */ 223 data = NULL; 224 return (data); 225 } 226 227 __strong_reference(_pthread_key_create, pthread_key_create); 228 __strong_reference(_pthread_key_delete, pthread_key_delete); 229 __strong_reference(_pthread_getspecific, pthread_getspecific); 230 __strong_reference(_pthread_setspecific, pthread_setspecific); 231 232