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; 54 int i; 55 56 /* User program might be preparing to call pthread_create() */ 57 _thr_check_init(); 58 59 curthread = tls_get_curthread(); 60 61 /* Lock the key table: */ 62 THR_LOCK_ACQUIRE(curthread, &_keytable_lock); 63 for (i = 0; i < PTHREAD_KEYS_MAX; i++) { 64 65 if (_thread_keytable[i].allocated == 0) { 66 _thread_keytable[i].allocated = 1; 67 _thread_keytable[i].destructor = destructor; 68 _thread_keytable[i].seqno++; 69 70 /* Unlock the key table: */ 71 THR_LOCK_RELEASE(curthread, &_keytable_lock); 72 *key = i; 73 return (0); 74 } 75 76 } 77 /* Unlock the key table: */ 78 THR_LOCK_RELEASE(curthread, &_keytable_lock); 79 return (EAGAIN); 80 } 81 82 int 83 _pthread_key_delete(pthread_key_t key) 84 { 85 struct pthread *curthread = tls_get_curthread(); 86 int ret = 0; 87 88 if ((unsigned int)key < PTHREAD_KEYS_MAX) { 89 /* Lock the key table: */ 90 THR_LOCK_ACQUIRE(curthread, &_keytable_lock); 91 92 if (_thread_keytable[key].allocated) 93 _thread_keytable[key].allocated = 0; 94 else 95 ret = EINVAL; 96 97 /* Unlock the key table: */ 98 THR_LOCK_RELEASE(curthread, &_keytable_lock); 99 } else 100 ret = EINVAL; 101 return (ret); 102 } 103 104 void 105 _thread_cleanupspecific(void) 106 { 107 struct pthread *curthread = tls_get_curthread(); 108 void (*destructor)( void *); 109 const void *data = NULL; 110 int key; 111 int i; 112 113 if (curthread->specific == NULL) 114 return; 115 116 /* Lock the key table: */ 117 THR_LOCK_ACQUIRE(curthread, &_keytable_lock); 118 for (i = 0; (i < PTHREAD_DESTRUCTOR_ITERATIONS) && 119 (curthread->specific_data_count > 0); i++) { 120 for (key = 0; (key < PTHREAD_KEYS_MAX) && 121 (curthread->specific_data_count > 0); key++) { 122 destructor = NULL; 123 124 if (_thread_keytable[key].allocated && 125 (curthread->specific[key].data != NULL)) { 126 if (curthread->specific[key].seqno == 127 _thread_keytable[key].seqno) { 128 data = 129 curthread->specific[key].data; 130 destructor = _thread_keytable[key].destructor; 131 } 132 curthread->specific[key].data = NULL; 133 curthread->specific_data_count--; 134 } else if (curthread->specific[key].data != NULL) { 135 /* 136 * This can happen if the key is deleted via 137 * pthread_key_delete without first setting the value 138 * to NULL in all threads. POSIX says that the 139 * destructor is not invoked in this case. 140 */ 141 curthread->specific[key].data = NULL; 142 curthread->specific_data_count--; 143 } 144 145 /* 146 * If there is a destructor, call it 147 * with the key table entry unlocked: 148 */ 149 if (destructor != NULL) { 150 /* 151 * Don't hold the lock while calling the 152 * destructor: 153 */ 154 THR_LOCK_RELEASE(curthread, &_keytable_lock); 155 destructor(__DECONST(void *, data)); 156 THR_LOCK_ACQUIRE(curthread, &_keytable_lock); 157 } 158 } 159 } 160 THR_LOCK_RELEASE(curthread, &_keytable_lock); 161 free(curthread->specific); 162 curthread->specific = NULL; 163 if (curthread->specific_data_count > 0) 164 stderr_debug("Thread %p has exited with leftover " 165 "thread-specific data after %d destructor iterations\n", 166 curthread, PTHREAD_DESTRUCTOR_ITERATIONS); 167 } 168 169 static inline struct pthread_specific_elem * 170 pthread_key_allocate_data(void) 171 { 172 struct pthread_specific_elem *new_data; 173 174 new_data = (struct pthread_specific_elem *) 175 malloc(sizeof(struct pthread_specific_elem) * PTHREAD_KEYS_MAX); 176 if (new_data != NULL) { 177 memset((void *) new_data, 0, 178 sizeof(struct pthread_specific_elem) * PTHREAD_KEYS_MAX); 179 } 180 return (new_data); 181 } 182 183 int 184 _pthread_setspecific(pthread_key_t key, const void *value) 185 { 186 struct pthread *pthread; 187 int ret = 0; 188 189 /* Point to the running thread: */ 190 pthread = tls_get_curthread(); 191 192 if ((pthread->specific) || 193 (pthread->specific = pthread_key_allocate_data())) { 194 if ((unsigned int)key < PTHREAD_KEYS_MAX) { 195 if (_thread_keytable[key].allocated) { 196 if (pthread->specific[key].data == NULL) { 197 if (value != NULL) 198 pthread->specific_data_count++; 199 } else if (value == NULL) 200 pthread->specific_data_count--; 201 pthread->specific[key].data = value; 202 pthread->specific[key].seqno = 203 _thread_keytable[key].seqno; 204 ret = 0; 205 } else 206 ret = EINVAL; 207 } else 208 ret = EINVAL; 209 } else 210 ret = ENOMEM; 211 return (ret); 212 } 213 214 void * 215 _pthread_getspecific(pthread_key_t key) 216 { 217 struct pthread *pthread; 218 const void *data; 219 220 /* Point to the running thread: */ 221 pthread = tls_get_curthread(); 222 223 /* Check if there is specific data: */ 224 if (pthread->specific != NULL && (unsigned int)key < PTHREAD_KEYS_MAX) { 225 /* Check if this key has been used before: */ 226 if (_thread_keytable[key].allocated && 227 (pthread->specific[key].seqno == _thread_keytable[key].seqno)) { 228 /* Return the value: */ 229 data = pthread->specific[key].data; 230 } else { 231 /* 232 * This key has not been used before, so return NULL 233 * instead: 234 */ 235 data = NULL; 236 } 237 } else 238 /* No specific data has been created, so just return NULL: */ 239 data = NULL; 240 return __DECONST(void *, data); 241 } 242 243 __strong_reference(_pthread_key_create, pthread_key_create); 244 __strong_reference(_pthread_key_delete, pthread_key_delete); 245 __strong_reference(_pthread_getspecific, pthread_getspecific); 246 __strong_reference(_pthread_setspecific, pthread_setspecific); 247 248