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 } else if (curthread->specific[key].data != NULL) { 130 /* 131 * This can happen if the key is deleted via 132 * pthread_key_delete without first setting the value 133 * to NULL in all threads. POSIX says that the 134 * destructor is not invoked in this case. 135 */ 136 curthread->specific[key].data = NULL; 137 curthread->specific_data_count--; 138 } 139 140 /* 141 * If there is a destructor, call it 142 * with the key table entry unlocked: 143 */ 144 if (destructor != NULL) { 145 /* 146 * Don't hold the lock while calling the 147 * destructor: 148 */ 149 THR_LOCK_RELEASE(curthread, &_keytable_lock); 150 destructor(__DECONST(void *, data)); 151 THR_LOCK_ACQUIRE(curthread, &_keytable_lock); 152 } 153 } 154 } 155 THR_LOCK_RELEASE(curthread, &_keytable_lock); 156 free(curthread->specific); 157 curthread->specific = NULL; 158 if (curthread->specific_data_count > 0) 159 stderr_debug("Thread %p has exited with leftover " 160 "thread-specific data after %d destructor iterations\n", 161 curthread, PTHREAD_DESTRUCTOR_ITERATIONS); 162 } 163 164 static inline struct pthread_specific_elem * 165 pthread_key_allocate_data(void) 166 { 167 struct pthread_specific_elem *new_data; 168 169 new_data = (struct pthread_specific_elem *) 170 malloc(sizeof(struct pthread_specific_elem) * PTHREAD_KEYS_MAX); 171 if (new_data != NULL) { 172 memset((void *) new_data, 0, 173 sizeof(struct pthread_specific_elem) * PTHREAD_KEYS_MAX); 174 } 175 return (new_data); 176 } 177 178 int 179 _pthread_setspecific(pthread_key_t key, const void *value) 180 { 181 struct pthread *pthread; 182 int ret = 0; 183 184 /* Point to the running thread: */ 185 pthread = tls_get_curthread(); 186 187 if ((pthread->specific) || 188 (pthread->specific = pthread_key_allocate_data())) { 189 if ((unsigned int)key < PTHREAD_KEYS_MAX) { 190 if (_thread_keytable[key].allocated) { 191 if (pthread->specific[key].data == NULL) { 192 if (value != NULL) 193 pthread->specific_data_count++; 194 } else if (value == NULL) 195 pthread->specific_data_count--; 196 pthread->specific[key].data = value; 197 pthread->specific[key].seqno = 198 _thread_keytable[key].seqno; 199 ret = 0; 200 } else 201 ret = EINVAL; 202 } else 203 ret = EINVAL; 204 } else 205 ret = ENOMEM; 206 return (ret); 207 } 208 209 void * 210 _pthread_getspecific(pthread_key_t key) 211 { 212 struct pthread *pthread; 213 const void *data; 214 215 /* Point to the running thread: */ 216 pthread = tls_get_curthread(); 217 218 /* Check if there is specific data: */ 219 if (pthread->specific != NULL && (unsigned int)key < PTHREAD_KEYS_MAX) { 220 /* Check if this key has been used before: */ 221 if (_thread_keytable[key].allocated && 222 (pthread->specific[key].seqno == _thread_keytable[key].seqno)) { 223 /* Return the value: */ 224 data = pthread->specific[key].data; 225 } else { 226 /* 227 * This key has not been used before, so return NULL 228 * instead: 229 */ 230 data = NULL; 231 } 232 } else 233 /* No specific data has been created, so just return NULL: */ 234 data = NULL; 235 return __DECONST(void *, data); 236 } 237 238 __strong_reference(_pthread_key_create, pthread_key_create); 239 __strong_reference(_pthread_key_delete, pthread_key_delete); 240 __strong_reference(_pthread_getspecific, pthread_getspecific); 241 __strong_reference(_pthread_setspecific, pthread_setspecific); 242 243