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 * $DragonFly: src/lib/libthread_xu/thread/thr_spec.c,v 1.5 2006/04/06 13:03:09 davidxu Exp $ 30 */ 31 32 #include "namespace.h" 33 #include <machine/tls.h> 34 35 #include <signal.h> 36 #include <stdlib.h> 37 #include <string.h> 38 #include <errno.h> 39 #include <pthread.h> 40 #include "un-namespace.h" 41 42 #include "thr_private.h" 43 44 struct pthread_key _thread_keytable[PTHREAD_KEYS_MAX]; 45 umtx_t _keytable_lock; 46 47 int 48 _pthread_key_create(pthread_key_t *key, void (*destructor) (void *)) 49 { 50 struct pthread *curthread; 51 int i; 52 53 /* User program might be preparing to call pthread_create() */ 54 _thr_check_init(); 55 56 curthread = tls_get_curthread(); 57 58 /* Lock the key table: */ 59 THR_LOCK_ACQUIRE(curthread, &_keytable_lock); 60 for (i = 0; i < PTHREAD_KEYS_MAX; i++) { 61 62 if (_thread_keytable[i].allocated == 0) { 63 _thread_keytable[i].allocated = 1; 64 _thread_keytable[i].destructor = destructor; 65 _thread_keytable[i].seqno++; 66 67 /* Unlock the key table: */ 68 THR_LOCK_RELEASE(curthread, &_keytable_lock); 69 *key = i; 70 return (0); 71 } 72 73 } 74 /* Unlock the key table: */ 75 THR_LOCK_RELEASE(curthread, &_keytable_lock); 76 return (EAGAIN); 77 } 78 79 int 80 _pthread_key_delete(pthread_key_t key) 81 { 82 struct pthread *curthread = tls_get_curthread(); 83 int ret = 0; 84 85 if ((unsigned int)key < PTHREAD_KEYS_MAX) { 86 /* Lock the key table: */ 87 THR_LOCK_ACQUIRE(curthread, &_keytable_lock); 88 89 if (_thread_keytable[key].allocated) 90 _thread_keytable[key].allocated = 0; 91 else 92 ret = EINVAL; 93 94 /* Unlock the key table: */ 95 THR_LOCK_RELEASE(curthread, &_keytable_lock); 96 } else 97 ret = EINVAL; 98 return (ret); 99 } 100 101 void 102 _thread_cleanupspecific(void) 103 { 104 struct pthread *curthread = tls_get_curthread(); 105 void (*destructor)( void *); 106 const void *data = NULL; 107 int key; 108 int i; 109 110 if (curthread->specific == NULL) 111 return; 112 113 /* Lock the key table: */ 114 THR_LOCK_ACQUIRE(curthread, &_keytable_lock); 115 for (i = 0; (i < PTHREAD_DESTRUCTOR_ITERATIONS) && 116 (curthread->specific_data_count > 0); i++) { 117 for (key = 0; (key < PTHREAD_KEYS_MAX) && 118 (curthread->specific_data_count > 0); key++) { 119 destructor = NULL; 120 121 if (_thread_keytable[key].allocated && 122 (curthread->specific[key].data != NULL)) { 123 if (curthread->specific[key].seqno == 124 _thread_keytable[key].seqno) { 125 data = 126 curthread->specific[key].data; 127 destructor = _thread_keytable[key].destructor; 128 } 129 curthread->specific[key].data = NULL; 130 curthread->specific_data_count--; 131 } else if (curthread->specific[key].data != NULL) { 132 /* 133 * This can happen if the key is deleted via 134 * pthread_key_delete without first setting the value 135 * to NULL in all threads. POSIX says that the 136 * destructor is not invoked in this case. 137 */ 138 curthread->specific[key].data = NULL; 139 curthread->specific_data_count--; 140 } 141 142 /* 143 * If there is a destructor, call it 144 * with the key table entry unlocked: 145 */ 146 if (destructor != NULL) { 147 /* 148 * Don't hold the lock while calling the 149 * destructor: 150 */ 151 THR_LOCK_RELEASE(curthread, &_keytable_lock); 152 destructor(__DECONST(void *, data)); 153 THR_LOCK_ACQUIRE(curthread, &_keytable_lock); 154 } 155 } 156 } 157 THR_LOCK_RELEASE(curthread, &_keytable_lock); 158 free(curthread->specific); 159 curthread->specific = NULL; 160 if (curthread->specific_data_count > 0) 161 stderr_debug("Thread %p has exited with leftover " 162 "thread-specific data after %d destructor iterations\n", 163 curthread, PTHREAD_DESTRUCTOR_ITERATIONS); 164 } 165 166 static inline struct pthread_specific_elem * 167 pthread_key_allocate_data(void) 168 { 169 struct pthread_specific_elem *new_data; 170 171 new_data = (struct pthread_specific_elem *) 172 malloc(sizeof(struct pthread_specific_elem) * PTHREAD_KEYS_MAX); 173 if (new_data != NULL) { 174 memset((void *) new_data, 0, 175 sizeof(struct pthread_specific_elem) * PTHREAD_KEYS_MAX); 176 } 177 return (new_data); 178 } 179 180 int 181 _pthread_setspecific(pthread_key_t key, const void *value) 182 { 183 struct pthread *pthread; 184 int ret = 0; 185 186 /* Point to the running thread: */ 187 pthread = tls_get_curthread(); 188 189 if ((pthread->specific) || 190 (pthread->specific = pthread_key_allocate_data())) { 191 if ((unsigned int)key < PTHREAD_KEYS_MAX) { 192 if (_thread_keytable[key].allocated) { 193 if (pthread->specific[key].data == NULL) { 194 if (value != NULL) 195 pthread->specific_data_count++; 196 } else if (value == NULL) 197 pthread->specific_data_count--; 198 pthread->specific[key].data = value; 199 pthread->specific[key].seqno = 200 _thread_keytable[key].seqno; 201 ret = 0; 202 } else 203 ret = EINVAL; 204 } else 205 ret = EINVAL; 206 } else 207 ret = ENOMEM; 208 return (ret); 209 } 210 211 void * 212 _pthread_getspecific(pthread_key_t key) 213 { 214 struct pthread *pthread; 215 const void *data; 216 217 /* Point to the running thread: */ 218 pthread = tls_get_curthread(); 219 220 /* Check if there is specific data: */ 221 if (pthread->specific != NULL && (unsigned int)key < PTHREAD_KEYS_MAX) { 222 /* Check if this key has been used before: */ 223 if (_thread_keytable[key].allocated && 224 (pthread->specific[key].seqno == _thread_keytable[key].seqno)) { 225 /* Return the value: */ 226 data = pthread->specific[key].data; 227 } else { 228 /* 229 * This key has not been used before, so return NULL 230 * instead: 231 */ 232 data = NULL; 233 } 234 } else 235 /* No specific data has been created, so just return NULL: */ 236 data = NULL; 237 return __DECONST(void *, data); 238 } 239 240 __strong_reference(_pthread_key_create, pthread_key_create); 241 __strong_reference(_pthread_key_delete, pthread_key_delete); 242 __strong_reference(_pthread_getspecific, pthread_getspecific); 243 __strong_reference(_pthread_setspecific, pthread_setspecific); 244 245