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 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 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 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 * 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 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 * 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