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 = 0; i < PTHREAD_KEYS_MAX; i++) { 60 61 if (_thread_keytable[i].allocated == 0) { 62 _thread_keytable[i].allocated = 1; 63 _thread_keytable[i].destructor = destructor; 64 _thread_keytable[i].seqno++; 65 66 /* Unlock the key table: */ 67 THR_LOCK_RELEASE(curthread, &_keytable_lock); 68 *key = i; 69 return (0); 70 } 71 72 } 73 /* Unlock the key table: */ 74 THR_LOCK_RELEASE(curthread, &_keytable_lock); 75 return (EAGAIN); 76 } 77 78 int 79 _pthread_key_delete(pthread_key_t key) 80 { 81 pthread_t curthread = tls_get_curthread(); 82 int ret = 0; 83 84 if ((unsigned int)key < PTHREAD_KEYS_MAX) { 85 /* Lock the key table: */ 86 THR_LOCK_ACQUIRE(curthread, &_keytable_lock); 87 88 if (_thread_keytable[key].allocated) 89 _thread_keytable[key].allocated = 0; 90 else 91 ret = EINVAL; 92 93 /* Unlock the key table: */ 94 THR_LOCK_RELEASE(curthread, &_keytable_lock); 95 } else 96 ret = EINVAL; 97 return (ret); 98 } 99 100 void 101 _thread_cleanupspecific(void) 102 { 103 pthread_t curthread = tls_get_curthread(); 104 void (*destructor)( void *); 105 const void *data = NULL; 106 int key; 107 int i; 108 109 if (curthread->specific == NULL) 110 return; 111 112 /* Lock the key table: */ 113 THR_LOCK_ACQUIRE(curthread, &_keytable_lock); 114 for (i = 0; (i < PTHREAD_DESTRUCTOR_ITERATIONS) && 115 (curthread->specific_data_count > 0); i++) { 116 for (key = 0; (key < PTHREAD_KEYS_MAX) && 117 (curthread->specific_data_count > 0); key++) { 118 destructor = NULL; 119 120 if (_thread_keytable[key].allocated && 121 (curthread->specific[key].data != NULL)) { 122 if (curthread->specific[key].seqno == 123 _thread_keytable[key].seqno) { 124 data = 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); 156 157 munmap(curthread->specific, _pthread_specific_bytes); 158 curthread->specific = NULL; 159 160 if (curthread->specific_data_count > 0) { 161 stderr_debug("Thread %p has exited with leftover " 162 "thread-specific data after %d destructor " 163 "iterations\n", 164 curthread, PTHREAD_DESTRUCTOR_ITERATIONS); 165 } 166 } 167 168 static inline struct pthread_specific_elem * 169 pthread_key_allocate_data(void) 170 { 171 struct pthread_specific_elem *new_data; 172 size_t bytes; 173 size_t pgmask; 174 175 bytes = _pthread_specific_bytes; 176 if (bytes == 0) { 177 pgmask = getpagesize() - 1; 178 bytes = sizeof(struct pthread_specific_elem) * PTHREAD_KEYS_MAX; 179 bytes = (bytes + pgmask) & ~pgmask; 180 _pthread_specific_bytes = bytes; 181 } 182 new_data = mmap(NULL, bytes, PROT_READ | PROT_WRITE, 183 MAP_ANON | MAP_PRIVATE, -1, 0); 184 if (new_data == MAP_FAILED) 185 new_data = NULL; 186 187 return (new_data); 188 } 189 190 int 191 _pthread_setspecific(pthread_key_t key, const void *value) 192 { 193 pthread_t pthread; 194 int ret = 0; 195 196 /* Point to the running thread: */ 197 pthread = tls_get_curthread(); 198 199 if (pthread->specific || 200 (pthread->specific = pthread_key_allocate_data()) != NULL) { 201 if ((unsigned int)key < PTHREAD_KEYS_MAX) { 202 if (_thread_keytable[key].allocated) { 203 if (pthread->specific[key].data == NULL) { 204 if (value != NULL) 205 pthread->specific_data_count++; 206 } else if (value == NULL) 207 pthread->specific_data_count--; 208 pthread->specific[key].data = value; 209 pthread->specific[key].seqno = 210 _thread_keytable[key].seqno; 211 ret = 0; 212 } else { 213 ret = EINVAL; 214 } 215 } else { 216 ret = EINVAL; 217 } 218 } else { 219 ret = ENOMEM; 220 } 221 return (ret); 222 } 223 224 void * 225 _pthread_getspecific(pthread_key_t key) 226 { 227 pthread_t pthread; 228 const void *data; 229 230 /* Point to the running thread: */ 231 pthread = tls_get_curthread(); 232 233 /* Check if there is specific data: */ 234 if (pthread->specific != NULL && (unsigned int)key < PTHREAD_KEYS_MAX) { 235 /* Check if this key has been used before: */ 236 if (_thread_keytable[key].allocated && 237 (pthread->specific[key].seqno == _thread_keytable[key].seqno)) { 238 /* Return the value: */ 239 data = pthread->specific[key].data; 240 } else { 241 /* 242 * This key has not been used before, so return NULL 243 * instead. 244 */ 245 data = NULL; 246 } 247 } else 248 /* No specific data has been created, so just return NULL: */ 249 data = NULL; 250 return __DECONST(void *, data); 251 } 252 253 __strong_reference(_pthread_key_create, pthread_key_create); 254 __strong_reference(_pthread_key_delete, pthread_key_delete); 255 __strong_reference(_pthread_getspecific, pthread_getspecific); 256 __strong_reference(_pthread_setspecific, pthread_setspecific); 257