lib/libkse/thread/thr_spec.c

   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  * $FreeBSD$
  30  */
  31 #include <signal.h>
  32 #include <stdlib.h>
  33 #include <string.h>
  34 #include <errno.h>
  35 #include <pthread.h>
  36
  37 #include "thr_private.h"
  38
  39
  40 struct pthread_key _thread_keytable[PTHREAD_KEYS_MAX];
  41
  42 /*
  43  * XXX - This breaks the linker if LT10_COMPAT_DEFAULT doesn't
  44  * also include a weak reference to the default symbol.
  45  */
  46 LT10_COMPAT_PRIVATE(_thread_keytable);
  47
  48 LT10_COMPAT_PRIVATE(_pthread_key_create);
  49 LT10_COMPAT_DEFAULT(pthread_key_create);
  50 LT10_COMPAT_PRIVATE(_pthread_key_delete);
  51 LT10_COMPAT_DEFAULT(pthread_key_delete);
  52 LT10_COMPAT_PRIVATE(_pthread_getspecific);
  53 LT10_COMPAT_DEFAULT(pthread_getspecific);
  54 LT10_COMPAT_PRIVATE(_pthread_setspecific);
  55 LT10_COMPAT_DEFAULT(pthread_setspecific);
  56
  57 __weak_reference(_pthread_key_create, pthread_key_create);
  58 __weak_reference(_pthread_key_delete, pthread_key_delete);
  59 __weak_reference(_pthread_getspecific, pthread_getspecific);
  60 __weak_reference(_pthread_setspecific, pthread_setspecific);
  61
  62
  63 int
  64 _pthread_key_create(pthread_key_t *key, void (*destructor) (void *))
  65 {
  66         struct pthread *curthread;
  67         int i;
  68
  69         if (_thr_initial == NULL)
  70                 _libpthread_init(NULL);
  71         curthread = _get_curthread();
  72
  73         /* Lock the key table: */
  74         THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
  75         for (i = 0; i < PTHREAD_KEYS_MAX; i++) {
  76
  77                 if (_thread_keytable[i].allocated == 0) {
  78                         _thread_keytable[i].allocated = 1;
  79                         _thread_keytable[i].destructor = destructor;
  80                         _thread_keytable[i].seqno++;
  81
  82                         /* Unlock the key table: */
  83                         THR_LOCK_RELEASE(curthread, &_keytable_lock);
  84                         *key = i;
  85                         return (0);
  86                 }
  87
  88         }
  89         /* Unlock the key table: */
  90         THR_LOCK_RELEASE(curthread, &_keytable_lock);
  91         return (EAGAIN);
  92 }
  93
  94 int
  95 _pthread_key_delete(pthread_key_t key)
  96 {
  97         struct pthread *curthread = _get_curthread();
  98         int ret = 0;
  99
 100         if ((unsigned int)key < PTHREAD_KEYS_MAX) {
 101                 /* Lock the key table: */
 102                 THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
 103
 104                 if (_thread_keytable[key].allocated)
 105                         _thread_keytable[key].allocated = 0;
 106                 else
 107                         ret = EINVAL;
 108
 109                 /* Unlock the key table: */
 110                 THR_LOCK_RELEASE(curthread, &_keytable_lock);
 111         } else
 112                 ret = EINVAL;
 113         return (ret);
 114 }
 115
 116 void
 117 _thread_cleanupspecific(void)
 118 {
 119         struct pthread  *curthread = _get_curthread();
 120         void            (*destructor)( void *);
 121         void            *data = NULL;
 122         int             key;
 123         int             i;
 124
 125         if (curthread->specific == NULL)
 126                 return;
 127
 128         /* Lock the key table: */
 129         THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
 130         for (i = 0; (i < PTHREAD_DESTRUCTOR_ITERATIONS) &&
 131             (curthread->specific_data_count > 0); i++) {
 132                 for (key = 0; (key < PTHREAD_KEYS_MAX) &&
 133                     (curthread->specific_data_count > 0); key++) {
 134                         destructor = NULL;
 135
 136                         if (_thread_keytable[key].allocated &&
 137                             (curthread->specific[key].data != NULL)) {
 138                                 if (curthread->specific[key].seqno ==
 139                                     _thread_keytable[key].seqno) {
 140                                         data = (void *)
 141                                             curthread->specific[key].data;
 142                                         destructor = _thread_keytable[key].destructor;
 143                                 }
 144                                 curthread->specific[key].data = NULL;
 145                                 curthread->specific_data_count--;
 146                         }
 147
 148                         /*
 149                          * If there is a destructore, call it
 150                          * with the key table entry unlocked:
 151                          */
 152                         if (destructor != NULL) {
 153                                 /*
 154                                  * Don't hold the lock while calling the
 155                                  * destructor:
 156                                  */
 157                                 THR_LOCK_RELEASE(curthread, &_keytable_lock);
 158                                 destructor(data);
 159                                 THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
 160                         }
 161                 }
 162         }
 163         THR_LOCK_RELEASE(curthread, &_keytable_lock);
 164         free(curthread->specific);
 165         curthread->specific = NULL;
 166         if (curthread->specific_data_count > 0)
 167                 stderr_debug("Thread %p has exited with leftover "
 168                     "thread-specific data after %d destructor iterations\n",
 169                     curthread, PTHREAD_DESTRUCTOR_ITERATIONS);
 170 }
 171
 172 static inline struct pthread_specific_elem *
 173 pthread_key_allocate_data(void)
 174 {
 175         struct pthread_specific_elem *new_data;
 176
 177         new_data = (struct pthread_specific_elem *)
 178             malloc(sizeof(struct pthread_specific_elem) * PTHREAD_KEYS_MAX);
 179         if (new_data != NULL) {
 180                 memset((void *) new_data, 0,
 181                     sizeof(struct pthread_specific_elem) * PTHREAD_KEYS_MAX);
 182         }
 183         return (new_data);
 184 }
 185
 186 int
 187 _pthread_setspecific(pthread_key_t key, const void *value)
 188 {
 189         struct pthread  *pthread;
 190         int             ret = 0;
 191
 192         /* Point to the running thread: */
 193         pthread = _get_curthread();
 194
 195         if ((pthread->specific) ||
 196             (pthread->specific = pthread_key_allocate_data())) {
 197                 if ((unsigned int)key < PTHREAD_KEYS_MAX) {
 198                         if (_thread_keytable[key].allocated) {
 199                                 if (pthread->specific[key].data == NULL) {
 200                                         if (value != NULL)
 201                                                 pthread->specific_data_count++;
 202                                 } else if (value == NULL)
 203                                         pthread->specific_data_count--;
 204                                 pthread->specific[key].data = value;
 205                                 pthread->specific[key].seqno =
 206                                     _thread_keytable[key].seqno;
 207                                 ret = 0;
 208                         } else
 209                                 ret = EINVAL;
 210                 } else
 211                         ret = EINVAL;
 212         } else
 213                 ret = ENOMEM;
 214         return (ret);
 215 }
 216
 217 void *
 218 _pthread_getspecific(pthread_key_t key)
 219 {
 220         struct pthread  *pthread;
 221         void            *data;
 222
 223         /* Point to the running thread: */
 224         pthread = _get_curthread();
 225
 226         /* Check if there is specific data: */
 227         if (pthread->specific != NULL && (unsigned int)key < PTHREAD_KEYS_MAX) {
 228                 /* Check if this key has been used before: */
 229                 if (_thread_keytable[key].allocated &&
 230                     (pthread->specific[key].seqno == _thread_keytable[key].seqno)) {
 231                         /* Return the value: */
 232                         data = (void *) pthread->specific[key].data;
 233                 } else {
 234                         /*
 235                          * This key has not been used before, so return NULL
 236                          * instead:
 237                          */
 238                         data = NULL;
 239                 }
 240         } else
 241                 /* No specific data has been created, so just return NULL: */
 242                 data = NULL;
 243         return (data);
 244 }