lib/libthread_xu/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. 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  * $FreeBSD: src/lib/libpthread/thread/thr_spec.c,v 1.22 2004/07/13 22:49:58 davidxu Exp $
  33  * $DragonFly: src/lib/libthread_xu/thread/thr_spec.c,v 1.2 2005/03/29 19:26:20 joerg Exp $
  34  */
  35
  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 "thr_private.h"
  44
  45 /* Static variables: */
  46 struct pthread_key _thread_keytable[PTHREAD_KEYS_MAX];
  47
  48 __weak_reference(_pthread_key_create, pthread_key_create);
  49 __weak_reference(_pthread_key_delete, pthread_key_delete);
  50 __weak_reference(_pthread_getspecific, pthread_getspecific);
  51 __weak_reference(_pthread_setspecific, pthread_setspecific);
  52
  53
  54 int
  55 _pthread_key_create(pthread_key_t *key, void (*destructor) (void *))
  56 {
  57         struct pthread *curthread = tls_get_curthread();
  58         int i;
  59
  60         /* Lock the key table: */
  61         THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
  62         for (i = 0; i < PTHREAD_KEYS_MAX; i++) {
  63
  64                 if (_thread_keytable[i].allocated == 0) {
  65                         _thread_keytable[i].allocated = 1;
  66                         _thread_keytable[i].destructor = destructor;
  67                         _thread_keytable[i].seqno++;
  68
  69                         /* Unlock the key table: */
  70                         THR_LOCK_RELEASE(curthread, &_keytable_lock);
  71                         *key = i;
  72                         return (0);
  73                 }
  74
  75         }
  76         /* Unlock the key table: */
  77         THR_LOCK_RELEASE(curthread, &_keytable_lock);
  78         return (EAGAIN);
  79 }
  80
  81 int
  82 _pthread_key_delete(pthread_key_t key)
  83 {
  84         struct pthread *curthread = tls_get_curthread();
  85         int ret = 0;
  86
  87         if ((unsigned int)key < PTHREAD_KEYS_MAX) {
  88                 /* Lock the key table: */
  89                 THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
  90
  91                 if (_thread_keytable[key].allocated)
  92                         _thread_keytable[key].allocated = 0;
  93                 else
  94                         ret = EINVAL;
  95
  96                 /* Unlock the key table: */
  97                 THR_LOCK_RELEASE(curthread, &_keytable_lock);
  98         } else
  99                 ret = EINVAL;
 100         return (ret);
 101 }
 102
 103 void
 104 _thread_cleanupspecific(void)
 105 {
 106         struct pthread  *curthread = tls_get_curthread();
 107         void            (*destructor)( void *);
 108         void            *data = NULL;
 109         int             key;
 110         int             i;
 111
 112         if (curthread->specific == NULL)
 113                 return;
 114
 115         /* Lock the key table: */
 116         THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
 117         for (i = 0; (i < PTHREAD_DESTRUCTOR_ITERATIONS) &&
 118             (curthread->specific_data_count > 0); i++) {
 119                 for (key = 0; (key < PTHREAD_KEYS_MAX) &&
 120                     (curthread->specific_data_count > 0); key++) {
 121                         destructor = NULL;
 122
 123                         if (_thread_keytable[key].allocated &&
 124                             (curthread->specific[key].data != NULL)) {
 125                                 if (curthread->specific[key].seqno ==
 126                                     _thread_keytable[key].seqno) {
 127                                         data = (void *)
 128                                             curthread->specific[key].data;
 129                                         destructor = _thread_keytable[key].destructor;
 130                                 }
 131                                 curthread->specific[key].data = NULL;
 132                                 curthread->specific_data_count--;
 133                         }
 134
 135                         /*
 136                          * If there is a destructore, call it
 137                          * with the key table entry unlocked:
 138                          */
 139                         if (destructor != NULL) {
 140                                 /*
 141                                  * Don't hold the lock while calling the
 142                                  * destructor:
 143                                  */
 144                                 THR_LOCK_RELEASE(curthread, &_keytable_lock);
 145                                 destructor(data);
 146                                 THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
 147                         }
 148                 }
 149         }
 150         THR_LOCK_RELEASE(curthread, &_keytable_lock);
 151         free(curthread->specific);
 152         curthread->specific = NULL;
 153         if (curthread->specific_data_count > 0)
 154                 stderr_debug("Thread %p has exited with leftover "
 155                     "thread-specific data after %d destructor iterations\n",
 156                     curthread, PTHREAD_DESTRUCTOR_ITERATIONS);
 157 }
 158
 159 static inline struct pthread_specific_elem *
 160 pthread_key_allocate_data(void)
 161 {
 162         struct pthread_specific_elem *new_data;
 163
 164         new_data = (struct pthread_specific_elem *)
 165             malloc(sizeof(struct pthread_specific_elem) * PTHREAD_KEYS_MAX);
 166         if (new_data != NULL) {
 167                 memset((void *) new_data, 0,
 168                     sizeof(struct pthread_specific_elem) * PTHREAD_KEYS_MAX);
 169         }
 170         return (new_data);
 171 }
 172
 173 int
 174 _pthread_setspecific(pthread_key_t key, const void *value)
 175 {
 176         struct pthread  *pthread;
 177         int             ret = 0;
 178
 179         /* Point to the running thread: */
 180         pthread = tls_get_curthread();
 181
 182         if ((pthread->specific) ||
 183             (pthread->specific = pthread_key_allocate_data())) {
 184                 if ((unsigned int)key < PTHREAD_KEYS_MAX) {
 185                         if (_thread_keytable[key].allocated) {
 186                                 if (pthread->specific[key].data == NULL) {
 187                                         if (value != NULL)
 188                                                 pthread->specific_data_count++;
 189                                 } else if (value == NULL)
 190                                         pthread->specific_data_count--;
 191                                 pthread->specific[key].data = value;
 192                                 pthread->specific[key].seqno =
 193                                     _thread_keytable[key].seqno;
 194                                 ret = 0;
 195                         } else
 196                                 ret = EINVAL;
 197                 } else
 198                         ret = EINVAL;
 199         } else
 200                 ret = ENOMEM;
 201         return (ret);
 202 }
 203
 204 void *
 205 _pthread_getspecific(pthread_key_t key)
 206 {
 207         struct pthread  *pthread;
 208         void            *data;
 209
 210         /* Point to the running thread: */
 211         pthread = tls_get_curthread();
 212
 213         /* Check if there is specific data: */
 214         if (pthread->specific != NULL && (unsigned int)key < PTHREAD_KEYS_MAX) {
 215                 /* Check if this key has been used before: */
 216                 if (_thread_keytable[key].allocated &&
 217                     (pthread->specific[key].seqno == _thread_keytable[key].seqno)) {
 218                         /* Return the value: */
 219                         data = (void *) pthread->specific[key].data;
 220                 } else {
 221                         /*
 222                          * This key has not been used before, so return NULL
 223                          * instead:
 224                          */
 225                         data = NULL;
 226                 }
 227         } else
 228                 /* No specific data has been created, so just return NULL: */
 229                 data = NULL;
 230         return (data);
 231 }