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 1.4 2006/04/05 12:12:23 davidxu 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 struct pthread_key _thread_keytable[PTHREAD_KEYS_MAX];
  46 umtx_t  _keytable_lock;
  47
  48 int
  49 _pthread_key_create(pthread_key_t *key, void (*destructor) (void *))
  50 {
  51         struct pthread *curthread = tls_get_curthread();
  52         int i;
  53
  54         /* Lock the key table: */
  55         THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
  56         for (i = 0; i < PTHREAD_KEYS_MAX; i++) {
  57
  58                 if (_thread_keytable[i].allocated == 0) {
  59                         _thread_keytable[i].allocated = 1;
  60                         _thread_keytable[i].destructor = destructor;
  61                         _thread_keytable[i].seqno++;
  62
  63                         /* Unlock the key table: */
  64                         THR_LOCK_RELEASE(curthread, &_keytable_lock);
  65                         *key = i;
  66                         return (0);
  67                 }
  68
  69         }
  70         /* Unlock the key table: */
  71         THR_LOCK_RELEASE(curthread, &_keytable_lock);
  72         return (EAGAIN);
  73 }
  74
  75 int
  76 _pthread_key_delete(pthread_key_t key)
  77 {
  78         struct pthread *curthread = tls_get_curthread();
  79         int ret = 0;
  80
  81         if ((unsigned int)key < PTHREAD_KEYS_MAX) {
  82                 /* Lock the key table: */
  83                 THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
  84
  85                 if (_thread_keytable[key].allocated)
  86                         _thread_keytable[key].allocated = 0;
  87                 else
  88                         ret = EINVAL;
  89
  90                 /* Unlock the key table: */
  91                 THR_LOCK_RELEASE(curthread, &_keytable_lock);
  92         } else
  93                 ret = EINVAL;
  94         return (ret);
  95 }
  96
  97 void
  98 _thread_cleanupspecific(void)
  99 {
 100         struct pthread  *curthread = tls_get_curthread();
 101         void            (*destructor)( void *);
 102         void            *data = NULL;
 103         int             key;
 104         int             i;
 105
 106         if (curthread->specific == NULL)
 107                 return;
 108
 109         /* Lock the key table: */
 110         THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
 111         for (i = 0; (i < PTHREAD_DESTRUCTOR_ITERATIONS) &&
 112             (curthread->specific_data_count > 0); i++) {
 113                 for (key = 0; (key < PTHREAD_KEYS_MAX) &&
 114                     (curthread->specific_data_count > 0); key++) {
 115                         destructor = NULL;
 116
 117                         if (_thread_keytable[key].allocated &&
 118                             (curthread->specific[key].data != NULL)) {
 119                                 if (curthread->specific[key].seqno ==
 120                                     _thread_keytable[key].seqno) {
 121                                         data = (void *)
 122                                             curthread->specific[key].data;
 123                                         destructor = _thread_keytable[key].destructor;
 124                                 }
 125                                 curthread->specific[key].data = NULL;
 126                                 curthread->specific_data_count--;
 127                         }
 128
 129                         /*
 130                          * If there is a destructore, call it
 131                          * with the key table entry unlocked:
 132                          */
 133                         if (destructor != NULL) {
 134                                 /*
 135                                  * Don't hold the lock while calling the
 136                                  * destructor:
 137                                  */
 138                                 THR_LOCK_RELEASE(curthread, &_keytable_lock);
 139                                 destructor(data);
 140                                 THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
 141                         }
 142                 }
 143         }
 144         THR_LOCK_RELEASE(curthread, &_keytable_lock);
 145         free(curthread->specific);
 146         curthread->specific = NULL;
 147         if (curthread->specific_data_count > 0)
 148                 stderr_debug("Thread %p has exited with leftover "
 149                     "thread-specific data after %d destructor iterations\n",
 150                     curthread, PTHREAD_DESTRUCTOR_ITERATIONS);
 151 }
 152
 153 static inline struct pthread_specific_elem *
 154 pthread_key_allocate_data(void)
 155 {
 156         struct pthread_specific_elem *new_data;
 157
 158         new_data = (struct pthread_specific_elem *)
 159             malloc(sizeof(struct pthread_specific_elem) * PTHREAD_KEYS_MAX);
 160         if (new_data != NULL) {
 161                 memset((void *) new_data, 0,
 162                     sizeof(struct pthread_specific_elem) * PTHREAD_KEYS_MAX);
 163         }
 164         return (new_data);
 165 }
 166
 167 int
 168 _pthread_setspecific(pthread_key_t key, const void *value)
 169 {
 170         struct pthread  *pthread;
 171         int             ret = 0;
 172
 173         /* Point to the running thread: */
 174         pthread = tls_get_curthread();
 175
 176         if ((pthread->specific) ||
 177             (pthread->specific = pthread_key_allocate_data())) {
 178                 if ((unsigned int)key < PTHREAD_KEYS_MAX) {
 179                         if (_thread_keytable[key].allocated) {
 180                                 if (pthread->specific[key].data == NULL) {
 181                                         if (value != NULL)
 182                                                 pthread->specific_data_count++;
 183                                 } else if (value == NULL)
 184                                         pthread->specific_data_count--;
 185                                 pthread->specific[key].data = value;
 186                                 pthread->specific[key].seqno =
 187                                     _thread_keytable[key].seqno;
 188                                 ret = 0;
 189                         } else
 190                                 ret = EINVAL;
 191                 } else
 192                         ret = EINVAL;
 193         } else
 194                 ret = ENOMEM;
 195         return (ret);
 196 }
 197
 198 void *
 199 _pthread_getspecific(pthread_key_t key)
 200 {
 201         struct pthread  *pthread;
 202         void            *data;
 203
 204         /* Point to the running thread: */
 205         pthread = tls_get_curthread();
 206
 207         /* Check if there is specific data: */
 208         if (pthread->specific != NULL && (unsigned int)key < PTHREAD_KEYS_MAX) {
 209                 /* Check if this key has been used before: */
 210                 if (_thread_keytable[key].allocated &&
 211                     (pthread->specific[key].seqno == _thread_keytable[key].seqno)) {
 212                         /* Return the value: */
 213                         data = (void *) pthread->specific[key].data;
 214                 } else {
 215                         /*
 216                          * This key has not been used before, so return NULL
 217                          * instead:
 218                          */
 219                         data = NULL;
 220                 }
 221         } else
 222                 /* No specific data has been created, so just return NULL: */
 223                 data = NULL;
 224         return (data);
 225 }
 226
 227 __strong_reference(_pthread_key_create, pthread_key_create);
 228 __strong_reference(_pthread_key_delete, pthread_key_delete);
 229 __strong_reference(_pthread_getspecific, pthread_getspecific);
 230 __strong_reference(_pthread_setspecific, pthread_setspecific);
 231