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  * $DragonFly: src/lib/libthread_xu/thread/thr_spec.c,v 1.5 2006/04/06 13:03:09 davidxu Exp $
  33  */
  34
  35 #include "namespace.h"
  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 "un-namespace.h"
  44
  45 #include "thr_private.h"
  46
  47 struct pthread_key _thread_keytable[PTHREAD_KEYS_MAX];
  48 umtx_t  _keytable_lock;
  49
  50 int
  51 _pthread_key_create(pthread_key_t *key, void (*destructor) (void *))
  52 {
  53         struct pthread *curthread = tls_get_curthread();
  54         int i;
  55
  56         /* Lock the key table: */
  57         THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
  58         for (i = 0; i < PTHREAD_KEYS_MAX; i++) {
  59
  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         struct pthread *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         struct pthread  *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 =
 124                                             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         free(curthread->specific);
 157         curthread->specific = NULL;
 158         if (curthread->specific_data_count > 0)
 159                 stderr_debug("Thread %p has exited with leftover "
 160                     "thread-specific data after %d destructor iterations\n",
 161                     curthread, PTHREAD_DESTRUCTOR_ITERATIONS);
 162 }
 163
 164 static inline struct pthread_specific_elem *
 165 pthread_key_allocate_data(void)
 166 {
 167         struct pthread_specific_elem *new_data;
 168
 169         new_data = (struct pthread_specific_elem *)
 170             malloc(sizeof(struct pthread_specific_elem) * PTHREAD_KEYS_MAX);
 171         if (new_data != NULL) {
 172                 memset((void *) new_data, 0,
 173                     sizeof(struct pthread_specific_elem) * PTHREAD_KEYS_MAX);
 174         }
 175         return (new_data);
 176 }
 177
 178 int
 179 _pthread_setspecific(pthread_key_t key, const void *value)
 180 {
 181         struct pthread  *pthread;
 182         int             ret = 0;
 183
 184         /* Point to the running thread: */
 185         pthread = tls_get_curthread();
 186
 187         if ((pthread->specific) ||
 188             (pthread->specific = pthread_key_allocate_data())) {
 189                 if ((unsigned int)key < PTHREAD_KEYS_MAX) {
 190                         if (_thread_keytable[key].allocated) {
 191                                 if (pthread->specific[key].data == NULL) {
 192                                         if (value != NULL)
 193                                                 pthread->specific_data_count++;
 194                                 } else if (value == NULL)
 195                                         pthread->specific_data_count--;
 196                                 pthread->specific[key].data = value;
 197                                 pthread->specific[key].seqno =
 198                                     _thread_keytable[key].seqno;
 199                                 ret = 0;
 200                         } else
 201                                 ret = EINVAL;
 202                 } else
 203                         ret = EINVAL;
 204         } else
 205                 ret = ENOMEM;
 206         return (ret);
 207 }
 208
 209 void *
 210 _pthread_getspecific(pthread_key_t key)
 211 {
 212         struct pthread  *pthread;
 213         const void      *data;
 214
 215         /* Point to the running thread: */
 216         pthread = tls_get_curthread();
 217
 218         /* Check if there is specific data: */
 219         if (pthread->specific != NULL && (unsigned int)key < PTHREAD_KEYS_MAX) {
 220                 /* Check if this key has been used before: */
 221                 if (_thread_keytable[key].allocated &&
 222                     (pthread->specific[key].seqno == _thread_keytable[key].seqno)) {
 223                         /* Return the value: */
 224                         data = pthread->specific[key].data;
 225                 } else {
 226                         /*
 227                          * This key has not been used before, so return NULL
 228                          * instead:
 229                          */
 230                         data = NULL;
 231                 }
 232         } else
 233                 /* No specific data has been created, so just return NULL: */
 234                 data = NULL;
 235         return __DECONST(void *, data);
 236 }
 237
 238 __strong_reference(_pthread_key_create, pthread_key_create);
 239 __strong_reference(_pthread_key_delete, pthread_key_delete);
 240 __strong_reference(_pthread_getspecific, pthread_getspecific);
 241 __strong_reference(_pthread_setspecific, pthread_setspecific);
 242