lib/libthr/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
  30 #include <sys/cdefs.h>
  31 __FBSDID("$FreeBSD$");
  32
  33 #include "namespace.h"
  34 #include <sys/mman.h>
  35 #include <signal.h>
  36 #include <stdlib.h>
  37 #include <string.h>
  38 #include <errno.h>
  39 #include <pthread.h>
  40 #include "un-namespace.h"
  41 #include "libc_private.h"
  42
  43 #include "thr_private.h"
  44
  45 static struct pthread_key _thread_keytable[PTHREAD_KEYS_MAX];
  46
  47 __weak_reference(_pthread_key_create, pthread_key_create);
  48 __weak_reference(_pthread_key_delete, pthread_key_delete);
  49 __weak_reference(_pthread_getspecific, pthread_getspecific);
  50 __weak_reference(_pthread_setspecific, pthread_setspecific);
  51
  52
  53 int
  54 _pthread_key_create(pthread_key_t *key, void (*destructor)(void *))
  55 {
  56         struct pthread *curthread;
  57         int i;
  58
  59         _thr_check_init();
  60
  61         curthread = _get_curthread();
  62
  63         THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
  64         for (i = 0; i < PTHREAD_KEYS_MAX; i++) {
  65
  66                 if (_thread_keytable[i].allocated == 0) {
  67                         _thread_keytable[i].allocated = 1;
  68                         _thread_keytable[i].destructor = destructor;
  69                         _thread_keytable[i].seqno++;
  70
  71                         THR_LOCK_RELEASE(curthread, &_keytable_lock);
  72                         *key = i + 1;
  73                         return (0);
  74                 }
  75
  76         }
  77         THR_LOCK_RELEASE(curthread, &_keytable_lock);
  78         return (EAGAIN);
  79 }
  80
  81 int
  82 _pthread_key_delete(pthread_key_t userkey)
  83 {
  84         struct pthread *curthread;
  85         int key, ret;
  86
  87         key = userkey - 1;
  88         if ((unsigned int)key >= PTHREAD_KEYS_MAX)
  89                 return (EINVAL);
  90         curthread = _get_curthread();
  91         THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
  92         if (_thread_keytable[key].allocated) {
  93                 _thread_keytable[key].allocated = 0;
  94                 ret = 0;
  95         } else {
  96                 ret = EINVAL;
  97         }
  98         THR_LOCK_RELEASE(curthread, &_keytable_lock);
  99         return (ret);
 100 }
 101
 102 void
 103 _thread_cleanupspecific(void)
 104 {
 105         struct pthread *curthread;
 106         void (*destructor)(void *);
 107         const void *data;
 108         int i, key;
 109
 110         curthread = _get_curthread();
 111         if (curthread->specific == NULL)
 112                 return;
 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].
 126                                             destructor;
 127                                 }
 128                                 curthread->specific[key].data = NULL;
 129                                 curthread->specific_data_count--;
 130                         } else if (curthread->specific[key].data != NULL) {
 131                                 /*
 132                                  * This can happen if the key is
 133                                  * deleted via pthread_key_delete
 134                                  * without first setting the value to
 135                                  * NULL in all threads.  POSIX says
 136                                  * that the destructor is not invoked
 137                                  * in this case.
 138                                  */
 139                                 curthread->specific[key].data = NULL;
 140                                 curthread->specific_data_count--;
 141                         }
 142
 143                         /*
 144                          * If there is a destructor, call it with the
 145                          * key table entry unlocked.
 146                          */
 147                         if (destructor != NULL) {
 148                                 THR_LOCK_RELEASE(curthread, &_keytable_lock);
 149                                 destructor(__DECONST(void *, data));
 150                                 THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
 151                         }
 152                 }
 153         }
 154         THR_LOCK_RELEASE(curthread, &_keytable_lock);
 155         munmap(curthread->specific, PTHREAD_KEYS_MAX * sizeof(struct
 156             pthread_specific_elem));
 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
 165 int
 166 _pthread_setspecific(pthread_key_t userkey, const void *value)
 167 {
 168         struct pthread *pthread;
 169         void *tmp;
 170         pthread_key_t key;
 171
 172         key = userkey - 1;
 173         if ((unsigned int)key >= PTHREAD_KEYS_MAX ||
 174             !_thread_keytable[key].allocated)
 175                 return (EINVAL);
 176
 177         pthread = _get_curthread();
 178         if (pthread->specific == NULL) {
 179                 tmp = mmap(NULL, PTHREAD_KEYS_MAX *
 180                     sizeof(struct pthread_specific_elem),
 181                     PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);
 182                 if (tmp == MAP_FAILED)
 183                         return (ENOMEM);
 184                 pthread->specific = tmp;
 185         }
 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 = _thread_keytable[key].seqno;
 193         return (0);
 194 }
 195
 196 void *
 197 _pthread_getspecific(pthread_key_t userkey)
 198 {
 199         struct pthread *pthread;
 200         const void *data;
 201         pthread_key_t key;
 202
 203         /* Check if there is specific data. */
 204         key = userkey - 1;
 205         if ((unsigned int)key >= PTHREAD_KEYS_MAX)
 206                 return (NULL);
 207
 208         pthread = _get_curthread();
 209         /* Check if this key has been used before. */
 210         if (_thread_keytable[key].allocated && pthread->specific != NULL &&
 211             pthread->specific[key].seqno == _thread_keytable[key].seqno) {
 212                 /* Return the value: */
 213                 data = 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         return (__DECONST(void *, data));
 222 }
 223
 224 void
 225 _thr_tsd_unload(struct dl_phdr_info *phdr_info)
 226 {
 227         struct pthread *curthread;
 228         void (*destructor)(void *);
 229         int key;
 230
 231         curthread = _get_curthread();
 232         THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
 233         for (key = 0; key < PTHREAD_KEYS_MAX; key++) {
 234                 if (!_thread_keytable[key].allocated)
 235                         continue;
 236                 destructor = _thread_keytable[key].destructor;
 237                 if (destructor == NULL)
 238                         continue;
 239                 if (__elf_phdr_match_addr(phdr_info, destructor))
 240                         _thread_keytable[key].destructor = NULL;
 241         }
 242         THR_LOCK_RELEASE(curthread, &_keytable_lock);
 243 }