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  * $FreeBSD$
  30  */
  31
  32 #include "namespace.h"
  33 #include <sys/mman.h>
  34 #include <signal.h>
  35 #include <stdlib.h>
  36 #include <string.h>
  37 #include <errno.h>
  38 #include <pthread.h>
  39 #include "un-namespace.h"
  40 #include "libc_private.h"
  41
  42 #include "thr_private.h"
  43
  44 struct pthread_key _thread_keytable[PTHREAD_KEYS_MAX];
  45
  46 __weak_reference(_pthread_key_create, pthread_key_create);
  47 __weak_reference(_pthread_key_delete, pthread_key_delete);
  48 __weak_reference(_pthread_getspecific, pthread_getspecific);
  49 __weak_reference(_pthread_setspecific, pthread_setspecific);
  50
  51
  52 int
  53 _pthread_key_create(pthread_key_t *key, void (*destructor)(void *))
  54 {
  55         struct pthread *curthread;
  56         int i;
  57
  58         _thr_check_init();
  59
  60         curthread = _get_curthread();
  61
  62         THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
  63         for (i = 0; i < PTHREAD_KEYS_MAX; i++) {
  64
  65                 if (_thread_keytable[i].allocated == 0) {
  66                         _thread_keytable[i].allocated = 1;
  67                         _thread_keytable[i].destructor = destructor;
  68                         _thread_keytable[i].seqno++;
  69
  70                         THR_LOCK_RELEASE(curthread, &_keytable_lock);
  71                         *key = i + 1;
  72                         return (0);
  73                 }
  74
  75         }
  76         THR_LOCK_RELEASE(curthread, &_keytable_lock);
  77         return (EAGAIN);
  78 }
  79
  80 int
  81 _pthread_key_delete(pthread_key_t userkey)
  82 {
  83         struct pthread *curthread;
  84         int key, ret;
  85
  86         key = userkey - 1;
  87         if ((unsigned int)key >= PTHREAD_KEYS_MAX)
  88                 return (EINVAL);
  89         curthread = _get_curthread();
  90         THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
  91         if (_thread_keytable[key].allocated) {
  92                 _thread_keytable[key].allocated = 0;
  93                 ret = 0;
  94         } else {
  95                 ret = EINVAL;
  96         }
  97         THR_LOCK_RELEASE(curthread, &_keytable_lock);
  98         return (ret);
  99 }
 100
 101 void
 102 _thread_cleanupspecific(void)
 103 {
 104         struct pthread *curthread;
 105         void (*destructor)(void *);
 106         const void *data;
 107         int i, key;
 108
 109         curthread = _get_curthread();
 110         if (curthread->specific == NULL)
 111                 return;
 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 = curthread->specific[key].data;
 124                                         destructor = _thread_keytable[key].
 125                                             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
 132                                  * deleted via pthread_key_delete
 133                                  * without first setting the value to
 134                                  * NULL in all threads.  POSIX says
 135                                  * that the destructor is not invoked
 136                                  * in this case.
 137                                  */
 138                                 curthread->specific[key].data = NULL;
 139                                 curthread->specific_data_count--;
 140                         }
 141
 142                         /*
 143                          * If there is a destructor, call it with the
 144                          * key table entry unlocked.
 145                          */
 146                         if (destructor != NULL) {
 147                                 THR_LOCK_RELEASE(curthread, &_keytable_lock);
 148                                 destructor(__DECONST(void *, data));
 149                                 THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
 150                         }
 151                 }
 152         }
 153         THR_LOCK_RELEASE(curthread, &_keytable_lock);
 154         munmap(curthread->specific, PTHREAD_KEYS_MAX * sizeof(struct
 155             pthread_specific_elem));
 156         curthread->specific = NULL;
 157         if (curthread->specific_data_count > 0) {
 158                 stderr_debug("Thread %p has exited with leftover "
 159                     "thread-specific data after %d destructor iterations\n",
 160                     curthread, PTHREAD_DESTRUCTOR_ITERATIONS);
 161         }
 162 }
 163
 164 int
 165 _pthread_setspecific(pthread_key_t userkey, const void *value)
 166 {
 167         struct pthread *pthread;
 168         void *tmp;
 169         pthread_key_t key;
 170
 171         key = userkey - 1;
 172         if ((unsigned int)key >= PTHREAD_KEYS_MAX ||
 173             !_thread_keytable[key].allocated)
 174                 return (EINVAL);
 175
 176         pthread = _get_curthread();
 177         if (pthread->specific == NULL) {
 178                 tmp = mmap(NULL, PTHREAD_KEYS_MAX *
 179                     sizeof(struct pthread_specific_elem),
 180                     PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);
 181                 if (tmp == MAP_FAILED)
 182                         return (ENOMEM);
 183                 pthread->specific = tmp;
 184         }
 185         if (pthread->specific[key].data == NULL) {
 186                 if (value != NULL)
 187                         pthread->specific_data_count++;
 188         } else if (value == NULL)
 189                 pthread->specific_data_count--;
 190         pthread->specific[key].data = value;
 191         pthread->specific[key].seqno = _thread_keytable[key].seqno;
 192         return (0);
 193 }
 194
 195 void *
 196 _pthread_getspecific(pthread_key_t userkey)
 197 {
 198         struct pthread *pthread;
 199         const void *data;
 200         pthread_key_t key;
 201
 202         /* Check if there is specific data. */
 203         key = userkey - 1;
 204         if ((unsigned int)key >= PTHREAD_KEYS_MAX)
 205                 return (NULL);
 206
 207         pthread = _get_curthread();
 208         /* Check if this key has been used before. */
 209         if (_thread_keytable[key].allocated && pthread->specific != NULL &&
 210             pthread->specific[key].seqno == _thread_keytable[key].seqno) {
 211                 /* Return the value: */
 212                 data = pthread->specific[key].data;
 213         } else {
 214                 /*
 215                  * This key has not been used before, so return NULL
 216                  * instead.
 217                  */
 218                 data = NULL;
 219         }
 220         return (__DECONST(void *, data));
 221 }
 222
 223 void
 224 _thr_tsd_unload(struct dl_phdr_info *phdr_info)
 225 {
 226         struct pthread *curthread;
 227         void (*destructor)(void *);
 228         int key;
 229
 230         curthread = _get_curthread();
 231         THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
 232         for (key = 0; key < PTHREAD_KEYS_MAX; key++) {
 233                 if (!_thread_keytable[key].allocated)
 234                         continue;
 235                 destructor = _thread_keytable[key].destructor;
 236                 if (destructor == NULL)
 237                         continue;
 238                 if (__elf_phdr_match_addr(phdr_info, destructor))
 239                         _thread_keytable[key].destructor = NULL;
 240         }
 241         THR_LOCK_RELEASE(curthread, &_keytable_lock);
 242 }