lib/libc_r/uthread/uthread_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/libc_r/uthread/uthread_spec.c,v 1.14.2.2 2002/10/22 14:44:03 fjoe Exp $
  33  * $DragonFly: src/lib/libc_r/uthread/uthread_spec.c,v 1.2 2003/06/17 04:26:48 dillon Exp $
  34  */
  35 #include <signal.h>
  36 #include <stdlib.h>
  37 #include <string.h>
  38 #include <errno.h>
  39 #include <pthread.h>
  40 #include "pthread_private.h"
  41
  42 /* Static variables: */
  43 static  struct pthread_key key_table[PTHREAD_KEYS_MAX];
  44
  45 __weak_reference(_pthread_key_create, pthread_key_create);
  46 __weak_reference(_pthread_key_delete, pthread_key_delete);
  47 __weak_reference(_pthread_getspecific, pthread_getspecific);
  48 __weak_reference(_pthread_setspecific, pthread_setspecific);
  49
  50
  51 int
  52 _pthread_key_create(pthread_key_t * key, void (*destructor) (void *))
  53 {
  54         for ((*key) = 0; (*key) < PTHREAD_KEYS_MAX; (*key)++) {
  55                 /* Lock the key table entry: */
  56                 _SPINLOCK(&key_table[*key].lock);
  57
  58                 if (key_table[(*key)].allocated == 0) {
  59                         key_table[(*key)].allocated = 1;
  60                         key_table[(*key)].destructor = destructor;
  61
  62                         /* Unlock the key table entry: */
  63                         _SPINUNLOCK(&key_table[*key].lock);
  64                         return (0);
  65                 }
  66
  67                 /* Unlock the key table entry: */
  68                 _SPINUNLOCK(&key_table[*key].lock);
  69         }
  70         return (EAGAIN);
  71 }
  72
  73 int
  74 _pthread_key_delete(pthread_key_t key)
  75 {
  76         int ret = 0;
  77
  78         if (key < PTHREAD_KEYS_MAX) {
  79                 /* Lock the key table entry: */
  80                 _SPINLOCK(&key_table[key].lock);
  81
  82                 if (key_table[key].allocated)
  83                         key_table[key].allocated = 0;
  84                 else
  85                         ret = EINVAL;
  86
  87                 /* Unlock the key table entry: */
  88                 _SPINUNLOCK(&key_table[key].lock);
  89         } else
  90                 ret = EINVAL;
  91         return (ret);
  92 }
  93
  94 void
  95 _thread_cleanupspecific(void)
  96 {
  97         struct pthread  *curthread = _get_curthread();
  98         void           *data = NULL;
  99         int             key;
 100         int             itr;
 101         void            (*destructor)( void *);
 102
 103         for (itr = 0; itr < PTHREAD_DESTRUCTOR_ITERATIONS; itr++) {
 104                 for (key = 0; key < PTHREAD_KEYS_MAX; key++) {
 105                         if (curthread->specific_data_count) {
 106                                 /* Lock the key table entry: */
 107                                 _SPINLOCK(&key_table[key].lock);
 108                                 destructor = NULL;
 109
 110                                 if (key_table[key].allocated) {
 111                                         if (curthread->specific_data[key]) {
 112                                                 data = (void *) curthread->specific_data[key];
 113                                                 curthread->specific_data[key] = NULL;
 114                                                 curthread->specific_data_count--;
 115                                                 destructor = key_table[key].destructor;
 116                                         }
 117                                 }
 118
 119                                 /* Unlock the key table entry: */
 120                                 _SPINUNLOCK(&key_table[key].lock);
 121
 122                                 /*
 123                                  * If there is a destructore, call it
 124                                  * with the key table entry unlocked:
 125                                  */
 126                                 if (destructor)
 127                                         destructor(data);
 128                         } else {
 129                                 free(curthread->specific_data);
 130                                 curthread->specific_data = NULL;
 131                                 return;
 132                         }
 133                 }
 134         }
 135         free(curthread->specific_data);
 136         curthread->specific_data = NULL;
 137 }
 138
 139 static inline const void **
 140 pthread_key_allocate_data(void)
 141 {
 142         const void    **new_data;
 143         if ((new_data = (const void **) malloc(sizeof(void *) * PTHREAD_KEYS_MAX)) != NULL) {
 144                 memset((void *) new_data, 0, sizeof(void *) * PTHREAD_KEYS_MAX);
 145         }
 146         return (new_data);
 147 }
 148
 149 int
 150 _pthread_setspecific(pthread_key_t key, const void *value)
 151 {
 152         struct pthread  *pthread;
 153         int             ret = 0;
 154
 155         /* Point to the running thread: */
 156         pthread = _get_curthread();
 157
 158         if ((pthread->specific_data) ||
 159             (pthread->specific_data = pthread_key_allocate_data())) {
 160                 if (key < PTHREAD_KEYS_MAX) {
 161                         if (key_table[key].allocated) {
 162                                 if (pthread->specific_data[key] == NULL) {
 163                                         if (value != NULL)
 164                                                 pthread->specific_data_count++;
 165                                 } else {
 166                                         if (value == NULL)
 167                                                 pthread->specific_data_count--;
 168                                 }
 169                                 pthread->specific_data[key] = value;
 170                                 ret = 0;
 171                         } else
 172                                 ret = EINVAL;
 173                 } else
 174                         ret = EINVAL;
 175         } else
 176                 ret = ENOMEM;
 177         return (ret);
 178 }
 179
 180 void *
 181 _pthread_getspecific(pthread_key_t key)
 182 {
 183         struct pthread  *pthread;
 184         void            *data;
 185
 186         /* Point to the running thread: */
 187         pthread = _get_curthread();
 188
 189         /* Check if there is specific data: */
 190         if (pthread->specific_data != NULL && key < PTHREAD_KEYS_MAX) {
 191                 /* Check if this key has been used before: */
 192                 if (key_table[key].allocated) {
 193                         /* Return the value: */
 194                         data = (void *) pthread->specific_data[key];
 195                 } else {
 196                         /*
 197                          * This key has not been used before, so return NULL
 198                          * instead:
 199                          */
 200                         data = NULL;
 201                 }
 202         } else
 203                 /* No specific data has been created, so just return NULL: */
 204                 data = NULL;
 205         return (data);
 206 }