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