nptl/pthread_setspecific.c

   1 /* Copyright (C) 2002, 2003, 2006 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <errno.h>
  21 #include <stdlib.h>
  22 #include "pthreadP.h"
  23
  24
  25 int
  26 __pthread_setspecific (key, value)
  27      pthread_key_t key;
  28      const void *value;
  29 {
  30   struct pthread *self;
  31   unsigned int idx1st;
  32   unsigned int idx2nd;
  33   struct pthread_key_data *level2;
  34   unsigned int seq;
  35
  36   self = THREAD_SELF;
  37
  38   /* Special case access to the first 2nd-level block.  This is the
  39      usual case.  */
  40   if (__builtin_expect (key < PTHREAD_KEY_2NDLEVEL_SIZE, 1))
  41     {
  42       /* Verify the key is sane.  */
  43       if (KEY_UNUSED ((seq = __pthread_keys[key].seq)))
  44         /* Not valid.  */
  45         return EINVAL;
  46
  47       level2 = &self->specific_1stblock[key];
  48
  49       /* Remember that we stored at least one set of data.  */
  50       if (value != NULL)
  51         THREAD_SETMEM (self, specific_used, true);
  52     }
  53   else
  54     {
  55       if (key >= PTHREAD_KEYS_MAX
  56           || KEY_UNUSED ((seq = __pthread_keys[key].seq)))
  57         /* Not valid.  */
  58         return EINVAL;
  59
  60       idx1st = key / PTHREAD_KEY_2NDLEVEL_SIZE;
  61       idx2nd = key % PTHREAD_KEY_2NDLEVEL_SIZE;
  62
  63       /* This is the second level array.  Allocate it if necessary.  */
  64       level2 = THREAD_GETMEM_NC (self, specific, idx1st);
  65       if (level2 == NULL)
  66         {
  67           if (value == NULL)
  68             /* We don't have to do anything.  The value would in any case
  69                be NULL.  We can save the memory allocation.  */
  70             return 0;
  71
  72           level2
  73             = (struct pthread_key_data *) calloc (PTHREAD_KEY_2NDLEVEL_SIZE,
  74                                                   sizeof (*level2));
  75           if (level2 == NULL)
  76             return ENOMEM;
  77
  78           THREAD_SETMEM_NC (self, specific, idx1st, level2);
  79         }
  80
  81       /* Pointer to the right array element.  */
  82       level2 = &level2[idx2nd];
  83
  84       /* Remember that we stored at least one set of data.  */
  85       THREAD_SETMEM (self, specific_used, true);
  86     }
  87
  88   /* Store the data and the sequence number so that we can recognize
  89      stale data.  */
  90   level2->seq = seq;
  91   level2->data = (void *) value;
  92
  93   return 0;
  94 }
  95 strong_alias (__pthread_setspecific, pthread_setspecific)
  96 strong_alias (__pthread_setspecific, __pthread_setspecific_internal)