nptl/pthread_key_create.c

   1 /* Copyright (C) 2002, 2003 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 "pthreadP.h"
  22
  23
  24 /* Internal mutex for __pthread_keys table handling.  */
  25 lll_lock_t __pthread_keys_lock = LLL_LOCK_INITIALIZER;
  26
  27
  28 /* For debugging purposes put the maximum number of keys in a variable.  */
  29 const int __pthread_pthread_keys_max = PTHREAD_KEYS_MAX;
  30 const int __pthread_pthread_key_2ndlevel_size = PTHREAD_KEY_2NDLEVEL_SIZE;
  31
  32
  33 int
  34 __pthread_key_create (key, destr)
  35      pthread_key_t *key;
  36      void (*destr) (void *);
  37 {
  38   int result = EAGAIN;
  39   size_t cnt;
  40
  41   lll_lock (__pthread_keys_lock);
  42
  43   /* Find a slot in __pthread_kyes which is unused.  */
  44   for (cnt = 0; cnt < PTHREAD_KEYS_MAX; ++cnt)
  45     if (KEY_UNUSED (__pthread_keys[cnt].seq)
  46         && KEY_USABLE (__pthread_keys[cnt].seq))
  47       {
  48         /* We found an unused slot.  */
  49         ++__pthread_keys[cnt].seq;
  50
  51         /* Remember the destructor.  */
  52         __pthread_keys[cnt].destr = destr;
  53
  54         /* Return the key to the caller.  */
  55         *key = cnt;
  56
  57         /* The call succeeded.  */
  58         result = 0;
  59
  60         /* We found a key and can stop now.  */
  61         break;
  62       }
  63
  64   lll_unlock (__pthread_keys_lock);
  65
  66   return result;
  67 }
  68 strong_alias (__pthread_key_create, pthread_key_create)
  69 strong_alias (__pthread_key_create, __pthread_key_create_internal)