sysdeps/htl/pt-key.h

   1 /* pthread_key internal declatations for the Hurd version.
   2    Copyright (C) 2002-2018 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Library General Public License as
   7    published by the Free Software Foundation; either version 2 of the
   8    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    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If
  17    not, see <http://www.gnu.org/licenses/>.  */
  18
  19 #include <pthread.h>
  20 #include <libc-lockP.h>
  21
  22 #define PTHREAD_KEY_MEMBERS \
  23   void **thread_specifics;              /* This is only resized by the thread, and always growing */ \
  24   unsigned thread_specifics_size;       /* Number of entries in thread_specifics */
  25
  26 #define PTHREAD_KEY_INVALID (void *) (-1)
  27
  28
  29 /* __PTHREAD_KEY_DESTRUCTORS is an array of destructors with
  30    __PTHREAD_KEY_SIZE elements.  If an element with index less than
  31    __PTHREAD_KEY_COUNT is invalid, it shall contain the value
  32    PTHREAD_KEY_INVALID which shall be distinct from NULL.
  33
  34    Normally, we just add new keys to the end of the array and realloc
  35    it as necessary.  The pthread_key_create routine may decide to
  36    rescan the array if __PTHREAD_KEY_FREE is large.  */
  37 extern void (**__pthread_key_destructors) (void *arg);
  38 extern int __pthread_key_size;
  39 extern int __pthread_key_count;
  40 /* Number of invalid elements in the array.  Does not include elements
  41    for which memory has been allocated but which have not yet been
  42    used (i.e. those elements with indexes greater than
  43    __PTHREAD_KEY_COUNT).  */
  44 extern int __pthread_key_invalid_count;
  45
  46 /* Protects the above variables.  This must be a recursive lock: the
  47    destructors may call pthread_key_delete.  */
  48 extern pthread_mutex_t __pthread_key_lock;
  49 \f
  50 #include <assert.h>
  51
  52 static inline void
  53 __pthread_key_lock_ready (void)
  54 {
  55   static pthread_once_t o = PTHREAD_ONCE_INIT;
  56
  57   void do_init (void)
  58   {
  59     int err;
  60     pthread_mutexattr_t attr;
  61
  62     err = __pthread_mutexattr_init (&attr);
  63     assert_perror (err);
  64
  65     err = __pthread_mutexattr_settype (&attr, PTHREAD_MUTEX_RECURSIVE);
  66     assert_perror (err);
  67
  68     err = _pthread_mutex_init (&__pthread_key_lock, &attr);
  69     assert_perror (err);
  70
  71     err = __pthread_mutexattr_destroy (&attr);
  72     assert_perror (err);
  73   }
  74
  75   __pthread_once (&o, do_init);
  76 }