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, see
17 <http://www.gnu.org/licenses/>. */
18
19 #include <errno.h>
20 #include "pthreadP.h"
21 #include <atomic.h>
22
23
24 int
25 attribute_protected
__pthread_key_create(pthread_key_t * key,void (* destr)(void *))26 __pthread_key_create (
27 pthread_key_t *key,
28 void (*destr) (void *))
29 {
30 /* Find a slot in __pthread_kyes which is unused. */
31 size_t cnt;
32 for (cnt = 0; cnt < PTHREAD_KEYS_MAX; ++cnt)
33 {
34 uintptr_t seq = __pthread_keys[cnt].seq;
35
36 if (KEY_UNUSED (seq) && KEY_USABLE (seq)
37 /* We found an unused slot. Try to allocate it. */
38 && ! atomic_compare_and_exchange_bool_acq (&__pthread_keys[cnt].seq,
39 seq + 1, seq))
40 {
41 /* Remember the destructor. */
42 __pthread_keys[cnt].destr = destr;
43
44 /* Return the key to the caller. */
45 *key = cnt;
46
47 /* The call succeeded. */
48 return 0;
49 }
50 }
51
52 return EAGAIN;
53 }
54 strong_alias (__pthread_key_create, pthread_key_create)
55 strong_alias (__pthread_key_create, __pthread_key_create_internal)
56