-/* Copyright (C) 2002, 2003 Free Software Foundation, Inc.
+/* Copyright (C) 2002, 2003, 2006 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library; if not, write to the Free
- Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
- 02111-1307 USA. */
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
#include <errno.h>
#include "pthreadP.h"
+#include <atomic.h>
-/* Internal mutex for __pthread_keys table handling. */
-lll_lock_t __pthread_keys_lock = LLL_LOCK_INITIALIZER;
-
int
-__pthread_key_create (key, destr)
- pthread_key_t *key;
- void (*destr) (void *);
+attribute_protected
+__pthread_key_create (
+ pthread_key_t *key,
+ void (*destr) (void *))
{
- int result = EAGAIN;
- size_t cnt;
-
- lll_lock (__pthread_keys_lock);
-
/* Find a slot in __pthread_kyes which is unused. */
+ size_t cnt;
for (cnt = 0; cnt < PTHREAD_KEYS_MAX; ++cnt)
- if (KEY_UNUSED (__pthread_keys[cnt].seq)
- && KEY_USABLE (__pthread_keys[cnt].seq))
- {
- /* We found an unused slot. */
- ++__pthread_keys[cnt].seq;
-
- /* Remember the destructor. */
- __pthread_keys[cnt].destr = destr;
-
- /* Return the key to the caller. */
- *key = cnt;
-
- /* The call succeeded. */
- result = 0;
-
- /* We found a key and can stop now. */
- break;
- }
-
- lll_unlock (__pthread_keys_lock);
-
- return result;
+ {
+ uintptr_t seq = __pthread_keys[cnt].seq;
+
+ if (KEY_UNUSED (seq) && KEY_USABLE (seq)
+ /* We found an unused slot. Try to allocate it. */
+ && ! atomic_compare_and_exchange_bool_acq (&__pthread_keys[cnt].seq,
+ seq + 1, seq))
+ {
+ /* Remember the destructor. */
+ __pthread_keys[cnt].destr = destr;
+
+ /* Return the key to the caller. */
+ *key = cnt;
+
+ /* The call succeeded. */
+ return 0;
+ }
+ }
+
+ return EAGAIN;
}
strong_alias (__pthread_key_create, pthread_key_create)
strong_alias (__pthread_key_create, __pthread_key_create_internal)