| /* Copyright (C) 2002-2014 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| Contributed by Ulrich Drepper <drepper@redhat.com>, 2002. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 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, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <errno.h> |
| #include "pthreadP.h" |
| #include <assert.h> |
| #include <atomic.h> |
| |
| static int |
| claim_key (pthread_key_t *key, void (*destr) (void *), size_t cnt) |
| { |
| 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; |
| return 0; |
| } |
| return -1; |
| } |
| |
| int |
| __pthread_key_create (key, destr) |
| pthread_key_t *key; |
| void (*destr) (void *); |
| { |
| /* Find a slot in __pthread_keys which is unused. */ |
| for (size_t cnt = PTHREAD_SIGNAL_SAFE_KEYS_MAX; cnt < PTHREAD_KEYS_MAX; ++cnt) |
| { |
| if (claim_key (key, destr, cnt) == 0) |
| return 0; |
| } |
| |
| return EAGAIN; |
| } |
| |
| int __google_pthread_signal_safe_key_create ( |
| pthread_key_t *key, void (*destr) (void *)) |
| { |
| /* Our implementation makes signal safe keys easy: they just have to |
| reside in the first (inline) block. */ |
| assert (PTHREAD_SIGNAL_SAFE_KEYS_MAX <= PTHREAD_KEY_1STLEVEL_SIZE); |
| /* Find a slot in __pthread_keys which is unused. */ |
| for (size_t cnt = 0; cnt < PTHREAD_SIGNAL_SAFE_KEYS_MAX; ++cnt) |
| { |
| if (claim_key (key, destr, cnt) == 0) |
| return 0; |
| } |
| |
| return EAGAIN; |
| } |
| strong_alias (__pthread_key_create, pthread_key_create) |
| hidden_def (__pthread_key_create) |
