diff options
Diffstat (limited to 'nptl/pthread_key_create.c')
| -rw-r--r-- | nptl/pthread_key_create.c | 55 |
1 files changed, 23 insertions, 32 deletions
diff --git a/nptl/pthread_key_create.c b/nptl/pthread_key_create.c index cf35bc8776..5fc8846243 100644 --- a/nptl/pthread_key_create.c +++ b/nptl/pthread_key_create.c @@ -1,4 +1,4 @@ -/* 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. @@ -19,45 +19,36 @@ #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 *); { - int result = EAGAIN; - size_t cnt; - - lll_lock (__pthread_keys_lock); - /* Find a slot in __pthread_kyes which is unused. */ - 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; + for (size_t cnt = 0; cnt < PTHREAD_KEYS_MAX; ++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; + + /* The call succeeded. */ + return 0; + } + } + + return EAGAIN; } strong_alias (__pthread_key_create, pthread_key_create) strong_alias (__pthread_key_create, __pthread_key_create_internal) |