diff options
Diffstat (limited to 'nptl/pthread_rwlock_unlock.c')
| -rw-r--r-- | nptl/pthread_rwlock_unlock.c | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/nptl/pthread_rwlock_unlock.c b/nptl/pthread_rwlock_unlock.c new file mode 100644 index 0000000000..9cae8b6c22 --- /dev/null +++ b/nptl/pthread_rwlock_unlock.c @@ -0,0 +1,57 @@ +/* Copyright (C) 2003 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Martin Schwidefsky <schwidefsky@de.ibm.com>, 2003. + + 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, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <errno.h> +#include <sysdep.h> +#include <lowlevellock.h> +#include <pthread.h> +#include <pthreadP.h> + +/* Unlock RWLOCK. */ +int +__pthread_rwlock_unlock (pthread_rwlock_t *rwlock) +{ + lll_mutex_lock (rwlock->__data.__lock); + if (rwlock->__data.__writer) + rwlock->__data.__writer = 0; + else + --rwlock->__data.__nr_readers; + if (rwlock->__data.__nr_readers == 0) + { + if (rwlock->__data.__nr_writers_queued) + { + ++rwlock->__data.__writer_wakeup; + lll_mutex_unlock (rwlock->__data.__lock); + lll_futex_wake (&rwlock->__data.__writer_wakeup, 1); + return 0; + } + else if (rwlock->__data.__nr_readers_queued) + { + ++rwlock->__data.__readers_wakeup; + lll_mutex_unlock (rwlock->__data.__lock); + lll_futex_wake (&rwlock->__data.__readers_wakeup, INT_MAX); + return 0; + } + } + lll_mutex_unlock (rwlock->__data.__lock); + return 0; +} + +weak_alias (__pthread_rwlock_unlock, pthread_rwlock_unlock) +strong_alias (__pthread_rwlock_unlock, __pthread_rwlock_unlock_internal) |