/* Copyright (C) 2002, 2007 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 <lowlevellock.h> int __pthread_rwlock_tryrdlock (rwlock) pthread_rwlock_t *rwlock; { int result = EBUSY; lll_lock (rwlock->__data.__lock, rwlock->__data.__shared); if (rwlock->__data.__writer == 0 && (rwlock->__data.__nr_writers_queued == 0 || PTHREAD_RWLOCK_PREFER_READER_P (rwlock))) { if (__builtin_expect (++rwlock->__data.__nr_readers == 0, 0)) { --rwlock->__data.__nr_readers; result = EAGAIN; } else result = 0; } lll_unlock (rwlock->__data.__lock, rwlock->__data.__shared); return result; } strong_alias (__pthread_rwlock_tryrdlock, pthread_rwlock_tryrdlock)