From 0b3366f6a93ac0f7e2028745ea557c0acd8722c6 Mon Sep 17 00:00:00 2001 From: "\"Steven J. Hill\"" Date: Sat, 7 May 2005 02:04:55 +0000 Subject: Import in NPTL code from glibc. For further information please consult the 'README.NPTL' file. --- libpthread/nptl/pthread_rwlock_tryrdlock.c | 50 ++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) create mode 100644 libpthread/nptl/pthread_rwlock_tryrdlock.c (limited to 'libpthread/nptl/pthread_rwlock_tryrdlock.c') diff --git a/libpthread/nptl/pthread_rwlock_tryrdlock.c b/libpthread/nptl/pthread_rwlock_tryrdlock.c new file mode 100644 index 000000000..446af0596 --- /dev/null +++ b/libpthread/nptl/pthread_rwlock_tryrdlock.c @@ -0,0 +1,50 @@ +/* Copyright (C) 2002 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper , 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, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include +#include "pthreadP.h" +#include + + +int +__pthread_rwlock_tryrdlock (rwlock) + pthread_rwlock_t *rwlock; +{ + int result = EBUSY; + + lll_mutex_lock (rwlock->__data.__lock); + + if (rwlock->__data.__writer == 0 + && (rwlock->__data.__nr_writers_queued == 0 + || rwlock->__data.__flags == 0)) + { + if (__builtin_expect (++rwlock->__data.__nr_readers == 0, 0)) + { + --rwlock->__data.__nr_readers; + result = EAGAIN; + } + else + result = 0; + } + + lll_mutex_unlock (rwlock->__data.__lock); + + return result; +} +strong_alias (__pthread_rwlock_tryrdlock, pthread_rwlock_tryrdlock) -- cgit v1.2.3