51 lines
1.5 KiB
C
51 lines
1.5 KiB
C
/* Copyright (C) 2002 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, write to the Free
|
|
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
|
|
02111-1307 USA. */
|
|
|
|
#include <errno.h>
|
|
#include "pthreadP.h"
|
|
#include <lowlevellock.h>
|
|
|
|
|
|
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)
|