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-rw-r--r--libpthread/nptl/pthread_rwlock_tryrdlock.c50
1 files changed, 50 insertions, 0 deletions
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 <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)