libpthread/nptl: core of the "Native Posix Threading Library" for uClibc

targetting arm,sh,i386,mips,sparc for now

Signed-off-by: Austin Foxley <austinf@cetoncorp.com>

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)