Moved OpenThreads directly into OpenSceneGraph/trunk rather than being introduced via svn:externals.

This change has been done to make it easier for OpenSceneGraph users to check out the svn via https 
without any conflicts introduced with a http externals.

include/OpenThreads/Condition

@@ -0,0 +1,93 @@
+/* -*-c++-*- OpenThreads library, Copyright (C) 2002 - 2007  The Open Thread Group
+ *
+ * This library is open source and may be redistributed and/or modified under  
+ * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or 
+ * (at your option) any later version.  The full license is in LICENSE file
+ * included with this distribution, and on the openscenegraph.org website.
+ * 
+ * This 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 
+ * OpenSceneGraph Public License for more details.
+*/
+
+
+//
+// Condition - C++ condition class
+// ~~~~~~~~~
+//
+
+#ifndef _OPENTHREADS_CONDITION_
+#define _OPENTHREADS_CONDITION_
+
+#include <OpenThreads/Exports>
+#include <OpenThreads/Mutex>
+
+namespace OpenThreads {
+
+/**
+ *  @class Condition
+ *  @brief  This class provides an object-oriented thread condition interface.
+ */
+class OPENTHREAD_EXPORT_DIRECTIVE Condition {
+
+public:
+
+    /**
+     *  Constructor
+     */
+    Condition();
+
+    /**
+     *  Destructor
+     */
+    virtual ~Condition();
+
+    /**
+     *  Wait on a mutex.
+     */
+    virtual int wait(Mutex *mutex);
+
+    /**
+     *  Wait on a mutex for a given amount of time (ms)
+     *
+     *  @return 0 if normal, -1 if errno set, errno code otherwise.
+     */
+    virtual int wait(Mutex *mutex, unsigned long int ms);
+
+    /**
+     *  Signal a SINGLE thread to wake if it's waiting.
+     *
+     *  @return 0 if normal, -1 if errno set, errno code otherwise.
+     */
+    virtual int signal();
+
+    /**
+     *  Wake all threads waiting on this condition.
+     *
+     *  @return 0 if normal, -1 if errno set, errno code otherwise.
+     */
+    virtual int broadcast();
+
+private:
+
+    /**
+     *  Private copy constructor, to prevent tampering.
+     */
+    Condition(const Condition &/*c*/) {};
+
+    /**
+     *  Private copy assignment, to prevent tampering.
+     */
+    Condition &operator=(const Condition &/*c*/) {return *(this);};
+
+    /**
+     *  Implementation-specific data
+     */
+    void *_prvData;
+
+};
+
+}
+
+#endif // !_OPENTHREADS_CONDITION_