+/*! ========================================================================
+** Extended Template and Library
+** Mutex Abstraction Class Implementation
+** $Id$
+**
+** Copyright (c) 2002 Robert B. Quattlebaum Jr.
+**
+** This package is free software; you can redistribute it and/or
+** modify it under the terms of the GNU General Public License as
+** published by the Free Software Foundation; either version 2 of
+** the License, or (at your option) any later version.
+**
+** This package 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
+** General Public License for more details.
+**
+** === N O T E S ===========================================================
+**
+** This is an internal header file, included by other ETL headers.
+** You should not attempt to use it directly.
+**
+** ========================================================================= */
+
+/* === S T A R T =========================================================== */
+
+#ifndef __ETL__RWLOCK_H_
+#define __ETL__RWLOCK_H_
+
+/* === H E A D E R S ======================================================= */
+
+/* === M A C R O S ========================================================= */
+
+/* === C L A S S E S & S T R U C T S ======================================= */
+
+_ETL_BEGIN_NAMESPACE
+
+class read_write_lock : private Mutex
+{
+public:
+
+ read_write_lock()
+ { }
+
+ ~read_write_lock()
+ { }
+
+ //! Exception-safe read-lock class
+ class read_lock
+ {
+ read_write_lock *_mtx;
+ public:
+ read_lock(read_write_lock &x):_mtx(&x) { _mtx->lock_read(); }
+ ~read_lock() { _mtx->unlock_read(); }
+ read_write_lock &get() { return *_mtx; }
+ };
+
+ //! Exception-safe write-lock class
+ class write_lock
+ {
+ read_write_lock *_mtx;
+ public:
+ write_lock(read_write_lock &x):_mtx(&x) { _mtx->lock_write(); }
+ ~read_lock() { _mtx->unlock_write(); }
+ read_write_lock &get() { return *_mtx; }
+ };
+
+ void lock_read(void)
+ { lock_mutex(); }
+
+ void lock_write(void)
+ { lock_mutex(); }
+
+ bool try_lock_read(void)
+ { return try_lock_mutex(); }
+
+ bool try_lock_write(void)
+ { return try_lock_mutex(); }
+
+ void unlock_write(void)
+ { unlock_mutex(); }
+
+ void unlock_read(void)
+ { unlock_mutex(); }
+};
+
+_ETL_END_NAMESPACE
+
+/* === E X T E R N S ======================================================= */
+
+/* === E N D =============================================================== */
+
+#endif