#if !defined(VOCAL_LOCKABLE_HXX)
#define VOCAL_LOCKABLE_HXX

/* ====================================================================
 * The Vovida Software License, Version 1.0 
 * 
 * Copyright (c) 2000 Vovida Networks, Inc.  All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 
 * 3. The names "VOCAL", "Vovida Open Communication Application Library",
 *    and "Vovida Open Communication Application Library (VOCAL)" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact vocal@vovida.org.
 *
 * 4. Products derived from this software may not be called "VOCAL", nor
 *    may "VOCAL" appear in their name, without prior written
 *    permission of Vovida Networks, Inc.
 * 
 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, TITLE AND
 * NON-INFRINGEMENT ARE DISCLAIMED.  IN NO EVENT SHALL VOVIDA
 * NETWORKS, INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT DAMAGES
 * IN EXCESS OF $1,000, NOR FOR ANY INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
 * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 * 
 * ====================================================================
 * 
 * This software consists of voluntary contributions made by Vovida
 * Networks, Inc. and many individuals on behalf of Vovida Networks,
 * Inc.  For more information on Vovida Networks, Inc., please see
 * <http://www.vovida.org/>.
 *
 */


static const char* const Lockable_hxx_Version =
    "$Id: Lockable.hxx,v 1.1 2001/03/23 13:43:10 icahoon Exp $";


#include "NonCopyable.hxx"


/** Infrastructure common to VOCAL.<br><br>
 */
namespace Vocal
{


/** Infrastructure common to VOCAL to create and manage threads.
 */
namespace Threads
{


/** Interface for things that can be locked.<br><br>
 *
 *  If a lockable doesn't naturally have a lock() method, like
 *  a read write mutex, it should use the most restrictive lock,
 *  i.e. a write lock.
 */
class Lockable : public NonCopyable
{
    protected:

        /** Default constructor
         */
    	Lockable();
	
    public:
    
        /** Virtual destructor
         */
	virtual ~Lockable();


        /** You must be able to lock a lockable.
         */
    	virtual void	lock() = 0;


        /** You must be able to unlock a lockable.
         */
	virtual void	unlock() = 0;


        /** You must be able to read lock a lockable. The default
         *  behavior is to call lock().
         */
	virtual void	readlock();
	

        /** You must be able to read lock a lockable. The default
         *  behavior is to call lock().
         */
	virtual void	writelock();
};


} // namespace Process
} // namespace Vocal


#endif // !defined(VOCAL__LOCKABLE_HXX)