#if !defined(VOCAL_MUTEX_HXX)
#define VOCAL_MUTEX_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 Mutex_hxx_Version =
    "$Id: Mutex.hxx,v 1.2 2001/03/23 20:22:41 icahoon Exp $";


#include "global.h"
#include "vthread.h"
#include "Lockable.hxx"


/** Infrastructure common to VOCAL.
 */
namespace Vocal 
{


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


/** Defines a simple mutex class which provides 'fast' mutex functionality, 
 *  meaning that if the calling thread already has the mutex locked, a call 
 *  to lock will block the thread forever.<br><br>
 */
class Mutex : public Lockable
{
    public:

        /** Create a VMutex object initialized with operating system
         *  dependent defaults (if any).
         */
        Mutex();


        /**
         ** Delete a VMutex object
         */
        virtual ~Mutex();


        /** Lock the mutex. If the mutex is currently unlocked, it
         *  becomes locked and owned by the calling thread, and
         *  lock returns immediately. If the mutex is already locked by 
         *  another thread, lock suspends the calling thread until the 
         *  mutex is unlocked. If the mutex is already locked by the calling 
         *  thread, the calling thread blocks forever.
         */
        virtual void    lock();


        /** Unlock the mutex. The mutex is assumed to be locked and owned
         *  by the calling thread, meaning that a call to unlock always
         *  returns it to the unlocked state. 
         */
        virtual void    unlock();


        /** Returns the operating system dependent unique id of the mutex.
         */
        vmutex_t    *   getId() const;


    private:


        mutable vmutex_t    myId;
};


} // namespace Threads
} // namespace Vocal


#endif // !defined(VOCAL_MUTEX_HXX)