/* ====================================================================
 * 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_cxx_Version =
    "$Id: Mutex.cxx,v 1.3 2002/11/09 01:53:00 derekm Exp $";


#include "global.h"
#include "Mutex.hxx"
#include <cassert>
#include <cerrno>


using Vocal::Threads::Mutex;
using Vocal::ReturnCode;
using Vocal::SUCCESS;

static vmutex_t local;

static
void safe()
{
   vmutex_init(&local);
}

Mutex::Mutex()
{
   static pthread_once_t initialized = PTHREAD_ONCE_INIT;
   pthread_once(&initialized, safe);
   
   vmutex_lock(&local);   
   ReturnCode  rc = vmutex_init(&myId);
   assert( rc != EINVAL);
   assert( rc != EBUSY);
   assert( rc != ENOMEM);
   assert( rc != EAGAIN);
   
   assert( rc == SUCCESS );
   vmutex_unlock(&local);   
}

Mutex::~Mutex ()
{
    ReturnCode  rc = vmutex_destroy(&myId);
    assert( rc != EBUSY );  // currently locked 
    assert( rc == SUCCESS );
}


void
Mutex::lock()
{
    ReturnCode  rc = vmutex_lock(&myId);
    assert( rc != EINVAL );
    assert( rc != EDEADLK );
    assert( rc == SUCCESS );
}


void
Mutex::unlock()
{
    ReturnCode  rc = vmutex_unlock(&myId);
    assert( rc != EINVAL );
    assert( rc != EPERM );
    assert( rc == SUCCESS );
}


vmutex_t *
Mutex::getId() const
{
    return ( &myId );
}