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sglLock.hpp

/*****************************************************************************
 * SGL: A Scene Graph Library
 *
 * Copyright (C) 1997-2001  Scott McMillan   All Rights Reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * 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 GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the Free
 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *****************************************************************************
 *     File: sglLock.hpp
 *   Author: Tom Stimson
 *  Created: 22 October 2000
 *  Summary: Binary semaphore.
 *****************************************************************************/

/*
 * Copyright (c) 1997-1999
 * Silicon Graphics Computer Systems, Inc.
 *
 * Permission to use, copy, modify, distribute and sell this software
 * and its documentation for any purpose is hereby granted without fee,
 * provided that the above copyright notice appear in all copies and
 * that both that copyright notice and this permission notice appear
 * in supporting documentation.  Silicon Graphics makes no
 * representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied warranty.
 */


#ifndef __SGL_LOCK_HPP
#define __SGL_LOCK_HPP

#include <sgl.h>

#if defined(sgi)
# include <mutex.h>
# include <time.h>
#elif defined(vxw)
# include <semLib.h>
#elif defined(WIN32)
//do nothing
#else // assume posix
# include <pthread.h>
#endif

//----------------------------------------------------------------------------

class SGL_DLL_API sglLock
{
public:
   sglLock();
   ~sglLock();

   void acquire();

   void release();

private:
   // not implemented
   sglLock(const sglLock &);
   sglLock &operator=(const sglLock &);

private:
#if defined(WIN32) || defined(sgi)
   volatile unsigned long m_lock;
   unsigned long m_last;
   unsigned long m_max;
   static unsigned long s_low_max;
   static unsigned long s_high_max;
#elif defined(vxw)
   SEM_ID m_lock;
#else // assume posix
   pthread_mutex_t m_lock;
#endif
};

#endif

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