text: //===========================================================================
  /*
      Software License Agreement (BSD License)
      Copyright (c) 2003-2012, CHAI3D.
      (www.chai3d.org)
  
      All rights reserved.
  
      Redistribution and use in source and binary forms, with or without
      modification, are permitted provided that the following conditions
      are met:
  
      * Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.
  
      * 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.
  
      * Neither the name of CHAI3D nor the names of its contributors may
      be used to endorse or promote products derived from this software
      without specific prior written permission.
  
      THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
      "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
      LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
      FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
      COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 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. 
  
      \author    <http://www.chai3d.org>
      \author    Sebastien Grange
      \version   $MAJOR.$MINOR.$RELEASE $Rev: 799 $
  */
  //===========================================================================
  
  //---------------------------------------------------------------------------
  #include "system/CMutex.h"
  //---------------------------------------------------------------------------
  
  //===========================================================================
  /*!
      Constructor of cMutex.
  */
  //===========================================================================
  cMutex::cMutex()
  {
  #if defined(WIN32) | defined(WIN64)
      InitializeCriticalSection(&m_mutex);
  #endif
  
  #if defined (LINUX) || defined (MACOSX)
      pthread_mutexattr_t mattr;
      pthread_mutexattr_init(&mattr);
      pthread_mutexattr_settype(&mattr, PTHREAD_MUTEX_RECURSIVE);
      pthread_mutexattr_setprotocol(&mattr, PTHREAD_PRIO_INHERIT);
      pthread_mutex_init(&m_mutex, &mattr);
  #endif
  }
  
  
  //===========================================================================
  /*!
      Destructor of cMutex.
  */
  //===========================================================================
  cMutex::~cMutex()
  {
  #if defined(WIN32) | defined(WIN64)
      DeleteCriticalSection(&m_mutex);
  #endif
  
  #if defined (LINUX) || defined (MACOSX)
      pthread_mutex_destroy(&m_mutex);
  #endif
  }
  
  
  //===========================================================================
  /*!
      Requests ownership of the mutex. The calling thread will wait until
      the mutex becomes available, or until a system timeout occurs (in which
      case the call is not successful).
  
      \return  \b true if successful, \b false otherwise.
  */
  //===========================================================================
  bool cMutex::acquire()
  {
      // create thread
  #if defined(WIN32) | defined(WIN64)
      EnterCriticalSection(&m_mutex);
      return true;
  #endif
  
  #if defined (LINUX) || defined (MACOSX)
      return (pthread_mutex_lock(&m_mutex) == 0);
  #endif
  }
  
  
  //===========================================================================
  /*!
      Requests ownership of the mutex. The calling thread will return \b false
      immediately if the mutex is already owned by another thread. Otherwise,
      the calling thread is granted ownership of the mutex.
  
      \return  \b true if successful, \b false otherwise.
  */
  //===========================================================================
  bool cMutex::tryAcquire()
  {
      // create thread
  #if defined(WIN32) | defined(WIN64)
      return (TryEnterCriticalSection(&m_mutex) != 0);
  #endif
  
  #if defined (LINUX) || defined (MACOSX)
      return (pthread_mutex_trylock(&m_mutex) == 0);
  #endif
  }
  
  
  //===========================================================================
  /*!
      Makes the calling thread release ownership of the mutex.
  */
  //===========================================================================
  void cMutex::release()
  {
      // create thread
  #if defined(WIN32) | defined(WIN64)
      LeaveCriticalSection(&m_mutex);
  #endif
  
  #if defined (LINUX) || defined (MACOSX)
      pthread_mutex_unlock(&m_mutex);
  #endif
  }
  