singletonholder.cpp

"More for C++" is a class library that provides some features that are usually common for object ori

//
//  This file is part of the "More for C++" library
//
//  Copyright (c) 1999-2003 by Thorsten Goertz ([e-mail])
//
//  The "More for C++" library is free software; you can redistribute it and/or
//  modify it under the terms of the license that comes with this package.
//
//  Read "license.txt" for more details.
//
//  THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED
//  WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES
//  OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.

////////////////////////////////////////////////////////////////////////////////

#include <more/create.hpp>
#include <more/synchronized.hpp>
#include "singletonholder.hpp"

using namespace more;
using namespace more::os;
using namespace more::util;

////////////////////////////////////////////////////////////////////////////////

void SingletonHolder::init( )
{
  ppMutex = new p<Mutex>( Mutex::create( ) );
  ppSingletons = new p<Singletons>( CREATE Singletons( ) );
}

////////////////////////////////////////////////////////////////////////////////

void SingletonHolder::dispose( )
{
  delete ppSingletons;
  ppSingletons = 0;
  delete ppMutex;
  ppMutex = 0;
}

////////////////////////////////////////////////////////////////////////////////

p<SingletonBase> SingletonHolder::access
(
  SingletonBase*& rpInstance,
  SingletonBase*  pNewInstance,
  bool            bUpdateInstance
)
{
  p<SingletonBase> pResult;

  synchronized( *ppMutex )
  {
    if( bUpdateInstance )
    {
      if( rpInstance != 0 )
      {
        ( *ppSingletons ) -> erase( rpInstance );
      }

      if( pNewInstance != 0 )
      {
        ( *ppSingletons ) -> insert( pNewInstance );
      }

      pResult = rpInstance = pNewInstance;
    }
    else
    {
      pResult = rpInstance;
    }

  } end_synchronized

  return pResult;
}

////////////////////////////////////////////////////////////////////////////////

SingletonHolder SingletonHolder::instance;

////////////////////////////////////////////////////////////////////////////////

p<Mutex>* SingletonHolder::ppMutex = 0;

////////////////////////////////////////////////////////////////////////////////

p<SingletonHolder::Singletons>* SingletonHolder::ppSingletons = 0;

////////////////////////////////////////////////////////////////////////////////