Chris@16: #ifndef BOOST_STATECHART_DETAIL_COUNTED_BASE_HPP_INCLUDED
Chris@16: #define BOOST_STATECHART_DETAIL_COUNTED_BASE_HPP_INCLUDED
Chris@16: //////////////////////////////////////////////////////////////////////////////
Chris@16: // Copyright 2002-2006 Andreas Huber Doenni
Chris@16: // Distributed under the Boost Software License, Version 1.0. (See accompany-
Chris@16: // ing file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@16: //////////////////////////////////////////////////////////////////////////////
Chris@16: 
Chris@16: 
Chris@16: 
Chris@16: #include <boost/detail/atomic_count.hpp>
Chris@16: #include <boost/config.hpp> // BOOST_NO_ARGUMENT_DEPENDENT_LOOKUP
Chris@16: 
Chris@16: 
Chris@16: 
Chris@16: namespace boost
Chris@16: {
Chris@16: namespace statechart
Chris@16: {
Chris@16: namespace detail
Chris@16: {
Chris@16: 
Chris@16: 
Chris@16:   
Chris@16: template< bool NeedsLocking >
Chris@16: struct count_base
Chris@16: {
Chris@16:   count_base() : count_( 0 ) {}
Chris@16:   mutable boost::detail::atomic_count count_;
Chris@16: };
Chris@16: 
Chris@16: template<>
Chris@16: struct count_base< false >
Chris@16: {
Chris@16:   count_base() : count_( 0 ) {}
Chris@16:   mutable long count_;
Chris@16: };
Chris@16: 
Chris@16: //////////////////////////////////////////////////////////////////////////////
Chris@16: template< bool NeedsLocking = true >
Chris@16: class counted_base : private count_base< NeedsLocking >
Chris@16: {
Chris@16:   typedef count_base< NeedsLocking > base_type;
Chris@16:   public:
Chris@16:     //////////////////////////////////////////////////////////////////////////
Chris@16:     bool ref_counted() const
Chris@16:     {
Chris@16:       return base_type::count_ != 0;
Chris@16:     }
Chris@16: 
Chris@16:     long ref_count() const
Chris@16:     {
Chris@16:       return base_type::count_;
Chris@16:     }
Chris@16: 
Chris@16:   protected:
Chris@16:     //////////////////////////////////////////////////////////////////////////
Chris@16:     counted_base() {}
Chris@16:     ~counted_base() {}
Chris@16: 
Chris@16:     // do nothing copy implementation is intentional (the number of
Chris@16:     // referencing pointers of the source and the destination is not changed
Chris@16:     // through the copy operation)
Chris@16:     counted_base( const counted_base & ) : base_type() {}
Chris@16:     counted_base & operator=( const counted_base & ) { return *this; }
Chris@16: 
Chris@16:   public:
Chris@16:     //////////////////////////////////////////////////////////////////////////
Chris@16:     // The following declarations should be private.
Chris@16:     // They are only public because many compilers lack template friends.
Chris@16:     //////////////////////////////////////////////////////////////////////////
Chris@16:     void add_ref() const
Chris@16:     {
Chris@16:       ++base_type::count_;
Chris@16:     }
Chris@16: 
Chris@16:     bool release() const
Chris@16:     {
Chris@16:       BOOST_ASSERT( base_type::count_ > 0 );
Chris@16:       return --base_type::count_ == 0;
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: 
Chris@16: 
Chris@16: } // namespace detail
Chris@16: } // namespace statechart
Chris@16: } // namespace boost
Chris@16: 
Chris@16: 
Chris@16: 
Chris@16: #endif