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