smart_ptr/detail/sp_counted_base_nt.hpp

0001 #ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_NT_HPP_INCLUDED
0002 #define BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_NT_HPP_INCLUDED
0003
0004 // MS compatible compilers support #pragma once
0005
0006 #if defined(_MSC_VER) && (_MSC_VER >= 1020)
0007 # pragma once
0008 #endif
0009
0010 //
0011 //  detail/sp_counted_base_nt.hpp
0012 //
0013 //  Copyright (c) 2001, 2002, 2003 Peter Dimov and Multi Media Ltd.
0014 //  Copyright 2004-2005 Peter Dimov
0015 //
0016 // Distributed under the Boost Software License, Version 1.0. (See
0017 // accompanying file LICENSE_1_0.txt or copy at
0018 // http://www.boost.org/LICENSE_1_0.txt)
0019 //
0020
0021 #include <boost/smart_ptr/detail/sp_typeinfo_.hpp>
0022 #include <boost/smart_ptr/detail/sp_noexcept.hpp>
0023 #include <boost/config.hpp>
0024 #include <boost/cstdint.hpp>
0025
0026 #if defined(BOOST_SP_REPORT_IMPLEMENTATION)
0027
0028 #include <boost/config/pragma_message.hpp>
0029 BOOST_PRAGMA_MESSAGE("Using single-threaded, non-atomic sp_counted_base")
0030
0031 #endif
0032
0033 namespace boost
0034 {
0035
0036 namespace detail
0037 {
0038
0039 class BOOST_SYMBOL_VISIBLE sp_counted_base
0040 {
0041 private:
0042
0043     sp_counted_base( sp_counted_base const & );
0044     sp_counted_base & operator= ( sp_counted_base const & );
0045
0046     boost::int_least32_t use_count_;        // #shared
0047     boost::int_least32_t weak_count_;       // #weak + (#shared != 0)
0048
0049 public:
0050
0051     sp_counted_base() BOOST_SP_NOEXCEPT: use_count_( 1 ), weak_count_( 1 )
0052     {
0053     }
0054
0055     virtual ~sp_counted_base() /*BOOST_SP_NOEXCEPT*/
0056     {
0057     }
0058
0059     // dispose() is called when use_count_ drops to zero, to release
0060     // the resources managed by *this.
0061
0062     virtual void dispose() BOOST_SP_NOEXCEPT = 0; // nothrow
0063
0064     // destroy() is called when weak_count_ drops to zero.
0065
0066     virtual void destroy() BOOST_SP_NOEXCEPT // nothrow
0067     {
0068         delete this;
0069     }
0070
0071     virtual void * get_deleter( sp_typeinfo_ const & ti ) BOOST_SP_NOEXCEPT = 0;
0072     virtual void * get_local_deleter( sp_typeinfo_ const & ti ) BOOST_SP_NOEXCEPT = 0;
0073     virtual void * get_untyped_deleter() BOOST_SP_NOEXCEPT = 0;
0074
0075     void add_ref_copy() BOOST_SP_NOEXCEPT
0076     {
0077         ++use_count_;
0078     }
0079
0080     bool add_ref_lock() BOOST_SP_NOEXCEPT // true on success
0081     {
0082         if( use_count_ == 0 ) return false;
0083         ++use_count_;
0084         return true;
0085     }
0086
0087     void release() BOOST_SP_NOEXCEPT
0088     {
0089         if( --use_count_ == 0 )
0090         {
0091             dispose();
0092             weak_release();
0093         }
0094     }
0095
0096     void weak_add_ref() BOOST_SP_NOEXCEPT
0097     {
0098         ++weak_count_;
0099     }
0100
0101     void weak_release() BOOST_SP_NOEXCEPT
0102     {
0103         if( --weak_count_ == 0 )
0104         {
0105             destroy();
0106         }
0107     }
0108
0109     long use_count() const BOOST_SP_NOEXCEPT
0110     {
0111         return use_count_;
0112     }
0113 };
0114
0115 } // namespace detail
0116
0117 } // namespace boost
0118
0119 #endif  // #ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_NT_HPP_INCLUDED