1 #ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_AIX_HPP_INCLUDED
2 #define BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_AIX_HPP_INCLUDED
5 // detail/sp_counted_base_aix.hpp
6 // based on: detail/sp_counted_base_w32.hpp
8 // Copyright (c) 2001, 2002, 2003 Peter Dimov and Multi Media Ltd.
9 // Copyright 2004-2005 Peter Dimov
10 // Copyright 2006 Michael van der Westhuizen
12 // Distributed under the Boost Software License, Version 1.0. (See
13 // accompanying file LICENSE_1_0.txt or copy at
14 // http://www.boost.org/LICENSE_1_0.txt)
17 // Lock-free algorithm by Alexander Terekhov
19 // Thanks to Ben Hitchings for the #weak + (#shared != 0)
23 #include <boost/detail/sp_typeinfo.hpp>
25 #include <sys/atomic_op.h>
33 inline void atomic_increment( int32_t* pw )
37 fetch_and_add( pw, 1 );
40 inline int32_t atomic_decrement( int32_t * pw )
44 int32_t originalValue;
47 originalValue = fetch_and_add( pw, -1 );
50 return (originalValue - 1);
53 inline int32_t atomic_conditional_increment( int32_t * pw )
55 // if( *pw != 0 ) ++*pw;
58 int32_t tmp = fetch_and_add( pw, 0 );
61 if( tmp == 0 ) return 0;
62 if( compare_and_swap( pw, &tmp, tmp + 1 ) ) return (tmp + 1);
70 sp_counted_base( sp_counted_base const & );
71 sp_counted_base & operator= ( sp_counted_base const & );
73 int32_t use_count_; // #shared
74 int32_t weak_count_; // #weak + (#shared != 0)
78 sp_counted_base(): use_count_( 1 ), weak_count_( 1 )
82 virtual ~sp_counted_base() // nothrow
86 // dispose() is called when use_count_ drops to zero, to release
87 // the resources managed by *this.
89 virtual void dispose() = 0; // nothrow
91 // destroy() is called when weak_count_ drops to zero.
93 virtual void destroy() // nothrow
98 virtual void * get_deleter( sp_typeinfo const & ti ) = 0;
99 virtual void * get_local_deleter( sp_typeinfo const & ti ) = 0;
100 virtual void * get_untyped_deleter() = 0;
104 atomic_increment( &use_count_ );
107 bool add_ref_lock() // true on success
109 return atomic_conditional_increment( &use_count_ ) != 0;
112 void release() // nothrow
114 if( atomic_decrement( &use_count_ ) == 0 )
121 void weak_add_ref() // nothrow
123 atomic_increment( &weak_count_ );
126 void weak_release() // nothrow
128 if( atomic_decrement( &weak_count_ ) == 0 )
134 long use_count() const // nothrow
136 return fetch_and_add( const_cast<int32_t*>(&use_count_), 0 );
140 } // namespace detail
144 #endif // #ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_AIX_HPP_INCLUDED