ceph/src/boost/libs/smart_ptr/include/boost/smart_ptr/detail/sp_counted_base_solaris.hpp

   1 #ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_SOLARIS_HPP_INCLUDED
   2 #define BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_SOLARIS_HPP_INCLUDED
   3
   4 //
   5 //  detail/sp_counted_base_solaris.hpp
   6 //   based on: detail/sp_counted_base_w32.hpp
   7 //
   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
  11 //
  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)
  15 //
  16 //
  17 //  Lock-free algorithm by Alexander Terekhov
  18 //
  19 //  Thanks to Ben Hitchings for the #weak + (#shared != 0)
  20 //  formulation
  21 //
  22
  23 #include <boost/detail/sp_typeinfo.hpp>
  24 #include <atomic.h>
  25
  26 namespace boost
  27 {
  28
  29 namespace detail
  30 {
  31
  32 class sp_counted_base
  33 {
  34 private:
  35
  36     sp_counted_base( sp_counted_base const & );
  37     sp_counted_base & operator= ( sp_counted_base const & );
  38
  39     uint32_t use_count_;        // #shared
  40     uint32_t weak_count_;       // #weak + (#shared != 0)
  41
  42 public:
  43
  44     sp_counted_base(): use_count_( 1 ), weak_count_( 1 )
  45     {
  46     }
  47
  48     virtual ~sp_counted_base() // nothrow
  49     {
  50     }
  51
  52     // dispose() is called when use_count_ drops to zero, to release
  53     // the resources managed by *this.
  54
  55     virtual void dispose() = 0; // nothrow
  56
  57     // destroy() is called when weak_count_ drops to zero.
  58
  59     virtual void destroy() // nothrow
  60     {
  61         delete this;
  62     }
  63
  64     virtual void * get_deleter( sp_typeinfo const & ti ) = 0;
  65     virtual void * get_untyped_deleter() = 0;
  66
  67     void add_ref_copy()
  68     {
  69         atomic_inc_32( &use_count_ );
  70     }
  71
  72     bool add_ref_lock() // true on success
  73     {
  74         for( ;; )
  75         {
  76             uint32_t tmp = static_cast< uint32_t const volatile& >( use_count_ );
  77             if( tmp == 0 ) return false;
  78             if( atomic_cas_32( &use_count_, tmp, tmp + 1 ) == tmp ) return true;
  79         }
  80     }
  81
  82     void release() // nothrow
  83     {
  84         if( atomic_dec_32_nv( &use_count_ ) == 0 )
  85         {
  86             dispose();
  87             weak_release();
  88         }
  89     }
  90
  91     void weak_add_ref() // nothrow
  92     {
  93         atomic_inc_32( &weak_count_ );
  94     }
  95
  96     void weak_release() // nothrow
  97     {
  98         if( atomic_dec_32_nv( &weak_count_ ) == 0 )
  99         {
 100             destroy();
 101         }
 102     }
 103
 104     long use_count() const // nothrow
 105     {
 106         return static_cast<long const volatile &>( use_count_ );
 107     }
 108 };
 109
 110 } // namespace detail
 111
 112 } // namespace boost
 113
 114 #endif  // #ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_SOLARIS_HPP_INCLUDED