ceph/src/boost/boost/smart_ptr/detail/sp_counted_base_gcc_sparc.hpp

   1 #ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_GCC_SPARC_HPP_INCLUDED
   2 #define BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_GCC_SPARC_HPP_INCLUDED
   3
   4 // MS compatible compilers support #pragma once
   5
   6 #if defined(_MSC_VER) && (_MSC_VER >= 1020)
   7 # pragma once
   8 #endif
   9
  10 //  detail/sp_counted_base_gcc_sparc.hpp - g++ on Sparc V8+
  11 //
  12 //  Copyright (c) 2006 Piotr Wyderski
  13 //  Copyright (c) 2006 Tomas Puverle
  14 //  Copyright (c) 2006 Peter Dimov
  15 //
  16 //  Distributed under the Boost Software License, Version 1.0.
  17 //  See accompanying file LICENSE_1_0.txt or copy at
  18 //  http://www.boost.org/LICENSE_1_0.txt
  19 //
  20 //  Thanks to Michael van der Westhuizen
  21
  22 #include <boost/smart_ptr/detail/sp_typeinfo_.hpp>
  23 #include <boost/smart_ptr/detail/sp_obsolete.hpp>
  24 #include <boost/config.hpp>
  25 #include <inttypes.h> // int32_t
  26
  27 #if defined(BOOST_SP_REPORT_IMPLEMENTATION)
  28
  29 #include <boost/config/pragma_message.hpp>
  30 BOOST_PRAGMA_MESSAGE("Using g++/Sparc sp_counted_base")
  31
  32 #endif
  33
  34 BOOST_SP_OBSOLETE()
  35
  36 namespace boost
  37 {
  38
  39 namespace detail
  40 {
  41
  42 inline int32_t compare_and_swap( int32_t * dest_, int32_t compare_, int32_t swap_ )
  43 {
  44     __asm__ __volatile__( "cas [%1], %2, %0"
  45                         : "+r" (swap_)
  46                         : "r" (dest_), "r" (compare_)
  47                         : "memory" );
  48
  49     return swap_;
  50 }
  51
  52 inline int32_t atomic_fetch_and_add( int32_t * pw, int32_t dv )
  53 {
  54     // long r = *pw;
  55     // *pw += dv;
  56     // return r;
  57
  58     for( ;; )
  59     {
  60         int32_t r = *pw;
  61
  62         if( __builtin_expect((compare_and_swap(pw, r, r + dv) == r), 1) )
  63         {
  64             return r;
  65         }
  66     }
  67 }
  68
  69 inline void atomic_increment( int32_t * pw )
  70 {
  71     atomic_fetch_and_add( pw, 1 );
  72 }
  73
  74 inline int32_t atomic_decrement( int32_t * pw )
  75 {
  76     return atomic_fetch_and_add( pw, -1 );
  77 }
  78
  79 inline int32_t atomic_conditional_increment( int32_t * pw )
  80 {
  81     // long r = *pw;
  82     // if( r != 0 ) ++*pw;
  83     // return r;
  84
  85     for( ;; )
  86     {
  87         int32_t r = *pw;
  88
  89         if( r == 0 )
  90         {
  91             return r;
  92         }
  93
  94         if( __builtin_expect( ( compare_and_swap( pw, r, r + 1 ) == r ), 1 ) )
  95         {
  96             return r;
  97         }
  98     }
  99 }
 100
 101 class BOOST_SYMBOL_VISIBLE sp_counted_base
 102 {
 103 private:
 104
 105     sp_counted_base( sp_counted_base const & );
 106     sp_counted_base & operator= ( sp_counted_base const & );
 107
 108     int32_t use_count_;        // #shared
 109     int32_t weak_count_;       // #weak + (#shared != 0)
 110
 111 public:
 112
 113     sp_counted_base(): use_count_( 1 ), weak_count_( 1 )
 114     {
 115     }
 116
 117     virtual ~sp_counted_base() // nothrow
 118     {
 119     }
 120
 121     // dispose() is called when use_count_ drops to zero, to release
 122     // the resources managed by *this.
 123
 124     virtual void dispose() = 0; // nothrow
 125
 126     // destroy() is called when weak_count_ drops to zero.
 127
 128     virtual void destroy() // nothrow
 129     {
 130         delete this;
 131     }
 132
 133     virtual void * get_deleter( sp_typeinfo_ const & ti ) = 0;
 134     virtual void * get_local_deleter( sp_typeinfo_ const & ti ) = 0;
 135     virtual void * get_untyped_deleter() = 0;
 136
 137     void add_ref_copy()
 138     {
 139         atomic_increment( &use_count_ );
 140     }
 141
 142     bool add_ref_lock() // true on success
 143     {
 144         return atomic_conditional_increment( &use_count_ ) != 0;
 145     }
 146
 147     void release() // nothrow
 148     {
 149         if( atomic_decrement( &use_count_ ) == 1 )
 150         {
 151             dispose();
 152             weak_release();
 153         }
 154     }
 155
 156     void weak_add_ref() // nothrow
 157     {
 158         atomic_increment( &weak_count_ );
 159     }
 160
 161     void weak_release() // nothrow
 162     {
 163         if( atomic_decrement( &weak_count_ ) == 1 )
 164         {
 165             destroy();
 166         }
 167     }
 168
 169     long use_count() const // nothrow
 170     {
 171         return const_cast< int32_t const volatile & >( use_count_ );
 172     }
 173 };
 174
 175 } // namespace detail
 176
 177 } // namespace boost
 178
 179 #endif  // #ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_GCC_SPARC_HPP_INCLUDED