ceph/src/boost/boost/smart_ptr/detail/sp_counted_base_acc_ia64.hpp

   1 #ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_ACC_IA64_HPP_INCLUDED
   2 #define BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_ACC_IA64_HPP_INCLUDED
   3
   4 //
   5 //  detail/sp_counted_base_acc_ia64.hpp - aC++ on HP-UX IA64
   6 //
   7 //  Copyright 2007 Baruch Zilber
   8 //  Copyright 2007 Boris Gubenko
   9 //
  10 //  Distributed under the Boost Software License, Version 1.0. (See
  11 //  accompanying file LICENSE_1_0.txt or copy at
  12 //  http://www.boost.org/LICENSE_1_0.txt)
  13 //
  14 //
  15 //  Lock-free algorithm by Alexander Terekhov
  16 //
  17
  18 #include <boost/detail/sp_typeinfo.hpp>
  19 #include <machine/sys/inline.h>
  20
  21 namespace boost
  22 {
  23
  24 namespace detail
  25 {
  26
  27 inline void atomic_increment( int * pw )
  28 {
  29     // ++*pw;
  30
  31     _Asm_fetchadd(_FASZ_W, _SEM_REL, pw, +1, _LDHINT_NONE);
  32 }
  33
  34 inline int atomic_decrement( int * pw )
  35 {
  36     // return --*pw;
  37
  38     int r = static_cast<int>(_Asm_fetchadd(_FASZ_W, _SEM_REL, pw, -1, _LDHINT_NONE));
  39     if (1 == r)
  40     {
  41         _Asm_mf();
  42     }
  43
  44     return r - 1;
  45 }
  46
  47 inline int atomic_conditional_increment( int * pw )
  48 {
  49     // if( *pw != 0 ) ++*pw;
  50     // return *pw;
  51
  52     int v = *pw;
  53
  54     for (;;)
  55     {
  56         if (0 == v)
  57         {
  58             return 0;
  59         }
  60
  61         _Asm_mov_to_ar(_AREG_CCV,
  62                        v,
  63                        (_UP_CALL_FENCE | _UP_SYS_FENCE | _DOWN_CALL_FENCE | _DOWN_SYS_FENCE));
  64         int r = static_cast<int>(_Asm_cmpxchg(_SZ_W, _SEM_ACQ, pw, v + 1, _LDHINT_NONE));
  65         if (r == v)
  66         {
  67             return r + 1;
  68         }
  69
  70         v = r;
  71     }
  72 }
  73
  74 class sp_counted_base
  75 {
  76 private:
  77
  78     sp_counted_base( sp_counted_base const & );
  79     sp_counted_base & operator= ( sp_counted_base const & );
  80
  81     int use_count_;        // #shared
  82     int weak_count_;       // #weak + (#shared != 0)
  83
  84 public:
  85
  86     sp_counted_base(): use_count_( 1 ), weak_count_( 1 )
  87     {
  88     }
  89
  90     virtual ~sp_counted_base() // nothrow
  91     {
  92     }
  93
  94     // dispose() is called when use_count_ drops to zero, to release
  95     // the resources managed by *this.
  96
  97     virtual void dispose() = 0; // nothrow
  98
  99     // destroy() is called when weak_count_ drops to zero.
 100
 101     virtual void destroy() // nothrow
 102     {
 103         delete this;
 104     }
 105
 106     virtual void * get_deleter( sp_typeinfo const & ti ) = 0;
 107     virtual void * get_local_deleter( sp_typeinfo const & ti ) = 0;
 108     virtual void * get_untyped_deleter() = 0;
 109
 110     void add_ref_copy()
 111     {
 112         atomic_increment( &use_count_ );
 113     }
 114
 115     bool add_ref_lock() // true on success
 116     {
 117         return atomic_conditional_increment( &use_count_ ) != 0;
 118     }
 119
 120     void release() // nothrow
 121     {
 122         if( atomic_decrement( &use_count_ ) == 0 )
 123         {
 124             dispose();
 125             weak_release();
 126         }
 127     }
 128
 129     void weak_add_ref() // nothrow
 130     {
 131         atomic_increment( &weak_count_ );
 132     }
 133
 134     void weak_release() // nothrow
 135     {
 136         if( atomic_decrement( &weak_count_ ) == 0 )
 137         {
 138             destroy();
 139         }
 140     }
 141
 142     long use_count() const // nothrow
 143     {
 144         return static_cast<int const volatile &>( use_count_ ); // TODO use ld.acq here
 145     }
 146 };
 147
 148 } // namespace detail
 149
 150 } // namespace boost
 151
 152 #endif  // #ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_ACC_IA64_HPP_INCLUDED