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