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/smart_ptr/detail/sp_obsolete.hpp>
  20 #include <boost/config.hpp>
  21 #include <machine/sys/inline.h>
  22
  23 #if defined(BOOST_SP_REPORT_IMPLEMENTATION)
  24
  25 #include <boost/config/pragma_message.hpp>
  26 BOOST_PRAGMA_MESSAGE("Using HP aCC++/HP-UX/IA64 sp_counted_base")
  27
  28 #endif
  29
  30 BOOST_SP_OBSOLETE()
  31
  32 namespace boost
  33 {
  34
  35 namespace detail
  36 {
  37
  38 inline void atomic_increment( int * pw )
  39 {
  40     // ++*pw;
  41
  42     _Asm_fetchadd(_FASZ_W, _SEM_REL, pw, +1, _LDHINT_NONE);
  43 }
  44
  45 inline int atomic_decrement( int * pw )
  46 {
  47     // return --*pw;
  48
  49     int r = static_cast<int>(_Asm_fetchadd(_FASZ_W, _SEM_REL, pw, -1, _LDHINT_NONE));
  50     if (1 == r)
  51     {
  52         _Asm_mf();
  53     }
  54
  55     return r - 1;
  56 }
  57
  58 inline int atomic_conditional_increment( int * pw )
  59 {
  60     // if( *pw != 0 ) ++*pw;
  61     // return *pw;
  62
  63     int v = *pw;
  64
  65     for (;;)
  66     {
  67         if (0 == v)
  68         {
  69             return 0;
  70         }
  71
  72         _Asm_mov_to_ar(_AREG_CCV,
  73                        v,
  74                        (_UP_CALL_FENCE | _UP_SYS_FENCE | _DOWN_CALL_FENCE | _DOWN_SYS_FENCE));
  75         int r = static_cast<int>(_Asm_cmpxchg(_SZ_W, _SEM_ACQ, pw, v + 1, _LDHINT_NONE));
  76         if (r == v)
  77         {
  78             return r + 1;
  79         }
  80
  81         v = r;
  82     }
  83 }
  84
  85 class BOOST_SYMBOL_VISIBLE sp_counted_base
  86 {
  87 private:
  88
  89     sp_counted_base( sp_counted_base const & );
  90     sp_counted_base & operator= ( sp_counted_base const & );
  91
  92     int use_count_;        // #shared
  93     int weak_count_;       // #weak + (#shared != 0)
  94
  95 public:
  96
  97     sp_counted_base(): use_count_( 1 ), weak_count_( 1 )
  98     {
  99     }
 100
 101     virtual ~sp_counted_base() // nothrow
 102     {
 103     }
 104
 105     // dispose() is called when use_count_ drops to zero, to release
 106     // the resources managed by *this.
 107
 108     virtual void dispose() = 0; // nothrow
 109
 110     // destroy() is called when weak_count_ drops to zero.
 111
 112     virtual void destroy() // nothrow
 113     {
 114         delete this;
 115     }
 116
 117     virtual void * get_deleter( sp_typeinfo_ const & ti ) = 0;
 118     virtual void * get_local_deleter( sp_typeinfo_ const & ti ) = 0;
 119     virtual void * get_untyped_deleter() = 0;
 120
 121     void add_ref_copy()
 122     {
 123         atomic_increment( &use_count_ );
 124     }
 125
 126     bool add_ref_lock() // true on success
 127     {
 128         return atomic_conditional_increment( &use_count_ ) != 0;
 129     }
 130
 131     void release() // nothrow
 132     {
 133         if( atomic_decrement( &use_count_ ) == 0 )
 134         {
 135             dispose();
 136             weak_release();
 137         }
 138     }
 139
 140     void weak_add_ref() // nothrow
 141     {
 142         atomic_increment( &weak_count_ );
 143     }
 144
 145     void weak_release() // nothrow
 146     {
 147         if( atomic_decrement( &weak_count_ ) == 0 )
 148         {
 149             destroy();
 150         }
 151     }
 152
 153     long use_count() const // nothrow
 154     {
 155         return static_cast<int const volatile &>( use_count_ ); // TODO use ld.acq here
 156     }
 157 };
 158
 159 } // namespace detail
 160
 161 } // namespace boost
 162
 163 #endif  // #ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_ACC_IA64_HPP_INCLUDED