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

   1 #ifndef BOOST_DETAIL_SP_COUNTED_BASE_GCC_MIPS_HPP_INCLUDED
   2 #define BOOST_DETAIL_SP_COUNTED_BASE_GCC_MIPS_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 //
  11 //  detail/sp_counted_base_gcc_mips.hpp - g++ on MIPS
  12 //
  13 //  Copyright (c) 2009, Spirent Communications, Inc.
  14 //
  15 //  Distributed under the Boost Software License, Version 1.0. (See
  16 //  accompanying file LICENSE_1_0.txt or copy at
  17 //  http://www.boost.org/LICENSE_1_0.txt)
  18 //
  19 //
  20 //  Lock-free algorithm by Alexander Terekhov
  21 //
  22
  23 #include <boost/smart_ptr/detail/sp_typeinfo_.hpp>
  24 #include <boost/smart_ptr/detail/sp_obsolete.hpp>
  25 #include <boost/config.hpp>
  26
  27 #if defined(BOOST_SP_REPORT_IMPLEMENTATION)
  28
  29 #include <boost/config/pragma_message.hpp>
  30 BOOST_PRAGMA_MESSAGE("Using g++/MIPS sp_counted_base")
  31
  32 #endif
  33
  34 BOOST_SP_OBSOLETE()
  35
  36 namespace boost
  37 {
  38
  39 namespace detail
  40 {
  41
  42 inline void atomic_increment( int * pw )
  43 {
  44     // ++*pw;
  45
  46     int tmp;
  47
  48     __asm__ __volatile__
  49     (
  50         "0:\n\t"
  51         ".set push\n\t"
  52 #if !defined(__mips_isa_rev) || (__mips_isa_rev < 6)
  53         ".set mips2\n\t"
  54 #endif
  55         "ll %0, %1\n\t"
  56         "addiu %0, 1\n\t"
  57         "sc %0, %1\n\t"
  58         ".set pop\n\t"
  59         "beqz %0, 0b":
  60         "=&r"( tmp ), "=m"( *pw ):
  61         "m"( *pw )
  62     );
  63 }
  64
  65 inline int atomic_decrement( int * pw )
  66 {
  67     // return --*pw;
  68
  69     int rv, tmp;
  70
  71     __asm__ __volatile__
  72     (
  73         "0:\n\t"
  74         ".set push\n\t"
  75 #if !defined(__mips_isa_rev) || (__mips_isa_rev < 6)
  76         ".set mips2\n\t"
  77 #endif
  78         "ll %1, %2\n\t"
  79         "addiu %0, %1, -1\n\t"
  80         "sc %0, %2\n\t"
  81         ".set pop\n\t"
  82         "beqz %0, 0b\n\t"
  83         "addiu %0, %1, -1":
  84         "=&r"( rv ), "=&r"( tmp ), "=m"( *pw ):
  85         "m"( *pw ):
  86         "memory"
  87     );
  88
  89     return rv;
  90 }
  91
  92 inline int atomic_conditional_increment( int * pw )
  93 {
  94     // if( *pw != 0 ) ++*pw;
  95     // return *pw;
  96
  97     int rv, tmp;
  98
  99     __asm__ __volatile__
 100     (
 101         "0:\n\t"
 102         ".set push\n\t"
 103 #if !defined(__mips_isa_rev) || (__mips_isa_rev < 6)
 104         ".set mips2\n\t"
 105 #endif
 106         "ll %0, %2\n\t"
 107         "beqz %0, 1f\n\t"
 108         "addiu %1, %0, 1\n\t"
 109         "sc %1, %2\n\t"
 110         ".set pop\n\t"
 111         "beqz %1, 0b\n\t"
 112         "addiu %0, %0, 1\n\t"
 113         "1:":
 114         "=&r"( rv ), "=&r"( tmp ), "=m"( *pw ):
 115         "m"( *pw ):
 116         "memory"
 117     );
 118
 119     return rv;
 120 }
 121
 122 class BOOST_SYMBOL_VISIBLE sp_counted_base
 123 {
 124 private:
 125
 126     sp_counted_base( sp_counted_base const & );
 127     sp_counted_base & operator= ( sp_counted_base const & );
 128
 129     int use_count_;        // #shared
 130     int weak_count_;       // #weak + (#shared != 0)
 131
 132 public:
 133
 134     sp_counted_base(): use_count_( 1 ), weak_count_( 1 )
 135     {
 136     }
 137
 138     virtual ~sp_counted_base() // nothrow
 139     {
 140     }
 141
 142     // dispose() is called when use_count_ drops to zero, to release
 143     // the resources managed by *this.
 144
 145     virtual void dispose() = 0; // nothrow
 146
 147     // destroy() is called when weak_count_ drops to zero.
 148
 149     virtual void destroy() // nothrow
 150     {
 151         delete this;
 152     }
 153
 154     virtual void * get_deleter( sp_typeinfo_ const & ti ) = 0;
 155     virtual void * get_local_deleter( sp_typeinfo_ const & ti ) = 0;
 156     virtual void * get_untyped_deleter() = 0;
 157
 158     void add_ref_copy()
 159     {
 160         atomic_increment( &use_count_ );
 161     }
 162
 163     bool add_ref_lock() // true on success
 164     {
 165         return atomic_conditional_increment( &use_count_ ) != 0;
 166     }
 167
 168     void release() // nothrow
 169     {
 170         if( atomic_decrement( &use_count_ ) == 0 )
 171         {
 172             dispose();
 173             weak_release();
 174         }
 175     }
 176
 177     void weak_add_ref() // nothrow
 178     {
 179         atomic_increment( &weak_count_ );
 180     }
 181
 182     void weak_release() // nothrow
 183     {
 184         if( atomic_decrement( &weak_count_ ) == 0 )
 185         {
 186             destroy();
 187         }
 188     }
 189
 190     long use_count() const // nothrow
 191     {
 192         return static_cast<int const volatile &>( use_count_ );
 193     }
 194 };
 195
 196 } // namespace detail
 197
 198 } // namespace boost
 199
 200 #endif  // #ifndef BOOST_DETAIL_SP_COUNTED_BASE_GCC_MIPS_HPP_INCLUDED