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