1 | #ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_GCC_SPARC_HPP_INCLUDED |
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2 | #define BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_GCC_SPARC_HPP_INCLUDED |
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3 | |
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4 | // MS compatible compilers support #pragma once |
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5 | |
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6 | #if defined(_MSC_VER) && (_MSC_VER >= 1020) |
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7 | # pragma once |
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8 | #endif |
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9 | |
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10 | // detail/sp_counted_base_gcc_sparc.hpp - g++ on Sparc V8+ |
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11 | // |
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12 | // Copyright (c) 2006 Piotr Wyderski |
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13 | // Copyright (c) 2006 Tomas Puverle |
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14 | // Copyright (c) 2006 Peter Dimov |
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15 | // |
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16 | // Distributed under the Boost Software License, Version 1.0. |
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17 | // See accompanying file LICENSE_1_0.txt or copy at |
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18 | // http://www.boost.org/LICENSE_1_0.txt |
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19 | // |
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20 | // Thanks to Michael van der Westhuizen |
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21 | |
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22 | #include <boost/detail/sp_typeinfo.hpp> |
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23 | #include <inttypes.h> // int32_t |
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24 | |
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25 | namespace boost |
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26 | { |
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27 | |
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28 | namespace detail |
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29 | { |
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30 | |
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31 | inline int32_t compare_and_swap( int32_t * dest_, int32_t compare_, int32_t swap_ ) |
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32 | { |
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33 | __asm__ __volatile__( "cas [%1], %2, %0" |
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34 | : "+r" (swap_) |
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35 | : "r" (dest_), "r" (compare_) |
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36 | : "memory" ); |
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37 | |
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38 | return swap_; |
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39 | } |
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40 | |
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41 | inline int32_t atomic_fetch_and_add( int32_t * pw, int32_t dv ) |
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42 | { |
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43 | // long r = *pw; |
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44 | // *pw += dv; |
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45 | // return r; |
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46 | |
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47 | for( ;; ) |
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48 | { |
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49 | int32_t r = *pw; |
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50 | |
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51 | if( __builtin_expect((compare_and_swap(pw, r, r + dv) == r), 1) ) |
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52 | { |
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53 | return r; |
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54 | } |
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55 | } |
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56 | } |
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57 | |
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58 | inline void atomic_increment( int32_t * pw ) |
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59 | { |
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60 | atomic_fetch_and_add( pw, 1 ); |
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61 | } |
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62 | |
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63 | inline int32_t atomic_decrement( int32_t * pw ) |
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64 | { |
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65 | return atomic_fetch_and_add( pw, -1 ); |
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66 | } |
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67 | |
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68 | inline int32_t atomic_conditional_increment( int32_t * pw ) |
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69 | { |
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70 | // long r = *pw; |
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71 | // if( r != 0 ) ++*pw; |
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72 | // return r; |
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73 | |
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74 | for( ;; ) |
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75 | { |
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76 | int32_t r = *pw; |
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77 | |
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78 | if( r == 0 ) |
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79 | { |
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80 | return r; |
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81 | } |
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82 | |
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83 | if( __builtin_expect( ( compare_and_swap( pw, r, r + 1 ) == r ), 1 ) ) |
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84 | { |
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85 | return r; |
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86 | } |
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87 | } |
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88 | } |
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89 | |
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90 | class sp_counted_base |
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91 | { |
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92 | private: |
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93 | |
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94 | sp_counted_base( sp_counted_base const & ); |
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95 | sp_counted_base & operator= ( sp_counted_base const & ); |
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96 | |
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97 | int32_t use_count_; // #shared |
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98 | int32_t weak_count_; // #weak + (#shared != 0) |
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99 | |
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100 | public: |
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101 | |
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102 | sp_counted_base(): use_count_( 1 ), weak_count_( 1 ) |
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103 | { |
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104 | } |
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105 | |
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106 | virtual ~sp_counted_base() // nothrow |
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107 | { |
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108 | } |
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109 | |
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110 | // dispose() is called when use_count_ drops to zero, to release |
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111 | // the resources managed by *this. |
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112 | |
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113 | virtual void dispose() = 0; // nothrow |
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114 | |
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115 | // destroy() is called when weak_count_ drops to zero. |
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116 | |
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117 | virtual void destroy() // nothrow |
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118 | { |
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119 | delete this; |
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120 | } |
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121 | |
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122 | virtual void * get_deleter( sp_typeinfo const & ti ) = 0; |
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123 | |
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124 | void add_ref_copy() |
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125 | { |
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126 | atomic_increment( &use_count_ ); |
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127 | } |
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128 | |
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129 | bool add_ref_lock() // true on success |
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130 | { |
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131 | return atomic_conditional_increment( &use_count_ ) != 0; |
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132 | } |
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133 | |
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134 | void release() // nothrow |
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135 | { |
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136 | if( atomic_decrement( &use_count_ ) == 1 ) |
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137 | { |
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138 | dispose(); |
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139 | weak_release(); |
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140 | } |
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141 | } |
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142 | |
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143 | void weak_add_ref() // nothrow |
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144 | { |
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145 | atomic_increment( &weak_count_ ); |
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146 | } |
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147 | |
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148 | void weak_release() // nothrow |
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149 | { |
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150 | if( atomic_decrement( &weak_count_ ) == 1 ) |
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151 | { |
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152 | destroy(); |
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153 | } |
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154 | } |
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155 | |
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156 | long use_count() const // nothrow |
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157 | { |
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158 | return const_cast< int32_t const volatile & >( use_count_ ); |
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159 | } |
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160 | }; |
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161 | |
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162 | } // namespace detail |
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163 | |
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164 | } // namespace boost |
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165 | |
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166 | #endif // #ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_GCC_SPARC_HPP_INCLUDED |
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