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