[3408] | 1 | #ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_GCC_PPC_HPP_INCLUDED |
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| 2 | #define BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_GCC_PPC_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_ppc.hpp - g++ on PowerPC |
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| 12 | // |
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| 13 | // Copyright (c) 2001, 2002, 2003 Peter Dimov and Multi Media Ltd. |
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| 14 | // Copyright 2004-2005 Peter Dimov |
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| 15 | // |
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| 16 | // Distributed under the Boost Software License, Version 1.0. (See |
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| 17 | // 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 | // |
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| 21 | // Lock-free algorithm by Alexander Terekhov |
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| 22 | // |
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| 23 | // Thanks to Ben Hitchings for the #weak + (#shared != 0) |
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| 24 | // formulation |
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| 25 | // |
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| 26 | |
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| 27 | #include <boost/detail/sp_typeinfo.hpp> |
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| 28 | |
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| 29 | namespace boost |
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| 30 | { |
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| 31 | |
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| 32 | namespace detail |
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| 33 | { |
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| 34 | |
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| 35 | inline void atomic_increment( int * pw ) |
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| 36 | { |
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| 37 | // ++*pw; |
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| 38 | |
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| 39 | int tmp; |
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| 40 | |
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| 41 | __asm__ |
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| 42 | ( |
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| 43 | "0:\n\t" |
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| 44 | "lwarx %1, 0, %2\n\t" |
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| 45 | "addi %1, %1, 1\n\t" |
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| 46 | "stwcx. %1, 0, %2\n\t" |
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| 47 | "bne- 0b": |
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| 48 | |
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| 49 | "=m"( *pw ), "=&b"( tmp ): |
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| 50 | "r"( pw ), "m"( *pw ): |
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| 51 | "cc" |
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| 52 | ); |
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| 53 | } |
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| 54 | |
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| 55 | inline int atomic_decrement( int * pw ) |
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| 56 | { |
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| 57 | // return --*pw; |
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| 58 | |
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| 59 | int rv; |
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| 60 | |
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| 61 | __asm__ __volatile__ |
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| 62 | ( |
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| 63 | "sync\n\t" |
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| 64 | "0:\n\t" |
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| 65 | "lwarx %1, 0, %2\n\t" |
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| 66 | "addi %1, %1, -1\n\t" |
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| 67 | "stwcx. %1, 0, %2\n\t" |
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| 68 | "bne- 0b\n\t" |
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| 69 | "isync": |
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| 70 | |
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| 71 | "=m"( *pw ), "=&b"( rv ): |
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| 72 | "r"( pw ), "m"( *pw ): |
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| 73 | "memory", "cc" |
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| 74 | ); |
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| 75 | |
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| 76 | return rv; |
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| 77 | } |
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| 78 | |
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| 79 | inline int atomic_conditional_increment( int * pw ) |
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| 80 | { |
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| 81 | // if( *pw != 0 ) ++*pw; |
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| 82 | // return *pw; |
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| 83 | |
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| 84 | int rv; |
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| 85 | |
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| 86 | __asm__ |
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| 87 | ( |
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| 88 | "0:\n\t" |
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| 89 | "lwarx %1, 0, %2\n\t" |
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| 90 | "cmpwi %1, 0\n\t" |
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| 91 | "beq 1f\n\t" |
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| 92 | "addi %1, %1, 1\n\t" |
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| 93 | "1:\n\t" |
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| 94 | "stwcx. %1, 0, %2\n\t" |
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| 95 | "bne- 0b": |
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| 96 | |
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| 97 | "=m"( *pw ), "=&b"( rv ): |
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| 98 | "r"( pw ), "m"( *pw ): |
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| 99 | "cc" |
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| 100 | ); |
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| 101 | |
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| 102 | return rv; |
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| 103 | } |
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| 104 | |
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| 105 | class sp_counted_base |
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| 106 | { |
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| 107 | private: |
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| 108 | |
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| 109 | sp_counted_base( sp_counted_base const & ); |
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| 110 | sp_counted_base & operator= ( sp_counted_base const & ); |
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| 111 | |
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| 112 | int use_count_; // #shared |
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| 113 | int weak_count_; // #weak + (#shared != 0) |
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| 114 | |
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| 115 | public: |
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| 116 | |
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| 117 | sp_counted_base(): use_count_( 1 ), weak_count_( 1 ) |
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| 118 | { |
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| 119 | } |
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| 120 | |
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| 121 | virtual ~sp_counted_base() // nothrow |
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| 122 | { |
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| 123 | } |
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| 124 | |
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| 125 | // dispose() is called when use_count_ drops to zero, to release |
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| 126 | // the resources managed by *this. |
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| 127 | |
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| 128 | virtual void dispose() = 0; // nothrow |
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| 129 | |
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| 130 | // destroy() is called when weak_count_ drops to zero. |
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| 131 | |
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| 132 | virtual void destroy() // nothrow |
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| 133 | { |
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| 134 | delete this; |
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| 135 | } |
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| 136 | |
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| 137 | virtual void * get_deleter( sp_typeinfo const & ti ) = 0; |
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| 138 | |
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| 139 | void add_ref_copy() |
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| 140 | { |
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| 141 | atomic_increment( &use_count_ ); |
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| 142 | } |
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| 143 | |
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| 144 | bool add_ref_lock() // true on success |
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| 145 | { |
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| 146 | return atomic_conditional_increment( &use_count_ ) != 0; |
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| 147 | } |
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| 148 | |
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| 149 | void release() // nothrow |
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| 150 | { |
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| 151 | if( atomic_decrement( &use_count_ ) == 0 ) |
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| 152 | { |
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| 153 | dispose(); |
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| 154 | weak_release(); |
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| 155 | } |
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| 156 | } |
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| 157 | |
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| 158 | void weak_add_ref() // nothrow |
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| 159 | { |
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| 160 | atomic_increment( &weak_count_ ); |
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| 161 | } |
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| 162 | |
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| 163 | void weak_release() // nothrow |
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| 164 | { |
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| 165 | if( atomic_decrement( &weak_count_ ) == 0 ) |
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| 166 | { |
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| 167 | destroy(); |
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| 168 | } |
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| 169 | } |
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| 170 | |
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| 171 | long use_count() const // nothrow |
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| 172 | { |
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| 173 | return static_cast<int const volatile &>( use_count_ ); |
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| 174 | } |
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| 175 | }; |
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| 176 | |
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| 177 | } // namespace detail |
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| 178 | |
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| 179 | } // namespace boost |
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| 180 | |
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| 181 | #endif // #ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_GCC_PPC_HPP_INCLUDED |
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