[3408] | 1 | #ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_ACC_IA64_HPP_INCLUDED |
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| 2 | #define BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_ACC_IA64_HPP_INCLUDED |
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| 3 | |
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| 4 | // |
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| 5 | // detail/sp_counted_base_acc_ia64.hpp - aC++ on HP-UX IA64 |
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| 6 | // |
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| 7 | // Copyright 2007 Baruch Zilber |
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| 8 | // Copyright 2007 Boris Gubenko |
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| 9 | // |
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| 10 | // Distributed under the Boost Software License, Version 1.0. (See |
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| 11 | // accompanying file LICENSE_1_0.txt or copy at |
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| 12 | // http://www.boost.org/LICENSE_1_0.txt) |
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| 13 | // |
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| 14 | // |
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| 15 | // Lock-free algorithm by Alexander Terekhov |
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| 16 | // |
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| 17 | |
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| 18 | #include <boost/detail/sp_typeinfo.hpp> |
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| 19 | #include <machine/sys/inline.h> |
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| 20 | |
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| 21 | namespace boost |
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| 22 | { |
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| 23 | |
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| 24 | namespace detail |
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| 25 | { |
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| 26 | |
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| 27 | inline void atomic_increment( int * pw ) |
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| 28 | { |
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| 29 | // ++*pw; |
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| 30 | |
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| 31 | _Asm_fetchadd(_FASZ_W, _SEM_REL, pw, +1, _LDHINT_NONE); |
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| 32 | } |
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| 33 | |
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| 34 | inline int atomic_decrement( int * pw ) |
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| 35 | { |
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| 36 | // return --*pw; |
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| 37 | |
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| 38 | int r = static_cast<int>(_Asm_fetchadd(_FASZ_W, _SEM_REL, pw, -1, _LDHINT_NONE)); |
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| 39 | if (1 == r) |
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| 40 | { |
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| 41 | _Asm_mf(); |
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| 42 | } |
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| 43 | |
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| 44 | return r - 1; |
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| 45 | } |
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| 46 | |
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| 47 | inline int atomic_conditional_increment( int * pw ) |
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| 48 | { |
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| 49 | // if( *pw != 0 ) ++*pw; |
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| 50 | // return *pw; |
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| 51 | |
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| 52 | int v = *pw; |
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| 53 | |
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| 54 | for (;;) |
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| 55 | { |
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| 56 | if (0 == v) |
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| 57 | { |
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| 58 | return 0; |
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| 59 | } |
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| 60 | |
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| 61 | _Asm_mov_to_ar(_AREG_CCV, |
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| 62 | v, |
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| 63 | (_UP_CALL_FENCE | _UP_SYS_FENCE | _DOWN_CALL_FENCE | _DOWN_SYS_FENCE)); |
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| 64 | int r = static_cast<int>(_Asm_cmpxchg(_SZ_W, _SEM_ACQ, pw, v + 1, _LDHINT_NONE)); |
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| 65 | if (r == v) |
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| 66 | { |
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| 67 | return r + 1; |
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| 68 | } |
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| 69 | |
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| 70 | v = r; |
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| 71 | } |
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| 72 | } |
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| 73 | |
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| 74 | class sp_counted_base |
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| 75 | { |
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| 76 | private: |
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| 77 | |
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| 78 | sp_counted_base( sp_counted_base const & ); |
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| 79 | sp_counted_base & operator= ( sp_counted_base const & ); |
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| 80 | |
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| 81 | int use_count_; // #shared |
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| 82 | int weak_count_; // #weak + (#shared != 0) |
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| 83 | |
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| 84 | public: |
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| 85 | |
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| 86 | sp_counted_base(): use_count_( 1 ), weak_count_( 1 ) |
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| 87 | { |
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| 88 | } |
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| 89 | |
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| 90 | virtual ~sp_counted_base() // nothrow |
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| 91 | { |
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| 92 | } |
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| 93 | |
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| 94 | // dispose() is called when use_count_ drops to zero, to release |
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| 95 | // the resources managed by *this. |
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| 96 | |
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| 97 | virtual void dispose() = 0; // nothrow |
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| 98 | |
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| 99 | // destroy() is called when weak_count_ drops to zero. |
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| 100 | |
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| 101 | virtual void destroy() // nothrow |
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| 102 | { |
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| 103 | delete this; |
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| 104 | } |
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| 105 | |
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| 106 | virtual void * get_deleter( sp_typeinfo const & ti ) = 0; |
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| 107 | |
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| 108 | void add_ref_copy() |
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| 109 | { |
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| 110 | atomic_increment( &use_count_ ); |
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| 111 | } |
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| 112 | |
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| 113 | bool add_ref_lock() // true on success |
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| 114 | { |
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| 115 | return atomic_conditional_increment( &use_count_ ) != 0; |
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| 116 | } |
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| 117 | |
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| 118 | void release() // nothrow |
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| 119 | { |
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| 120 | if( atomic_decrement( &use_count_ ) == 0 ) |
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| 121 | { |
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| 122 | dispose(); |
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| 123 | weak_release(); |
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| 124 | } |
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| 125 | } |
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| 126 | |
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| 127 | void weak_add_ref() // nothrow |
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| 128 | { |
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| 129 | atomic_increment( &weak_count_ ); |
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| 130 | } |
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| 131 | |
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| 132 | void weak_release() // nothrow |
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| 133 | { |
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| 134 | if( atomic_decrement( &weak_count_ ) == 0 ) |
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| 135 | { |
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| 136 | destroy(); |
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| 137 | } |
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| 138 | } |
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| 139 | |
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| 140 | long use_count() const // nothrow |
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| 141 | { |
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| 142 | return static_cast<int const volatile &>( use_count_ ); // TODO use ld.acq here |
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| 143 | } |
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| 144 | }; |
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| 145 | |
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| 146 | } // namespace detail |
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| 147 | |
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| 148 | } // namespace boost |
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| 149 | |
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| 150 | #endif // #ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_ACC_IA64_HPP_INCLUDED |
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