Jeff Thompson | 3d613fd | 2013-10-15 15:39:04 -0700 | [diff] [blame] | 1 | #ifndef NDNBOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_CW_PPC_HPP_INCLUDED |
| 2 | #define NDNBOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_CW_PPC_HPP_INCLUDED |
Jeff Thompson | f7d4994 | 2013-08-01 16:47:40 -0700 | [diff] [blame] | 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_cw_ppc.hpp - CodeWarrior on PowerPC |
| 12 | // |
| 13 | // Copyright (c) 2001, 2002, 2003 Peter Dimov and Multi Media Ltd. |
| 14 | // Copyright 2004-2005 Peter Dimov |
| 15 | // |
| 16 | // Distributed under the Boost Software License, Version 1.0. (See |
| 17 | // accompanying file LICENSE_1_0.txt or copy at |
| 18 | // http://www.boost.org/LICENSE_1_0.txt) |
| 19 | // |
| 20 | // |
| 21 | // Lock-free algorithm by Alexander Terekhov |
| 22 | // |
| 23 | // Thanks to Ben Hitchings for the #weak + (#shared != 0) |
| 24 | // formulation |
| 25 | // |
| 26 | |
Jeff Thompson | 2277ce5 | 2013-08-01 17:34:11 -0700 | [diff] [blame] | 27 | #include <ndnboost/detail/sp_typeinfo.hpp> |
Jeff Thompson | f7d4994 | 2013-08-01 16:47:40 -0700 | [diff] [blame] | 28 | |
| 29 | namespace ndnboost |
| 30 | { |
| 31 | |
| 32 | namespace detail |
| 33 | { |
| 34 | |
| 35 | inline void atomic_increment( register long * pw ) |
| 36 | { |
| 37 | register int a; |
| 38 | |
| 39 | asm |
| 40 | { |
| 41 | loop: |
| 42 | |
| 43 | lwarx a, 0, pw |
| 44 | addi a, a, 1 |
| 45 | stwcx. a, 0, pw |
| 46 | bne- loop |
| 47 | } |
| 48 | } |
| 49 | |
| 50 | inline long atomic_decrement( register long * pw ) |
| 51 | { |
| 52 | register int a; |
| 53 | |
| 54 | asm |
| 55 | { |
| 56 | sync |
| 57 | |
| 58 | loop: |
| 59 | |
| 60 | lwarx a, 0, pw |
| 61 | addi a, a, -1 |
| 62 | stwcx. a, 0, pw |
| 63 | bne- loop |
| 64 | |
| 65 | isync |
| 66 | } |
| 67 | |
| 68 | return a; |
| 69 | } |
| 70 | |
| 71 | inline long atomic_conditional_increment( register long * pw ) |
| 72 | { |
| 73 | register int a; |
| 74 | |
| 75 | asm |
| 76 | { |
| 77 | loop: |
| 78 | |
| 79 | lwarx a, 0, pw |
| 80 | cmpwi a, 0 |
| 81 | beq store |
| 82 | |
| 83 | addi a, a, 1 |
| 84 | |
| 85 | store: |
| 86 | |
| 87 | stwcx. a, 0, pw |
| 88 | bne- loop |
| 89 | } |
| 90 | |
| 91 | return a; |
| 92 | } |
| 93 | |
| 94 | class sp_counted_base |
| 95 | { |
| 96 | private: |
| 97 | |
| 98 | sp_counted_base( sp_counted_base const & ); |
| 99 | sp_counted_base & operator= ( sp_counted_base const & ); |
| 100 | |
| 101 | long use_count_; // #shared |
| 102 | long weak_count_; // #weak + (#shared != 0) |
| 103 | |
| 104 | public: |
| 105 | |
| 106 | sp_counted_base(): use_count_( 1 ), weak_count_( 1 ) |
| 107 | { |
| 108 | } |
| 109 | |
| 110 | virtual ~sp_counted_base() // nothrow |
| 111 | { |
| 112 | } |
| 113 | |
| 114 | // dispose() is called when use_count_ drops to zero, to release |
| 115 | // the resources managed by *this. |
| 116 | |
| 117 | virtual void dispose() = 0; // nothrow |
| 118 | |
| 119 | // destroy() is called when weak_count_ drops to zero. |
| 120 | |
| 121 | virtual void destroy() // nothrow |
| 122 | { |
| 123 | delete this; |
| 124 | } |
| 125 | |
| 126 | virtual void * get_deleter( sp_typeinfo const & ti ) = 0; |
| 127 | virtual void * get_untyped_deleter() = 0; |
| 128 | |
| 129 | void add_ref_copy() |
| 130 | { |
| 131 | atomic_increment( &use_count_ ); |
| 132 | } |
| 133 | |
| 134 | bool add_ref_lock() // true on success |
| 135 | { |
| 136 | return atomic_conditional_increment( &use_count_ ) != 0; |
| 137 | } |
| 138 | |
| 139 | void release() // nothrow |
| 140 | { |
| 141 | if( atomic_decrement( &use_count_ ) == 0 ) |
| 142 | { |
| 143 | dispose(); |
| 144 | weak_release(); |
| 145 | } |
| 146 | } |
| 147 | |
| 148 | void weak_add_ref() // nothrow |
| 149 | { |
| 150 | atomic_increment( &weak_count_ ); |
| 151 | } |
| 152 | |
| 153 | void weak_release() // nothrow |
| 154 | { |
| 155 | if( atomic_decrement( &weak_count_ ) == 0 ) |
| 156 | { |
| 157 | destroy(); |
| 158 | } |
| 159 | } |
| 160 | |
| 161 | long use_count() const // nothrow |
| 162 | { |
| 163 | return static_cast<long const volatile &>( use_count_ ); |
| 164 | } |
| 165 | }; |
| 166 | |
| 167 | } // namespace detail |
| 168 | |
| 169 | } // namespace ndnboost |
| 170 | |
Jeff Thompson | 3d613fd | 2013-10-15 15:39:04 -0700 | [diff] [blame] | 171 | #endif // #ifndef NDNBOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_CW_PPC_HPP_INCLUDED |