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