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