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
atomic_increment(int * pw)27 inline void atomic_increment( int * pw )
28 {
29 // ++*pw;
30
31 _Asm_fetchadd(_FASZ_W, _SEM_REL, pw, +1, _LDHINT_NONE);
32 }
33
atomic_decrement(int * pw)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
atomic_conditional_increment(int * pw)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
sp_counted_base()86 sp_counted_base(): use_count_( 1 ), weak_count_( 1 )
87 {
88 }
89
~sp_counted_base()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
destroy()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_local_deleter( sp_typeinfo const & ti ) = 0;
108 virtual void * get_untyped_deleter() = 0;
109
add_ref_copy()110 void add_ref_copy()
111 {
112 atomic_increment( &use_count_ );
113 }
114
add_ref_lock()115 bool add_ref_lock() // true on success
116 {
117 return atomic_conditional_increment( &use_count_ ) != 0;
118 }
119
release()120 void release() // nothrow
121 {
122 if( atomic_decrement( &use_count_ ) == 0 )
123 {
124 dispose();
125 weak_release();
126 }
127 }
128
weak_add_ref()129 void weak_add_ref() // nothrow
130 {
131 atomic_increment( &weak_count_ );
132 }
133
weak_release()134 void weak_release() // nothrow
135 {
136 if( atomic_decrement( &weak_count_ ) == 0 )
137 {
138 destroy();
139 }
140 }
141
use_count() const142 long use_count() const // nothrow
143 {
144 return static_cast<int const volatile &>( use_count_ ); // TODO use ld.acq here
145 }
146 };
147
148 } // namespace detail
149
150 } // namespace boost
151
152 #endif // #ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_ACC_IA64_HPP_INCLUDED
153