1 #ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_GCC_SPARC_HPP_INCLUDED
2 #define BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_GCC_SPARC_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 // detail/sp_counted_base_gcc_sparc.hpp - g++ on Sparc V8+
11 //
12 // Copyright (c) 2006 Piotr Wyderski
13 // Copyright (c) 2006 Tomas Puverle
14 // Copyright (c) 2006 Peter Dimov
15 //
16 // Distributed under the Boost Software License, Version 1.0.
17 // See accompanying file LICENSE_1_0.txt or copy at
18 // http://www.boost.org/LICENSE_1_0.txt
19 //
20 // Thanks to Michael van der Westhuizen
21
22 #include <boost/detail/sp_typeinfo.hpp>
23 #include <inttypes.h> // int32_t
24
25 namespace boost
26 {
27
28 namespace detail
29 {
30
compare_and_swap(int32_t * dest_,int32_t compare_,int32_t swap_)31 inline int32_t compare_and_swap( int32_t * dest_, int32_t compare_, int32_t swap_ )
32 {
33 __asm__ __volatile__( "cas [%1], %2, %0"
34 : "+r" (swap_)
35 : "r" (dest_), "r" (compare_)
36 : "memory" );
37
38 return swap_;
39 }
40
atomic_fetch_and_add(int32_t * pw,int32_t dv)41 inline int32_t atomic_fetch_and_add( int32_t * pw, int32_t dv )
42 {
43 // long r = *pw;
44 // *pw += dv;
45 // return r;
46
47 for( ;; )
48 {
49 int32_t r = *pw;
50
51 if( __builtin_expect((compare_and_swap(pw, r, r + dv) == r), 1) )
52 {
53 return r;
54 }
55 }
56 }
57
atomic_increment(int32_t * pw)58 inline void atomic_increment( int32_t * pw )
59 {
60 atomic_fetch_and_add( pw, 1 );
61 }
62
atomic_decrement(int32_t * pw)63 inline int32_t atomic_decrement( int32_t * pw )
64 {
65 return atomic_fetch_and_add( pw, -1 );
66 }
67
atomic_conditional_increment(int32_t * pw)68 inline int32_t atomic_conditional_increment( int32_t * pw )
69 {
70 // long r = *pw;
71 // if( r != 0 ) ++*pw;
72 // return r;
73
74 for( ;; )
75 {
76 int32_t r = *pw;
77
78 if( r == 0 )
79 {
80 return r;
81 }
82
83 if( __builtin_expect( ( compare_and_swap( pw, r, r + 1 ) == r ), 1 ) )
84 {
85 return r;
86 }
87 }
88 }
89
90 class sp_counted_base
91 {
92 private:
93
94 sp_counted_base( sp_counted_base const & );
95 sp_counted_base & operator= ( sp_counted_base const & );
96
97 int32_t use_count_; // #shared
98 int32_t weak_count_; // #weak + (#shared != 0)
99
100 public:
101
sp_counted_base()102 sp_counted_base(): use_count_( 1 ), weak_count_( 1 )
103 {
104 }
105
~sp_counted_base()106 virtual ~sp_counted_base() // nothrow
107 {
108 }
109
110 // dispose() is called when use_count_ drops to zero, to release
111 // the resources managed by *this.
112
113 virtual void dispose() = 0; // nothrow
114
115 // destroy() is called when weak_count_ drops to zero.
116
destroy()117 virtual void destroy() // nothrow
118 {
119 delete this;
120 }
121
122 virtual void * get_deleter( sp_typeinfo const & ti ) = 0;
123 virtual void * get_local_deleter( sp_typeinfo const & ti ) = 0;
124 virtual void * get_untyped_deleter() = 0;
125
add_ref_copy()126 void add_ref_copy()
127 {
128 atomic_increment( &use_count_ );
129 }
130
add_ref_lock()131 bool add_ref_lock() // true on success
132 {
133 return atomic_conditional_increment( &use_count_ ) != 0;
134 }
135
release()136 void release() // nothrow
137 {
138 if( atomic_decrement( &use_count_ ) == 1 )
139 {
140 dispose();
141 weak_release();
142 }
143 }
144
weak_add_ref()145 void weak_add_ref() // nothrow
146 {
147 atomic_increment( &weak_count_ );
148 }
149
weak_release()150 void weak_release() // nothrow
151 {
152 if( atomic_decrement( &weak_count_ ) == 1 )
153 {
154 destroy();
155 }
156 }
157
use_count() const158 long use_count() const // nothrow
159 {
160 return const_cast< int32_t const volatile & >( use_count_ );
161 }
162 };
163
164 } // namespace detail
165
166 } // namespace boost
167
168 #endif // #ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_GCC_SPARC_HPP_INCLUDED
169