1 #ifndef BOOST_DETAIL_SP_COUNTED_BASE_GCC_MIPS_HPP_INCLUDED
2 #define BOOST_DETAIL_SP_COUNTED_BASE_GCC_MIPS_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_mips.hpp - g++ on MIPS
12 //
13 // Copyright (c) 2009, Spirent Communications, Inc.
14 //
15 // Distributed under the Boost Software License, Version 1.0. (See
16 // accompanying file LICENSE_1_0.txt or copy at
17 // http://www.boost.org/LICENSE_1_0.txt)
18 //
19 //
20 // Lock-free algorithm by Alexander Terekhov
21 //
22
23 #include <boost/detail/sp_typeinfo.hpp>
24
25 namespace boost
26 {
27
28 namespace detail
29 {
30
atomic_increment(int * pw)31 inline void atomic_increment( int * pw )
32 {
33 // ++*pw;
34
35 int tmp;
36
37 __asm__ __volatile__
38 (
39 "0:\n\t"
40 ".set push\n\t"
41 ".set mips2\n\t"
42 "ll %0, %1\n\t"
43 "addiu %0, 1\n\t"
44 "sc %0, %1\n\t"
45 ".set pop\n\t"
46 "beqz %0, 0b":
47 "=&r"( tmp ), "=m"( *pw ):
48 "m"( *pw )
49 );
50 }
51
atomic_decrement(int * pw)52 inline int atomic_decrement( int * pw )
53 {
54 // return --*pw;
55
56 int rv, tmp;
57
58 __asm__ __volatile__
59 (
60 "0:\n\t"
61 ".set push\n\t"
62 ".set mips2\n\t"
63 "ll %1, %2\n\t"
64 "addiu %0, %1, -1\n\t"
65 "sc %0, %2\n\t"
66 ".set pop\n\t"
67 "beqz %0, 0b\n\t"
68 "addiu %0, %1, -1":
69 "=&r"( rv ), "=&r"( tmp ), "=m"( *pw ):
70 "m"( *pw ):
71 "memory"
72 );
73
74 return rv;
75 }
76
atomic_conditional_increment(int * pw)77 inline int atomic_conditional_increment( int * pw )
78 {
79 // if( *pw != 0 ) ++*pw;
80 // return *pw;
81
82 int rv, tmp;
83
84 __asm__ __volatile__
85 (
86 "0:\n\t"
87 ".set push\n\t"
88 ".set mips2\n\t"
89 "ll %0, %2\n\t"
90 "beqz %0, 1f\n\t"
91 "addiu %1, %0, 1\n\t"
92 "sc %1, %2\n\t"
93 ".set pop\n\t"
94 "beqz %1, 0b\n\t"
95 "addiu %0, %0, 1\n\t"
96 "1:":
97 "=&r"( rv ), "=&r"( tmp ), "=m"( *pw ):
98 "m"( *pw ):
99 "memory"
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
sp_counted_base()117 sp_counted_base(): use_count_( 1 ), weak_count_( 1 )
118 {
119 }
120
~sp_counted_base()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
destroy()132 virtual void destroy() // nothrow
133 {
134 delete this;
135 }
136
137 virtual void * get_deleter( sp_typeinfo const & ti ) = 0;
138 virtual void * get_local_deleter( sp_typeinfo const & ti ) = 0;
139 virtual void * get_untyped_deleter() = 0;
140
add_ref_copy()141 void add_ref_copy()
142 {
143 atomic_increment( &use_count_ );
144 }
145
add_ref_lock()146 bool add_ref_lock() // true on success
147 {
148 return atomic_conditional_increment( &use_count_ ) != 0;
149 }
150
release()151 void release() // nothrow
152 {
153 if( atomic_decrement( &use_count_ ) == 0 )
154 {
155 dispose();
156 weak_release();
157 }
158 }
159
weak_add_ref()160 void weak_add_ref() // nothrow
161 {
162 atomic_increment( &weak_count_ );
163 }
164
weak_release()165 void weak_release() // nothrow
166 {
167 if( atomic_decrement( &weak_count_ ) == 0 )
168 {
169 destroy();
170 }
171 }
172
use_count() const173 long use_count() const // nothrow
174 {
175 return static_cast<int const volatile &>( use_count_ );
176 }
177 };
178
179 } // namespace detail
180
181 } // namespace boost
182
183 #endif // #ifndef BOOST_DETAIL_SP_COUNTED_BASE_GCC_MIPS_HPP_INCLUDED
184