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1 | #ifndef BOOST_SMART_PTR_DETAIL_SPINLOCK_W32_HPP_INCLUDED |
2 | #define BOOST_SMART_PTR_DETAIL_SPINLOCK_W32_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 | // Copyright (c) 2008 Peter Dimov | |
12 | // | |
13 | // Distributed under the Boost Software License, Version 1.0. | |
14 | // See accompanying file LICENSE_1_0.txt or copy at | |
15 | // http://www.boost.org/LICENSE_1_0.txt) | |
16 | // | |
17 | ||
18 | #include <boost/smart_ptr/detail/sp_interlocked.hpp> | |
19 | #include <boost/smart_ptr/detail/yield_k.hpp> | |
20 | ||
20effc67 TL |
21 | #if defined(BOOST_SP_REPORT_IMPLEMENTATION) |
22 | ||
23 | #include <boost/config/pragma_message.hpp> | |
24 | BOOST_PRAGMA_MESSAGE("Using Win32 spinlock") | |
25 | ||
26 | #endif | |
27 | ||
7c673cae FG |
28 | // BOOST_COMPILER_FENCE |
29 | ||
30 | #if defined(__INTEL_COMPILER) | |
31 | ||
32 | #define BOOST_COMPILER_FENCE __memory_barrier(); | |
33 | ||
34 | #elif defined( _MSC_VER ) && _MSC_VER >= 1310 | |
35 | ||
36 | extern "C" void _ReadWriteBarrier(); | |
37 | #pragma intrinsic( _ReadWriteBarrier ) | |
38 | ||
39 | #define BOOST_COMPILER_FENCE _ReadWriteBarrier(); | |
40 | ||
41 | #elif defined(__GNUC__) | |
42 | ||
43 | #define BOOST_COMPILER_FENCE __asm__ __volatile__( "" : : : "memory" ); | |
44 | ||
45 | #else | |
46 | ||
47 | #define BOOST_COMPILER_FENCE | |
48 | ||
49 | #endif | |
50 | ||
51 | // | |
52 | ||
53 | namespace boost | |
54 | { | |
55 | ||
56 | namespace detail | |
57 | { | |
58 | ||
59 | class spinlock | |
60 | { | |
61 | public: | |
62 | ||
63 | long v_; | |
64 | ||
65 | public: | |
66 | ||
67 | bool try_lock() | |
68 | { | |
69 | long r = BOOST_SP_INTERLOCKED_EXCHANGE( &v_, 1 ); | |
70 | ||
71 | BOOST_COMPILER_FENCE | |
72 | ||
73 | return r == 0; | |
74 | } | |
75 | ||
76 | void lock() | |
77 | { | |
78 | for( unsigned k = 0; !try_lock(); ++k ) | |
79 | { | |
80 | boost::detail::yield( k ); | |
81 | } | |
82 | } | |
83 | ||
84 | void unlock() | |
85 | { | |
86 | BOOST_COMPILER_FENCE | |
87 | *const_cast< long volatile* >( &v_ ) = 0; | |
88 | } | |
89 | ||
90 | public: | |
91 | ||
92 | class scoped_lock | |
93 | { | |
94 | private: | |
95 | ||
96 | spinlock & sp_; | |
97 | ||
98 | scoped_lock( scoped_lock const & ); | |
99 | scoped_lock & operator=( scoped_lock const & ); | |
100 | ||
101 | public: | |
102 | ||
103 | explicit scoped_lock( spinlock & sp ): sp_( sp ) | |
104 | { | |
105 | sp.lock(); | |
106 | } | |
107 | ||
108 | ~scoped_lock() | |
109 | { | |
110 | sp_.unlock(); | |
111 | } | |
112 | }; | |
113 | }; | |
114 | ||
115 | } // namespace detail | |
116 | } // namespace boost | |
117 | ||
118 | #define BOOST_DETAIL_SPINLOCK_INIT {0} | |
119 | ||
120 | #endif // #ifndef BOOST_SMART_PTR_DETAIL_SPINLOCK_W32_HPP_INCLUDED |