1 #ifndef BOOST_SMART_PTR_DETAIL_SPINLOCK_NT_HPP_INCLUDED
2 #define BOOST_SMART_PTR_DETAIL_SPINLOCK_NT_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/assert.hpp>
19 
20 namespace boost
21 {
22 
23 namespace detail
24 {
25 
26 class spinlock
27 {
28 public:
29 
30     bool locked_;
31 
32 public:
33 
try_lock()34     inline bool try_lock()
35     {
36         if( locked_ )
37         {
38             return false;
39         }
40         else
41         {
42             locked_ = true;
43             return true;
44         }
45     }
46 
lock()47     inline void lock()
48     {
49         BOOST_ASSERT( !locked_ );
50         locked_ = true;
51     }
52 
unlock()53     inline void unlock()
54     {
55         BOOST_ASSERT( locked_ );
56         locked_ = false;
57     }
58 
59 public:
60 
61     class scoped_lock
62     {
63     private:
64 
65         spinlock & sp_;
66 
67         scoped_lock( scoped_lock const & );
68         scoped_lock & operator=( scoped_lock const & );
69 
70     public:
71 
scoped_lock(spinlock & sp)72         explicit scoped_lock( spinlock & sp ): sp_( sp )
73         {
74             sp.lock();
75         }
76 
~scoped_lock()77         ~scoped_lock()
78         {
79             sp_.unlock();
80         }
81     };
82 };
83 
84 } // namespace detail
85 } // namespace boost
86 
87 #define BOOST_DETAIL_SPINLOCK_INIT { false }
88 
89 #endif // #ifndef BOOST_SMART_PTR_DETAIL_SPINLOCK_NT_HPP_INCLUDED
90