Merge c:/dyninst/pc_bluegene/dyninst into dyn_pc_integration
[dyninst.git] / external / boost / detail / spinlock_sync.hpp
1 #ifndef BOOST_DETAIL_SPINLOCK_SYNC_HPP_INCLUDED
2 #define BOOST_DETAIL_SPINLOCK_SYNC_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/detail/yield_k.hpp>
19
20 #if defined( __ia64__ ) && defined( __INTEL_COMPILER )
21 # include <ia64intrin.h>
22 #endif
23
24 namespace boost
25 {
26
27 namespace detail
28 {
29
30 class spinlock
31 {
32 public:
33
34     int v_;
35
36 public:
37
38     bool try_lock()
39     {
40         int r = __sync_lock_test_and_set( &v_, 1 );
41         return r == 0;
42     }
43
44     void lock()
45     {
46         for( unsigned k = 0; !try_lock(); ++k )
47         {
48             boost::detail::yield( k );
49         }
50     }
51
52     void unlock()
53     {
54         __sync_lock_release( &v_ );
55     }
56
57 public:
58
59     class scoped_lock
60     {
61     private:
62
63         spinlock & sp_;
64
65         scoped_lock( scoped_lock const & );
66         scoped_lock & operator=( scoped_lock const & );
67
68     public:
69
70         explicit scoped_lock( spinlock & sp ): sp_( sp )
71         {
72             sp.lock();
73         }
74
75         ~scoped_lock()
76         {
77             sp_.unlock();
78         }
79     };
80 };
81
82 } // namespace detail
83 } // namespace boost
84
85 #define BOOST_DETAIL_SPINLOCK_INIT {0}
86
87 #endif // #ifndef BOOST_DETAIL_SPINLOCK_SYNC_HPP_INCLUDED