summaryrefslogtreecommitdiffstats
path: root/contrib/src/boost/smart_ptr/detail/spinlock_sync.hpp
blob: f948306a3f24c4eac3dfc8257b2d8e34dde21cf4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
#ifndef BOOST_SMART_PTR_DETAIL_SPINLOCK_SYNC_HPP_INCLUDED

#define BOOST_SMART_PTR_DETAIL_SPINLOCK_SYNC_HPP_INCLUDED


// MS compatible compilers support #pragma once


#if defined(_MSC_VER) && (_MSC_VER >= 1020)

# pragma once

#endif


//

//  Copyright (c) 2008 Peter Dimov

//

//  Distributed under the Boost Software License, Version 1.0.

//  See accompanying file LICENSE_1_0.txt or copy at

//  http://www.boost.org/LICENSE_1_0.txt)

//


#include <boost/smart_ptr/detail/yield_k.hpp>


#if defined( __ia64__ ) && defined( __INTEL_COMPILER )

# include <ia64intrin.h>

#endif


namespace boost
{

namespace detail
{

class spinlock
{
public:

    int v_;

public:

    bool try_lock()
    {
        int r = __sync_lock_test_and_set( &v_, 1 );
        return r == 0;
    }

    void lock()
    {
        for( unsigned k = 0; !try_lock(); ++k )
        {
            boost::detail::yield( k );
        }
    }

    void unlock()
    {
        __sync_lock_release( &v_ );
    }

public:

    class scoped_lock
    {
    private:

        spinlock & sp_;

        scoped_lock( scoped_lock const & );
        scoped_lock & operator=( scoped_lock const & );

    public:

        explicit scoped_lock( spinlock & sp ): sp_( sp )
        {
            sp.lock();
        }

        ~scoped_lock()
        {
            sp_.unlock();
        }
    };
};

} // namespace detail

} // namespace boost


#define BOOST_DETAIL_SPINLOCK_INIT {0}


#endif // #ifndef BOOST_SMART_PTR_DETAIL_SPINLOCK_SYNC_HPP_INCLUDED