source:
vendors/XIOS/current/extern/boost/include/boost/smart_ptr/detail/spinlock_gcc_arm.hpp
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3428
Last change on this file since 3428 was 3428, checked in by rblod, 12 years ago | |
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1 | #ifndef BOOST_SMART_PTR_DETAIL_SPINLOCK_GCC_ARM_HPP_INCLUDED |
2 | #define BOOST_SMART_PTR_DETAIL_SPINLOCK_GCC_ARM_HPP_INCLUDED |
3 | |
4 | // |
5 | // Copyright (c) 2008 Peter Dimov |
6 | // |
7 | // Distributed under the Boost Software License, Version 1.0. |
8 | // See accompanying file LICENSE_1_0.txt or copy at |
9 | // http://www.boost.org/LICENSE_1_0.txt) |
10 | // |
11 | |
12 | #include <boost/smart_ptr/detail/yield_k.hpp> |
13 | |
14 | namespace boost |
15 | { |
16 | |
17 | namespace detail |
18 | { |
19 | |
20 | class spinlock |
21 | { |
22 | public: |
23 | |
24 | int v_; |
25 | |
26 | public: |
27 | |
28 | bool try_lock() |
29 | { |
30 | int r; |
31 | |
32 | __asm__ __volatile__( |
33 | "swp %0, %1, [%2]": |
34 | "=&r"( r ): // outputs |
35 | "r"( 1 ), "r"( &v_ ): // inputs |
36 | "memory", "cc" ); |
37 | |
38 | return r == 0; |
39 | } |
40 | |
41 | void lock() |
42 | { |
43 | for( unsigned k = 0; !try_lock(); ++k ) |
44 | { |
45 | boost::detail::yield( k ); |
46 | } |
47 | } |
48 | |
49 | void unlock() |
50 | { |
51 | __asm__ __volatile__( "" ::: "memory" ); |
52 | *const_cast< int volatile* >( &v_ ) = 0; |
53 | } |
54 | |
55 | public: |
56 | |
57 | class scoped_lock |
58 | { |
59 | private: |
60 | |
61 | spinlock & sp_; |
62 | |
63 | scoped_lock( scoped_lock const & ); |
64 | scoped_lock & operator=( scoped_lock const & ); |
65 | |
66 | public: |
67 | |
68 | explicit scoped_lock( spinlock & sp ): sp_( sp ) |
69 | { |
70 | sp.lock(); |
71 | } |
72 | |
73 | ~scoped_lock() |
74 | { |
75 | sp_.unlock(); |
76 | } |
77 | }; |
78 | }; |
79 | |
80 | } // namespace detail |
81 | } // namespace boost |
82 | |
83 | #define BOOST_DETAIL_SPINLOCK_INIT {0} |
84 | |
85 | #endif // #ifndef BOOST_SMART_PTR_DETAIL_SPINLOCK_GCC_ARM_HPP_INCLUDED |
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