boost/smart_ptr/detail/spinlock_nt.hpp

   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
  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
  47     inline void lock()
  48     {
  49         BOOST_ASSERT( !locked_ );
  50         locked_ = true;
  51     }
  52
  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
  72         explicit scoped_lock( spinlock & sp ): sp_( sp )
  73         {
  74             sp.lock();
  75         }
  76
  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