smart_ptr/detail/spinlock_nt.hpp

0001 #ifndef BOOST_SMART_PTR_DETAIL_SPINLOCK_NT_HPP_INCLUDED
0002 #define BOOST_SMART_PTR_DETAIL_SPINLOCK_NT_HPP_INCLUDED
0003
0004 // MS compatible compilers support #pragma once
0005
0006 #if defined(_MSC_VER) && (_MSC_VER >= 1020)
0007 # pragma once
0008 #endif
0009
0010 //
0011 //  Copyright (c) 2008 Peter Dimov
0012 //
0013 //  Distributed under the Boost Software License, Version 1.0.
0014 //  See accompanying file LICENSE_1_0.txt or copy at
0015 //  http://www.boost.org/LICENSE_1_0.txt)
0016 //
0017
0018 #include <boost/assert.hpp>
0019
0020 #if defined(BOOST_SP_REPORT_IMPLEMENTATION)
0021
0022 #include <boost/config/pragma_message.hpp>
0023 BOOST_PRAGMA_MESSAGE("Using single-threaded spinlock emulation")
0024
0025 #endif
0026
0027 namespace boost
0028 {
0029
0030 namespace detail
0031 {
0032
0033 class spinlock
0034 {
0035 public:
0036
0037     bool locked_;
0038
0039 public:
0040
0041     inline bool try_lock()
0042     {
0043         if( locked_ )
0044         {
0045             return false;
0046         }
0047         else
0048         {
0049             locked_ = true;
0050             return true;
0051         }
0052     }
0053
0054     inline void lock()
0055     {
0056         BOOST_ASSERT( !locked_ );
0057         locked_ = true;
0058     }
0059
0060     inline void unlock()
0061     {
0062         BOOST_ASSERT( locked_ );
0063         locked_ = false;
0064     }
0065
0066 public:
0067
0068     class scoped_lock
0069     {
0070     private:
0071
0072         spinlock & sp_;
0073
0074         scoped_lock( scoped_lock const & );
0075         scoped_lock & operator=( scoped_lock const & );
0076
0077     public:
0078
0079         explicit scoped_lock( spinlock & sp ): sp_( sp )
0080         {
0081             sp.lock();
0082         }
0083
0084         ~scoped_lock()
0085         {
0086             sp_.unlock();
0087         }
0088     };
0089 };
0090
0091 } // namespace detail
0092 } // namespace boost
0093
0094 #define BOOST_DETAIL_SPINLOCK_INIT { false }
0095
0096 #endif // #ifndef BOOST_SMART_PTR_DETAIL_SPINLOCK_NT_HPP_INCLUDED