Chris@16: #ifndef BOOST_SMART_PTR_DETAIL_SPINLOCK_W32_HPP_INCLUDED
Chris@16: #define BOOST_SMART_PTR_DETAIL_SPINLOCK_W32_HPP_INCLUDED
Chris@16: 
Chris@16: // MS compatible compilers support #pragma once
Chris@16: 
Chris@16: #if defined(_MSC_VER) && (_MSC_VER >= 1020)
Chris@16: # pragma once
Chris@16: #endif
Chris@16: 
Chris@16: //
Chris@16: //  Copyright (c) 2008 Peter Dimov
Chris@16: //
Chris@16: //  Distributed under the Boost Software License, Version 1.0.
Chris@16: //  See accompanying file LICENSE_1_0.txt or copy at
Chris@16: //  http://www.boost.org/LICENSE_1_0.txt)
Chris@16: //
Chris@16: 
Chris@101: #include <boost/smart_ptr/detail/sp_interlocked.hpp>
Chris@16: #include <boost/smart_ptr/detail/yield_k.hpp>
Chris@16: 
Chris@16: // BOOST_COMPILER_FENCE
Chris@16: 
Chris@16: #if defined(__INTEL_COMPILER)
Chris@16: 
Chris@16: #define BOOST_COMPILER_FENCE __memory_barrier();
Chris@16: 
Chris@16: #elif defined( _MSC_VER ) && _MSC_VER >= 1310
Chris@16: 
Chris@16: extern "C" void _ReadWriteBarrier();
Chris@16: #pragma intrinsic( _ReadWriteBarrier )
Chris@16: 
Chris@16: #define BOOST_COMPILER_FENCE _ReadWriteBarrier();
Chris@16: 
Chris@16: #elif defined(__GNUC__)
Chris@16: 
Chris@16: #define BOOST_COMPILER_FENCE __asm__ __volatile__( "" : : : "memory" );
Chris@16: 
Chris@16: #else
Chris@16: 
Chris@16: #define BOOST_COMPILER_FENCE
Chris@16: 
Chris@16: #endif
Chris@16: 
Chris@16: //
Chris@16: 
Chris@16: namespace boost
Chris@16: {
Chris@16: 
Chris@16: namespace detail
Chris@16: {
Chris@16: 
Chris@16: class spinlock
Chris@16: {
Chris@16: public:
Chris@16: 
Chris@16:     long v_;
Chris@16: 
Chris@16: public:
Chris@16: 
Chris@16:     bool try_lock()
Chris@16:     {
Chris@101:         long r = BOOST_SP_INTERLOCKED_EXCHANGE( &v_, 1 );
Chris@16: 
Chris@16:         BOOST_COMPILER_FENCE
Chris@16: 
Chris@16:         return r == 0;
Chris@16:     }
Chris@16: 
Chris@16:     void lock()
Chris@16:     {
Chris@16:         for( unsigned k = 0; !try_lock(); ++k )
Chris@16:         {
Chris@16:             boost::detail::yield( k );
Chris@16:         }
Chris@16:     }
Chris@16: 
Chris@16:     void unlock()
Chris@16:     {
Chris@16:         BOOST_COMPILER_FENCE
Chris@16:         *const_cast< long volatile* >( &v_ ) = 0;
Chris@16:     }
Chris@16: 
Chris@16: public:
Chris@16: 
Chris@16:     class scoped_lock
Chris@16:     {
Chris@16:     private:
Chris@16: 
Chris@16:         spinlock & sp_;
Chris@16: 
Chris@16:         scoped_lock( scoped_lock const & );
Chris@16:         scoped_lock & operator=( scoped_lock const & );
Chris@16: 
Chris@16:     public:
Chris@16: 
Chris@16:         explicit scoped_lock( spinlock & sp ): sp_( sp )
Chris@16:         {
Chris@16:             sp.lock();
Chris@16:         }
Chris@16: 
Chris@16:         ~scoped_lock()
Chris@16:         {
Chris@16:             sp_.unlock();
Chris@16:         }
Chris@16:     };
Chris@16: };
Chris@16: 
Chris@16: } // namespace detail
Chris@16: } // namespace boost
Chris@16: 
Chris@16: #define BOOST_DETAIL_SPINLOCK_INIT {0}
Chris@16: 
Chris@16: #endif // #ifndef BOOST_SMART_PTR_DETAIL_SPINLOCK_W32_HPP_INCLUDED