| #ifndef BOOST_SMART_PTR_DETAIL_SPINLOCK_W32_HPP_INCLUDED |
| #define BOOST_SMART_PTR_DETAIL_SPINLOCK_W32_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/sp_interlocked.hpp> |
| #include <boost/smart_ptr/detail/yield_k.hpp> |
| |
| // BOOST_COMPILER_FENCE |
| |
| #if defined(__INTEL_COMPILER) |
| |
| #define BOOST_COMPILER_FENCE __memory_barrier(); |
| |
| #elif defined( _MSC_VER ) && _MSC_VER >= 1310 |
| |
| extern "C" void _ReadWriteBarrier(); |
| #pragma intrinsic( _ReadWriteBarrier ) |
| |
| #define BOOST_COMPILER_FENCE _ReadWriteBarrier(); |
| |
| #elif defined(__GNUC__) |
| |
| #define BOOST_COMPILER_FENCE __asm__ __volatile__( "" : : : "memory" ); |
| |
| #else |
| |
| #define BOOST_COMPILER_FENCE |
| |
| #endif |
| |
| // |
| |
| namespace boost |
| { |
| |
| namespace detail |
| { |
| |
| class spinlock |
| { |
| public: |
| |
| long v_; |
| |
| public: |
| |
| bool try_lock() |
| { |
| long r = BOOST_SP_INTERLOCKED_EXCHANGE( &v_, 1 ); |
| |
| BOOST_COMPILER_FENCE |
| |
| return r == 0; |
| } |
| |
| void lock() |
| { |
| for( unsigned k = 0; !try_lock(); ++k ) |
| { |
| boost::detail::yield( k ); |
| } |
| } |
| |
| void unlock() |
| { |
| BOOST_COMPILER_FENCE |
| *const_cast< long volatile* >( &v_ ) = 0; |
| } |
| |
| 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_W32_HPP_INCLUDED |