#ifndef BOOST_SMART_PTR_DETAIL_SPINLOCK_SYNC_HPP_INCLUDED #define BOOST_SMART_PTR_DETAIL_SPINLOCK_SYNC_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/yield_k.hpp> #if defined( __ia64__ ) && defined( __INTEL_COMPILER ) # include <ia64intrin.h> #endif namespace boost { namespace detail { class spinlock { public: int v_; public: bool try_lock() { int r = __sync_lock_test_and_set( &v_, 1 ); return r == 0; } void lock() { for( unsigned k = 0; !try_lock(); ++k ) { boost::detail::yield( k ); } } void unlock() { __sync_lock_release( &v_ ); } 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_SYNC_HPP_INCLUDED