diff --git a/include/boost/smart_ptr/detail/spinlock.hpp b/include/boost/smart_ptr/detail/spinlock.hpp index 88d7ad6..deffb67 100644 --- a/include/boost/smart_ptr/detail/spinlock.hpp +++ b/include/boost/smart_ptr/detail/spinlock.hpp @@ -31,7 +31,10 @@ #include #include -#if defined( BOOST_SP_USE_PTHREADS ) +#if defined( BOOST_SP_USE_STD_ATOMIC ) +# include + +#elif defined( BOOST_SP_USE_PTHREADS ) # include #elif defined(__GNUC__) && defined( __arm__ ) && !defined( __thumb__ ) diff --git a/include/boost/smart_ptr/detail/spinlock_std_atomic.hpp b/include/boost/smart_ptr/detail/spinlock_std_atomic.hpp new file mode 100644 index 0000000..a61c1cd --- /dev/null +++ b/include/boost/smart_ptr/detail/spinlock_std_atomic.hpp @@ -0,0 +1,83 @@ +#ifndef BOOST_SMART_PTR_DETAIL_SPINLOCK_STD_ATOMIC_HPP_INCLUDED +#define BOOST_SMART_PTR_DETAIL_SPINLOCK_STD_ATOMIC_HPP_INCLUDED + +// MS compatible compilers support #pragma once + +#if defined(_MSC_VER) && (_MSC_VER >= 1020) +# pragma once +#endif + +// +// Copyright (c) 2014 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 +#include + +namespace boost +{ + +namespace detail +{ + +class spinlock +{ +public: + + std::atomic_flag v_; + +public: + + bool try_lock() + { + return !v_.test_and_set( std::memory_order_acquire ); + } + + void lock() + { + for( unsigned k = 0; !try_lock(); ++k ) + { + boost::detail::yield( k ); + } + } + + void unlock() + { + v_ .clear( std::memory_order_release ); + } + +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 { ATOMIC_FLAG_INIT } + +#endif // #ifndef BOOST_SMART_PTR_DETAIL_SPINLOCK_STD_ATOMIC_HPP_INCLUDED