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Diffstat (limited to '3rdParty/Boost/src/boost/smart_ptr/detail/sp_counted_base_std_atomic.hpp')
-rw-r--r-- | 3rdParty/Boost/src/boost/smart_ptr/detail/sp_counted_base_std_atomic.hpp | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/3rdParty/Boost/src/boost/smart_ptr/detail/sp_counted_base_std_atomic.hpp b/3rdParty/Boost/src/boost/smart_ptr/detail/sp_counted_base_std_atomic.hpp new file mode 100644 index 0000000..cab8453 --- /dev/null +++ b/3rdParty/Boost/src/boost/smart_ptr/detail/sp_counted_base_std_atomic.hpp @@ -0,0 +1,137 @@ +#ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_STD_ATOMIC_HPP_INCLUDED +#define BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_STD_ATOMIC_HPP_INCLUDED + +// MS compatible compilers support #pragma once + +#if defined(_MSC_VER) && (_MSC_VER >= 1020) +# pragma once +#endif + +// detail/sp_counted_base_std_atomic.hpp - C++11 std::atomic +// +// Copyright (c) 2007, 2013 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/detail/sp_typeinfo.hpp> +#include <atomic> +#include <cstdint> + +namespace boost +{ + +namespace detail +{ + +inline void atomic_increment( std::atomic_int_least32_t * pw ) +{ + pw->fetch_add( 1, std::memory_order_relaxed ); +} + +inline std::int_least32_t atomic_decrement( std::atomic_int_least32_t * pw ) +{ + return pw->fetch_sub( 1, std::memory_order_acq_rel ); +} + +inline std::int_least32_t atomic_conditional_increment( std::atomic_int_least32_t * pw ) +{ + // long r = *pw; + // if( r != 0 ) ++*pw; + // return r; + + std::int_least32_t r = pw->load( std::memory_order_relaxed ); + + for( ;; ) + { + if( r == 0 ) + { + return r; + } + + if( pw->compare_exchange_weak( r, r + 1, std::memory_order_relaxed, std::memory_order_relaxed ) ) + { + return r; + } + } +} + +class sp_counted_base +{ +private: + + sp_counted_base( sp_counted_base const & ); + sp_counted_base & operator= ( sp_counted_base const & ); + + std::atomic_int_least32_t use_count_; // #shared + std::atomic_int_least32_t weak_count_; // #weak + (#shared != 0) + +public: + + sp_counted_base(): use_count_( 1 ), weak_count_( 1 ) + { + } + + virtual ~sp_counted_base() // nothrow + { + } + + // dispose() is called when use_count_ drops to zero, to release + // the resources managed by *this. + + virtual void dispose() = 0; // nothrow + + // destroy() is called when weak_count_ drops to zero. + + virtual void destroy() // nothrow + { + delete this; + } + + virtual void * get_deleter( sp_typeinfo const & ti ) = 0; + virtual void * get_untyped_deleter() = 0; + + void add_ref_copy() + { + atomic_increment( &use_count_ ); + } + + bool add_ref_lock() // true on success + { + return atomic_conditional_increment( &use_count_ ) != 0; + } + + void release() // nothrow + { + if( atomic_decrement( &use_count_ ) == 1 ) + { + dispose(); + weak_release(); + } + } + + void weak_add_ref() // nothrow + { + atomic_increment( &weak_count_ ); + } + + void weak_release() // nothrow + { + if( atomic_decrement( &weak_count_ ) == 1 ) + { + destroy(); + } + } + + long use_count() const // nothrow + { + return use_count_.load( std::memory_order_acquire ); + } +}; + +} // namespace detail + +} // namespace boost + +#endif // #ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_STD_ATOMIC_HPP_INCLUDED |