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- #ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_CLANG_HPP_INCLUDED
- #define BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_CLANG_HPP_INCLUDED
- // MS compatible compilers support #pragma once
- #if defined(_MSC_VER) && (_MSC_VER >= 1020)
- # pragma once
- #endif
- // detail/sp_counted_base_clang.hpp - __c11 clang intrinsics
- //
- // Copyright (c) 2007, 2013, 2015 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_typeinfo_.hpp>
- #include <boost/smart_ptr/detail/sp_noexcept.hpp>
- #include <boost/config.hpp>
- #include <boost/cstdint.hpp>
- namespace boost
- {
- namespace detail
- {
- typedef _Atomic( boost::int_least32_t ) atomic_int_least32_t;
- inline void atomic_increment( atomic_int_least32_t * pw ) BOOST_SP_NOEXCEPT
- {
- __c11_atomic_fetch_add( pw, 1, __ATOMIC_RELAXED );
- }
- inline boost::int_least32_t atomic_decrement( atomic_int_least32_t * pw ) BOOST_SP_NOEXCEPT
- {
- return __c11_atomic_fetch_sub( pw, 1, __ATOMIC_ACQ_REL );
- }
- inline boost::int_least32_t atomic_conditional_increment( atomic_int_least32_t * pw ) BOOST_SP_NOEXCEPT
- {
- // long r = *pw;
- // if( r != 0 ) ++*pw;
- // return r;
- boost::int_least32_t r = __c11_atomic_load( pw, __ATOMIC_RELAXED );
- for( ;; )
- {
- if( r == 0 )
- {
- return r;
- }
- if( __c11_atomic_compare_exchange_weak( pw, &r, r + 1, __ATOMIC_RELAXED, __ATOMIC_RELAXED ) )
- {
- return r;
- }
- }
- }
- #if defined(__clang__)
- # pragma clang diagnostic push
- # pragma clang diagnostic ignored "-Wweak-vtables"
- #endif
- class BOOST_SYMBOL_VISIBLE sp_counted_base
- {
- private:
- sp_counted_base( sp_counted_base const & );
- sp_counted_base & operator= ( sp_counted_base const & );
- atomic_int_least32_t use_count_; // #shared
- atomic_int_least32_t weak_count_; // #weak + (#shared != 0)
- public:
- sp_counted_base() BOOST_SP_NOEXCEPT
- {
- __c11_atomic_init( &use_count_, 1 );
- __c11_atomic_init( &weak_count_, 1 );
- }
- virtual ~sp_counted_base() /*BOOST_SP_NOEXCEPT*/
- {
- }
- // dispose() is called when use_count_ drops to zero, to release
- // the resources managed by *this.
- virtual void dispose() BOOST_SP_NOEXCEPT = 0; // nothrow
- // destroy() is called when weak_count_ drops to zero.
- virtual void destroy() BOOST_SP_NOEXCEPT // nothrow
- {
- delete this;
- }
- virtual void * get_deleter( sp_typeinfo_ const & ti ) BOOST_SP_NOEXCEPT = 0;
- virtual void * get_local_deleter( sp_typeinfo_ const & ti ) BOOST_SP_NOEXCEPT = 0;
- virtual void * get_untyped_deleter() BOOST_SP_NOEXCEPT = 0;
- void add_ref_copy() BOOST_SP_NOEXCEPT
- {
- atomic_increment( &use_count_ );
- }
- bool add_ref_lock() BOOST_SP_NOEXCEPT // true on success
- {
- return atomic_conditional_increment( &use_count_ ) != 0;
- }
- void release() BOOST_SP_NOEXCEPT
- {
- if( atomic_decrement( &use_count_ ) == 1 )
- {
- dispose();
- weak_release();
- }
- }
- void weak_add_ref() BOOST_SP_NOEXCEPT
- {
- atomic_increment( &weak_count_ );
- }
- void weak_release() BOOST_SP_NOEXCEPT
- {
- if( atomic_decrement( &weak_count_ ) == 1 )
- {
- destroy();
- }
- }
- long use_count() const BOOST_SP_NOEXCEPT
- {
- return __c11_atomic_load( const_cast< atomic_int_least32_t* >( &use_count_ ), __ATOMIC_ACQUIRE );
- }
- };
- #if defined(__clang__)
- # pragma clang diagnostic pop
- #endif
- } // namespace detail
- } // namespace boost
- #endif // #ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_CLANG_HPP_INCLUDED
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