Chris@16: /*
Chris@101:  *          Copyright Andrey Semashev 2007 - 2015.
Chris@16:  * Distributed under the Boost Software License, Version 1.0.
Chris@16:  *    (See accompanying file LICENSE_1_0.txt or copy at
Chris@16:  *          http://www.boost.org/LICENSE_1_0.txt)
Chris@16:  */
Chris@16: /*!
Chris@16:  * \file   thread_specific.hpp
Chris@16:  * \author Andrey Semashev
Chris@16:  * \date   01.03.2008
Chris@16:  *
Chris@16:  * \brief  This header is the Boost.Log library implementation, see the library documentation
Chris@16:  *         at http://www.boost.org/doc/libs/release/libs/log/doc/html/index.html.
Chris@16:  */
Chris@16: 
Chris@16: #ifndef BOOST_LOG_DETAIL_THREAD_SPECIFIC_HPP_INCLUDED_
Chris@16: #define BOOST_LOG_DETAIL_THREAD_SPECIFIC_HPP_INCLUDED_
Chris@16: 
Chris@16: #include <boost/static_assert.hpp>
Chris@16: #include <boost/type_traits/is_pod.hpp>
Chris@16: #include <boost/log/detail/config.hpp>
Chris@16: 
Chris@16: #ifdef BOOST_HAS_PRAGMA_ONCE
Chris@16: #pragma once
Chris@16: #endif
Chris@16: 
Chris@16: #if !defined(BOOST_LOG_NO_THREADS)
Chris@16: 
Chris@16: #include <boost/log/detail/header.hpp>
Chris@16: 
Chris@16: namespace boost {
Chris@16: 
Chris@16: BOOST_LOG_OPEN_NAMESPACE
Chris@16: 
Chris@16: namespace aux {
Chris@16: 
Chris@16: //! Base class for TLS to hide platform-specific storage management
Chris@16: class thread_specific_base
Chris@16: {
Chris@16: private:
Chris@16:     union key_storage
Chris@16:     {
Chris@16:         void* as_pointer;
Chris@16:         unsigned int as_dword;
Chris@16:     };
Chris@16: 
Chris@16:     key_storage m_Key;
Chris@16: 
Chris@16: protected:
Chris@16:     BOOST_LOG_API thread_specific_base();
Chris@16:     BOOST_LOG_API ~thread_specific_base();
Chris@16:     BOOST_LOG_API void* get_content() const;
Chris@16:     BOOST_LOG_API void set_content(void* value) const;
Chris@16: 
Chris@16:     //  Copying prohibited
Chris@16:     BOOST_DELETED_FUNCTION(thread_specific_base(thread_specific_base const&))
Chris@16:     BOOST_DELETED_FUNCTION(thread_specific_base& operator= (thread_specific_base const&))
Chris@16: };
Chris@16: 
Chris@16: //! A TLS wrapper for small POD types with least possible overhead
Chris@16: template< typename T >
Chris@16: class thread_specific :
Chris@16:     public thread_specific_base
Chris@16: {
Chris@16:     BOOST_STATIC_ASSERT_MSG(sizeof(T) <= sizeof(void*) && is_pod< T >::value, "Boost.Log: Thread-specific values must be PODs and must not exceed the size of a pointer");
Chris@16: 
Chris@16:     //! Union to perform type casting
Chris@16:     union value_storage
Chris@16:     {
Chris@16:         void* as_pointer;
Chris@16:         T as_value;
Chris@16:     };
Chris@16: 
Chris@16: public:
Chris@16:     //! Default constructor
Chris@16:     BOOST_DEFAULTED_FUNCTION(thread_specific(), {})
Chris@16:     //! Initializing constructor
Chris@16:     thread_specific(T const& value)
Chris@16:     {
Chris@16:         set(value);
Chris@16:     }
Chris@16:     //! Assignment
Chris@16:     thread_specific& operator= (T const& value)
Chris@16:     {
Chris@16:         set(value);
Chris@16:         return *this;
Chris@16:     }
Chris@16: 
Chris@16:     //! Accessor
Chris@16:     T get() const
Chris@16:     {
Chris@16:         value_storage cast = {};
Chris@16:         cast.as_pointer = thread_specific_base::get_content();
Chris@16:         return cast.as_value;
Chris@16:     }
Chris@16: 
Chris@16:     //! Setter
Chris@16:     void set(T const& value)
Chris@16:     {
Chris@16:         value_storage cast = {};
Chris@16:         cast.as_value = value;
Chris@16:         thread_specific_base::set_content(cast.as_pointer);
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: } // namespace aux
Chris@16: 
Chris@16: BOOST_LOG_CLOSE_NAMESPACE // namespace log
Chris@16: 
Chris@16: } // namespace boost
Chris@16: 
Chris@16: #include <boost/log/detail/footer.hpp>
Chris@16: 
Chris@16: #endif // !defined(BOOST_LOG_NO_THREADS)
Chris@16: 
Chris@16: #endif // BOOST_LOG_DETAIL_THREAD_SPECIFIC_HPP_INCLUDED_