vn-verdnaturachat/ios/Pods/boost-for-react-native/boost/log/detail/thread_specific.hpp

117 lines
2.9 KiB
C++

/*
* Copyright Andrey Semashev 2007 - 2015.
* 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)
*/
/*!
* \file thread_specific.hpp
* \author Andrey Semashev
* \date 01.03.2008
*
* \brief This header is the Boost.Log library implementation, see the library documentation
* at http://www.boost.org/doc/libs/release/libs/log/doc/html/index.html.
*/
#ifndef BOOST_LOG_DETAIL_THREAD_SPECIFIC_HPP_INCLUDED_
#define BOOST_LOG_DETAIL_THREAD_SPECIFIC_HPP_INCLUDED_
#include <boost/static_assert.hpp>
#include <boost/type_traits/is_pod.hpp>
#include <boost/log/detail/config.hpp>
#ifdef BOOST_HAS_PRAGMA_ONCE
#pragma once
#endif
#if !defined(BOOST_LOG_NO_THREADS)
#include <boost/log/detail/header.hpp>
namespace boost {
BOOST_LOG_OPEN_NAMESPACE
namespace aux {
//! Base class for TLS to hide platform-specific storage management
class thread_specific_base
{
private:
#if defined(BOOST_THREAD_PLATFORM_WIN32)
typedef unsigned long key_storage;
#else
typedef void* key_storage;
#endif
key_storage m_Key;
protected:
BOOST_LOG_API thread_specific_base();
BOOST_LOG_API ~thread_specific_base();
BOOST_LOG_API void* get_content() const;
BOOST_LOG_API void set_content(void* value) const;
// Copying prohibited
BOOST_DELETED_FUNCTION(thread_specific_base(thread_specific_base const&))
BOOST_DELETED_FUNCTION(thread_specific_base& operator= (thread_specific_base const&))
};
//! A TLS wrapper for small POD types with least possible overhead
template< typename T >
class thread_specific :
public thread_specific_base
{
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");
//! Union to perform type casting
union value_storage
{
void* as_pointer;
T as_value;
};
public:
//! Default constructor
BOOST_DEFAULTED_FUNCTION(thread_specific(), {})
//! Initializing constructor
thread_specific(T const& value)
{
set(value);
}
//! Assignment
thread_specific& operator= (T const& value)
{
set(value);
return *this;
}
//! Accessor
T get() const
{
value_storage cast = {};
cast.as_pointer = thread_specific_base::get_content();
return cast.as_value;
}
//! Setter
void set(T const& value)
{
value_storage cast = {};
cast.as_value = value;
thread_specific_base::set_content(cast.as_pointer);
}
};
} // namespace aux
BOOST_LOG_CLOSE_NAMESPACE // namespace log
} // namespace boost
#include <boost/log/detail/footer.hpp>
#endif // !defined(BOOST_LOG_NO_THREADS)
#endif // BOOST_LOG_DETAIL_THREAD_SPECIFIC_HPP_INCLUDED_