ceph/src/boost/libs/log/include/boost/log/attributes/current_thread_id.hpp

   1 /*
   2  *          Copyright Andrey Semashev 2007 - 2015.
   3  * Distributed under the Boost Software License, Version 1.0.
   4  *    (See accompanying file LICENSE_1_0.txt or copy at
   5  *          http://www.boost.org/LICENSE_1_0.txt)
   6  */
   7 /*!
   8  * \file   current_thread_id.hpp
   9  * \author Andrey Semashev
  10  * \date   12.09.2009
  11  *
  12  * The header contains implementation of a current thread id attribute
  13  */
  14
  15 #ifndef BOOST_LOG_ATTRIBUTES_CURRENT_THREAD_ID_HPP_INCLUDED_
  16 #define BOOST_LOG_ATTRIBUTES_CURRENT_THREAD_ID_HPP_INCLUDED_
  17
  18 #include <boost/log/detail/config.hpp>
  19
  20 #ifdef BOOST_HAS_PRAGMA_ONCE
  21 #pragma once
  22 #endif
  23
  24 #if defined(BOOST_LOG_NO_THREADS)
  25 #error Boost.Log: The current_thread_id attribute is only available in multithreaded builds
  26 #endif
  27
  28 #include <boost/smart_ptr/intrusive_ptr.hpp>
  29 #include <boost/log/detail/thread_id.hpp>
  30 #include <boost/log/attributes/attribute.hpp>
  31 #include <boost/log/attributes/attribute_cast.hpp>
  32 #include <boost/log/attributes/attribute_value_impl.hpp>
  33 #include <boost/log/detail/header.hpp>
  34
  35 namespace boost {
  36
  37 BOOST_LOG_OPEN_NAMESPACE
  38
  39 //! Thread identifier type
  40 typedef boost::log::aux::thread::id thread_id;
  41
  42 namespace attributes {
  43
  44 /*!
  45  * \brief A class of an attribute that always returns the current thread identifier
  46  *
  47  * \note This attribute can be registered globally, it will still return the correct
  48  *       thread identifier, no matter which thread emits the log record.
  49  */
  50 class current_thread_id :
  51     public attribute
  52 {
  53 public:
  54     //! A held attribute value type
  55     typedef thread_id value_type;
  56
  57 protected:
  58     //! Factory implementation
  59     class BOOST_SYMBOL_VISIBLE impl :
  60         public attribute_value::impl
  61     {
  62     public:
  63         bool dispatch(type_dispatcher& dispatcher)
  64         {
  65             type_dispatcher::callback< value_type > callback =
  66                 dispatcher.get_callback< value_type >();
  67             if (callback)
  68             {
  69                 callback(boost::log::aux::this_thread::get_id());
  70                 return true;
  71             }
  72             else
  73                 return false;
  74         }
  75
  76         intrusive_ptr< attribute_value::impl > detach_from_thread()
  77         {
  78             typedef attribute_value_impl< value_type > detached_value;
  79             return new detached_value(boost::log::aux::this_thread::get_id());
  80         }
  81
  82         typeindex::type_index get_type() const { return typeindex::type_id< value_type >(); }
  83     };
  84
  85 public:
  86     /*!
  87      * Default constructor
  88      */
  89     current_thread_id() : attribute(new impl())
  90     {
  91     }
  92     /*!
  93      * Constructor for casting support
  94      */
  95     explicit current_thread_id(cast_source const& source) :
  96         attribute(source.as< impl >())
  97     {
  98     }
  99 };
 100
 101 } // namespace attributes
 102
 103 BOOST_LOG_CLOSE_NAMESPACE // namespace log
 104
 105 } // namespace boost
 106
 107 #include <boost/log/detail/footer.hpp>
 108
 109 #endif // BOOST_LOG_ATTRIBUTES_CURRENT_THREAD_ID_HPP_INCLUDED_