[Boost-users] [Boost.Log] Adding indentation to log messages written via BOOST_LOG_TRIVIAL

Subject: [Boost-users] [Boost.Log] Adding indentation to log messages written via BOOST_LOG_TRIVIAL
From: Torri, Stephen CIV NSWCDD, W15 (stephen.torri_at_[hidden])
Date: 2010-08-06 12:28:21

Symptom: Adding indentation to log messages sometimes results in no indentation being added to incoming log messages.

Environment: Fedora 13
             Boost version: trunk (1.44 prior to beta release)
             Boost.Log version: 1.0
             Compiler: GCC 4.4.4

Research: As I read the documentation I see that the Boost.Log talks about a non-empty log record is considered to be tied to the current thread. Since my program is single threaded I did not consider my initial attempt of using inline functions in a separate namespace with a namespace variable to keep track of indentation level to be a problem. My first attempt looked like:

namespace project {
  namespace log {
    static boost::uint32_t indent_level = 0;

#ifdef DEBUG
#include <boost/log/trivial.hpp>
#include <boost/format.hpp>

        /*!
         * \brief Record the entering of a function
         * \param function String name of the function being entered
       */
      template <typename Function>
      inline void record_enter ( Function const& function )
      {
        BOOST_LOG_TRIVIAL(trace) << std::string ( indent_level, ' ' ) << boost::str ( boost::format ( "(Enter) %1%" ) % function );
          indent_level += 2;
      }

        /*!
         * \brief Record the exiting from a function
         * \param function String name of the function being exited
       */
      template <typename Function>
      inline void record_exit ( Function const& function )
      {
        BOOST_LOG_TRIVIAL(trace) << std::string ( indent_level, ' ' ) << boost::str ( boost::format ( "(Exit) %1%" ) % function );
          indent_level -= 2;
        }

        /*!
         * \brief Record a message with one input
         * \param format_string String written in the Boost.Format style to be used to parse input
         * \param t1 Input value
         */
             template <typename Format, typename T1>
        inline void record_debug ( Format const& format_string, T1 const& t1 )
        {
          BOOST_LOG_TRIVIAL(debug) << std::string ( indent_level, ' ' ) << boost::str ( boost::format ( format_string ) % t1 );
      }
  
#else
      template <typename Function>
      inline void record_enter ( Function const& )
      {}   

        template <typename Function>
      inline void record_exit ( Function const& )
      {}

             template <typename Format, typename T1>
        inline void record_debug ( Format const&, T1 const& )
        {}
  } // namespace log
} // namespace project
#endif 

When I run the code I see that the indentation is tracking by steps of 2 as I go into functions and reduced by 2 as I exit. There are exceptions where the indentation is 0 for a few lines or so then resumes the correct level. The problem I think is that there are more than one thread handling what I send to Boost.Log via BOOST_LOG_TRIVIAL. It as if there is one thread that has the correct level and another thread that has indent_level set to 0. For example:

1 [2010-Aug-06 12:03:15.329757] [0x88bb070] [trace] (Enter) void Test::functionA()
2 [2010-Aug-06 12:03:15.330867] [0x88bb070] [debug]   Function A: do something
3 [2010-Aug-06 12:03:15.330989] [0x88bb070] [trace]   (Enter) double Value::CalcX()
4 [2010-Aug-06 12:03:15.331124] [0x88bb070] [debug] X: 5
5 [2010-Aug-06 12:03:15.331188] [0x88bb070] [debug]     Y: 10
6 [2010-Aug-06 12:03:15.331252] [0x88bb070] [trace]   (Enter) double Value::CalcX()

My intial guess is that I have Boost.Log compiled multi-threaded and I have a single-threaded solution. Is there a way to track which thread was recording a message in Boost.Log? I would like to confirm Boost.Log is using different threads to handle my messages. Also is there a better way to do what I want?
 
Stephen

Stephen Torri, PhD
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17214 Ave B Suite 121
Dahlgren, Va. 22448
540-653-7055

I am not a contracting officer.  I cannot modify or initiate contracts, nor do I have the authority to financially commit the government in any way.