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   exception_handler_feature.hpp
Chris@16:  * \author Andrey Semashev
Chris@16:  * \date   17.07.2009
Chris@16:  *
Chris@16:  * The header contains implementation of an exception handler support feature.
Chris@16:  */
Chris@16: 
Chris@16: #ifndef BOOST_LOG_SOURCES_EXCEPTION_HANDLER_FEATURE_HPP_INCLUDED_
Chris@16: #define BOOST_LOG_SOURCES_EXCEPTION_HANDLER_FEATURE_HPP_INCLUDED_
Chris@16: 
Chris@16: #include <boost/mpl/if.hpp>
Chris@16: #include <boost/move/core.hpp>
Chris@16: #include <boost/move/utility.hpp>
Chris@16: #include <boost/type_traits/is_same.hpp>
Chris@16: #include <boost/log/detail/config.hpp>
Chris@16: #include <boost/log/detail/light_function.hpp>
Chris@16: #include <boost/log/detail/locks.hpp>
Chris@101: #include <boost/log/core/record.hpp>
Chris@16: #include <boost/log/sources/threading_models.hpp>
Chris@16: #include <boost/log/utility/strictest_lock.hpp>
Chris@16: #if !defined(BOOST_LOG_NO_THREADS)
Chris@16: #include <boost/thread/exceptions.hpp>
Chris@16: #endif
Chris@16: #include <boost/log/detail/header.hpp>
Chris@16: 
Chris@16: #ifdef BOOST_HAS_PRAGMA_ONCE
Chris@16: #pragma once
Chris@16: #endif
Chris@16: 
Chris@16: namespace boost {
Chris@16: 
Chris@16: BOOST_LOG_OPEN_NAMESPACE
Chris@16: 
Chris@16: namespace sources {
Chris@16: 
Chris@16: /*!
Chris@16:  * \brief Exception handler feature implementation
Chris@16:  */
Chris@16: template< typename BaseT >
Chris@16: class basic_exception_handler_logger :
Chris@16:     public BaseT
Chris@16: {
Chris@16:     //! Base type
Chris@16:     typedef BaseT base_type;
Chris@16:     typedef basic_exception_handler_logger this_type;
Chris@16:     BOOST_COPYABLE_AND_MOVABLE_ALT(this_type)
Chris@16: 
Chris@16: public:
Chris@16:     //! Threading model being used
Chris@16:     typedef typename base_type::threading_model threading_model;
Chris@16:     //! Final logger type
Chris@16:     typedef typename base_type::final_type final_type;
Chris@16:     //! Exception handler function type
Chris@16:     typedef boost::log::aux::light_function< void () > exception_handler_type;
Chris@16: 
Chris@16: #if defined(BOOST_LOG_DOXYGEN_PASS)
Chris@16:     //! Lock requirement for the open_record_unlocked method
Chris@16:     typedef typename strictest_lock<
Chris@16:         typename base_type::open_record_lock,
Chris@16:         no_lock< threading_model >
Chris@16:     >::type open_record_lock;
Chris@16:     //! Lock requirement for the push_record_unlocked method
Chris@16:     typedef typename strictest_lock<
Chris@16:         typename base_type::push_record_lock,
Chris@16:         no_lock< threading_model >
Chris@16:     >::type push_record_lock;
Chris@16: #endif // defined(BOOST_LOG_DOXYGEN_PASS)
Chris@16: 
Chris@16:     //! Lock requirement for the swap_unlocked method
Chris@16:     typedef typename strictest_lock<
Chris@16:         typename base_type::swap_lock,
Chris@16: #ifndef BOOST_LOG_NO_THREADS
Chris@16:         boost::log::aux::exclusive_lock_guard< threading_model >
Chris@16: #else
Chris@16:         no_lock< threading_model >
Chris@16: #endif // !defined(BOOST_LOG_NO_THREADS)
Chris@16:     >::type swap_lock;
Chris@16: 
Chris@16: private:
Chris@16:     //! Exception handler
Chris@16:     exception_handler_type m_ExceptionHandler;
Chris@16: 
Chris@16: public:
Chris@16:     /*!
Chris@16:      * Default constructor. The constructed logger does not have an exception handler.
Chris@16:      */
Chris@16:     basic_exception_handler_logger() : base_type()
Chris@16:     {
Chris@16:     }
Chris@16:     /*!
Chris@16:      * Copy constructor
Chris@16:      */
Chris@16:     basic_exception_handler_logger(basic_exception_handler_logger const& that) :
Chris@16:         base_type(static_cast< base_type const& >(that)),
Chris@16:         m_ExceptionHandler(that.m_ExceptionHandler)
Chris@16:     {
Chris@16:     }
Chris@16:     /*!
Chris@16:      * Move constructor
Chris@16:      */
Chris@16:     basic_exception_handler_logger(BOOST_RV_REF(basic_exception_handler_logger) that) :
Chris@16:         base_type(boost::move(static_cast< base_type& >(that))),
Chris@16:         m_ExceptionHandler(boost::move(that.m_ExceptionHandler))
Chris@16:     {
Chris@16:     }
Chris@16:     /*!
Chris@16:      * Constructor with arguments. Passes arguments to other features.
Chris@16:      */
Chris@16:     template< typename ArgsT >
Chris@16:     explicit basic_exception_handler_logger(ArgsT const& args) :
Chris@16:         base_type(args)
Chris@16:     {
Chris@16:     }
Chris@16: 
Chris@16:     /*!
Chris@16:      * The method sets exception handler function. The function will be called with no arguments
Chris@16:      * in case if an exception occurs during either \c open_record or \c push_record method
Chris@16:      * execution. Since exception handler is called from a \c catch statement, the exception
Chris@16:      * can be rethrown in order to determine its type.
Chris@16:      *
Chris@16:      * By default no handler is installed, thus any exception is propagated as usual.
Chris@16:      *
Chris@16:      * \sa <tt>utility/exception_handler.hpp</tt>
Chris@16:      * \param handler Exception handling function
Chris@16:      *
Chris@16:      * \note The exception handler can be invoked in several threads concurrently.
Chris@16:      *
Chris@16:      * \note Thread interruptions are not affected by exception handlers.
Chris@16:      */
Chris@16:     template< typename HandlerT >
Chris@16:     void set_exception_handler(HandlerT const& handler)
Chris@16:     {
Chris@16: #ifndef BOOST_LOG_NO_THREADS
Chris@16:         boost::log::aux::exclusive_lock_guard< threading_model > lock(this->get_threading_model());
Chris@16: #endif
Chris@16:         m_ExceptionHandler = handler;
Chris@16:     }
Chris@16: 
Chris@16: protected:
Chris@16:     /*!
Chris@16:      * Unlocked \c open_record
Chris@16:      */
Chris@16:     template< typename ArgsT >
Chris@16:     record open_record_unlocked(ArgsT const& args)
Chris@16:     {
Chris@16:         try
Chris@16:         {
Chris@16:             return base_type::open_record_unlocked(args);
Chris@16:         }
Chris@16: #ifndef BOOST_LOG_NO_THREADS
Chris@16:         catch (thread_interrupted&)
Chris@16:         {
Chris@16:             throw;
Chris@16:         }
Chris@16: #endif
Chris@16:         catch (...)
Chris@16:         {
Chris@16:             handle_exception();
Chris@16:             return record();
Chris@16:         }
Chris@16:     }
Chris@16: 
Chris@16:     /*!
Chris@16:      * Unlocked \c push_record
Chris@16:      */
Chris@16:     void push_record_unlocked(BOOST_RV_REF(record) rec)
Chris@16:     {
Chris@16:         try
Chris@16:         {
Chris@16:             base_type::push_record_unlocked(boost::move(rec));
Chris@16:         }
Chris@16: #ifndef BOOST_LOG_NO_THREADS
Chris@16:         catch (thread_interrupted&)
Chris@16:         {
Chris@16:             throw;
Chris@16:         }
Chris@16: #endif
Chris@16:         catch (...)
Chris@16:         {
Chris@16:             handle_exception();
Chris@16:         }
Chris@16:     }
Chris@16: 
Chris@16:     /*!
Chris@16:      * Unlocked swap
Chris@16:      */
Chris@16:     void swap_unlocked(basic_exception_handler_logger& that)
Chris@16:     {
Chris@16:         base_type::swap_unlocked(static_cast< base_type& >(that));
Chris@16:         m_ExceptionHandler.swap(that.m_ExceptionHandler);
Chris@16:     }
Chris@16: 
Chris@16: private:
Chris@16: #if !defined(BOOST_LOG_DOXYGEN_PASS)
Chris@16:     //! The function handles the intercepted exception
Chris@16:     void handle_exception()
Chris@16:     {
Chris@16: #ifndef BOOST_LOG_NO_THREADS
Chris@16:         // Here's the trick with the lock type. Since the lock
Chris@16:         // is only needed when an exception is caught, we indicate
Chris@16:         // no locking requirements in the push_record_lock type.
Chris@16:         // However, if other features don't require locking either,
Chris@16:         // we shall acquire a read lock here, when an exception is caught.
Chris@16:         // If other features do require locking, the thread model is
Chris@16:         // already locked by now, and we don't do locking at all.
Chris@16:         typedef typename mpl::if_<
Chris@16:             is_same< no_lock< threading_model >, typename final_type::push_record_lock >,
Chris@16:             boost::log::aux::shared_lock_guard< threading_model >,
Chris@16:             no_lock< threading_model >
Chris@16:         >::type lock_type;
Chris@16:         lock_type lock(base_type::get_threading_model());
Chris@16: #endif // !defined(BOOST_LOG_NO_THREADS)
Chris@16: 
Chris@16:         if (m_ExceptionHandler.empty())
Chris@16:             throw;
Chris@16:         m_ExceptionHandler();
Chris@16:     }
Chris@16: #endif // !defined(BOOST_LOG_DOXYGEN_PASS)
Chris@16: };
Chris@16: 
Chris@16: /*!
Chris@16:  * \brief Exception handler support feature
Chris@16:  *
Chris@16:  * The logger with this feature will provide an additional method to
Chris@16:  * install an exception handler functional object. This functional
Chris@16:  * object will be called if during either opening or pushing a record
Chris@16:  * an exception is thrown from the logging core.
Chris@16:  */
Chris@16: struct exception_handler
Chris@16: {
Chris@16:     template< typename BaseT >
Chris@16:     struct apply
Chris@16:     {
Chris@16:         typedef basic_exception_handler_logger< BaseT > type;
Chris@16:     };
Chris@16: };
Chris@16: 
Chris@16: } // namespace sources
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 // BOOST_LOG_SOURCES_EXCEPTION_HANDLER_FEATURE_HPP_INCLUDED_