frameschedulerworkunits.h

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// The DAGFrameScheduler is a Multi-Threaded lock free and wait free scheduling library.
// © Copyright 2010 - 2016 BlackTopp Studios Inc.
/* This file is part of The DAGFrameScheduler.

    The DAGFrameScheduler is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    The DAGFrameScheduler is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with The DAGFrameScheduler.  If not, see <http://www.gnu.org/licenses/>.
*/
/* The original authors have included a copy of the license specified above in the
   'doc' folder. See 'gpl.txt'
*/
/* We welcome the use of the DAGFrameScheduler to anyone, including companies who wish to
   Build professional software and charge for their product.

   However there are some practical restrictions, so if your project involves
   any of the following you should contact us and we will try to work something
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        your distribution

   These and other limitations could cause serious legal problems if you ignore
   them, so it is best to simply contact us or the Free Software Foundation, if
   you have any questions.

   Joseph Toppi - toppij@gmail.com
   John Blackwood - makoenergy02@gmail.com
*/

#ifndef _frameschedulerworkunits_h
#define _frameschedulerworkunits_h

#include "datatypes.h"

#if !defined(SWIG) || defined(SWIG_THREADING) // Do not read when in swig and not in the threading module
#include "workunit.h"
#include "workunitkey.h"
#endif
/// @file
/// @brief This defines a number of workunits that are required for doing some tasks that the Framescheduler requires.

namespace Mezzanine
{
    namespace Threading
    {
        // Forward Declare
        class FrameScheduler;

        /// @brief Gather all the thread specific logs and commit them to the main log.
        /// @details All the logs are double buffered. This reads from the commitable buffer
        /// which should otherwise be unused. This task was separated from the log swapper
        /// top minimize contention.
        class MEZZ_LIB LogAggregator : public DefaultWorkUnit
        {
            private:
                /// @brief The frameScheduler to aggregate;
                /// @note On Linux AMD64 this pointer brings the size of this class to 64 bytes a common cache line size.
                FrameScheduler* AggregationTarget;

                /// @brief Used to signal any special condition that forced an abnormal log flush
                Boole ForcedLog;

            public:
                /// @brief Create a default log agregator with no target
                LogAggregator();

                /// @brief Virtual Deconstructor
                virtual ~LogAggregator();

                /// @brief Used to indicate the next log flush is abnormally forced
                /// @param Force Can be passed to unset the abnormal log flush.
                void NextFlushForced(Boole Force=true);

                /// @brief This does the actual work of log aggregation.
                /// @param CurrentThreadStorage This is used to retrieve the framescheduler that will have its log aggregated.
                /// @details If there is no currently set aggregation target this sets it to whatever scheduler is in
                /// the passed ThreadSpecificStorage
                virtual void DoWork(DefaultThreadSpecificStorage::Type& CurrentThreadStorage);

                /// @brief Get the current Aggregation Target
                /// @return A FrameScheduler pointer or NULL if one is not set
                FrameScheduler* GetAggregationTarget() const;

                /// @brief Set which framescheduler will be aggregated.
                /// @param NewTarget A pointer to the  FrameScheduler to aggregate.
                /// @details If set to NULL this will use whatever FrameScheduler is in the next
                /// ThreadSpecificStorage passed during DoWork. This will never delete a framescheduler.
                void SetAggregationTarget(FrameScheduler* NewTarget);
        }; //LogAggregator

        /// @brief Sorts all of the WorkUnits in the @ref FrameScheduler.
        class MEZZ_LIB WorkSorter : public DefaultWorkUnit
        {
                friend class FrameScheduler;
            protected:
                /// @brief 1 in every this many frames Sorting happens.
                Whole SortingFrequency;

                /// @brief How long since the last sort?
                Whole FramesSinceLastSort;

                /// @brief A freshly sorted WorkUnitsMain or an empty vector.
                std::vector<WorkUnitKey> WorkUnitsMain;

                /// @brief A freshly sorted WorkUnitsAffinity or an empty vector.
                std::vector<WorkUnitKey> WorkUnitsAffinity;

            public:
                /// @brief Default constructor.
                WorkSorter();

                /// @brief This usually does nothing, but sometimes it will do a whole bunch of work sorting.
                /// @param CurrentThreadStorage Just to get a reference to the framescheduler. So the WorkUnits can sorted and passed back to the Scheduler outisde of scheduling.
                virtual void DoWork(DefaultThreadSpecificStorage::Type& CurrentThreadStorage);

                /// @brief Set how often this actually does work
                /// @param FramesBetweenSorts 1 in every this many frame this will sort the work units.
                virtual void SetSortingFrequency(Whole FramesBetweenSorts);

                /// @brief Check how often this sorts.
                /// @return A Whole containing the sorting frequency.
                virtual Whole GetSortingFrequency();
        };//WorkSorter
    }//Threading
}//Mezzanine

#endif