SimpleExecStreamGovernor.h

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/*
// $Id: //open/dev/fennel/exec/SimpleExecStreamGovernor.h#8 $
// Fennel is a library of data storage and processing components.
// Copyright (C) 2005-2009 The Eigenbase Project
// Copyright (C) 2005-2009 SQLstream, Inc.
// Copyright (C) 2005-2009 LucidEra, Inc.
// Portions Copyright (C) 1999-2009 John V. Sichi
//
// This program 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 2 of the License, or (at your option)
// any later version approved by The Eigenbase Project.
//
// This program 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 this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#ifndef Fennel_SimpleExecStreamGovernor_Included
#define Fennel_SimpleExecStreamGovernor_Included

#include "fennel/exec/ExecStreamGovernor.h"

#include <boost/scoped_array.hpp>

FENNEL_BEGIN_NAMESPACE

class FENNEL_EXEC_EXPORT SimpleExecStreamGovernor
    : public ExecStreamGovernor
{
    uint perGraphAllocation;

    inline uint computePerGraphAllocation();

    void assignCachePages(
        std::vector<SharedExecStream> &streams,
        boost::scoped_array<ExecStreamResourceRequirements> const &reqts,
        bool assignMin);

    uint distributeCachePages(
        std::vector<SharedExecStream> &streams,
        boost::scoped_array<ExecStreamResourceRequirements> const &reqts,
        boost::scoped_array<double> const &sqrtDiffOptMin,
        double totalSqrtDiffs,
        uint excessAvailable, bool assignOpt);

public:
    explicit SimpleExecStreamGovernor(
        ExecStreamResourceKnobs const &knobSettings,
        ExecStreamResourceQuantity const &resourcesAvailable,
        SharedTraceTarget pTraceTarget,
        std::string name);

    virtual ~SimpleExecStreamGovernor();

    // implement the ExecStreamGovernor interface
    virtual bool setResourceKnob(
        ExecStreamResourceKnobs const &knob,
        ExecStreamResourceKnobType knobType);
    virtual bool setResourceAvailability(
        ExecStreamResourceQuantity const &available,
        ExecStreamResourceType resourceType);
    virtual void requestResources(ExecStreamGraph &graph);
    virtual void returnResources(ExecStreamGraph &graph);
};

inline uint SimpleExecStreamGovernor::computePerGraphAllocation()
{
    return (resourcesAvailable.nCachePages + resourcesAssigned.nCachePages) /
        knobSettings.expectedConcurrentStatements;
}

FENNEL_END_NAMESPACE

#endif

// End SimpleExecStreamGovernor.h

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