managedSwap.h

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/*   rambrain - a dynamical physical memory extender
 *   Copyright (C) 2015 M. Imgrund, A. Arth
 *   mimgrund (at) mpifr-bonn.mpg.de
 *   arth (at) usm.uni-muenchen.de
 *
 *   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 3 of the License, or
 *   (at your option) any later version.
 *
 *   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, see <http://www.gnu.org/licenses/>.
 */

#ifndef MANAGEDSWAP_H
#define MANAGEDSWAP_H

#include "managedMemoryChunk.h"
#include "common.h"
#include "managedMemory.h"
#include "rambrain_atomics.h"
#include "configreader.h"

namespace rambrain
{

class managedSwap
{
public:
    managedSwap ( global_bytesize size );
    virtual ~managedSwap();

    //Returns size of sucessfully swapped chunks
    virtual global_bytesize swapOut ( managedMemoryChunk **chunklist, unsigned int nchunks ) = 0;
    virtual global_bytesize swapOut ( managedMemoryChunk *chunk )  = 0;
    virtual global_bytesize swapIn ( managedMemoryChunk **chunklist, unsigned int nchunks ) = 0;
    virtual global_bytesize swapIn ( managedMemoryChunk *chunk ) = 0;
    virtual void swapDelete ( managedMemoryChunk *chunk ) = 0;


    virtual bool extendSwapByPolicy ( global_bytesize min_size ) {
        errmsg ( "Your swap module does not support extending swap by policy" );
        return false;
    };
    virtual bool extendSwap ( global_bytesize size ) {
        errmsg ( "Your swap module does not support extending swap" );
        return false;
    }

    virtual inline global_bytesize getSwapSize() const {
        return swapSize;
    }
    virtual inline global_bytesize getUsedSwap() const {
        return swapUsed;
    }
    virtual inline global_bytesize getFreeSwap() const {
        return swapFree;
    }

    //Simple getter
    virtual inline swapPolicy getSwapPolicy() const {
        return policy;
    }

    //Simple setter returning old policy
    virtual inline swapPolicy setSwapPolicy ( swapPolicy newPolicy ) {
        swapPolicy oldPolicy = policy;
        policy = newPolicy;
        return oldPolicy;
    }

    inline size_t getMemoryAlignment() const {
        return memoryAlignment;
    }
    void claimUsageof ( global_bytesize bytes, bool rambytes, bool used );
    void waitForCleanExit();

    virtual inline bool checkForAIO() {
        return false;
    }

    virtual void close() = 0;

    //Caching Control.
    virtual inline bool cleanupCachedElements ( rambrain::global_bytesize minimum_size = 0 ) {
        return true;
    }
    virtual inline void invalidateCacheFor ( managedMemoryChunk &chunk ) {}

protected:
    global_bytesize swapSize;
    global_bytesize swapUsed;
    global_bytesize swapFree;
    unsigned int totalSwapActionsQueued = 0;

    size_t memoryAlignment = 1;

    swapPolicy policy = swapPolicy::fixed;

    bool closed = false;
};


}




#endif