Page Replacement Scheme , clock Algorithm

/** @file PageReplacementScheme.hpp * @brief PageReplacementScheme class API/Includes * * @author Student Name * @note cwid: 123456 * @date Fall 2019 * @note ide: g++ 8.2.0 / GNU Make 4.2.1 * * Header include file for our PageReplacementScheme class. The * PageReplacementScheme class is an abstract base class that defines * the interface for implementing different page replacement schemes. * Basically any page replacement scheme needs to be able to select a * physical frame of memory to be replaced, using whatever algorithm * the scheme implements. This abstract interface defines the api * calls supported so that the PagingSystem simulator can use any * particular PageReplacementScheme. */ #ifndef PAGE_REPLACEMENT_SCHEME_HPP #define PAGE_REPLACEMENT_SCHEME_HPP #include "PagingSystem.hpp" #include <string> // forward declaration needed for circular references class PagingSystem; /// @brief FrameNumber are the valid frame number references used for /// for this simulation. Valid FrameNumber range from 0 to N. /// Negative frame numbers are invalid, and may be used as error flags. typedef int FrameNumber; using namespace std; /** @class PageReplacementScheme * @brief PageReplacementScheme abstract base class * * This class defines the interface or API for the helper page * replacement scheme. A PagingSystem simulation will instanciate * a derived class of this API, and will expect it to implement the * interface defined by this abstract base class. */ class PageReplacementScheme { protected: // derived classes need to be able to access the sys member instance /// @brief The paging system that this paging scheme is /// supporting PagingSystem* sys; public: PageReplacementScheme(PagingSystem* sys); // virtual function, concrete subclasses can override if needed virtual ~PageReplacementScheme(); // pure virtual functions, concrete subclasses must implement virtual void resetScheme() = 0; virtual void pageHit(FrameNumber frame) = 0; virtual string getSchemeStatus() = 0; virtual FrameNumber makeReplacementDecision() = 0; }; #endif // PAGE_REPLACEMENT_SCHEME_HPP