virtualMemoryManagerInterface.hpp

#pragma once
#include <iostream>
#include <cassert>
#include <cmath>

using namespace std;

enum ReplacementPolicy
{
	FIFO,
	LRU
};

class virtualMemoryManagerInterface
{
public:
	virtualMemoryManagerInterface(ReplacementPolicy p, unsigned int pS, unsigned int nF, unsigned int vA) : policy(p), N(pS), numFrames(nF), virtualAddressSpaceSize(vA) {
		assert(virtualAddressSpaceSize > N);
		assert(pow(2, virtualAddressSpaceSize) > numFrames * pow(2,N));
	}

	/** This is the method the test bench will drive in emulating memory management.
	*	Your memory manager should return the physical address corresponding to the given virtual
	*	address. This function must NOT return until any page swapping is completed, if necessary.
	*	This function is to effect page swaps by calling the other key function (defined below)
	*/
	virtual unsigned long long memoryAccess(unsigned long long address) = 0;

	/** This is the method your memory manager should call to swap pages.
	*	This function has been instrumented by the TAs to report memory system performance.
	*	@param frameNumber the physical frame to write to swap file (write is emulated)
	*	@param pageNumber the (virtual) page number to read from swap file into the given frame
	*/
	void swap(unsigned int frameNumber, unsigned int pageNumber) {
		///@todo ta instrumentation to go here
		///students should instrument memorymanager performance in their own class for their internal verification or may
		///modify this code for their testing purpose; however the TAs instrumentation will used for determining grade basis.
		numSwaps++;
	}

	/** Report the to-date number of page swaps, used by test benches to quantify performance.
	*	@returns the number of page swaps
	*/
	unsigned long long& numberPageSwaps() { return numSwaps; }

protected:
	ReplacementPolicy policy;

	unsigned int N; /// N = Page Address bits size, 2^ N = The physical frame/virtual page size to manage (bytes)
	unsigned int numFrames; /// total number of physical frames. Phy mem size = numFrames * 2^N
	unsigned int virtualAddressSpaceSize; ///  2^virtualAddressSpaceSize = total virtual address space (bytes)

	unsigned long long numSwaps = 0; ///total number of page swaps performed

};