// addrspace.h 
//	Data structures to keep track of executing user programs 
//	(address spaces).
//
//	For now, we don't keep any information about address spaces.
//	The user level CPU state is saved and restored in the thread
//	executing the user program (see thread.h).
//
// Copyright (c) 1992-1996 The Regents of the University of California.
// All rights reserved.  See copyright.h for copyright notice and limitation 
// of liability and disclaimer of warranty provisions.

#ifndef ADDRSPACE_H
#define ADDRSPACE_H

#include "copyright.h"
#include "filesys.h"

#define UserStackSize		1024 	// increase this as necessary!

class AddrSpace {
public:
  AddrSpace();			// Create an address space.
  ~AddrSpace();			// De-allocate an address space

  bool Load(char* fileName);		// Load a program into addr space from
  // a file
// return false if not found

  void Execute(char* fileName);             	// Run a program
  // assumes the program has already
                                // been loaded

  void SaveState();			// Save/restore address space-specific
  void RestoreState();		// info on a context switch 

  // Translate virtual address _vaddr_
  // to physical address _paddr_. _mode_
  // is 0 for Read, 1 for Write.
  ExceptionType Translate(unsigned int vaddr, unsigned int* paddr, int mode);

private:
  TranslationEntry* pageTable;	// Assume linear page table translation
  // for now!
  unsigned int numPages;		// Number of pages in the virtual 
  // address space

  void InitRegisters();		// Initialize user-level CPU registers,
  // before jumping to user code

};

#endif // ADDRSPACE_H

#ifndef FRAME_TABLE_H
#define FRAME_TABLE_H

#include "machine.h"
#include "list.h"

/**
 * Data structure of Virtual Memory
 */
typedef TranslationEntry* PageTable;

/**
 * Data structure of Physical Memory
 */
class FrameTable {
public:
  /**
   * Initialize a frame table
   */
  FrameTable();
  ~FrameTable();

  /**
   * Allocate pageNum of frames (pages) and collect
   * corresponding translation information into a page table.
   *
   * @param pageNum numbers of pages
   * @return a new Page table, NULL if not enough memory space
   */
  PageTable Allocate(uint pageNum);

  /**
   * Release the physical memory frame
   * which the info stored in PageTable
   */
  void Release(PageTable ptb, int pageNum);

  /**
   * @return the remaining numbers of entry of the frame table
   */
  uint RemainSize();

private:
  List<int> available;
};

#endif /* FRAME_TABLE_H */