init: init nachos hw01, should pass jenkins os_group_20_hw job but fail on os_group_20_ta job

code/filesys/pbitmap.h

@@ -0,0 +1,35 @@
+// pbitmap.h 
+//	Data structures defining a "persistent" bitmap -- a bitmap
+//	that can be stored and fetched off of disk
+//
+//    A persistent bitmap can either be initialized from the disk
+//    when it is created, or it can be initialized later using
+//    the FetchFrom method
+//
+// Copyright (c) 1992,1993,1995 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 PBITMAP_H
+#define PBITMAP_H
+
+#include "copyright.h"
+#include "bitmap.h"
+#include "openfile.h"
+
+// The following class defines a persistent bitmap.  It inherits all
+// the behavior of a bitmap (see bitmap.h), adding the ability to
+// be read from and stored to the disk.
+
+class PersistentBitmap : public Bitmap {
+  public:
+    PersistentBitmap(OpenFile *file,int numItems); //initialize bitmap from disk 
+    PersistentBitmap(int numItems); // or don't...
+
+    ~PersistentBitmap(); 			// deallocate bitmap
+
+    void FetchFrom(OpenFile *file);     // read bitmap from the disk
+    void WriteBack(OpenFile *file); 	// write bitmap contents to disk 
+};
+
+#endif // PBITMAP_H