1 files changed, 18 insertions, 17 deletions

diff --git a/vm/page.h b/vm/page.h
index 29159fb..9cea048 100644
--- a/vm/page.h
+++ b/vm/page.h
@@ -8,32 +8,33 @@
 /* supplemental page table entry */
 struct page_table_entry
 {
-  void *uvaddr;
-  bool loaded;
+  void *upage;            /* virtual address of page */
+  bool loaded;            /* indicates if page is loaded */
   enum
-  {
-    PAGE_SEGMENT,
-    PAGE_MEMORY_MAPPED_FILE,
-  } type;
+    {
+      PAGE_SEGMENT,
+      PAGE_MEMORY_MAPPED_FILE,
+    } type;               /* type of page */
 
   union
-  {
-    struct segment
     {
-      struct file *file;
-      off_t ofs;
-      uint32_t read_bytes;
-      uint32_t zero_bytes;
-      bool writable;
-    } segment;
-  };
+      /* structure needed for lazy loading of data segments */
+      struct segment
+        {
+          struct file *file;
+          off_t ofs;
+          uint32_t read_bytes;
+          uint32_t zero_bytes;
+          bool writable;
+        } segment;
+    };
 
-  struct hash_elem elem;
+  struct hash_elem elem;  /* Hash element. */
 };
 
 void page_table_init (struct hash *ht);
 void page_table_free (struct hash *ht);
-struct page_table_entry *page_table_fetch (struct hash *ht, void *uvaddr);
+struct page_table_entry *page_table_fetch (struct hash *ht, void *upage);
 bool page_table_insert_segment (struct file *file, off_t ofs, uint8_t *upage,
     uint32_t read_bytes, uint32_t zero_bytes, bool writable);
 bool page_load (struct page_table_entry *pte);