refactor: extract init_pages

src/threads/thread.c

@@ -265,11 +265,24 @@ thread_create (const char *name, int priority,
 #ifdef USERPROG
   /* Initialize the thread's file descriptor table. */
   t->fd_counter = MINIMUM_USER_FD;
+  bool success = hash_init (&t->open_files, fd_hash, fd_less, NULL);
+  if (success)
+    {
+      success = hash_init (&t->child_results, process_result_hash,
+                           process_result_less, t);
+      if (!success)
+        hash_destroy (&t->open_files, NULL);
+#ifdef VM
+      else
+        {
+          success = init_pages (&t->pages);
+          if (!success)
+            hash_destroy (&t->child_results, NULL);
+        }
+#endif
+    }
 
-  if (!hash_init (&t->open_files, fd_hash, fd_less, NULL)
+  if (!success)
-      || !hash_init (&t->child_results, process_result_hash,
-                     process_result_less, t)
-      || !hash_init (&t->pages, page_hash, page_less, NULL))
     {
       palloc_free_page (t);
       free (t->result);

src/vm/page.c

@@ -14,10 +14,22 @@
 #define SWAP_FLAG_BIT 9
 #define ADDR_START_BIT 12
 
+static unsigned page_hash (const struct hash_elem *e, void *aux UNUSED);
+static bool page_less (const struct hash_elem *a_, const struct hash_elem *b_,
+                       void *aux UNUSED);
+
+/* Initialise a supplementary page table. */
+bool
+init_pages (struct hash *pages)
+{
+  ASSERT (pages != NULL);
+  return hash_init (pages, page_hash, page_less, NULL);
+}
+
 /* Hashing function needed for the SPT table. Returns a hash for an entry,
    based on its upage. */
-unsigned
+static unsigned
-page_hash (const struct hash_elem *e, UNUSED void *aux)
+page_hash (const struct hash_elem *e, void *aux UNUSED)
 {
   struct page_entry *page = hash_entry (e, struct page_entry, elem);
   return hash_ptr (page->upage);
@@ -25,7 +37,7 @@ page_hash (const struct hash_elem *e, UNUSED void *aux)
 
 /* Comparator function for the SPT table. Compares two entries based on their
    upages. */
-bool
+static bool
 page_less (const struct hash_elem *a_, const struct hash_elem *b_,
            void *aux UNUSED)
 {
@@ -116,7 +128,7 @@ page_get (void *upage)
 }
 
 bool
-page_load_file (struct page_entry *page, bool writable)
+page_load_file (struct page_entry *page)
 {
   /* Allocate a frame for the page. If a frame allocation fails, then
      frame_alloc should try to evict a page. If it is still NULL, the OS
@@ -128,7 +140,7 @@ page_load_file (struct page_entry *page, bool writable)
     PANIC ("Could not allocate a frame to load page into memory.");
 
   /* Map the page to the frame. */
-  if (!install_page (page->upage, frame, writable))
+  if (!install_page (page->upage, frame, page->writable))
     {
       frame_free (frame);
       return false;