From f2aba977b4a78a024549004978fcda4171b7d0e1 Mon Sep 17 00:00:00 2001
From: Gleb Koval <gleb@koval.net>
Date: Wed, 4 Dec 2024 11:17:46 +0000
Subject: [PATCH] fix: extract supplemental and shared_files initialisation

---
 src/threads/init.c   |  2 ++
 src/threads/thread.c |  6 +-----
 src/vm/page.c        | 23 ++++++++++++++++++++++-
 src/vm/page.h        | 11 +++--------
 4 files changed, 28 insertions(+), 14 deletions(-)

diff --git a/src/threads/init.c b/src/threads/init.c
index 69ac6af..a292b91 100644
--- a/src/threads/init.c
+++ b/src/threads/init.c
@@ -31,6 +31,7 @@
 #else
 #include "tests/threads/tests.h"
 #endif
+#include "vm/page.h"
 #ifdef VM
 #include "vm/frame.h"
 #include "devices/swap.h"
@@ -121,6 +122,7 @@ main (void)
   exception_init ();
   syscall_init ();
 #endif
+  shared_files_init ();
 
   /* Start thread scheduler and enable interrupts. */
   thread_start ();
diff --git a/src/threads/thread.c b/src/threads/thread.c
index 8487ff8..ed37d2f 100644
--- a/src/threads/thread.c
+++ b/src/threads/thread.c
@@ -134,10 +134,6 @@ thread_start (void)
                   t))
     PANIC ("Failed to initialise child results table for main thread.");
 
-  /* Initialise the shared files table and lock. */
-  if (!hash_init (&shared_files, shared_file_hash, shared_file_less, NULL))
-    PANIC ("Failed to initialise shared pages table.");
-
   lock_init (&shared_files_lock);
 
   /* Create the idle thread. */
@@ -272,7 +268,7 @@ thread_create (const char *name, int priority,
   if (!hash_init (&t->open_files, fd_hash, fd_less, NULL)
       || !hash_init (&t->child_results, process_result_hash,
                      process_result_less, t)
-      || !hash_init (&t->pages, page_hash, page_less, NULL))
+      || !init_pages (t))
     {
       palloc_free_page (t);
       free (t->result);
diff --git a/src/vm/page.c b/src/vm/page.c
index 0470e37..cf5f1f7 100644
--- a/src/vm/page.c
+++ b/src/vm/page.c
@@ -9,17 +9,29 @@
 #include "userprog/process.h"
 #include "vm/frame.h"
 
+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);
 static struct shared_page_entry *shared_page_insert (struct file *file,
                                                      void *upage, void *frame);
 static struct shared_file_entry *shared_file_get (struct file *file);
+static struct shared_page_entry *shared_page_get (struct file *file,
+                                                  void *upage);
 static unsigned shared_page_hash (const struct hash_elem *e, void *aux UNUSED);
 static bool shared_page_less (const struct hash_elem *a_,
                               const struct hash_elem *b_, void *aux UNUSED);
 
+/* Initialise a thread's supplemental pages table. */
+bool
+init_pages (struct thread *t)
+{
+  return hash_init (&t->pages, page_hash, page_less, NULL);
+}
+
 /* Hashing function needed for the SPT table. Returns a hash for an entry,
    based on its upage. */
 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);
@@ -167,6 +179,15 @@ page_cleanup (struct hash_elem *e, void *aux UNUSED)
   free (page);
 }
 
+/* Initialise the shared files and table and lock. */
+bool
+shared_files_init ()
+{
+  lock_init (&shared_files_lock);
+  if (!hash_init (&shared_files, shared_file_hash, shared_file_less, NULL))
+    PANIC ("Failed to initialise shared_files table.");
+}
+
 /* Hashing function needed for the shared_file table. Returns a hash for an
    entry based on its file pointer. */
 unsigned
diff --git a/src/vm/page.h b/src/vm/page.h
index 9b7254e..c6fb36c 100644
--- a/src/vm/page.h
+++ b/src/vm/page.h
@@ -43,20 +43,15 @@ struct shared_page_entry {
   struct hash_elem elem;
 };
 
-unsigned page_hash (const struct hash_elem *e, void *aux);
-bool page_less (const struct hash_elem *a_, const struct hash_elem *b_,
-                void *aux);
+bool init_pages (struct thread *t);
 struct page_entry *page_insert (struct file *file, off_t ofs, void *upage,
                                 uint32_t read_bytes, uint32_t zero_bytes,
                                 bool writable, enum page_type type);
 struct page_entry *page_get (void *upage);
 bool page_load (struct page_entry *page);
-void page_cleanup (struct hash_elem *e, void *aux);
+void page_cleanup (struct hash_elem *e, void *aux UNUSED);
 
-unsigned shared_file_hash (const struct hash_elem *e, void *aux);
-bool shared_file_less (const struct hash_elem *a_, const struct hash_elem *b_,
-                       void *aux);
-struct shared_page_entry *shared_page_get (struct file *file, void *upage);
+void shared_files_init ();
 
 void page_set_swap (struct thread *, void *, size_t);
 size_t page_get_swap (struct thread *, void *);