Fix rox checking and make filesys_lock global

src/threads/synch.c

@@ -212,7 +212,6 @@ donate_priority (struct thread *donee) {
   ASSERT (intr_get_level () == INTR_OFF);
 
   struct thread *donor = thread_current ();
-  list_remove (&donor->donor_elem);
   list_push_back (&donee->donors_list, &donor->donor_elem);
   
   while (donee != NULL)
@@ -261,7 +260,6 @@ lock_acquire (struct lock *lock)
   ASSERT (!lock_held_by_current_thread (lock));
 
   struct thread *t = thread_current ();
-  ASSERT (t->waiting_lock == NULL);
 
   enum intr_level old_level = intr_disable ();
   if (lock->holder != NULL)
@@ -343,6 +341,7 @@ lock_release (struct lock *lock)
      released, transfer the remaining orphaned donors to its donor list. */
   if (max_donor != NULL)
     {
+      list_remove (&max_donor->donor_elem);
       while (!list_empty (&orphan_list))
         list_push_back (&max_donor->donors_list, list_pop_front (&orphan_list));
     }

src/threads/thread.c

@@ -373,9 +373,7 @@ thread_exit (void)
      and schedule another process.  That process will destroy us
      when it calls thread_schedule_tail(). */
   intr_disable ();
-  struct thread *t = thread_current ();
-  list_remove (&t->allelem);
-  list_remove (&t->donor_elem);
+  list_remove (&thread_current()->allelem);
   thread_current ()->status = THREAD_DYING;
   schedule ();
   NOT_REACHED ();
@@ -681,7 +679,6 @@ init_thread (struct thread *t, const char *name, int nice, int priority,
   t->base_priority
       = thread_mlfqs ? calculate_bsd_priority (recent_cpu, nice) : priority;
   list_init (&t->donors_list);
-  list_push_back (&t->donors_list, &t->donor_elem);
   t->waiting_lock = NULL;
 
   t->nice = nice;

src/userprog/process.c

@@ -47,9 +47,6 @@ struct process_start_data
                           tokens while maintaining state. */
     char file_name[FNAME_MAX_LEN + 1]; /* Name of the file of the process to
                                       be started. */
-    struct semaphore load_sema;
-
-    bool success;
   };
 
 static thread_func start_process NO_RETURN;
@@ -65,7 +62,11 @@ process_execute (const char *cmd)
   char *cmd_copy;
   tid_t tid;
   
-  struct process_start_data data;
+  struct process_start_data *data = malloc (sizeof (struct process_start_data));
+  if (data == NULL)
+    {
+      return TID_ERROR;
+    }
 
   /* Make a copy of command.
      Otherwise there's a race between the caller and load(). */
@@ -79,39 +80,21 @@ process_execute (const char *cmd)
 
   /* Retrieve first argument of command, which is the file name
      of the process. */
-  char *file_name = strtok_r (cmd_copy, " ", &data.cmd_saveptr);
+  char *file_name = strtok_r (cmd_copy, " ", &data->cmd_saveptr);
 
-  /* NOTE: Currently, the file being executed is closed in load () and then
-          reopened here. Because load is an exported public function, this
-          might be necessary. */
-  lock_acquire (&filesys_lock);
   /* Validates that the current file to be executed is a valid file */
-  bool valid_file = filesys_open (file_name) != NULL;
-  lock_release (&filesys_lock);
-  if (!valid_file)
+  if (filesys_open (file_name) == NULL)
     return TID_ERROR;
 
   /* Create a new thread to execute the command, by initializing
      it running the function 'start_process' with the appropriate
      arguments. For details of arguments, see 'start_process'. */
-  data.cmd = cmd_copy;
-  strlcpy (data.file_name, file_name, FNAME_MAX_LEN + 1);
-  sema_init (&data.load_sema, 0);
-  data.success = false;
-
-  tid = thread_create (file_name, PRI_DEFAULT, start_process, &data);
+  data->cmd = cmd_copy;
+  strlcpy (data->file_name, file_name, FNAME_MAX_LEN + 1);
 
+  tid = thread_create (file_name, PRI_DEFAULT, start_process, data);
   if (tid == TID_ERROR)
-    {
-      palloc_free_page (cmd_copy);
-    }
-  else
-    {
-      sema_down (&data.load_sema);
-      if (!data.success)
-        tid = TID_ERROR;
-    }
-
+    palloc_free_page (cmd_copy); 
   return tid;
 }
 
@@ -129,6 +112,7 @@ static void
 start_process (void *proc_start_data)
 {
   struct intr_frame if_;
+  bool success;
 
   struct process_start_data *data = proc_start_data;
 
@@ -137,38 +121,34 @@ start_process (void *proc_start_data)
   if_.gs = if_.fs = if_.es = if_.ds = if_.ss = SEL_UDSEG;
   if_.cs = SEL_UCSEG;
   if_.eflags = FLAG_IF | FLAG_MBS;
-  
-  lock_acquire (&filesys_lock);
-  
-  /* Prevent writing to the file being executed. */
-  struct file *exec_file = filesys_open (data->file_name);
-  thread_current ()->exec_file = exec_file;
-  file_deny_write (exec_file);
-  lock_release (&filesys_lock);
+  success = load (data->file_name, &if_.eip, &if_.esp);
 
-  data->success = load (data->file_name, &if_.eip, &if_.esp);
-
-  /* If load failed, free process startup data and quit. */
-  if (!data->success)
+  /* If load failed, quit. */
+  if (!success) 
     {
       palloc_free_page (data->cmd);
-      sema_up (&data->load_sema);
-      thread_exit ();
+      goto fail;
     }
 
   /* Initialize user process stack and free page used to store the
      command that executed the process. */
-  bool success = process_init_stack (data->cmd_saveptr, &if_.esp, data->file_name);
+  success = process_init_stack (data->cmd_saveptr, &if_.esp, data->file_name);
   palloc_free_page (data->cmd);
-  data->success = success;
-  sema_up (&data->load_sema);
   
-  /* If stack initialization failed, free process resources and quit. */
+  /* If stack initialization failed, free resources and quit. */
   if (!success)
     {
-      thread_exit ();
+      process_exit ();
+      goto fail;
     }
 
+  /* NOTE: Currently, the file being executed is closed in load () and then 
+           reopened here. Because load is an exported public function, this
+           might be necessary. */
+  struct file *exec_file = filesys_open (data->file_name);
+  thread_current ()->exec_file = exec_file;
+  file_deny_write (exec_file);
+
   /* Start the user process by simulating a return from an
      interrupt, implemented by intr_exit (in
      threads/intr-stubs.S).  Because intr_exit takes all of its
@@ -177,6 +157,11 @@ start_process (void *proc_start_data)
      and jump to it. */
   asm volatile ("movl %0, %%esp; jmp intr_exit" : : "g" (&if_) : "memory");
   NOT_REACHED ();
+
+/* If starting the process failed, free its common resources and exit. */
+ fail:
+  free (data);
+  thread_exit ();
 }
 
 /* Helper function that initializes the stack of a newly created 
@@ -307,9 +292,7 @@ process_wait (tid_t child_tid UNUSED)
         break;
     }
   if (child_result == NULL)
-    {
-      return -1;
-    }
+    return -1;
   /* Wait for child to die. */
   sema_down (&child_result->sema);
   /* We need lock release in process_exit, so we need to acquire (and possibly
@@ -323,7 +306,6 @@ process_wait (tid_t child_tid UNUSED)
   int exit_status = child_result->exit_status;
   lock_release (&child_result->lock);
   free (child_result);
-
   return exit_status;
 }
 
@@ -331,23 +313,11 @@ process_wait (tid_t child_tid UNUSED)
 void
 process_exit (void)
 {
-
-
   struct thread *cur = thread_current ();
   uint32_t *pd;
 
   printf ("%s: exit(%d)\n", cur->name, cur->exit_status);
-
-  /* Clean up all open files */
-  hash_destroy (&cur->open_files, fd_cleanup);
-
-  /* Close the executable file. */
-  if (cur->exec_file != NULL)
-    {
-      lock_acquire (&filesys_lock);
-      file_close (cur->exec_file);
-      lock_release (&filesys_lock);
-    }
+  file_close (cur->exec_file);
 
   /* Update process result. */
   if (cur->result != NULL)
@@ -372,11 +342,10 @@ process_exit (void)
   /* Free child process results or signal parent's death. */
   struct list_elem *e;
   for (e = list_begin (&cur->child_results);
-       e != list_end (&cur->child_results);)
+       e != list_end (&cur->child_results); e = list_next (e))
     {
       struct process_result *result
           = list_entry (e, struct process_result, elem);
-      struct list_elem *next = list_next (e);
       lock_acquire (&result->lock);
       /* Child has died (and was not waited for). Free the result. */
       if (sema_try_down (&result->sema))
@@ -390,7 +359,6 @@ process_exit (void)
           sema_up (&result->sema);
           lock_release (&result->lock);
         }
-      e = next;
     }
 
   /* Destroy the current process's page directory and switch back
@@ -509,7 +477,6 @@ load (const char *file_name, void (**eip) (void), void **esp)
   off_t file_ofs;
   bool success = false;
   int i;
-  lock_acquire (&filesys_lock);
 
   /* Allocate and activate page directory. */
   t->pagedir = pagedir_create ();
@@ -609,7 +576,6 @@ load (const char *file_name, void (**eip) (void), void **esp)
  done:
   /* We arrive here whether the load is successful or not. */
   file_close (file);
-  lock_release (&filesys_lock);
   return success;
 }
 

src/userprog/syscall.c

@@ -378,20 +378,6 @@ fd_less (const struct hash_elem *a_, const struct hash_elem *b_,
   return a->fd < b->fd;
 }
 
-/* Function to clean up an open file entry. Closes the file and frees the
-   associated memory. */
-void
-fd_cleanup (struct hash_elem *e, void *aux UNUSED)
-{
-  struct open_file *file_info = hash_entry (e, struct open_file, elem);
-
-  lock_acquire (&filesys_lock);
-  file_close (file_info->file);
-  lock_release (&filesys_lock);
-
-  free (file_info);
-}
-
 /* Gets a file from its descriptor (FD number). If there is no file with the fd
    FD it returns NULL. */
 static struct open_file *

src/userprog/syscall.h

@@ -14,6 +14,5 @@ void syscall_init (void);
 
 unsigned fd_hash (const struct hash_elem *element, void *aux);
 bool fd_less (const struct hash_elem *a, const struct hash_elem *b, void *aux);
-void fd_cleanup (struct hash_elem *e, void *aux);
 
 #endif /* userprog/syscall.h */