thread: Do not disable interrupts unnecessarily while initializing stack.

[pintos-anon] / src / threads / thread.c

diff --git a/src/threads/thread.c b/src/threads/thread.c
index 92d1aa899efe1d8bf84c6c7056ae7d45215c687b..87f22b80607b4faba8ae2b1e9f93dc5d6659d8cc 100644 (file)
--- a/src/threads/thread.c
+++ b/src/threads/thread.c
@@ -24,6 +24,10 @@
    that are ready to run but not actually running. */
 static struct list ready_list;
 
    that are ready to run but not actually running. */
 static struct list ready_list;
 

+/* List of all processes.  Processes are added to this list
+   when they are first scheduled and removed when they exit. */
+static struct list all_list;
+

 /* Idle thread. */
 static struct thread *idle_thread;
 
 /* Idle thread. */
 static struct thread *idle_thread;
 


@@ -64,7 +68,7 @@ static void init_thread (struct thread *, const char *name, int priority);
 static bool is_thread (struct thread *) UNUSED;
 static void *alloc_frame (struct thread *, size_t size);
 static void schedule (void);
 static bool is_thread (struct thread *) UNUSED;
 static void *alloc_frame (struct thread *, size_t size);
 static void schedule (void);

-void schedule_tail (struct thread *prev);
+void thread_schedule_tail (struct thread *prev);

 static tid_t allocate_tid (void);
 
 /* Initializes the threading system by transforming the code
 static tid_t allocate_tid (void);
 
 /* Initializes the threading system by transforming the code


@@ -87,6 +91,7 @@ thread_init (void)
 
   lock_init (&tid_lock);
   list_init (&ready_list);
 
   lock_init (&tid_lock);
   list_init (&ready_list);

+  list_init (&all_list);

 
   /* Set up a thread structure for the running thread. */
   initial_thread = running_thread ();
 
   /* Set up a thread structure for the running thread. */
   initial_thread = running_thread ();


@@ -191,6 +196,7 @@ thread_create (const char *name, int priority,
   /* Stack frame for switch_threads(). */
   sf = alloc_frame (t, sizeof *sf);
   sf->eip = switch_entry;
   /* Stack frame for switch_threads(). */
   sf = alloc_frame (t, sizeof *sf);
   sf->eip = switch_entry;

+  sf->ebp = 0;

 
   /* Add to run queue. */
   thread_unblock (t);
 
   /* Add to run queue. */
   thread_unblock (t);


@@ -280,9 +286,11 @@ thread_exit (void)
   process_exit ();
 #endif
 
   process_exit ();
 #endif
 

-  /* Just set our status to dying and schedule another process.
-     We will be destroyed during the call to schedule_tail(). */
+  /* Remove thread from all threads list, set our status to dying,
+     and schedule another process.  That process will destroy us
+     when it calls thread_schedule_tail(). */

   intr_disable ();
   intr_disable ();

+  list_remove (&thread_current()->allelem);

   thread_current ()->status = THREAD_DYING;
   schedule ();
   NOT_REACHED ();
   thread_current ()->status = THREAD_DYING;
   schedule ();
   NOT_REACHED ();


@@ -306,6 +314,23 @@ thread_yield (void)
   intr_set_level (old_level);
 }
 
   intr_set_level (old_level);
 }
 

+/* Invoke function 'func' on all threads, passing along 'aux'.
+   This function must be called with interrupts off. */
+void
+thread_foreach (thread_action_func *func, void *aux)
+{
+  struct list_elem *e;
+
+  ASSERT (intr_get_level () == INTR_OFF);
+
+  for (e = list_begin (&all_list); e != list_end (&all_list);
+       e = list_next (e))
+    {
+      struct thread *t = list_entry (e, struct thread, allelem);
+      func (t, aux);
+    }
+}
+

 /* Sets the current thread's priority to NEW_PRIORITY. */
 void
 thread_set_priority (int new_priority) 
 /* Sets the current thread's priority to NEW_PRIORITY. */
 void
 thread_set_priority (int new_priority) 


@@ -426,6 +451,8 @@ is_thread (struct thread *t)
 static void
 init_thread (struct thread *t, const char *name, int priority)
 {
 static void
 init_thread (struct thread *t, const char *name, int priority)
 {

+  enum intr_level old_level;
+

   ASSERT (t != NULL);
   ASSERT (PRI_MIN <= priority && priority <= PRI_MAX);
   ASSERT (name != NULL);
   ASSERT (t != NULL);
   ASSERT (PRI_MIN <= priority && priority <= PRI_MAX);
   ASSERT (name != NULL);


@@ -436,6 +463,10 @@ init_thread (struct thread *t, const char *name, int priority)
   t->stack = (uint8_t *) t + PGSIZE;
   t->priority = priority;
   t->magic = THREAD_MAGIC;
   t->stack = (uint8_t *) t + PGSIZE;
   t->priority = priority;
   t->magic = THREAD_MAGIC;

+
+  old_level = intr_disable ();
+  list_push_back (&all_list, &t->allelem);
+  intr_set_level (old_level);

 }
 
 /* Allocates a SIZE-byte frame at the top of thread T's stack and
 }
 
 /* Allocates a SIZE-byte frame at the top of thread T's stack and


@@ -482,7 +513,7 @@ next_thread_to_run (void)
    After this function and its caller returns, the thread switch
    is complete. */
 void
    After this function and its caller returns, the thread switch
    is complete. */
 void

-schedule_tail (struct thread *prev) 
+thread_schedule_tail (struct thread *prev)

 {
   struct thread *cur = running_thread ();
   
 {
   struct thread *cur = running_thread ();
   


@@ -516,8 +547,8 @@ schedule_tail (struct thread *prev)
    running to some other state.  This function finds another
    thread to run and switches to it.
 
    running to some other state.  This function finds another
    thread to run and switches to it.
 

-   It's not safe to call printf() until schedule_tail() has
-   completed. */
+   It's not safe to call printf() until thread_schedule_tail()
+   has completed. */

 static void
 schedule (void) 
 {
 static void
 schedule (void) 
 {


@@ -531,7 +562,7 @@ schedule (void)
 
   if (cur != next)
     prev = switch_threads (cur, next);
 
   if (cur != next)
     prev = switch_threads (cur, next);

-  schedule_tail (prev); 
+  thread_schedule_tail (prev);

 }
 
 /* Returns a tid to use for a new thread. */
 }
 
 /* Returns a tid to use for a new thread. */