Change assembly from AT&T to Intel syntax.

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

diff --git a/src/threads/thread.c b/src/threads/thread.c
index b50eafe4f75e71280ebfd4b76b34fad1eebe4859..01ce7d33227a19196762199f3c349bab4890b688 100644 (file)
--- a/src/threads/thread.c
+++ b/src/threads/thread.c
@@ -41,6 +41,11 @@ struct kernel_thread_frame
     void *aux;                  /* Auxiliary data for function. */
   };
 
     void *aux;                  /* Auxiliary data for function. */
   };
 

+/* Statistics. */
+static long long idle_ticks;    /* # of timer ticks spent idle. */
+static long long kernel_ticks;  /* # of timer ticks in kernel threads. */
+static long long user_ticks;    /* # of timer ticks in user programs. */
+

 static void kernel_thread (thread_func *, void *aux);
 
 static void idle (void *aux UNUSED);
 static void kernel_thread (thread_func *, void *aux);
 
 static void idle (void *aux UNUSED);


@@ -49,16 +54,16 @@ static struct thread *next_thread_to_run (void);
 static void init_thread (struct thread *, const char *name, int priority);
 static bool is_thread (struct thread *);
 static void *alloc_frame (struct thread *, size_t size);
 static void init_thread (struct thread *, const char *name, int priority);
 static bool is_thread (struct thread *);
 static void *alloc_frame (struct thread *, size_t size);

-static void destroy_thread (struct thread *);

 static void schedule (void);
 void schedule_tail (struct thread *prev);
 static tid_t allocate_tid (void);
 
 /* Initializes the threading system by transforming the code
 static void schedule (void);
 void schedule_tail (struct thread *prev);
 static tid_t allocate_tid (void);
 
 /* Initializes the threading system by transforming the code

-   that's currently running into a thread.  Note that this is
-   possible only because the loader was careful to put the bottom
-   of the stack at a page boundary; it won't work in general.
-   Also initializes the run queue.
+   that's currently running into a thread.  This can't work in
+   general and it is possible in this case only because loader.S
+   was careful to put the bottom of the stack at a page boundary.
+
+   Also initializes the run queue and the tid lock.

 
    After calling this function, be sure to initialize the page
    allocator before trying to create any threads with
 
    After calling this function, be sure to initialize the page
    allocator before trying to create any threads with


@@ -69,15 +74,13 @@ thread_init (void)
   ASSERT (intr_get_level () == INTR_OFF);
 
   lock_init (&tid_lock, "tid");
   ASSERT (intr_get_level () == INTR_OFF);
 
   lock_init (&tid_lock, "tid");

+  list_init (&ready_list);

 
   /* Set up a thread structure for the running thread. */
   initial_thread = running_thread ();
   init_thread (initial_thread, "main", PRI_DEFAULT);
   initial_thread->status = THREAD_RUNNING;
   initial_thread->tid = allocate_tid ();
 
   /* Set up a thread structure for the running thread. */
   initial_thread = running_thread ();
   init_thread (initial_thread, "main", PRI_DEFAULT);
   initial_thread->status = THREAD_RUNNING;
   initial_thread->tid = allocate_tid ();

-
-  /* Initialize run queue. */
-  list_init (&ready_list);

 }
 
 /* Starts preemptive thread scheduling by enabling interrupts.
 }
 
 /* Starts preemptive thread scheduling by enabling interrupts.


@@ -89,6 +92,30 @@ thread_start (void)
   intr_enable ();
 }
 
   intr_enable ();
 }
 

+/* Called by the timer interrupt handler at each timer tick to
+   update statistics. */
+void
+thread_tick (void) 
+{
+  struct thread *t = thread_current ();
+  if (t == idle_thread)
+    idle_ticks++;
+#ifdef USERPROG
+  else if (t->pagedir != NULL)
+    user_ticks++;
+#endif
+  else
+    kernel_ticks++;
+}
+
+/* Prints thread statistics. */
+void
+thread_print_stats (void) 
+{
+  printf ("Thread: %lld idle ticks, %lld kernel ticks, %lld user ticks\n",
+          idle_ticks, kernel_ticks, user_ticks);
+}
+

 /* Creates a new kernel thread named NAME with the given initial
    PRIORITY, which executes FUNCTION passing AUX as the argument,
    and adds it to the ready queue.  If thread_start() has been
 /* Creates a new kernel thread named NAME with the given initial
    PRIORITY, which executes FUNCTION passing AUX as the argument,
    and adds it to the ready queue.  If thread_start() has been


@@ -115,7 +142,7 @@ thread_create (const char *name, int priority,
   ASSERT (function != NULL);
 
   /* Allocate thread. */
   ASSERT (function != NULL);
 
   /* Allocate thread. */

-  t = palloc_get (PAL_ZERO);
+  t = palloc_get_page (PAL_ZERO);

   if (t == NULL)
     return TID_ERROR;
 
   if (t == NULL)
     return TID_ERROR;
 


@@ -143,9 +170,25 @@ thread_create (const char *name, int priority,
   return tid;
 }
 
   return tid;
 }
 

-/* Transitions a blocked thread T from its current state to the
-   ready-to-run state.  This is an error if T is not blocked.
-   (Use thread_yield() to make the running thread ready.) */
+/* Puts the current thread to sleep.  It will not be scheduled
+   again until awoken by thread_unblock().
+
+   This function must be called with interrupts turned off.  It
+   is usually a better idea to use one of the synchronization
+   primitives in synch.h. */
+void
+thread_block (void) 
+{
+  ASSERT (!intr_context ());
+  ASSERT (intr_get_level () == INTR_OFF);
+
+  thread_current ()->status = THREAD_BLOCKED;
+  schedule ();
+}
+
+/* Transitions a blocked thread T to the ready-to-run state.
+   This is an error if T is not blocked.  (Use thread_yield() to
+   make the running thread ready.) */

 void
 thread_unblock (struct thread *t) 
 {
 void
 thread_unblock (struct thread *t) 
 {


@@ -200,6 +243,10 @@ thread_exit (void)
 {
   ASSERT (!intr_context ());
 
 {
   ASSERT (!intr_context ());
 

+#ifdef USERPROG
+  process_exit ();
+#endif
+

   /* Just set our status to dying and schedule another process.
      We will be destroyed during the call to schedule_tail(). */
   intr_disable ();
   /* Just set our status to dying and schedule another process.
      We will be destroyed during the call to schedule_tail(). */
   intr_disable ();


@@ -224,22 +271,6 @@ thread_yield (void)
   schedule ();
   intr_set_level (old_level);
 }
   schedule ();
   intr_set_level (old_level);
 }

-
-/* Puts the current thread to sleep.  It will not be scheduled
-   again until awoken by thread_unblock().
-
-   This function must be called with interrupts turned off.  It
-   is usually a better idea to use one of the synchronization
-   primitives in synch.h. */
-void
-thread_block (void) 
-{
-  ASSERT (!intr_context ());
-  ASSERT (intr_get_level () == INTR_OFF);
-
-  thread_current ()->status = THREAD_BLOCKED;
-  schedule ();
-}

 \f
 /* Idle thread.  Executes when no other thread is ready to run. */
 static void
 \f
 /* Idle thread.  Executes when no other thread is ready to run. */
 static void


@@ -254,7 +285,8 @@ idle (void *aux UNUSED)
       thread_block ();
       intr_enable ();
 
       thread_block ();
       intr_enable ();
 

-      /* Use CPU `hlt' instruction to wait for interrupt. */
+      /* Use CPU `hlt' instruction to wait for interrupt.
+         See [IA32-v2a] "HLT" and [IA32-v3] 7.7. */

       asm ("hlt");
     }
 }
       asm ("hlt");
     }
 }


@@ -280,7 +312,7 @@ running_thread (void)
      down to the start of a page.  Because `struct thread' is
      always at the beginning of a page and the stack pointer is
      somewhere in the middle, this locates the curent thread. */
      down to the start of a page.  Because `struct thread' is
      always at the beginning of a page and the stack pointer is
      somewhere in the middle, this locates the curent thread. */

-  asm ("movl %%esp, %0\n" : "=g" (esp));
+  asm ("mov %0, %%esp" : "=g" (esp));

   return pg_round_down (esp);
 }
 
   return pg_round_down (esp);
 }
 


@@ -335,20 +367,6 @@ next_thread_to_run (void)
     return list_entry (list_pop_front (&ready_list), struct thread, elem);
 }
 
     return list_entry (list_pop_front (&ready_list), struct thread, elem);
 }
 

-/* Destroys T, which must not be the running thread. */
-static void
-destroy_thread (struct thread *t) 
-{
-  ASSERT (is_thread (t));
-  ASSERT (t != thread_current ());
-
-#ifdef USERPROG
-  process_destroy (t);
-#endif
-  if (t != initial_thread)
-    palloc_free (t);
-}
-

 /* Completes a thread switch by activating the new thread's page
    tables, and, if the previous thread is dying, destroying it.
 
 /* Completes a thread switch by activating the new thread's page
    tables, and, if the previous thread is dying, destroying it.
 


@@ -359,6 +377,10 @@ destroy_thread (struct thread *t)
    the first time a thread is scheduled it is called by
    switch_entry() (see switch.S).
 
    the first time a thread is scheduled it is called by
    switch_entry() (see switch.S).
 

+   It's not safe to call printf() until the thread switch is
+   complete.  In practice that means that printf()s should be
+   added at the end of the function.
+

    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


@@ -376,17 +398,24 @@ schedule_tail (struct thread *prev)
   process_activate ();
 #endif
 
   process_activate ();
 #endif
 

-  /* If the thread we switched from is dying, destroy it.
-     This must happen late because it's not a good idea to
-     e.g. destroy the page table you're currently using. */
+  /* If the thread we switched from is dying, destroy its struct
+     thread.  This must happen late so that thread_exit() doesn't
+     pull out the rug under itself. */

   if (prev != NULL && prev->status == THREAD_DYING) 
   if (prev != NULL && prev->status == THREAD_DYING) 

-    destroy_thread (prev);
+    {
+      ASSERT (prev != cur);
+      if (prev != initial_thread)
+        palloc_free_page (prev);
+    }

 }
 
 /* Schedules a new process.  At entry, interrupts must be off and
    the running process's state must have been changed from
    running to some other state.  This function finds another
 }
 
 /* Schedules a new process.  At entry, interrupts must be off and
    the running process's state must have been changed from
    running to some other state.  This function finds another

-   thread to run and switches to it. */
+   thread to run and switches to it.
+
+   It's not safe to call printf() until schedule_tail() has
+   completed. */

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