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 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
- 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
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 ();
-
- /* Initialize run queue. */
- list_init (&ready_list);
}
/* Starts preemptive thread scheduling by enabling interrupts.
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
ASSERT (function != NULL);
/* Allocate thread. */
- t = palloc_get (PAL_ZERO);
+ t = palloc_get_page (PAL_ZERO);
if (t == NULL)
return TID_ERROR;
{
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 ();
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.
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)
- 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