Comments.

[pintos-anon] / src / devices / timer.c

diff --git a/src/devices/timer.c b/src/devices/timer.c
index 9c611a1d3eda68b6fd2317304faaef9381f9eb40..ec9778321e3339aa2f32bb5496ece5e71a5ea969 100644 (file)
--- a/src/devices/timer.c
+++ b/src/devices/timer.c
@@ -1,10 +1,14 @@
 #include "devices/timer.h"
 #include <debug.h>
+#include <inttypes.h>
 #include <round.h>
+#include <stdio.h>
 #include "threads/interrupt.h"
 #include "threads/io.h"
 #include "threads/thread.h"
   
+/* See [8254] for hardware details of the 8254 timer chip. */
+
 #if TIMER_FREQ < 19
 #error 8254 timer requires TIMER_FREQ >= 19
 #endif
@@ -91,12 +95,20 @@ timer_ns2ticks (int64_t ns)
 {
   return DIV_ROUND_UP (ns * TIMER_FREQ, 1000000000);
 }
+
+/* Prints timer statistics. */
+void
+timer_print_stats (void) 
+{
+  printf ("Timer: %"PRId64" ticks\n", ticks);
+}
 \f
 /* Timer interrupt handler. */
 static void
 timer_interrupt (struct intr_frame *args UNUSED)
 {
   ticks++;
+  thread_tick ();
   if (ticks % TIME_SLICE == 0)
     intr_yield_on_return ();
 }