X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Fdevices%2Ftimer.c;h=ecf6c5aacdfee97c6577c8b60912475ef99e4e77;hb=64f0952217e8b1a53461f5a98a070cb2da266171;hp=8f4838f048e04ec80d0060fc10cd1a3d77da3216;hpb=275c68384d654e4c1f9ac4a3eadd2c3d4e46cf86;p=pintos-anon

diff --git a/src/devices/timer.c b/src/devices/timer.c
index 8f4838f..ecf6c5a 100644
--- a/src/devices/timer.c
+++ b/src/devices/timer.c
@@ -1,9 +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
@@ -20,7 +25,7 @@ static volatile int64_t ticks;
 
 static intr_handler_func timer_interrupt;
 
-/* Sets up the 8254 Programmable Interrupt Timer (PIT) to
+/* Sets up the 8254 Programmable Interval Timer (PIT) to
    interrupt PIT_FREQ times per second, and registers the
    corresponding interrupt. */
 void
@@ -55,14 +60,15 @@ timer_elapsed (int64_t then)
   return timer_ticks () - then;
 }
 
-/* Suspends executions for approximately TICKS timer ticks. */
+/* Suspends execution for approximately TICKS timer ticks. */
 void
 timer_sleep (int64_t ticks) 
 {
   int64_t start = timer_ticks ();
 
+  ASSERT (intr_get_level () == INTR_ON);
   while (timer_elapsed (start) < ticks) 
-    continue;
+    thread_yield ();
 }
 
 /* Returns MS milliseconds in timer ticks, rounding up. */
@@ -89,12 +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);
+}
 
 /* Timer interrupt handler. */
 static void
 timer_interrupt (struct intr_frame *args UNUSED)
 {
   ticks++;
+  thread_tick ();
   if (ticks % TIME_SLICE == 0)
     intr_yield_on_return ();
 }