X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Fdevices%2Ftimer.c;h=4271c7354a86b6bf153045cad2666c5e2855faa5;hb=bd1397c2e890c82bd58bb2e6eefa223172b3d632;hp=4b8dd2a47865b8828b9a6f326d4a7f03d970e222;hpb=44d0fa6a2b24a84e5eb0d54959ed91c1d4f15343;p=pintos-anon

diff --git a/src/devices/timer.c b/src/devices/timer.c
index 4b8dd2a..4271c73 100644
--- a/src/devices/timer.c
+++ b/src/devices/timer.c
@@ -7,7 +7,7 @@
 #error 8254 timer requires TIMER_FREQ >= 19
 #endif
 
-static volatile uint64_t ticks;
+static volatile int64_t ticks;
 
 static void
 irq20_timer (struct intr_frame *args UNUSED)
@@ -30,28 +30,43 @@ timer_init (void)
   outb (0x40, count & 0xff);
   outb (0x40, count >> 8);
 
-  intr_register (0x20, 0, IF_OFF, irq20_timer, "8254 Timer");
+  intr_register (0x20, 0, INTR_OFF, irq20_timer, "8254 Timer");
 }
 
-uint64_t
+int64_t
 timer_ticks (void) 
 {
-  enum if_level old_level = intr_disable ();
-  uint64_t t = ticks;
+  enum intr_level old_level = intr_disable ();
+  int64_t t = ticks;
   intr_set_level (old_level);
   return t;
 }
 
-uint64_t
-timer_elapsed (uint64_t then) 
+int64_t
+timer_elapsed (int64_t then) 
 {
-  uint64_t now = timer_ticks ();
-  return now > then ? now - then : ((uint64_t) -1 - then) + now + 1;
+  return timer_ticks () - then;
 }
 
-/* Suspends execution for at least DURATION ticks. */
+/* Suspends execution for approximately DURATION milliseconds. */
 void
-timer_wait_until (uint64_t duration) 
+timer_msleep (int64_t ms) 
 {
-  /* FIXME */
+  int64_t ticks = (int64_t) ms * TIMER_FREQ / 1000;
+  int64_t start = timer_ticks ();
+
+  while (timer_elapsed (start) < ticks) 
+    continue;
+}
+
+void
+timer_usleep (int64_t us) 
+{
+  timer_msleep (us / 1000 + 1);
+}
+
+void
+timer_nsleep (int64_t ns) 
+{
+  timer_msleep (ns / 1000000 + 1);
 }