1 files changed, 10 insertions, 6 deletions

diff --git a/pintos-progos/threads/thread.h b/pintos-progos/threads/thread.h
index eebf42c..9cc5ef7 100644
--- a/pintos-progos/threads/thread.h
+++ b/pintos-progos/threads/thread.h
@@ -76,11 +76,13 @@ typedef int tid_t;
    set to THREAD_MAGIC.  Stack overflow will normally change this
    value, triggering the assertion. */
 /* The `elem' member has a dual purpose.  It can be an element in
-   the run queue (thread.c), or it can be an element in a
-   semaphore wait list (synch.c).  It can be used these two ways
-   only because they are mutually exclusive: only a thread in the
-   ready state is on the run queue, whereas only a thread in the
-   blocked state is on a semaphore wait list. */
+   the run queue (thread.c), it can be an element in a semaphore
+   wait list (synch.c), or it can be an element in the alarm sleep
+   list (timer.c).  It can be used these two ways only because they
+   are mutually exclusive: only a thread in the ready state is on
+   the run queue, only a thread in the blocked state is on a semaphore
+   wait list, whereas only a thread waiting for an alarm event is on
+   the alarm sleep list. */
 struct thread
   {
     /* Owned by thread.c. */
@@ -91,7 +93,7 @@ struct thread
     int priority;                       /* Priority. */
     struct list_elem allelem;           /* List element for all threads list. */
 
-    /* Shared between thread.c and synch.c. */
+    /* Shared between thread.c, synch.c and timer.c. */
     struct list_elem elem;              /* List element. */
 
 #ifdef USERPROG
@@ -103,6 +105,8 @@ struct thread
 
     /* Owned by thread.c. */
     unsigned magic;                     /* Detects stack overflow. */
+
+    int64_t alarm_tick;                 /* absolute tick when to trigger an alarm event */
   };
 
 /* If false (default), use round-robin scheduler.