src/threads/synch.c

@@ -355,7 +355,14 @@ cond_wait (struct condition *cond, struct lock *lock)
   ASSERT (lock_held_by_current_thread (lock));
   
   sema_init (&waiter.semaphore, 0);
-  list_push_back (&cond->waiters, &waiter.elem);
+
+  /* Insert the semaphore_elem into the waiters list in order of priority.
+     We pass the priority of the current thread as aux to sema_priority_more
+     because the thread has not been sema'd down yet (See sema_priority_more) */
+  int priority = thread_current ()->priority;
+  list_insert_ordered (&cond->waiters, &waiter.elem, sema_priority_more,
+                       &priority);
+
   lock_release (lock);
   sema_down (&waiter.semaphore);
   lock_acquire (lock);