Add donation-related information to the thread structure, w/ T

src/threads/thread.h

@@ -90,6 +90,15 @@ struct thread
     int priority;                       /* Priority. */
     struct list_elem allelem;           /* List element for all threads list. */
 
+    /* Donation Related */
+    int base_priority;                  /* Base priority of the thread. */
+    struct list donors_list;            /* List of threads that have donated
+                                           to this thread. */
+    struct lock *waiting_lock;          /* The lock that the current thread is
+                                           waiting for. */
+    struct list_elem donor_elem;        /* List element so that thread can be
+                                           enlisted in other donors list. */
+
     /* Shared between thread.c and synch.c. */
     struct list_elem elem;              /* List element. */