+/* Waits for thread TID to die and returns its exit status. If
+ it was terminated by the kernel (i.e. killed due to an
+ exception), returns -1. If TID is invalid or if it was not a
+ child of the calling process, or if process_wait() has already
+ been successfully called for the given TID, returns -1
+ immediately, without waiting.
+
+ This function will be implemented in problem 2-2. For now, it
+ does nothing. */
+int
+process_wait (tid_t child_tid UNUSED)
+{
+ return -1;
+}
+