code: private void clearExceptionalCompletion() {
          int h = System.identityHashCode(this);
          final ReentrantLock lock = exceptionTableLock;
          lock.lock();
          try {
              ExceptionNode[] t = exceptionTable;
              int i = h & (t.length - 1);
              ExceptionNode e = t[i];
              ExceptionNode pred = null;
              while (e != null) {
                  ExceptionNode next = e.next;
                  if (e.get() == this) {
                      if (pred == null)
                          t[i] = next;
                      else
                          pred.next = next;
                      break;
                  }
                  pred = e;
                  e = next;
              }
              expungeStaleExceptions();
              status = 0;
          } finally {
              lock.unlock();
          }
      }
docs: Removes exception node and clears status