}
        } finally {
          lock.unlock();
        }
      }
    }
  }

  /** Enters this monitor when the guard is satisfied. Blocks indefinitely. */
  public void enterWhenUninterruptibly(Guard guard) {
    if (guard.monitor != this) {
      throw new IllegalMonitorStateException();
    }
    final ReentrantLock lock = this.lock;
    boolean signalBeforeWaiting = lock.isHeldByCurrentThread();