super(fair);
      this.readLock = new CycleDetectingReentrantReadLock(this);
      this.writeLock = new CycleDetectingReentrantWriteLock(this);
      this.lockGraphNode = Preconditions.checkNotNull(lockGraphNode);
    }

    ///// Overridden ReentrantReadWriteLock methods. /////

    @Override
    public ReadLock readLock() {
      return readLock;
    }

    @Override

  private ReentrantLock lockA;
  private ReentrantLock lockB;
  private ReentrantLock lockC;
  private ReentrantReadWriteLock.ReadLock readLockA;
  private ReentrantReadWriteLock.ReadLock readLockB;
  private ReentrantReadWriteLock.ReadLock readLockC;
  private ReentrantReadWriteLock.WriteLock writeLockA;
  private ReentrantReadWriteLock.WriteLock writeLockB;
  private ReentrantReadWriteLock.WriteLock writeLockC;

  private ReentrantLock lockA;
  private ReentrantLock lockB;
  private ReentrantLock lockC;
  private ReentrantReadWriteLock.ReadLock readLockA;
  private ReentrantReadWriteLock.ReadLock readLockB;
  private ReentrantReadWriteLock.ReadLock readLockC;
  private ReentrantReadWriteLock.WriteLock writeLockA;
  private ReentrantReadWriteLock.WriteLock writeLockB;
  private ReentrantReadWriteLock.WriteLock writeLockC;

  // threadpool, so that we avoid the possibility of running the runner_ in the
  // threadpool of GPU event mgr, as that can trigger more callbacks to be
  // scheduled on that same threadpool, causing a deadlock in cases where the
  // caller of event_mgr->ThenExecute() blocks on the completion of the callback
  // (as in the case of ConstOp kernel creation on GPU, which involves copying a
  // CPU tensor to GPU).

                }
                assertTrue(hasNonZero, "Each array should have a signature");
            }
        }

        @Test
        @DisplayName("Should handle high concurrency without deadlock")
        void testHighConcurrencyNoDeadlock() throws InterruptedException {
            int threadCount = 100;
            int operationsPerThread = 50;

   * This covers a bug where if a listener was installed that would stop the manager if any service
   * fails and something failed during startup before service.start was called on all the services,
   * then awaitStopped would deadlock due to an IllegalStateException that was thrown when trying to
   * stop the timer(!).
   */
  public void testFailStart_stopOthers() throws TimeoutException {
    Service a = new FailStartService();

                this.state = 6;
                ioe = ioe0;
            }
        case 4: /* failed to connect - reset the transport */
            // thread is cleaned up by connect routine, joining it here causes a deadlock
            this.thread = null;
            this.state = 6;
            break;
        default:
            log.error("Invalid state: " + this.state);
            this.thread = null;

    private final ReadWriteLock delegate;

    WeakSafeReadWriteLock() {
      this.delegate = new ReentrantReadWriteLock();
    }

    @Override
    public Lock readLock() {
      return new WeakSafeLock(delegate.readLock(), this);
    }

    @Override
    public Lock writeLock() {
      return new WeakSafeLock(delegate.writeLock(), this);
    }
  }

// call Session::Extend().
bool ExtendSessionGraphHelper(TF_Session* session, TF_Status* status) {
  if (session->graph != nullptr) {
    // Take the graph lock before the session lock to avoid deadlock. This is
    // safe since session->graph does not change.
    session->graph->mu.lock();
    mutex_lock session_lock(session->mu);
    const Graph& graph = session->graph->graph;

     * @return the handle info or null if not found
     */
    public HandleInfo getHandleByGuid(HandleGuid guid) {
        lock.readLock().lock();
        try {
            return guidToHandle.get(guid);
        } finally {
            lock.readLock().unlock();
        }
    }

    /**
     * Get handle information by path
     * @param path the file path