lockFound := false
		for _, uid := range dm.readLocks {
			if isLocked(uid) {
				lockFound = true
				break
			}
		}
		if !lockFound {
			panic("Trying to RUnlock() while no RLock() is active")
		}

		// Copy write locks to stack array
		copy(locks, dm.readLocks)
	}

	// Tolerance is not set, defaults to half of the locker clients.

    ReentrantReadWriteLock readWriteLockC = factory.newReentrantReadWriteLock("ReadWriteC");
    readLockA = readWriteLockA.readLock();
    readLockB = readWriteLockB.readLock();
    readLockC = readWriteLockC.readLock();
    writeLockA = readWriteLockA.writeLock();
    writeLockB = readWriteLockB.writeLock();
    writeLockC = readWriteLockC.writeLock();

    ReentrantReadWriteLock readWriteLockC = factory.newReentrantReadWriteLock("ReadWriteC");
    readLockA = readWriteLockA.readLock();
    readLockB = readWriteLockB.readLock();
    readLockC = readWriteLockC.readLock();
    writeLockA = readWriteLockA.writeLock();
    writeLockB = readWriteLockB.writeLock();
    writeLockC = readWriteLockC.writeLock();

      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

  }

  /**
   * Using this as the blocker object allows introspection and debugging tools to see that the
   * currentRunner thread is blocked on the progress of the interruptor thread, which can help
   * identify deadlocks.
   */
  @VisibleForTesting
  static final class Blocker extends AbstractOwnableSynchronizer implements Runnable {
    private final InterruptibleTask<?> task;

    private Blocker(InterruptibleTask<?> task) {

    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);
    }
  }

  }

  /**
   * Using this as the blocker object allows introspection and debugging tools to see that the
   * currentRunner thread is blocked on the progress of the interruptor thread, which can help
   * identify deadlocks.
   */
  @VisibleForTesting
  static final class Blocker extends AbstractOwnableSynchronizer implements Runnable {
    private final InterruptibleTask<?> task;

    private Blocker(InterruptibleTask<?> task) {

	updateResourceMetrics(driveSubsystem, writesKBPerSec, writeKib/diffInSeconds, labels, false)

	rdAwait := 0.0
	if diffStats.ReadIOs > 0 {
		rdAwait = float64(diffStats.ReadTicks) / float64(diffStats.ReadIOs)
	}
	updateResourceMetrics(driveSubsystem, readsAwait, rdAwait, labels, false)

	wrAwait := 0.0
	if diffStats.WriteIOs > 0 {

// is a pending execution. Since StartExecute is equivalent to grabbing a lock,
// multiple DeviceThreads should always be accessed in the same order to avoid
// deadlocks.
class DeviceThread {
 public:
  // Starts a background thread waiting for `StartExecute`.
  explicit DeviceThread(const std::string& device, const bool is_async,
                        const int in_flight_nodes_limit)

}

TEST(PARALLEL_DEVICE, TestCollectiveSync) { TestCollective(/*async=*/false); }

// Note that ops on the parallel device currently don't execute
// asynchronously. The test is just that we don't get deadlocks.
TEST(PARALLEL_DEVICE, TestCollectiveAsync) { TestCollective(/*async=*/true); }

void RegisterCollectiveMulFunction(TFE_Context* context,
                                   const char* function_name, int group_size,