if (!workerLeaseService.isWorkerThread()) {
            throw new IllegalStateException("The current thread is not registered as a worker thread.");
        }
        synchronized (this) {
            if (owner == null) {
                owner = currentThread;
                return null;
            } else if (owner == currentThread) {
                return currentThread;
            }

   *
   * @param queue the queue to be wrapped in a synchronized view
   * @return a synchronized view of the specified queue
   * @since 14.0
   */
  public static <E extends @Nullable Object> Queue<E> synchronizedQueue(Queue<E> queue) {
    return Synchronized.queue(queue, null);
  }

  /**
   * Returns a synchronized (thread-safe) deque backed by the specified deque. In order to guarantee

) : Closeable {
    override fun close() {
        // we synchronize access to all resources used by callbacks
        // in case there was still an event being dispatched at closing time.
        synchronized(writeContext) {
            unsafeWrite(null)
            writeContext.close()
        }
    }

    fun write(value: T, trace: PropertyTrace? = null) {
        synchronized(writeContext) {
            withPropertyTrace(trace) {

   *
   * @param queue the queue to be wrapped in a synchronized view
   * @return a synchronized view of the specified queue
   * @since 14.0
   */
  public static <E extends @Nullable Object> Queue<E> synchronizedQueue(Queue<E> queue) {
    return Synchronized.queue(queue, null);
  }

  /**
   * Returns a synchronized (thread-safe) deque backed by the specified deque. In order to guarantee

                // we are in the transport thread, ie. on idle disconnecting
                // this is synchronous operation
                // This does not handle compound requests
                synchronized ( this.inLock ) {
                    Long peekKey = peekKey();
                    if ( peekKey == firstKey ) {
                        doRecv(response);
                        response.received();

	// the acquire in profBuf.read synchronizes with *all* prior
	// setProfLabel operations, not just the most recent one. This
	// is important because profBuf.read will observe different
	// labels set by different setProfLabel operations on
	// different goroutines, so it needs to synchronize with all
	// of them (this wouldn't be an issue if we could synchronize
	// on &getg().labels since we would synchronize with each

    void finalizeConfiguration(Gradle gradle);

    /**
     * Synchronizes the property values of the provided cache configurations with those of this cache configuration
     * by setting the provided configuration's properties to be backed by the properties of this configuration.
     */
    void synchronize(CacheConfigurationsInternal cacheConfigurationsInternal);

            bus.handleSubscriberException(e.getCause(), context(event));
          }
        });
  }

  /**
   * Invokes the subscriber method. This method can be overridden to make the invocation
   * synchronized.
   */
  @VisibleForTesting
  void invokeSubscriberMethod(Object event) throws InvocationTargetException {
    try {
      method.invoke(target, checkNotNull(event));
    } catch (IllegalArgumentException e) {

            bus.handleSubscriberException(e.getCause(), context(event));
          }
        });
  }

  /**
   * Invokes the subscriber method. This method can be overridden to make the invocation
   * synchronized.
   */
  @VisibleForTesting
  void invokeSubscriberMethod(Object event) throws InvocationTargetException {
    try {
      method.invoke(target, checkNotNull(event));
    } catch (IllegalArgumentException e) {

        private final Set<T> producing = new HashSet<>();

        @Override
        public <V> V guardByKey(T key, Supplier<V> supplier) {
            synchronized (producing) {
                while (!producing.add(key)) {
                    try {
                        producing.wait();
                    } catch (InterruptedException e) {