waiter1.start();
    waiter1.awaitWaiting();

    WaiterThread waiter2 = new WaiterThread(future);
    waiter2.start();
    waiter2.awaitWaiting();
    // The waiter queue should be waiter2->waiter1

    // This should wake up waiter1 and cause the waiter1 node to be removed.
    waiter1.interrupt();

    waiter1.join();
    waiter2.awaitWaiting(); // should still be blocked

            urlFilterService.delete(sid);
        } catch (final Exception e) {
            logger.warn("Failed to delete UrlFilter: sessionId={}", sid, e);
        }

        try {
            // clear queue
            urlQueueService.clearCache();
            urlQueueService.delete(sid);
        } catch (final Exception e) {
            logger.warn("Failed to delete UrlQueue: sessionId={}", sid, e);
        }

    /** Array of supported file protocols for URL classification. */
    protected String[] fileProtocols = { "file:", "smb:", "smb1:", "ftp:", "storage:" };

    /** Queue to track the current XML element hierarchy during parsing. */
    protected LinkedList<String> tagQueue;

    /** List to store parsed label types for access control. */
    protected List<LabelType> labelList;

    waiter1.start();
    waiter1.awaitWaiting();

    WaiterThread waiter2 = new WaiterThread(future);
    waiter2.start();
    waiter2.awaitWaiting();
    // The waiter queue should be waiter2->waiter1

    // This should wake up waiter1 and cause the waiter1 node to be removed.
    waiter1.interrupt();

    waiter1.join();
    waiter2.awaitWaiting(); // should still be blocked

  //   so that it looks like we timed out even though we didn't. For comparison FutureTask respects
  //   completion preferably and AQS is non-deterministic (depends on where in the queue the waiter
  //   is). If we wanted to be strict about it, we could store the unpark() time in the Waiter node
  //   and we could use that to make a decision about whether or not we timed out prior to being
  //   unparked.

  //   so that it looks like we timed out even though we didn't. For comparison FutureTask respects
  //   completion preferably and AQS is non-deterministic (depends on where in the queue the waiter
  //   is). If we wanted to be strict about it, we could store the unpark() time in the Waiter node
  //   and we could use that to make a decision about whether or not we timed out prior to being
  //   unparked.

Fixed a situation when, sometimes, the scheduler incorrectly placed a pod in the `unschedulable` queue instead of the `backoff` queue. This happened when some plugin previously declared the pod as `unschedulable` and then in a later attempt encounters some other error. Scheduling of that pod then got delayed by up to five minutes, after which periodic flushing moved the pod back into the `active` queue. ([#120334](https://github.com/kubernetes/kubernetes/pull/120334), [@pohly](https://github.com/pohly))...

    mostRecentRebuildFailed = false
  }

  /**
   * Returns a snapshot of the entry named [key], or null if it doesn't exist is not currently
   * readable. If a value is returned, it is moved to the head of the LRU queue.
   */
  @Synchronized
  @Throws(IOException::class)
  operator fun get(key: String): Snapshot? {
    initialize()

    checkNotClosed()
    validateKey(key)

    threadPool.shutdown();
    threadPool.awaitTermination(300, SECONDS);

    // Since we're not doing any more cache operations, and the cache only expires/evicts when doing
    // other operations, the cache and the removal queue won't change from this point on.

    // Verify that each received removal notification was valid
    for (RemovalNotification<String, String> notification : removalListener) {

 * rate limit itself.
 *
 * {@snippet :
 * class CrawlingService extends AbstractScheduledService {
 *   private Set<Uri> visited;
 *   private Queue<Uri> toCrawl;
 *   protected void startUp() throws Exception {
 *     toCrawl = readStartingUris();
 *   }
 *
 *   protected void runOneIteration() throws Exception {
 *     Uri uri = toCrawl.remove();