*
 * <p>Valid:
 *
 * <ul>
 *   <li>Live: valid key/value are set
 *   <li>Loading: loading is pending
 * </ul>
 *
 * <p>Invalid:
 *
 * <ul>
 *   <li>Expired: time expired (key/value may still be set)
 *   <li>Collected: key/value was partially collected, but not yet cleaned up
 *   <li>Unset: marked as unset, awaiting cleanup or reuse
 * </ul>
 */
@GwtIncompatible

  /** The HTTP {@code ETag} header field name. */
  public static final String ETAG = "ETag";
  /** The HTTP {@code Expires} header field name. */
  public static final String EXPIRES = "Expires";
  /** The HTTP {@code Last-Modified} header field name. */
  public static final String LAST_MODIFIED = "Last-Modified";
  /** The HTTP {@code Link} header field name. */

                // This is a duplicate check, as preWriteCleanup already purged expired
                // entries, but let's accommodate an incorrect expiration queue.
                enqueueNotification(
                    entryKey, hash, value, valueReference.getWeight(), RemovalCause.EXPIRED);
              } else {
                recordLockedRead(e, now);
                statsCounter.recordHits(1);

    // it still should only have executed once due to memoization
    assertEquals(1, countingSupplier.calls);

    Thread.sleep(150);

    assertEquals(20, (int) memoizedSupplier.get());
    // old value expired
    assertEquals(2, countingSupplier.calls);

    assertEquals(20, (int) memoizedSupplier.get());
    // it still should only have executed twice due to memoization
    assertEquals(2, countingSupplier.calls);
  }

    // it still should only have executed once due to memoization
    assertEquals(1, countingSupplier.calls);

    Thread.sleep(150);

    assertEquals(20, (int) memoizedSupplier.get());
    // old value expired
    assertEquals(2, countingSupplier.calls);

    assertEquals(20, (int) memoizedSupplier.get());
    // it still should only have executed twice due to memoization
    assertEquals(2, countingSupplier.calls);
  }

        new RemovalListener<Integer, Integer>() {
          @Override
          public void onRemoval(RemovalNotification<Integer, Integer> notification) {
            switch (notification.getCause()) {
              case EXPIRED:
                stats[0]++;
                break;
              case EXPLICIT:
                stats[1]++;
                break;
              case REPLACED:
                stats[2]++;

   * useful in testing, or to disable caching temporarily without a code change.
   *
   * <p>Expired entries may be counted in {@link Cache#size}, but will never be visible to read or
   * write operations. Expired entries are cleaned up as part of the routine maintenance described
   * in the class javadoc.
   *

                }
              });
    }

    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

 *
 * @author Anthony Zana
 */
public class UninterruptiblesTest extends TestCase {
  private static final String EXPECTED_TAKE = "expectedTake";

  /** Timeout to use when we don't expect the timeout to expire. */
  private static final long LONG_DELAY_MS = 2500;

  private static final long SLEEP_SLACK = 2;

  private final TearDownStack tearDownStack = new TearDownStack();

        new RemovalListener<Integer, Integer>() {
          @Override
          public void onRemoval(RemovalNotification<Integer, Integer> notification) {
            switch (notification.getCause()) {
              case EXPIRED:
                stats[0]++;
                break;
              case EXPLICIT:
                stats[1]++;
                break;
              case REPLACED:
                stats[2]++;