- Fixed an issue in asynchronous preemption: Scheduler now checks if preemption is ongoing for a Pod before initiating new preemption calls. ([#134730](https://github.com/kubernetes/kubernetes/pull/134730), [@ania-borowiec](https://github.com/ania-borowiec)) [SIG Scheduling and Testing]

-   Our users' guide, [Guava Explained]
-   [A nice collection](https://www.tfnico.com/presentations/google-guava) of
    other helpful links

## Links

-   [GitHub project](https://github.com/google/guava)
-   [Issue tracker: Report a defect or feature request](https://github.com/google/guava/issues/new)
-   [StackOverflow: Ask "how-to" and "why-didn't-it-work" questions](https://stackoverflow.com/questions/ask?tags=guava+java)

import static org.junit.Assert.assertTrue;
import static org.junit.Assert.fail;

/**
 * Let's Encrypt expiring root test.
 *
 * Read https://community.letsencrypt.org/t/mobile-client-workarounds-for-isrg-issue/137807
 * for background.
 */
@RunWith(AndroidJUnit4.class)
public class LetsEncryptTest {
  @Test public void getFailsWithoutAdditionalCert() throws IOException {
    OkHttpClient client = new OkHttpClient();

  // For a (long) discussion about this specific issue and the general futility of life.
  //
  // For the time being we are OK with the problem discussed above since it requires a caller to
  // introduce a very specific kind of data-race. And given the other operations performed by these
  // methods that involve volatile read/write operations, in practice there is no issue. Also, the

restarts. More information [here](https://github.com/kubernetes/kubernetes/issues/20995)
  * Pod IP allocation-related issues. Deleting the docker checkpoint prior to
restarting the daemon alleviates this issue, but hasn’t been verified to
completely eliminate the IP allocation issue. More information [here](https://github.com/kubernetes/kubernetes/issues/21523#issuecomment-191498969)

### Bug or Regression

 [japicmp_gradle]: https://github.com/melix/japicmp-gradle-plugin
 [java_sams]: https://kotlinlang.org/docs/reference/java-interop.html#sam-conversions
 [kotlin_sams]: https://youtrack.jetbrains.com/issue/KT-11129
 [mockito]: https://site.mockito.org/
 [proguard_problems]: https://github.com/square/okhttp/issues/5167
 [require_android_5]: https://code.cash.app/okhttp-3-13-requires-android-5

  /** see {@link WorkerRunningState} */
  @LazyInit
  @GuardedBy("queue")
  private WorkerRunningState workerRunningState = IDLE;

  /**
   * This counter prevents an ABA issue where a thread may successfully schedule the worker, the
   * worker runs and exhausts the queue, another thread enqueues a task and fails to schedule the

  /** see {@link WorkerRunningState} */
  @LazyInit
  @GuardedBy("queue")
  private WorkerRunningState workerRunningState = IDLE;

  /**
   * This counter prevents an ABA issue where a thread may successfully schedule the worker, the
   * worker runs and exhausts the queue, another thread enqueues a task and fails to schedule the

  cause DNS problems when DNS pods were restarted. ([#127780](https://github.com/kubernetes/kubernetes/pull/127780), [@danwinship](https://github.com/danwinship))