* worker runs and exhausts the queue, another thread enqueues a task and fails to schedule the
   * worker, and then the first thread's call to delegate.execute() returns. Without this counter,
   * it would observe the QUEUING state and set it to QUEUED, and the worker would never be
   * scheduled again for future submissions.
   */
  @GuardedBy("queue")
  private long workerRunCount = 0;

   * be performed atomically on the returned map. Additionally, {@code size} and {@code
   * containsValue} are implemented as bulk read operations, and thus may fail to observe concurrent
   * writes.
   *
   * @return a serializable concurrent map having the requested features
   */
  public <K, V> ConcurrentMap<K, V> makeMap() {
    if (!useCustomMap) {

    /*
     * Padding from 40 into 64 bytes, same size as cache line. Might be beneficial to add a fourth
     * long here, to minimize chance of interference between consecutive locks, but I couldn't
     * observe any benefit from that.
     */
    long unused1;
    long unused2;
    long unused3;

    PaddedLock() {
      super(false);
    }
  }

  /**
   * The HTTP <a href="https://patcg-individual-drafts.github.io/topics/">{@code
   * Observe-Browsing-Topics}</a> header field name.
   *
   * @since 32.0.0
   */
  public static final String OBSERVE_BROWSING_TOPICS = "Observe-Browsing-Topics";

  /**
   * The HTTP <a
   * href="https://wicg.github.io/turtledove/#handling-direct-from-seller-signals">{@code

 *
 * Every [edit] call must be matched by a call to [Editor.commit] or [Editor.abort]. Committing is
 * atomic: a read observes the full set of values as they were before or after the commit, but never
 * a mix of values.
 *
 * Clients call [get] to read a snapshot of an entry. The read will observe the value at the time
 * that [get] was called. Updates and removals after the call do not impact ongoing reads.
 *

  /** Ciphers in order we observed directly on the socket. */
  private lateinit var handshakeEnabledCipherSuites: List<String>

  /** Ciphers in order we observed on sslSocketFactory defaults. */
  private lateinit var defaultEnabledCipherSuites: List<String>

  /** Ciphers in order we observed on sslSocketFactory supported. */

  // * Future completion can be observed if the waitersField field contains a TOMBSTONE

  // Timed Get
  // There are a few design constraints to consider
  // * We want to be responsive to small timeouts, unpark() has non trivial latency overheads (I
  //   have observed 12 micros on 64-bit linux systems to wake up a parked thread). So if the

  // * Future completion can be observed if the waitersField field contains a TOMBSTONE

  // Timed Get
  // There are a few design constraints to consider
  // * We want to be responsive to small timeouts, unpark() has non trivial latency overheads (I
  //   have observed 12 micros on 64-bit linux systems to wake up a parked thread). So if the

   * only become known via CAS failures, convergence can be slow,
   * and because threads are typically not bound to CPUS forever,
   * may not occur at all. However, despite these limitations,
   * observed contention rates are typically low in these cases.
   *
   * It is possible for a Cell to become unused when threads that
   * once hashed to it terminate, as well as in the case where

            }
          };
      executor.execute(errorTask);
      service.execute(barrierTask); // submit directly to the service
      // the barrier task runs after the error task so we know that the error has been observed by
      // SequentialExecutor by the time the barrier is satisfied
      barrier.await(1, SECONDS);
      executor.execute(barrierTask);
      // timeout means the second task wasn't even tried