RUNNING,
  }

  /** Underlying executor that all submitted Runnable objects are run on. */
  private final Executor executor;

  @GuardedBy("queue")
  private final Deque<Runnable> queue = new ArrayDeque<>();

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

  /**

    final L listener;
    final Executor executor;

    @GuardedBy("this")
    final Queue<ListenerCallQueue.Event<L>> waitQueue = new ArrayDeque<>();

    @GuardedBy("this")
    final Queue<Object> labelQueue = new ArrayDeque<>();

    @GuardedBy("this")
    boolean isThreadScheduled;

    PerListenerQueue(L listener, Executor executor) {

  int length;

  private Segment<Object, Object> segment;
  private ReferenceEntry<Object, Object> head;
  private @Nullable ReferenceEntry<Object, Object> chain;

  @SuppressWarnings("GuardedBy")
  @BeforeExperiment
  void setUp() {
    LocalCache<Object, Object> cache =
        new LocalCache<>(CacheBuilder.newBuilder().concurrencyLevel(1), null);
    segment = cache.segments[0];
    chain = null;

    static final Logger log = Logger.getLogger(NewExecutionListQueue.class.getName());

    @GuardedBy("this")
    private @Nullable RunnableExecutorPair head;

    @GuardedBy("this")
    private @Nullable RunnableExecutorPair tail;

    @GuardedBy("this")
    private boolean executed;

    void add(Runnable runnable, Executor executor) {

        }
        return toReturn;
      }

      @GuardedBy("lock")
      /*
       * The GuardedBy checker warns us that we're not holding cancellationDelegate.lock. But in
       * fact we are holding it because it is the same as this.lock, which we know we are holding,
       * thanks to @GuardedBy above. (cancellationDelegate.lock is initialized to this.lock in the

    final Monitor monitor = new Monitor();

    @GuardedBy("monitor")
    final SetMultimap<State, Service> servicesByState =
        MultimapBuilder.enumKeys(State.class).linkedHashSetValues().build();

    @GuardedBy("monitor")
    final Multiset<State> states = servicesByState.keys();

    @GuardedBy("monitor")
    final IdentityHashMap<Service, Stopwatch> startupTimers = new IdentityHashMap<>();

   */
  private static final class State {
    final int fileThreshold;
    final boolean resetWhenGarbageCollected;

    @GuardedBy("this")
    @Nullable MemoryOutput memory;

    @GuardedBy("this")
    @Nullable File file;

    @GuardedBy("this")
    OutputStream out;

    State(int fileThreshold, boolean resetWhenGarbageCollected) {
      this.fileThreshold = fileThreshold;

  int length;

  private Segment<Object, Object> segment;
  private ReferenceEntry<Object, Object> head;
  private @Nullable ReferenceEntry<Object, Object> chain;

  @SuppressWarnings("GuardedBy")
  @BeforeExperiment
  void setUp() {
    LocalCache<Object, Object> cache =
        new LocalCache<>(CacheBuilder.newBuilder().concurrencyLevel(1), null);
    segment = cache.segments[0];
    chain = null;

   *
   * @since 10.0
   */
  public abstract static class Guard {

    @Weak final Monitor monitor;
    final Condition condition;

    @GuardedBy("monitor.lock")
    int waiterCount = 0;

    /** The next active guard */
    @GuardedBy("monitor.lock")
    @Nullable Guard next;

    protected Guard(Monitor monitor) {
      this.monitor = checkNotNull(monitor, "monitor");

   * one of three states:
   *   - Active: shutdown == false
   *   - Shutdown: runningTasks > 0 and shutdown == true
   *   - Terminated: runningTasks == 0 and shutdown == true
   */
  @GuardedBy("lock")
  private int runningTasks = 0;

  @GuardedBy("lock")
  private boolean shutdown = false;

  @Override
  public void execute(Runnable command) {
    startTask();
    try {
      command.run();
    } finally {