*
   * @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")
    @CheckForNull
    Guard next;

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

  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;

     * tail of the queue on write.
     */
    @GuardedBy("this")
    final Queue<ReferenceEntry<K, V>> writeQueue;

    /**
     * A queue of elements currently in the map, ordered by access time. Elements are added to the
     * tail of the queue on access (note that writes count as accesses).
     */
    @GuardedBy("this")
    final Queue<ReferenceEntry<K, V>> accessQueue;

  /**
   * The runnable, executor pairs to execute. This acts as a stack threaded through the {@link
   * RunnableExecutorPair#next} field.
   */
  @GuardedBy("this")
  @CheckForNull
  private RunnableExecutorPair runnables;

  @GuardedBy("this")
  private boolean executed;

  /** Creates a new, empty {@link ExecutionList}. */
  public ExecutionList() {}

  /**

import java.util.Map;
import java.util.concurrent.CancellationException;
import java.util.concurrent.Executor;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import javax.annotation.concurrent.GuardedBy;
import junit.framework.TestCase;

/** Tests for {@link AbstractFuture} with the cancellation cause system property set */
@AndroidIncompatible // custom classloading

import java.util.Map;
import java.util.concurrent.CancellationException;
import java.util.concurrent.Executor;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import javax.annotation.concurrent.GuardedBy;
import junit.framework.TestCase;

/** Tests for {@link AbstractFuture} with the cancellation cause system property set */
@AndroidIncompatible // custom classloading

     * tail of the queue on write.
     */
    @GuardedBy("this")
    final Queue<ReferenceEntry<K, V>> writeQueue;

    /**
     * A queue of elements currently in the map, ordered by access time. Elements are added to the
     * tail of the queue on access (note that writes count as accesses).
     */
    @GuardedBy("this")
    final Queue<ReferenceEntry<K, V>> accessQueue;

import com.google.common.collect.MapMaker.Dummy;
import com.google.common.primitives.Ints;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import com.google.errorprone.annotations.concurrent.GuardedBy;
import com.google.errorprone.annotations.concurrent.LazyInit;
import com.google.j2objc.annotations.Weak;
import com.google.j2objc.annotations.WeakOuter;
import java.io.IOException;
import java.io.InvalidObjectException;

import com.google.errorprone.annotations.CanIgnoreReturnValue;
import com.google.errorprone.annotations.ForOverride;
import com.google.errorprone.annotations.concurrent.GuardedBy;
import com.google.j2objc.annotations.WeakOuter;
import java.util.concurrent.Executor;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import javax.annotation.CheckForNull;

/**

     *   - 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();