import java.lang.ref.ReferenceQueue;
import java.lang.ref.WeakReference;
import javax.annotation.CheckForNull;

/**
 * Weak reference with a {@code finalizeReferent()} method which a background thread invokes after
 * the garbage collector reclaims the referent. This is a simpler alternative to using a {@link
 * ReferenceQueue}.
 *
 * @author Bob Lee
 * @since 2.0
 */
@J2ktIncompatible
@GwtIncompatible

import java.lang.ref.ReferenceQueue;
import java.lang.ref.SoftReference;
import javax.annotation.CheckForNull;

/**
 * Soft reference with a {@code finalizeReferent()} method which a background thread invokes after
 * the garbage collector reclaims the referent. This is a simpler alternative to using a {@link
 * ReferenceQueue}.
 *
 * @author Bob Lee
 * @since 2.0
 */
@J2ktIncompatible
@GwtIncompatible

import java.lang.ref.PhantomReference;
import java.lang.ref.ReferenceQueue;
import javax.annotation.CheckForNull;

/**
 * Phantom reference with a {@code finalizeReferent()} method which a background thread invokes
 * after the garbage collector reclaims the referent. This is a simpler alternative to using a
 * {@link ReferenceQueue}.
 *
 * <p>Unlike a normal phantom reference, this reference will be cleared automatically.

import java.util.concurrent.TimeoutException;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A TimeLimiter that runs method calls in the background using an {@link ExecutorService}. If the
 * time limit expires for a given method call, the thread running the call will be interrupted.
 *
 * @author Kevin Bourrillion
 * @author Jens Nyman
 * @since 1.0
 */

@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault
public interface FinalizableReference {
  /**
   * Invoked on a background thread after the referent has been garbage collected unless security
   * restrictions prevented starting a background thread, in which case this method is invoked when
   * new references are created.
   */
  void finalizeReferent();

    public void finalizeReferent() {
      finalizeReferentCalled = true;
    }
  }

  /**
   * Keeps a weak reference to the underlying reference queue. When this reference is cleared, we
   * know that the background thread has stopped and released its strong reference.
   */
  private WeakReference<ReferenceQueue<Object>> queueReference;


  public void testThatFinalizerStops() {
    weaklyReferenceQueue();

    public void finalizeReferent() {
      finalizeReferentCalled = true;
    }
  }

  /**
   * Keeps a weak reference to the underlying reference queue. When this reference is cleared, we
   * know that the background thread has stopped and released its strong reference.
   */
  private WeakReference<ReferenceQueue<Object>> queueReference;


  public void testThatFinalizerStops() {
    weaklyReferenceQueue();

import java.lang.ref.ReferenceQueue;
import java.lang.ref.WeakReference;
import javax.annotation.CheckForNull;

/**
 * Weak reference with a {@code finalizeReferent()} method which a background thread invokes after
 * the garbage collector reclaims the referent. This is a simpler alternative to using a {@link
 * ReferenceQueue}.
 *
 * @author Bob Lee
 * @since 2.0
 */
@J2ktIncompatible
@GwtIncompatible

    stoppingThread.join(1000);
    assertFalse("stopAsync has deadlocked!.", stoppingThread.isAlive());
    failLeave.countDown(); // release the background thread
  }

  /**
   * Catches a bug where when constructing a service manager failed, later interactions with the
   * service could cause IllegalStateExceptions inside the partially constructed ServiceManager.

import java.lang.ref.ReferenceQueue;
import java.lang.ref.SoftReference;
import javax.annotation.CheckForNull;

/**
 * Soft reference with a {@code finalizeReferent()} method which a background thread invokes after
 * the garbage collector reclaims the referent. This is a simpler alternative to using a {@link
 * ReferenceQueue}.
 *
 * @author Bob Lee
 * @since 2.0
 */
@J2ktIncompatible
@GwtIncompatible