* @author Bob Lee
 * @since 2.0
 */
@DoNotMock("Use an instance of one of the Finalizable*Reference classes")
@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

 * @author Bob Lee
 * @since 2.0
 */
@DoNotMock("Use an instance of one of the Finalizable*Reference classes")
@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

  /** Name of FinalizableReference.class. */
  private static final String FINALIZABLE_REFERENCE = "com.google.common.base.FinalizableReference";

  /**
   * Starts the Finalizer thread. FinalizableReferenceQueue calls this method reflectively.
   *
   * @param finalizableReferenceClass FinalizableReference.class.
   * @param queue a reference queue that the thread will poll.

  /** Name of FinalizableReference.class. */
  private static final String FINALIZABLE_REFERENCE = "com.google.common.base.FinalizableReference";

  /**
   * Starts the Finalizer thread. FinalizableReferenceQueue calls this method reflectively.
   *
   * @param finalizableReferenceClass FinalizableReference.class.
   * @param queue a reference queue that the thread will poll.

 *
 * @author Bob Lee
 * @since 2.0
 */
@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault
public abstract class FinalizableWeakReference<T> extends WeakReference<T>
    implements FinalizableReference {
  /**
   * Constructs a new finalizable weak reference.
   *
   * @param referent to weakly reference
   * @param queue that should finalize the referent
   */

 *
 * @author Bob Lee
 * @since 2.0
 */
@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault
public abstract class FinalizablePhantomReference<T> extends PhantomReference<T>
    implements FinalizableReference {
  /**
   * Constructs a new finalizable phantom reference.
   *
   * @param referent to phantom reference
   * @param queue that should finalize the referent
   */

 *
 * @author Bob Lee
 * @since 2.0
 */
@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault
public abstract class FinalizableWeakReference<T> extends WeakReference<T>
    implements FinalizableReference {
  /**
   * Constructs a new finalizable weak reference.
   *
   * @param referent to weakly reference
   * @param queue that should finalize the referent
   */

import java.util.logging.Level;
import java.util.logging.Logger;
import javax.annotation.CheckForNull;

/**
 * A reference queue with an associated background thread that dequeues references and invokes
 * {@link FinalizableReference#finalizeReferent()} on them.
 *
 * <p>Keep a strong reference to this object until all of the associated referents have been
 * finalized. If this object is garbage collected earlier, the backing thread will not invoke {@code

import java.util.logging.Level;
import java.util.logging.Logger;
import javax.annotation.CheckForNull;

/**
 * A reference queue with an associated background thread that dequeues references and invokes
 * {@link FinalizableReference#finalizeReferent()} on them.
 *
 * <p>Keep a strong reference to this object until all of the associated referents have been
 * finalized. If this object is garbage collected earlier, the backing thread will not invoke {@code

 *
 * @author Bob Lee
 * @since 2.0
 */
@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault
public abstract class FinalizableSoftReference<T> extends SoftReference<T>
    implements FinalizableReference {
  /**
   * Constructs a new finalizable soft reference.
   *
   * @param referent to softly reference
   * @param queue that should finalize the referent
   */