*
     * 2) To detect when FinalizableReference's class loader has to be garbage collected, at which
     * point, Finalizer can stop running
     */

    Finalizer finalizer = new Finalizer(finalizableReferenceClass, queue, frqReference);
    String threadName = "com.google.common.base.internal.Finalizer";
    Thread thread = null;
    if (bigThreadConstructor != null) {
      try {
        boolean inheritThreadLocals = false;

     *
     * 2) To detect when FinalizableReference's class loader has to be garbage collected, at which
     * point, Finalizer can stop running
     */

    Finalizer finalizer = new Finalizer(finalizableReferenceClass, queue, frqReference);
    String threadName = "com.google.common.base.internal.Finalizer";
    Thread thread = null;
    if (bigThreadConstructor != null) {
      try {
        boolean inheritThreadLocals = false;

  /** Reference to Finalizer.startFinalizer(). */
  private static final FinalizerStarter finalizerStarter;

  static {
    Class<?> finalizer = loadFinalizer(new SystemLoader(), new DecoupledLoader());
    finalizerStarter =
        finalizer != null
            ? new ReflectiveStarter(getStartFinalizer(finalizer))
            : new DirectStarter();
  }

  /** Reference to Finalizer.startFinalizer(). */
  private static final FinalizerStarter finalizerStarter;

  static {
    Class<?> finalizer = loadFinalizer(new SystemLoader(), new DecoupledLoader());
    finalizerStarter =
        finalizer != null
            ? new ReflectiveStarter(getStartFinalizer(finalizer))
            : new DirectStarter();
  }

  @Test
  public void testGetFinalizerUrl() {
    assertThat(getClass().getResource("internal/Finalizer.class")).isNotNull();
  }

  @Test
  public void testFinalizeClassHasNoNestedClasses() throws Exception {
    // Ensure that the Finalizer class has no nested classes.
    // See https://github.com/google/guava/issues/1505
    assertThat(Finalizer.class.getDeclaredClasses()).isEmpty();
  }

    assertThat(frqC).isNotSameInstanceAs(sepFrqC);
    // Check the assumptions above.

    // FRQ tries to load the Finalizer class (for the reference-collecting thread) in a few ways.
    // If the class is accessible to the system ClassLoader (ClassLoader.getSystemClassLoader())
    // then FRQ does not bother to load Finalizer.class through a separate ClassLoader. That happens

    assertThat(frqC).isNotSameInstanceAs(sepFrqC);
    // Check the assumptions above.

    // FRQ tries to load the Finalizer class (for the reference-collecting thread) in a few ways.
    // If the class is accessible to the system ClassLoader (ClassLoader.getSystemClassLoader())
    // then FRQ does not bother to load Finalizer.class through a separate ClassLoader. That happens

 * RuntimeException}.
 *
 * <p>Here's an example that tests a {@code finalize} method:
 *
 * {@snippet :
 * final CountDownLatch latch = new CountDownLatch(1);
 * Object x = new MyClass() {
 *   ...
 *   protected void finalize() { latch.countDown(); ... }
 * };
 * x = null; // Hint to the JIT that x is stack-unreachable
 * GcFinalization.await(latch);
 * }
 *

 * RuntimeException}.
 *
 * <p>Here's an example that tests a {@code finalize} method:
 *
 * {@snippet :
 * final CountDownLatch latch = new CountDownLatch(1);
 * Object x = new MyClass() {
 *   ...
 *   protected void finalize() { latch.countDown(); ... }
 * };
 * x = null; // Hint to the JIT that x is stack-unreachable
 * GcFinalization.await(latch);
 * }
 *

and Java’s <code>volatile</code> variables.
</p>

<h3 id="finalizer">Finalizers</h3>

<p>
The <a href="/pkg/runtime/"><code>runtime</code></a> package provides
a <code>SetFinalizer</code> function that adds a finalizer to be called when
a particular object is no longer reachable by the program.