* point, Finalizer can stop running
     */
    if (!finalizableReferenceClass.getName().equals(FINALIZABLE_REFERENCE)) {
      throw new IllegalArgumentException("Expected " + FINALIZABLE_REFERENCE + ".");
    }

    Finalizer finalizer = new Finalizer(finalizableReferenceClass, queue, frqReference);
    String threadName = Finalizer.class.getName();
    Thread thread = null;

  /**
   * Iterates through the given loaders until it finds one that can load Finalizer.
   *
   * @return Finalizer.class
   */
  private static Class<?> loadFinalizer(FinalizerLoader... loaders) {
    for (FinalizerLoader loader : loaders) {
      Class<?> finalizer = loader.loadFinalizer();
      if (finalizer != null) {
        return finalizer;
      }
    }

    throw new AssertionError();
  }

  public void testGetFinalizerUrl() {
    assertNotNull(getClass().getResource("internal/Finalizer.class"));
  }

  public void testFinalizeClassHasNoNestedClasses() throws Exception {
    // Ensure that the Finalizer class has no nested classes.
    // See https://github.com/google/guava/issues/1505
    assertEquals(Collections.emptyList(), Arrays.asList(Finalizer.class.getDeclaredClasses()));
  }

# FinalizableReferenceQueue is unused.
-keepnames class com.google.common.base.internal.Finalizer {
  *** startFinalizer(...);
}
# However, it cannot "spot" that this method needs to be kept IF the class is.
-keepclassmembers class com.google.common.base.internal.Finalizer {
  *** startFinalizer(...);
}
-keepnames class com.google.common.base.FinalizableReference {
  void finalizeReferent();
}

    GcFinalization.awaitClear(finalizableWeakReference);

    Field sepFrqUserFinalizedF = sepFrqUserC.getField("finalized");
    Semaphore finalizeCount = (Semaphore) sepFrqUserFinalizedF.get(null);
    boolean finalized = finalizeCount.tryAcquire(5, SECONDS);
    assertTrue(finalized);

    Field sepFrqUserFrqF = sepFrqUserC.getField("frq");
    Closeable frq = (Closeable) sepFrqUserFrqF.get(null);
    frq.close();

   * separate method to make it somewhat more likely to be unreachable.
   */
  private static void createUnreachableLatchFinalizer(CountDownLatch latch) {
    Object unused =
        new Object() {
          @SuppressWarnings({"removal", "Finalize"}) // b/260137033
          @Override
          protected void finalize() {
            latch.countDown();

  // in this list can only be removed.
  // Finalizers may be processed and removed in any order.  Order is NOT enforced
  // because it introduces significant risk of stuck finalizers.
  // finalizers is a shared field, any actor with permission can reorder it.
  // If the finalizer list is processed in order, then this can lead to a situation
  // in which the component responsible for the first finalizer in the list is

   * separate method to make it somewhat more likely to be unreachable.
   */
  private static void createUnreachableLatchFinalizer(CountDownLatch latch) {
    Object unused =
        new Object() {
          @SuppressWarnings({"removal", "Finalize"}) // b/260137033
          @Override
          protected void finalize() {
            latch.countDown();

  //
  // The job controller creates pods with a finalizer. When a pod terminates
  // (succeeded or failed), the controller does three steps to account for it
  // in the job status:
  //
  // 1. Add the pod UID to the arrays in this field.
  // 2. Remove the pod finalizer.
  // 3. Remove the pod UID from the arrays while increasing the corresponding
  //     counter.
  //

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.