// These constants allow the deserialization code to set final fields. This
  // holder class makes sure they are not initialized unless an instance is
  // deserialized.
  @GwtIncompatible // java serialization is not supported
  @J2ktIncompatible
  static class FieldSettersHolder {
    static final Serialization.FieldSetter<? super ImmutableMultimap<?, ?>> MAP_FIELD_SETTER =

  // These constants allow the deserialization code to set final fields. This
  // holder class makes sure they are not initialized unless an instance is
  // deserialized.
  @GwtIncompatible // java serialization is not supported
  @J2ktIncompatible
  static class FieldSettersHolder {
    static final Serialization.FieldSetter<? super ImmutableMultimap<?, ?>> MAP_FIELD_SETTER =

     * problem, we've since marked that field as volatile.)
     *
     * When MapIteratorCache is used from Immutable* classes, the TSAN failure doesn't indicate a
     * real problem: The Entry objects are ImmutableMap entries, whose fields are all final and thus
     * safe to read even when the Entry object is unsafely published. But with a mutable graph, the

     * problem, we've since marked that field as volatile.)
     *
     * When MapIteratorCache is used from Immutable* classes, the TSAN failure doesn't indicate a
     * real problem: The Entry objects are ImmutableMap entries, whose fields are all final and thus
     * safe to read even when the Entry object is unsafely published. But with a mutable graph, the

     * purposes, the "count" field, tracking the number of elements, serves as that volatile
     * variable ensuring visibility. This is convenient because this field needs to be read in many
     * read operations anyway:
     *
     * - All (unsynchronized) read operations must first read the "count" field, and should not look
     * at table entries if it is 0.
     *

  @WeakOuter
  private final class ServiceDelegate extends AbstractService {

    // A handle to the running task so that we can stop it when a shutdown has been requested.
    // These two fields are volatile because their values will be accessed from multiple threads.
    @CheckForNull private volatile Cancellable runningTask;
    @CheckForNull private volatile ScheduledExecutorService executorService;

    checkHelperVersion(NO_ATOMIC_FIELD_UPDATER, "SynchronizedAtomicHelper");

    // Run the corresponding FuturesTest test method in a new classloader that disallows
    // certain core jdk classes.
    ClassLoader oldClassLoader = Thread.currentThread().getContextClassLoader();
    Thread.currentThread().setContextClassLoader(NO_ATOMIC_FIELD_UPDATER);
    try {
      runTestMethod(NO_ATOMIC_FIELD_UPDATER);

    equalsTester = new EqualsTester();
    equalObject1 = new ValidTestObject(1, 2);
    equalObject2 = new ValidTestObject(1, 2);
    notEqualObject1 = new ValidTestObject(0, 2);
  }

  /** Test null reference yields error */
  public void testAddNullReference() {
    try {
      equalsTester.addEqualityGroup((Object) null);
      fail("Should fail on null reference");
    } catch (NullPointerException e) {
    }
  }

   * next} field is lazily initialized. The type of that field would be {@code @Nullable T}, and the
   * code would be responsible for populating a "real" {@code T} (which might still be the value
   * {@code null}!) before returning it to callers. Depending on how the code is structured, a
   * nullness analysis might not understand that the field has been populated. To avoid that problem

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.math;

import static java.lang.annotation.ElementType.FIELD;
import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.ElementType.PARAMETER;
import static java.lang.annotation.ElementType.TYPE;
import static java.lang.annotation.RetentionPolicy.RUNTIME;