code: /*
   * Copyright (c) 2016-present, RxJava Contributors.
   *
   * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in
   * compliance with the License. You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software distributed under the License is
   * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See
   * the License for the specific language governing permissions and limitations under the License.
   */
  
  package io.reactivex.rxjava3.disposables;
  
  import java.util.Objects;
  import java.util.concurrent.atomic.AtomicReference;
  
  import io.reactivex.rxjava3.annotations.NonNull;
  
  /**
   * Base class for Disposable containers that manage some other type that
   * has to be run when the container is disposed.
   *
   * @param <T> the type contained
   */
  abstract class ReferenceDisposable<T> extends AtomicReference<T> implements Disposable {
  
      private static final long serialVersionUID = 6537757548749041217L;
  
      ReferenceDisposable(T value) {
          super(Objects.requireNonNull(value, "value is null"));
      }
  
      protected abstract void onDisposed(@NonNull T value);
  
      @Override
      public final void dispose() {
          T value = get();
          if (value != null) {
              value = getAndSet(null);
              if (value != null) {
                  onDisposed(value);
              }
          }
      }
  
      @Override
      public final boolean isDisposed() {
          return get() == null;
      }
  }
  