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.internal.operators.observable;
  
  import java.util.Objects;
  import java.util.concurrent.TimeoutException;
  import java.util.concurrent.atomic.*;
  
  import io.reactivex.rxjava3.core.*;
  import io.reactivex.rxjava3.disposables.Disposable;
  import io.reactivex.rxjava3.exceptions.Exceptions;
  import io.reactivex.rxjava3.functions.Function;
  import io.reactivex.rxjava3.internal.disposables.*;
  import io.reactivex.rxjava3.internal.operators.observable.ObservableTimeoutTimed.TimeoutSupport;
  import io.reactivex.rxjava3.plugins.RxJavaPlugins;
  
  public final class ObservableTimeout<T, U, V> extends AbstractObservableWithUpstream<T, T> {
      final ObservableSource<U> firstTimeoutIndicator;
      final Function<? super T, ? extends ObservableSource<V>> itemTimeoutIndicator;
      final ObservableSource<? extends T> other;
  
      public ObservableTimeout(
              Observable<T> source,
              ObservableSource<U> firstTimeoutIndicator,
              Function<? super T, ? extends ObservableSource<V>> itemTimeoutIndicator,
              ObservableSource<? extends T> other) {
          super(source);
          this.firstTimeoutIndicator = firstTimeoutIndicator;
          this.itemTimeoutIndicator = itemTimeoutIndicator;
          this.other = other;
      }
  
      @Override
      protected void subscribeActual(Observer<? super T> observer) {
          if (other == null) {
              TimeoutObserver<T> parent = new TimeoutObserver<>(observer, itemTimeoutIndicator);
              observer.onSubscribe(parent);
              parent.startFirstTimeout(firstTimeoutIndicator);
              source.subscribe(parent);
          } else {
              TimeoutFallbackObserver<T> parent = new TimeoutFallbackObserver<>(observer, itemTimeoutIndicator, other);
              observer.onSubscribe(parent);
              parent.startFirstTimeout(firstTimeoutIndicator);
              source.subscribe(parent);
          }
      }
  
      interface TimeoutSelectorSupport extends TimeoutSupport {
          void onTimeoutError(long idx, Throwable ex);
      }
  
      static final class TimeoutObserver<T> extends AtomicLong
      implements Observer<T>, Disposable, TimeoutSelectorSupport {
  
          private static final long serialVersionUID = 3764492702657003550L;
  
          final Observer<? super T> downstream;
  
          final Function<? super T, ? extends ObservableSource<?>> itemTimeoutIndicator;
  
          final SequentialDisposable task;
  
          final AtomicReference<Disposable> upstream;
  
          TimeoutObserver(Observer<? super T> actual, Function<? super T, ? extends ObservableSource<?>> itemTimeoutIndicator) {
              this.downstream = actual;
              this.itemTimeoutIndicator = itemTimeoutIndicator;
              this.task = new SequentialDisposable();
              this.upstream = new AtomicReference<>();
          }
  
          @Override
          public void onSubscribe(Disposable d) {
              DisposableHelper.setOnce(upstream, d);
          }
  
          @Override
          public void onNext(T t) {
              long idx = get();
              if (idx == Long.MAX_VALUE || !compareAndSet(idx, idx + 1)) {
                  return;
              }
  
              Disposable d = task.get();
              if (d != null) {
                  d.dispose();
              }
  
              downstream.onNext(t);
  
              ObservableSource<?> itemTimeoutObservableSource;
  
              try {
                  itemTimeoutObservableSource = Objects.requireNonNull(
                          itemTimeoutIndicator.apply(t),
                          "The itemTimeoutIndicator returned a null ObservableSource.");
              } catch (Throwable ex) {
                  Exceptions.throwIfFatal(ex);
                  upstream.get().dispose();
                  getAndSet(Long.MAX_VALUE);
                  downstream.onError(ex);
                  return;
              }
  
              TimeoutConsumer consumer = new TimeoutConsumer(idx + 1, this);
              if (task.replace(consumer)) {
                  itemTimeoutObservableSource.subscribe(consumer);
              }
          }
  
          void startFirstTimeout(ObservableSource<?> firstTimeoutIndicator) {
              if (firstTimeoutIndicator != null) {
                  TimeoutConsumer consumer = new TimeoutConsumer(0L, this);
                  if (task.replace(consumer)) {
                      firstTimeoutIndicator.subscribe(consumer);
                  }
              }
          }
  
          @Override
          public void onError(Throwable t) {
              if (getAndSet(Long.MAX_VALUE) != Long.MAX_VALUE) {
                  task.dispose();
  
                  downstream.onError(t);
              } else {
                  RxJavaPlugins.onError(t);
              }
          }
  
          @Override
          public void onComplete() {
              if (getAndSet(Long.MAX_VALUE) != Long.MAX_VALUE) {
                  task.dispose();
  
                  downstream.onComplete();
              }
          }
  
          @Override
          public void onTimeout(long idx) {
              if (compareAndSet(idx, Long.MAX_VALUE)) {
                  DisposableHelper.dispose(upstream);
  
                  downstream.onError(new TimeoutException());
              }
          }
  
          @Override
          public void onTimeoutError(long idx, Throwable ex) {
              if (compareAndSet(idx, Long.MAX_VALUE)) {
                  DisposableHelper.dispose(upstream);
  
                  downstream.onError(ex);
              } else {
                  RxJavaPlugins.onError(ex);
              }
          }
  
          @Override
          public void dispose() {
              DisposableHelper.dispose(upstream);
              task.dispose();
          }
  
          @Override
          public boolean isDisposed() {
              return DisposableHelper.isDisposed(upstream.get());
          }
      }
  
      static final class TimeoutFallbackObserver<T>
      extends AtomicReference<Disposable>
      implements Observer<T>, Disposable, TimeoutSelectorSupport {
  
          private static final long serialVersionUID = -7508389464265974549L;
  
          final Observer<? super T> downstream;
  
          final Function<? super T, ? extends ObservableSource<?>> itemTimeoutIndicator;
  
          final SequentialDisposable task;
  
          final AtomicLong index;
  
          final AtomicReference<Disposable> upstream;
  
          ObservableSource<? extends T> fallback;
  
          TimeoutFallbackObserver(Observer<? super T> actual,
                  Function<? super T, ? extends ObservableSource<?>> itemTimeoutIndicator,
                          ObservableSource<? extends T> fallback) {
              this.downstream = actual;
              this.itemTimeoutIndicator = itemTimeoutIndicator;
              this.task = new SequentialDisposable();
              this.fallback = fallback;
              this.index = new AtomicLong();
              this.upstream = new AtomicReference<>();
          }
  
          @Override
          public void onSubscribe(Disposable d) {
              DisposableHelper.setOnce(upstream, d);
          }
  
          @Override
          public void onNext(T t) {
              long idx = index.get();
              if (idx == Long.MAX_VALUE || !index.compareAndSet(idx, idx + 1)) {
                  return;
              }
  
              Disposable d = task.get();
              if (d != null) {
                  d.dispose();
              }
  
              downstream.onNext(t);
  
              ObservableSource<?> itemTimeoutObservableSource;
  
              try {
                  itemTimeoutObservableSource = Objects.requireNonNull(
                          itemTimeoutIndicator.apply(t),
                          "The itemTimeoutIndicator returned a null ObservableSource.");
              } catch (Throwable ex) {
                  Exceptions.throwIfFatal(ex);
                  upstream.get().dispose();
                  index.getAndSet(Long.MAX_VALUE);
                  downstream.onError(ex);
                  return;
              }
  
              TimeoutConsumer consumer = new TimeoutConsumer(idx + 1, this);
              if (task.replace(consumer)) {
                  itemTimeoutObservableSource.subscribe(consumer);
              }
          }
  
          void startFirstTimeout(ObservableSource<?> firstTimeoutIndicator) {
              if (firstTimeoutIndicator != null) {
                  TimeoutConsumer consumer = new TimeoutConsumer(0L, this);
                  if (task.replace(consumer)) {
                      firstTimeoutIndicator.subscribe(consumer);
                  }
              }
          }
  
          @Override
          public void onError(Throwable t) {
              if (index.getAndSet(Long.MAX_VALUE) != Long.MAX_VALUE) {
                  task.dispose();
  
                  downstream.onError(t);
  
                  task.dispose();
              } else {
                  RxJavaPlugins.onError(t);
              }
          }
  
          @Override
          public void onComplete() {
              if (index.getAndSet(Long.MAX_VALUE) != Long.MAX_VALUE) {
                  task.dispose();
  
                  downstream.onComplete();
  
                  task.dispose();
              }
          }
  
          @Override
          public void onTimeout(long idx) {
              if (index.compareAndSet(idx, Long.MAX_VALUE)) {
                  DisposableHelper.dispose(upstream);
  
                  ObservableSource<? extends T> f = fallback;
                  fallback = null;
  
                  f.subscribe(new ObservableTimeoutTimed.FallbackObserver<T>(downstream, this));
              }
          }
  
          @Override
          public void onTimeoutError(long idx, Throwable ex) {
              if (index.compareAndSet(idx, Long.MAX_VALUE)) {
                  DisposableHelper.dispose(this);
  
                  downstream.onError(ex);
              } else {
                  RxJavaPlugins.onError(ex);
              }
          }
  
          @Override
          public void dispose() {
              DisposableHelper.dispose(upstream);
              DisposableHelper.dispose(this);
              task.dispose();
          }
  
          @Override
          public boolean isDisposed() {
              return DisposableHelper.isDisposed(get());
          }
      }
  
      static final class TimeoutConsumer extends AtomicReference<Disposable>
      implements Observer<Object>, Disposable {
  
          private static final long serialVersionUID = 8708641127342403073L;
  
          final TimeoutSelectorSupport parent;
  
          final long idx;
  
          TimeoutConsumer(long idx, TimeoutSelectorSupport parent) {
              this.idx = idx;
              this.parent = parent;
          }
  
          @Override
          public void onSubscribe(Disposable d) {
              DisposableHelper.setOnce(this, d);
          }
  
          @Override
          public void onNext(Object t) {
              Disposable upstream = get();
              if (upstream != DisposableHelper.DISPOSED) {
                  upstream.dispose();
                  lazySet(DisposableHelper.DISPOSED);
                  parent.onTimeout(idx);
              }
          }
  
          @Override
          public void onError(Throwable t) {
              if (get() != DisposableHelper.DISPOSED) {
                  lazySet(DisposableHelper.DISPOSED);
                  parent.onTimeoutError(idx, t);
              } else {
                  RxJavaPlugins.onError(t);
              }
          }
  
          @Override
          public void onComplete() {
              if (get() != DisposableHelper.DISPOSED) {
                  lazySet(DisposableHelper.DISPOSED);
                  parent.onTimeout(idx);
              }
          }
  
          @Override
          public void dispose() {
              DisposableHelper.dispose(this);
          }
  
          @Override
          public boolean isDisposed() {
              return DisposableHelper.isDisposed(this.get());
          }
      }
  
  }
  