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.flowable;
  
  import static io.reactivex.rxjava3.internal.util.ExceptionHelper.timeoutMessage;
  
  import java.util.concurrent.*;
  import java.util.concurrent.atomic.*;
  
  import org.reactivestreams.*;
  
  import io.reactivex.rxjava3.core.*;
  import io.reactivex.rxjava3.internal.disposables.SequentialDisposable;
  import io.reactivex.rxjava3.internal.subscriptions.*;
  import io.reactivex.rxjava3.plugins.RxJavaPlugins;
  
  public final class FlowableTimeoutTimed<T> extends AbstractFlowableWithUpstream<T, T> {
      final long timeout;
      final TimeUnit unit;
      final Scheduler scheduler;
      final Publisher<? extends T> other;
  
      public FlowableTimeoutTimed(Flowable<T> source,
              long timeout, TimeUnit unit, Scheduler scheduler, Publisher<? extends T> other) {
          super(source);
          this.timeout = timeout;
          this.unit = unit;
          this.scheduler = scheduler;
          this.other = other;
      }
  
      @Override
      protected void subscribeActual(Subscriber<? super T> s) {
          if (other == null) {
              TimeoutSubscriber<T> parent = new TimeoutSubscriber<>(s, timeout, unit, scheduler.createWorker());
              s.onSubscribe(parent);
              parent.startTimeout(0L);
              source.subscribe(parent);
          } else {
              TimeoutFallbackSubscriber<T> parent = new TimeoutFallbackSubscriber<>(s, timeout, unit, scheduler.createWorker(), other);
              s.onSubscribe(parent);
              parent.startTimeout(0L);
              source.subscribe(parent);
          }
      }
  
      static final class TimeoutSubscriber<T> extends AtomicLong
      implements FlowableSubscriber<T>, Subscription, TimeoutSupport {
  
          private static final long serialVersionUID = 3764492702657003550L;
  
          final Subscriber<? super T> downstream;
  
          final long timeout;
  
          final TimeUnit unit;
  
          final Scheduler.Worker worker;
  
          final SequentialDisposable task;
  
          final AtomicReference<Subscription> upstream;
  
          final AtomicLong requested;
  
          TimeoutSubscriber(Subscriber<? super T> actual, long timeout, TimeUnit unit, Scheduler.Worker worker) {
              this.downstream = actual;
              this.timeout = timeout;
              this.unit = unit;
              this.worker = worker;
              this.task = new SequentialDisposable();
              this.upstream = new AtomicReference<>();
              this.requested = new AtomicLong();
          }
  
          @Override
          public void onSubscribe(Subscription s) {
              SubscriptionHelper.deferredSetOnce(upstream, requested, s);
          }
  
          @Override
          public void onNext(T t) {
              long idx = get();
              if (idx == Long.MAX_VALUE || !compareAndSet(idx, idx + 1)) {
                  return;
              }
  
              task.get().dispose();
  
              downstream.onNext(t);
  
              startTimeout(idx + 1);
          }
  
          void startTimeout(long nextIndex) {
              task.replace(worker.schedule(new TimeoutTask(nextIndex, this), timeout, unit));
          }
  
          @Override
          public void onError(Throwable t) {
              if (getAndSet(Long.MAX_VALUE) != Long.MAX_VALUE) {
                  task.dispose();
  
                  downstream.onError(t);
  
                  worker.dispose();
              } else {
                  RxJavaPlugins.onError(t);
              }
          }
  
          @Override
          public void onComplete() {
              if (getAndSet(Long.MAX_VALUE) != Long.MAX_VALUE) {
                  task.dispose();
  
                  downstream.onComplete();
  
                  worker.dispose();
              }
          }
  
          @Override
          public void onTimeout(long idx) {
              if (compareAndSet(idx, Long.MAX_VALUE)) {
                  SubscriptionHelper.cancel(upstream);
  
                  downstream.onError(new TimeoutException(timeoutMessage(timeout, unit)));
  
                  worker.dispose();
              }
          }
  
          @Override
          public void request(long n) {
              SubscriptionHelper.deferredRequest(upstream, requested, n);
          }
  
          @Override
          public void cancel() {
              SubscriptionHelper.cancel(upstream);
              worker.dispose();
          }
      }
  
      static final class TimeoutTask implements Runnable {
  
          final TimeoutSupport parent;
  
          final long idx;
  
          TimeoutTask(long idx, TimeoutSupport parent) {
              this.idx = idx;
              this.parent = parent;
          }
  
          @Override
          public void run() {
              parent.onTimeout(idx);
          }
      }
  
      static final class TimeoutFallbackSubscriber<T> extends SubscriptionArbiter
      implements FlowableSubscriber<T>, TimeoutSupport {
  
          private static final long serialVersionUID = 3764492702657003550L;
  
          final Subscriber<? super T> downstream;
  
          final long timeout;
  
          final TimeUnit unit;
  
          final Scheduler.Worker worker;
  
          final SequentialDisposable task;
  
          final AtomicReference<Subscription> upstream;
  
          final AtomicLong index;
  
          long consumed;
  
          Publisher<? extends T> fallback;
  
          TimeoutFallbackSubscriber(Subscriber<? super T> actual, long timeout, TimeUnit unit,
                  Scheduler.Worker worker, Publisher<? extends T> fallback) {
              super(true);
              this.downstream = actual;
              this.timeout = timeout;
              this.unit = unit;
              this.worker = worker;
              this.fallback = fallback;
              this.task = new SequentialDisposable();
              this.upstream = new AtomicReference<>();
              this.index = new AtomicLong();
          }
  
          @Override
          public void onSubscribe(Subscription s) {
              if (SubscriptionHelper.setOnce(upstream, s)) {
                  setSubscription(s);
              }
          }
  
          @Override
          public void onNext(T t) {
              long idx = index.get();
              if (idx == Long.MAX_VALUE || !index.compareAndSet(idx, idx + 1)) {
                  return;
              }
  
              task.get().dispose();
  
              consumed++;
  
              downstream.onNext(t);
  
              startTimeout(idx + 1);
          }
  
          void startTimeout(long nextIndex) {
              task.replace(worker.schedule(new TimeoutTask(nextIndex, this), timeout, unit));
          }
  
          @Override
          public void onError(Throwable t) {
              if (index.getAndSet(Long.MAX_VALUE) != Long.MAX_VALUE) {
                  task.dispose();
  
                  downstream.onError(t);
  
                  worker.dispose();
              } else {
                  RxJavaPlugins.onError(t);
              }
          }
  
          @Override
          public void onComplete() {
              if (index.getAndSet(Long.MAX_VALUE) != Long.MAX_VALUE) {
                  task.dispose();
  
                  downstream.onComplete();
  
                  worker.dispose();
              }
          }
  
          @Override
          public void onTimeout(long idx) {
              if (index.compareAndSet(idx, Long.MAX_VALUE)) {
                  SubscriptionHelper.cancel(upstream);
  
                  long c = consumed;
                  if (c != 0L) {
                      produced(c);
                  }
  
                  Publisher<? extends T> f = fallback;
                  fallback = null;
  
                  f.subscribe(new FallbackSubscriber<T>(downstream, this));
  
                  worker.dispose();
              }
          }
  
          @Override
          public void cancel() {
              super.cancel();
              worker.dispose();
          }
      }
  
      static final class FallbackSubscriber<T> implements FlowableSubscriber<T> {
  
          final Subscriber<? super T> downstream;
  
          final SubscriptionArbiter arbiter;
  
          FallbackSubscriber(Subscriber<? super T> actual, SubscriptionArbiter arbiter) {
              this.downstream = actual;
              this.arbiter = arbiter;
          }
  
          @Override
          public void onSubscribe(Subscription s) {
              arbiter.setSubscription(s);
          }
  
          @Override
          public void onNext(T t) {
              downstream.onNext(t);
          }
  
          @Override
          public void onError(Throwable t) {
              downstream.onError(t);
          }
  
          @Override
          public void onComplete() {
              downstream.onComplete();
          }
      }
  
      interface TimeoutSupport {
  
          void onTimeout(long idx);
  
      }
  }
  